WO2007048006A2

WO2007048006A2 - Combustion-powered driving tool

Info

Publication number: WO2007048006A2
Application number: PCT/US2006/041184
Authority: WO
Inventors: John F. Larkin; Brian W. Lamb
Original assignee: Black & Decker Inc.
Priority date: 2005-10-21
Filing date: 2006-10-20
Publication date: 2007-04-26
Also published as: WO2007048006A3

Abstract

A driving tool includes a piston housing 320, a piston 324 and an auxiliary housing 322 coupled in fluid communication with the piston housing. The piston is received in the piston housing, the piston cooperating with the piston housing to define a combustion chamber 334. Movement of the piston in a predetermined direction compresses air in the piston housing that is vented into the auxiliary housing. The compressed air in the auxiliary housing is discharged into the piston housing to perform at least one of purging exhaust gases from the combustion chamber, mixing air and fuel in the combustion chamber, and moving the piston toward a firing position.

Description

COMBUSTION-POWERED DRIVING TOOL

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/729,263 entitled "Combustion-powered driving tool" filed October 21 , 2005, the disclosure of which is hereby incorporated by reference as if fully set forth in detail herein.

INTRODUCTION [0002] The present disclosure generally relates to the driving tools, such as nailers, and more particularly to a combustion-type driving tool.

[0003] Combustion-powered driving tools, such as combustion-powered fastening tools or nailers, provide increased portability over pneumatic tools. Combustion-powered tools do not require a user to manage a bulky air compressor or pneumatic tubing. Typically, combustion-powered fastening tools comprise systems designated for the intake of air, the injection of a combustible fuel into a combustion chamber, the ignition of a fuel/air mixture, the containment of combustion reaction (combustion chamber), and the exhaust of combustion chamber waste gases. These combustion-based features are in addition to components required to drive a fastener such as a piston housing, a piston disposed within the piston housing, a driving member connected to the piston to drive a fastener into a workpiece upon combustion, a triggering mechanism to initiate pressure buildup on the piston, a retraction system to return the piston to firing position, and safety components such as trigger lockouts. [0004] The combustion reaction produces gases that drive the piston and as such, combustion-powered tools must consider issues that are not found in pneumatic fastening tools. Such combustion-related issues may include: ensuring proper fuel/air mixture ratio, completely removing combustion reaction exhaust gases from combustion chamber prior to subsequent firing, ensuring complete mixing of fuel/air mixture, maximizing efficiency of combustion chamber volume and piston size, utilizing effective ignition methods and fuel compression techniques, controlling temperature of combustion chamber, ensuring proper fuel dispensation, and maintenance of power requirements for electrical ignition methods, exhaust means, and injection means. For instance, a non-stoichiometric mixture of combustible fuel and air may lead to incomplete combustion, inefficient use of fuel gas, and diminished piston-driving power. Exhaust gas buildup in the combustion chamber may contribute to incomplete combustion. For instance, waste products from previous combustion reactions may dilute the stoichiometric fuel/air mixture required for efficient subsequent combustion reactions. Improper mixing of the combustible fuel and air may lead to an inefficient combustion reaction, as hydrocarbon fuel requires contact with oxygen for a combustion reaction to occur. Inefficient ignition methods may result in reduced piston-driving power. For example, a poorly timed or positioned ignition may cause a delayed or slowly propagated combustion flame front, thereby decreasing the peak pressure emitted by the combustion reaction. Effective fuel compression can result in turbulence within the combustion chamber, providing properly mixed combustion reactants. Ineffective fuel compression may lead to excessive seal stresses and therefore increased seat maintenance. Increased fastener cycle times result in increased successive combustion reactions. Heat buildup can occur due to the increased combustion reactions if proper cooling methods are not utilized. Excessive combustion chamber temperatures may alter proper combustion conditions or cause seat deformation, therefore resulting in decreased combustion and seat efficiency. Combustion-powered tool users may be inconvenienced by inefficient electrical power usage, as regular replacement or charging of batteries may become a hindrance or cause a tool to become unproductive. Further, improper fuel dispensation may lead to inefficient combustion reactions. For instance, injection of too much or too little fuel results in an improper fuel/air mixture, and too little injection pressure may not induce turbulence of the mixture (a fuel concentration issue if no other mixing methods are utilized).

[0005] Therefore it would be desirable to provide a combustion-powered driving tool with improved air intake and exhaust systems, improved ignition and injection systems, improved electric power and fuel management systems, improved piston retraction systems, and improved reliability, safety, and adaptability.

SUMMARY

[0006] In one form, the present teachings provide for various improvements in driving tools, such as combustion-powered driving tools. [0007] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS [0008] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. [0009] Figure 1 is a perspective view of a combustion-powered driving tool constructed in accordance with the teachings of the present disclosure; [0010] Figure 2 is an exploded perspective view of the combustion-powered driving tool of Figure 1 ;

[0011] Figure 3 is a side view of the combustion-powered driving tool of Figure 1 illustrating detachment/attachment of a source of electrical power; [0012] Figure 4 is a perspective view of a portion of the combustion-powered driving tool of Figure 1 illustrating the source of electrical power removed from a body portion of the combustion-powered driving tool;

[0013] Figure 5 is a perspective view of the combustion-powered driving tool of

Figure 1 illustrating detachment/attachment of a pack that provides source of electrical power; [0014] Figure 6 is a perspective view similar to that of Figure 4 but illustrating a canister of fuel installed to the body portion of the combustion-powered driving tool; [0015] Figure 7 is a perspective view of a portion of the combustion-powered driving tool of Figure 1 illustrating the pack in more detail; [0016] Figure 8 is a side elevation view of a portion of the combustion-powered driving tool of Figure 1 illustrating the pack in more detail;

[0017] Figure 9 is a side elevation view in partial section of the combustion- powered driving tool of Figure 1 ;

[0018] Figure 10 is an exploded perspective view of a portion of the combustion- powered driving tool of Figure 1 illustrating the pack and the canister of fuel in more detail;

[0019] Figure 1 1 is a sectional view of a portion of a second combustion- powered driving tool constructed in accordance with the teachings of the present disclosure; [0020] Figure 12 is a sectional view of a portion of a third combustion-powered driving tool constructed in accordance with the teachings of the present disclosure;

[0021] Figure 13 is a sectional view of a portion of a fourth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure; [0022] Figure 14 is a sectional view of a portion of a fifth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure; [0023] Figure 15 is a sectional view of a portion of a sixth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure; [0024] Figure 16 is a sectional view of a portion of a seventh combustion- powered driving tool constructed in accordance with the teachings of the present disclosure;

[0025] Figure 17 is a sectional view of a portion of a eighth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure; [0026] Figure 18 is a sectional view of a portion of a ninth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure; [0027] Figure 19 is a sectional view of a portion of a tenth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure; [0028] Figure 20 is a sectional view of a portion of a eleventh combustion- powered driving tool constructed in accordance with the teachings of the present disclosure; [0029] Figure 21 is a sectional view of a portion of a twelfth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure; [0030] Figures 22A through 22D are sectional views of a portion of a thirteenth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure; [0031] Figure 23 is a sectional view of a portion of fourteenth combustion- powered driving tool constructed in accordance with the teachings of the present disclosure;

[0032] Figure 24 is a sectional view of a portion of a fifteenth combustion- powered driving tool constructed in accordance with the teachings of the present disclosure;

[0033] Figure 25 is a sectional view of a portion of a sixteenth combustion- powered driving tool constructed in accordance with the teachings of the present disclosure; [0034] Figure 26 is a sectional view of a portion of a seventeenth combustion- powered driving tool constructed in accordance with the teachings of the present disclosure;

[0035] Figures 28A through 28C are sectional views of a portion of an eighteenth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure; [0036] Figure 29 is a sectional view of a portion of a nineteenth combustion- powered driving tool constructed in accordance with the teachings of the present disclosure;

[0037] Figure 30 is a sectional view of a portion of a twentieth combustion- powered driving tool constructed in accordance with the teachings of the present disclosure;

[0038] Figure 31 is a sectional view of a portion of a twenty-first combustion- powered driving tool constructed in accordance with the teachings of the present disclosure; [0039] Figure 32 is a sectional view of a portion of a twenty-second combustion- powered driving tool constructed in accordance with the teachings of the present disclosure;

[0040] Figures 33 and 34 are alternate embodiments of the combustion- powered driving tool of Figure 32; [0041] Figure 35 is a sectional view of a portion of a twenty-third combustion- powered driving tool constructed in accordance with the teachings of the present disclosure;

[0042] Figure 36 is a sectional view of a portion of a twenty-fourth combustion- powered driving tool constructed in accordance with the teachings of the present disclosure;

[0043] Figure 37 is a sectional view of a portion of a twenty-fifth combustion- powered driving tool constructed in accordance with the teachings of the present disclosure; [0044] Figure 38 is a sectional view of a portion of a twenty-sixth combustion- powered driving tool constructed in accordance with the teachings of the present disclosure;

[0045] Figures 39A and 39B are sectional views of a portion of a twenty-seventh combustion-powered driving tool constructed in accordance with the teachings of the present disclosure; [0046] Figure 40 is a side elevation view of a portion of a twenty-eighth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure;

[0047] Figures 41 through 48 are sectional views of a portion of a twenty-ninth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure; [0048] Figures 49 through 57 are sectional views of a portion of a thirtieth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure;

[0049] Figures 58 through 66 are sectional views of a portion of a thirty-first combustion-powered driving tool constructed in accordance with the teachings of the present disclosure;

[0050] Figure 67 is a sectional view of a portion of a thirty-second combustion- powered driving tool constructed in accordance with the teachings of the present disclosure; [0051] Figure 68 is a sectional view of a portion of a thirty-third combustion- powered driving tool constructed in accordance with the teachings of the present disclosure;

[0052] Figure 69 is a sectional view of a portion of a thirty-fourth combustion- powered driving tool constructed in accordance with the teachings of the present disclosure;

[0053] Figure 70 is a sectional view of a portion of a thirty-fifth combustion- powered driving tool constructed in accordance with the teachings of the present disclosure; [0054] Figure 71 is a top plan view of a thirty-sixth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure;

[0055] Figure 72 is a perspective view of a portion of a thirty-seventh combustion-powered driving tool constructed in accordance with the teachings of the present disclosure; [0056] Figure 73 is a side elevation view of a portion of a thirty-eighth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure; and

[0057] Figure 74 is a side elevation view of a portion of a thirty-ninth combustion-powered driving tool constructed in accordance with the teachings of the present disclosure. DETAILED DESCRIPTION OF THE VARIOUS EMBODIMENTS

[0058] With reference to Figure 1 of the drawings, a combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is generally indicated by reference numeral 10. The tool 10 can include a body portion 12 and a magazine 14. The body portion 12 can include a housing 16, a motor assembly 18, a nose piece 20 and a source of electrical power, such as a battery pack 22. The magazine 14 can be coupled to the body portion 12 and can be configured to hold a plurality of fasteners, such as nails or staples, and sequentially dispense the fasteners into the nosepiece 20. Portions of the body portion 12 and/or magazine 14 not specifically discussed herein may be constructed in any appropriate manner, such as that which is described in co-pending U.S. Patent Application Serial No. 1 1/215,794, the disclosure of which is hereby incorporated by reference as if fully set forth in detail herein.

[0059] With reference to Figure 2, the body portion 12 can include a trigger assembly 30 that can conventionally include a switch 32 that can be electrically coupled to the battery pack 22. The switch 32 can generate a trigger switch signal when a trigger 34 is actuated; the trigger switch signal can be employed as a condition or prerequisite for initiating a combustion event. It will be appreciated that the body portion 12 can include a fuel-dispensing means (not shown) for dispensing fuel or a fuel/air mixture into a combustion chamber (not shown) and a combustion initiating means (not shown) for initiating a combustion event in the combustion chamber. The combustion chamber, fuel-dispensing means and the combustion initiating means could be contained within the motor assembly 18, but in the particular example provided, the fuel dispensing means is partially contained in the battery pack 22. [0060] The battery pack 22 can include a re-chargeable battery 40, which can include one or more NICAD, nickel-metal hydride or lithium-ion battery cells, a fuel distribution system 42 and a pair of terminals 44 are coupled in electrical connection to the re-chargeable battery 40. The fuel distribution system 42 can include an inlet 50, an outlet 52, and a conduit 54 that can couple the outlet 52 to a fuel injector, such as a shuttle valve (not shown), that is associated with a combustion chamber (not shown) of the motor assembly 18. The inlet 50 can be coupled to a fuel cartridge 58 that can be removably received into a cavity 60 in the housing 16. The fuel cartridge 58 can include a sealed valve 62 that may be opened via a spike or needle 64 that can be associated with the inlet 50. The spike or needle 64 can be hollow. A seal 66 can be employed to seal the interface between the fuel cartridge 58 and the inlet 50. The outlet 52 can be coupled in fluid communication to the inlet 50 and can include a valve 70 that can be coupled in fluid communication to the conduit 54. A seal 72 can be employed to seal the interface between the outlet 52 and the conduit 54. An opposite end of the conduit 54 can be coupled to the combustion chamber (not shown) of the motor assembly 18. [0061] With additional reference to Figure 3, an exhaust system 80 can be coupled to the combustion chamber (not shown) of the motor assembly 18 and can include an exhaust conduit 82 that can be employed to discharge combustion gases from the motor assembly 18 subsequent to the driving of a fastener. In the particular example provided, the exhaust conduit 82 extends along the magazine 14 (Fig. 4) and terminates at a handle 84 that is defined by the housing 16 to thereby vent the exhaust gases at a point that is spaced apart from an air intake 86 of the motor assembly 18. [0062] A latch 90 can be coupled to the housing 16 and can be employed to selectively couple or release the battery pack 22 from the housing 16. [0063] With reference to Figures 2 and 4, the terminals 44 can be configured to releasably engage mating terminals 100 that can be coupled to the housing 16. The mating terminals 100 can be electrically coupled to the trigger switch 32 and an ignition source, such as a spark plug (not shown) that is associated with the motor assembly 18. [0064] In Figure 5, the battery pack 22 is illustrated as being installed to the housing 12. To facilitate electrical connection of the terminals 44 (Fig. 2) and the mating terminals 100 (Fig. 4), the latch 90 can be pressed inwardly (e.g., by the thumb of the user) while the battery pack 22 is inserted to the housing 16.

[0065] In Figure 6, the fuel cartridge 58 is illustrated as being received in the housing 16.

[0066] Figures 7 and 8 illustrate the battery pack 22 in more detail.

[0067] In Figure 9, the mating terminals 100 are illustrated as including a tab 120. The mating terminals 100 can be formed of a resilient material that causes the tabs 120 to extend toward the latch 90. The housing 16 can be formed with appropriate structure (e.g., bosses) that can be employed to ensure that the tabs 120 are appropriately located relative to the latch 90. When the battery pack 22 is to be coupled to the housing 16, the terminals 44 engage a tapered portion of the tabs 120 and urge the tabs 120 away from the terminals 44 so that the terminals 44 may be aligned to a recess 122. Alignment of the terminals 44 in the recess 122 permits the mating terminals 100 to deflect toward the latch 90 such that the tabs 120 are disposed in-line with the terminals 44 and as such, the terminals 44 and the mating terminals 100 cooperate to retain the battery pack 22 to the housing 16. To remove the battery pack 22, the latch 90 is pushed into the housing 16 to cause the tabs 120 to deflect away from the terminals 44.

[0068] Figure 10 illustrates the removable coupling of the fuel cartridge 58 with the inlet 50. [0069] Returning to Figure 2, gaseous fuel under relatively high pressure can be dispensed from the fuel cartridge 58 to the fuel dispensing system 42. Fuel can be output from the fuel dispensing system 42 (via the outlet 52 and the conduit 54) at a relatively lower pressure to a fuel injector (not shown) associated with the motor assembly 18. The fuel injector can dispense a predetermined amount of fuel into the combustion chamber 200 in the motor assembly 18 when the trigger 34 is actuated. The trigger switch 32 can generate the trigger signal when the trigger 34 is actuated; the trigger signal can be received by an ignition source, such as a spark plug (not shown) that can be associated with the motor assembly 18. The ignition source can initiate a combustion event in the combustion chamber 200 to produce gases that drive a piston 220 downwardly to cause a driver 222 to contact and drive a fastener. Combustion gases produced in the combustion event can be discharged through the exhaust system 80. The exhaust system 80 can utilize ports and/or valves in a manner that is known in the art to couple the exhaust conduit 82 to the combustion chamber 200. The air intake system 86 can include a fan (not shown) or other means for moving fresh air into the combustion chamber 200; the fresh air can be employed to help purge the combustion gases from the combustion chamber 200.

[0070] In another aspect of the disclosure, an alternative air intake system is disclosed. Some combustion tools, such as that illustrated in Figures 1 through 10, utilize a motorized fan to assist in the intake of air into the combustion chamber and the mixing of combustible fuel and air. A battery or other power source may be implemented to power the fan for each combustion cycle. In some applications it may be desirable to reduce power requirements for repetitive combustion tool usage. [0071] With reference to Figure 11 , a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion-powered driving tool 300 can include a motor assembly 318 that can include a first cylinder 320, a second cylinder 322, a first piston 324, a first valve 326, a second valve 328 and a third valve 330. The piston 324 is slidably received in the first cylinder 320 and can be coupled a driver blade D. The piston 324 can cooperate with the first cylinder 320 to define a first chamber 334, which can function as a combustion chamber, and a second chamber 336. The first chamber 334 can be coupled in fluid communication to a fuel delivery system (not shown), which can be employed to charge the first chamber 334 with a charge of a combustible gaseous fuel. An ignition device, such as a spark plug, can be coupled to the first chamber 334 and can be operable to ignite the fuel. [0072] The first valve 326 can couple the second chamber 336 in fluid communication with the second cylinder 322. The first valve 326 can be a normally closed valve that can open (to permit fluid communication) when a pressure in the second chamber 336 exceeds a first predetermined pressure differential. In the particular example provided, the first valve 326 is a reed valve that opens when the pressure in the second chamber 336 exceeds the pressure in the second cylinder 322. [0073] The second valve 328 can be a normally closed valve that can open to permit fluid communication between the second chamber 336 and the atmosphere when a pressure in the second chamber 336 is less than a second predetermined pressure differential. In the particular example provided, the second valve 328 is a reed valve that opens when the pressure in the second chamber 336 is less than atmospheric pressure.

[0074] The third valve 330 can couple the second cylinder 322 in fluid communication with the first chamber 334. The third valve 330 can be a normally closed valve that can open to permit fluid communication in a desired manner. In the particular example provided, the third valve 330 includes a solenoid 340 that can be controlled via a controller 342 to selectively open the third valve 330.

[0075] Gases produced during a combustion event in the first chamber 334 can move the piston 324 toward the second valve 328 so that the pressure in the second chamber 336 increases. When the pressure in the second chamber 336 exceeds the pressure in the second cylinder 322, the first valve 326 can open so that gases (i.e., fresh air) in the second chamber 336 flows into and pressurizes the second cylinder 322. The second valve 336 can open to permit fresh air to be drawn into the second chamber 336 from the atmosphere when the piston 324 is moved toward the third valve 330. An electric signal may be sent from the controller 342 to the solenoid 340 to open the third valve 330 at a desired time to release the pressurized fresh air that is stored in the second cylinder 322. The pressurized fresh air may be employed to purge the combustion gases from the first chamber 334 and provide fresh air for a subsequent combustion event.

[0076] In one embodiment, the purging air forces exhaust gases from the previous combustion out a vent (not shown) in the first chamber 334. In another embodiment, the backward motion of the piston 324 (relative to the nose or tip of the combustion-powered driving tool) can force exhaust gases out a vent (not shown) in the first chamber 334, prior to admission of air from the second cylinder 322. An air intake system implemented in this manner can admit air into the first chamber 334 with adequate pressure to sufficiently mix with fuel, using electrical energy only for actuation of the solenoid 340 (apart from the first combustion, which may require a fan or other intake or mixing means).

[0077] With reference to Figure 12, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion-powered driving tool 400 can include a motor assembly 418 that includes an in-line double piston system. More specifically, the motor assembly 418 can include a housing 420 that can define a first chamber 422, a second chamber 424 and a transfer chamber 426. A wall member 428 can be disposed between the first and second chambers 422 and 424. A first valve 430 can be disposed in fluid communication with the first chamber 422 and the transfer chamber 426. A second valve 432 can be disposed in fluid communication with the transfer chamber 426 and the second chamber 424. A first piston 442 can be slidably received in the first chamber 422 and a second piston 444 can be slidably received in the second chamber 424. A rod 446 can extend through the wall member 428 and can be fixedly coupled to the first and second pistons 442 and 444. An intake port 450 can be formed through the housing 420 and can couple the first chamber 422 and the atmosphere in fluid communication.

[0078] The motor assembly 418 can include a fuel dispensing system (not shown) that can dispense a gaseous fuel into the second chamber 424, and an ignition system, such as a spark plug (not shown), that can selectively ignite the fuel in the second chamber 424. Gases produced during a combustion event in the second chamber 424 can drive the second piston 444 in a direction away from the wall member 428. As the rod 446 connects the first piston 442 to the second piston 444, the first piston 442 can travel toward the wall member 428 and close off the intake port 450. It will be appreciated that further travel of the first piston 442 toward the wall member 428 will compress the fresh air that is contained within the first chamber 422. The first valve 430, which can be a reed valve or a solenoid-controlled valve for example, can open to permit the pressurized fresh air in the first chamber 422 to enter the transfer chamber 426. Similarly, the second valve 432, which can be a reed valve or a solenoid- controlled valve for example, can open to permit pressurized air in the transfer chamber 426 to enter the second chamber 424. It will be appreciated that air may be discharged from the transfer chamber 426 into the second chamber 424 at a desired time. For example, the air may be discharged from the transfer chamber 426 into the second chamber 424 prior to or subsequent to the closing of an exhaust valve or port so that the fresh air that is contained within the second chamber 424 can be compressed as the second piston 444 returns toward the wall member 428. If the air is discharged from the transfer chamber 426 into the second chamber 424 prior to the closing of the exhaust valve or port, it will be appreciated that such air may be employed to aid in purging combustion gases from the second chamber. As another example, the air may be discharged from the transfer chamber 426 into the second chamber 424 after the second piston 424 has been returned to a position proximate the wall member 428. The discharged air may be employed, for example, as a jet of fresh air that aids in mixing the gaseous fuel in the second chamber 424 with the fresh air. Electrical power is not required for this air intake system unless, for example, a solenoid is used to control the opening of one or both of the first and second valves 430 and 432.

[0079] With reference to Figure 13, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion-powered driving tool 500 can include a motor assembly 518 that includes a first cylinder 520, a second cylinder 522, a cylinder indexing system 524, and a piston 526 that is slidably received in the first cylinder 520. The second cylinder 522 can be rotatably mounted to the first cylinder 520 in any appropriate manner, such as via a pivot pin 528 that extends through the second cylinder 522 and is received into a wall of the first cylinder 520. The second cylinder 522 can define a plurality of circumferentially spaced apart chamber portions (e.g., 530a, 530b) that can be selectively indexed to a location within the first cylinder 520 by the cylinder indexing system 524. Stated another way, the second cylinder 522 may be partitioned into multiple chamber portions that are radially divided perpendicular to a common plane to address the heat build-up and precision issues. The multiple chamber portions can comprise equal volume compartments with equivalent cross-sectional areas to standardize fuel consumption and heat distribution throughout subsequent combustion events. The common plane may be disposed generally perpendicular to the axis along which the piston 526 slides within the first cylinder 520. The second cylinder 522 is rotatable on an axis that is generally parallel to the axis along which the piston 526 slides. [0080] In the particular example provided, the cylinder indexing system 524 includes an electric motor 540, which can be a stepper motor, and a transmission 542 that can include a pinion 544, which can be coupled for rotation with an output shaft of the motor 540, and a driven gear 546 that can be coupled for rotation with the pivot pin 528. It will be appreciated that any other appropriate means may be employed to index the second cylinder 522 within the first cylinder 520, such as a system that employs a ratchet and a pawl. It will also be appreciated that seals (not specifically shown) can be employed to seal the interface between the second cylinder 522 and the first cylinder 520.

[0081] The motor assembly 518 can include a fuel dispensing system (not shown) that can dispense a gaseous fuel into the chamber portion that is received in the first cylinder 520 (e.g., chamber portion 530a in the example illustrated), and an ignition system, such as a spark plug (not shown), that can selectively ignite the fuel in the chamber portion. Gases produced during a combustion event in the chamber portion can drive the piston 526 in a direction away from the second cylinder 522. Combustion gases can be vented from the first cylinder 520 and the second cylinder 522 may be rotated by the cylinder indexing system 524 to align a next one of the chamber portions (e.g., chamber portion 530b in the example illustrated) into the first cylinder 520. A means for exhausting the waste gases from the subsequent combustion reaction may include a vent in the combustion chamber where the motion of the piston returning to firing position forces exhaust gases out the vent or simply by rotating the combustion chamber which transports the exhaust gases. In the foregoing manner, combustion air quality may be enhanced by reliably rotating fresh air in and exhaust gases out, and the thermal load of rapid successive combustion reactions may be spread over multiple chambers. Construction of the combustion-powered driving tool 500 in this manner can better handle the heat associated with rapid firings or cycling of the tool 500, as well as improve the quality of the combustion air in the motor assembly 518 by cycling fresh air into the motor assembly 518.

[0082] While the combustion-powered driving tool 500 has been described above as including a motor assembly 518 that injects gaseous fuel into a chamber portion (e.g., chamber portion 530a) after the chamber portion has been received into the first cylinder 520, those of skill in the art will appreciate that the charging of a chamber portion could be performed at a different time. For example, the chamber portion could be charged prior to rotating that chamber portion into the first cylinder 520. In this regard, fuel may be injected into each chamber portion during a stage in the rotation process via fuel lines originating from a shuttle valve or fuel regulator. During rotation, the second cylinder 522 may actuate a trigger or other mechanism (not shown) to open a valve (not shown), thereby initiating fuel flow to a particular chamber portion. [0083] With reference to Figure 14, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion-powered driving tool 600 can include a motor assembly 618 with an exhaust system 620 that implements a crank driven piston 622 to cyclically control a volume of a combustion chamber 624. An object of this embodiment is to facilitate exhaust and intake with a single motion. A crank 626 may be driven by compression of a safety or contact trip (not shown) against a workpiece (not shown). For example, a rack (not shown) may be formed on a linkage associated with a contact trip and the teeth of the rack may be meshingly engaged to teeth formed on the crank 626. An arm 628 can include a second rack 630 that can also be meshingly engaged to the crank 626. Accordingly, movement of the contact trip can cause the crank 626 to rotate, which can cause corresponding motion of the arm 628. It will be appreciated that the crank 626 could have two sets of teeth to permit the movement of the arm 628 to be magnified or reduced relative to the movement of the contact trip. In situations where no magnification or reduction in movement is desired, the crank 626 may be omitted and the arm 628 could be directly coupled to the contact trip. The arm 628 can be coupled to the piston 622 (e.g., via another rack-and-pinion arrangement) to cause the piston 622 to reciprocate in a desired manner via compression and release of the contact trip to thereby cyclically expand and reduce the volume of the combustion chamber 624. For instance, at a rest state (i.e., contact trip is in its normal, extended position), the piston 622 and a drive piston 640, which can be coupled to a driver D, can be positioned a predetermined distance away from one another. Upon retraction of the contact trip, the crank 626 can drives the piston 622 in a direction opposite the nose of the tool, thereby increasing the volume of the combustion chamber 624. The contact trip may also close an exhaust valve (not shown) in the combustion chamber 624. Rearward motion of the piston 622 may create a vacuum in the combustion chamber 624, providing a pressure gradient for fuel/air injection (e.g., through a reed valve, not shown). A trigger actuation may initiate a combustion reaction in the combustion chamber 624, via an ignition source such as a spark plug. Combustion pressure may drive the piston 640 and the driver D forwardly (e.g., to install a fastener) such that the volume of the combustion chamber 624 is maximized. When the contact trip is withdrawn from the workpiece, the combustion chamber exhaust valve may open and the crank 626 can drive the piston 622 toward the piston 640, thereby reducing the volume of the combustion chamber 624. As will be appreciated, the piston 622 can push the exhaust gases from the combustion chamber 624 out the exhaust valve. Furthermore, a retraction system, such as one discussed later or another suitable system may also retract the piston 640 (so that the piston 640 is moving toward the piston 622). As the pistons 622 and 640 converge, combustion waste gases are forced from the combustion chamber 624 via the exhaust valve. When the combustion chamber volume is minimized (e.g., eliminated) waste gases may be fully purged and the system returns to rest state, prepared for the next cycle.

[0084] With reference to Figure 15, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion-powered driving tool 700 can include a motor assembly 718 with an ignition system 720 that includes a battery 722, a controller 724, a contact trip switch 726, a trigger switch 728 and an igniter, such as a spark plug 730. The contact trip switch 726 can be coupled to a contact trip 732 and can be configured to generate a contact trip signal when the contact trip 732 has been engaged to a workpiece. The trigger switch 728 can be coupled to a trigger 734 and can be configured to generate a trigger signal with the trigger 734 has been actuated by a user. The controller 724 can receive the contact trip signal and the trigger signal and can selectively apply electrical power to the spark plug 730 to thereby initiate a combustion event in the combustion chamber 740 of the motor assembly 718. The controller 724 can include a mode select switch 744 that permits the tool 700 to be used in different modes, such as a sequential fire mode, a bump fire mode and an inactive mode. The sequential fire mode can be a mode in which the controller 724 will apply electrical power to the spark plug 730 only if the contact trip 732 is pressed against a workpiece prior to actuation of a trigger 728 for a spark to be generated in the combustion chamber 740. In this regard, a user may not constantly keep the trigger 728 depressed and simply press the contact trip 732 of the tool 700 to initiate a combustion event in the combustion chamber 740. [0085] With reference to Figure 16, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion-powered driving tool 800 can include a motor assembly 818 with an ignition system that employs multiple ignition sources, such as multiple spark plugs 820a and 820b. It will be appreciated from this disclosure that ineffective distribution or placement of ignition sources within combustion chambers may lead to inefficient fuel usage and decreased piston driving power. For example, a spark plug positioned parallel to the face of a piston may leave too large a gap across which flames must propagate. Multiple ignition sources, such as spark plugs 820a and 820b in a combustion chamber 822 of a combustion-powered driving tool may contribute to increased piston-driving power. For instance, multiple ignition sparks in the combustion chamber 822 may decrease the distance for flames to propagate, and thus increase the peak pressure obtained in the combustion reaction. The resultant peak pressure increase in the combustion chamber 822 may contribute to increased piston-driving power. In one example, the spark plugs 820a and 820b are positioned moderately apart from one another such that flame distribution is fairly uniform across a cross section of the combustion chamber 822. Those of skill in the art may appreciate several methods available for timing or synchronizing the ignitions.

[0086] With reference to Figure 17, a fuel injection system for a combustion- powered driving tool is disclosed. The fuel injection system 850 can include a fuel injector 852 and a controller 854. The fuel injector 852 can include a valve body 860, which can be coupled in fluid communication to a source of fuel 862, a valve element 864, a spring 865 and a solenoid 866. The spring 865 can bias the valve element 864 into a position that closes an outlet 868 of the valve body 860 through which fuel may be dispensed into a combustion chamber. The solenoid 866 can be operated to move the valve element 864 and thereby open the outlet 868. The controller 854 is coupled to the solenoid 866 and generates an electrical signal for operating the solenoid 866. In the particular example provided, the controller 854 outputs a pulse-width modulated signal to control the solenoid 866. The controller 854 can vary the duty cycle of the pulse- width modulated signal to correspondingly vary the amount of fuel that is dispensed from the fuel injector 852. A micro-controlled, modulated fuel injection system may control the air/fuel ratio in the combustion chamber on a shot by shot basis, since logic may be introduced. This may provide more ideal combustion conditions, especially in varying environmental conditions (i.e., temperature, pressure, humidity, etc.). [0087] With reference to Figure 18, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion-powered driving tool 900 can include a motor assembly 918 with a plurality of fuel injectors 920 that are operably coupled to a combustion chamber 922. The fuel injectors 920 could be of the type that is described above in conjunction with Figure 18, or could be conventional shuttle valve type. The fuel injectors 920 may be configured and/or placed for optimal fuel dispersion and/or mixing of fuel and air. For example, multiple fuel injectors 920 can be positioned radially and oriented at angles (congruent or otherwise) such that fuel dispensation creates a vortex effect within the combustion chamber 922. Fuel proportions dispensed by each fuel injector 920 may be monitored or controlled by fuel line conjunctions (i.e., fluid flow restrictions directed by piping or fluid line configuration), varied fuel line diameters, injection valve shape and configuration, etc. Fuel dispersion utilizing multiple fuel injection valves in the above manner may be optimized to create fuel and air turbulence within the combustion chamber 922. A turbulent fuel/air mixture may increase fuel efficiency and piston-driving power by ensuring a more complete combustion reaction. Current combustion-powered fastening tools may use a fan to create turbulence within the combustion chamber, however the above multi-point fuel injection system may create turbulence without expending electrical power.

[0088] With reference to Figure 19, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion-powered driving tool 950 can include a motor assembly 958 that can employ a fuel injection system 960 that can include a fuel canister 962, an oxidizer canister 964, a fuel injector 966 and an oxidizer injector 968. The fuel canister 962 and the fuel injector 966 can be configured and operated in a conventional manner to inject fuel into a combustion chamber 970 into the motor assembly 958. The oxidizer canister 964 can contain an appropriate oxidizer, such as gaseous oxygen, which can be dispensed into the combustion chamber 970 via the oxidizer injector 968. Injection of an oxidizer into the combustion chamber 970 could eliminate the need for an ambient air supply.

[0089] Ambient air is generally composed of approximately 78% nitrogen, 21 % oxygen, and 1 % argon on a per volume basis. Since oxygen is essentially the only combustion-required element of ambient air, approximately 79% of the air unnecessarily occupies combustion chamber volume. For instance, a simple idealized combustion reaction of a typical hydrocarbon, butane, requires thirteen (13) molecules of oxygen for every two (2) molecules of butane (2C₄H₁₀ + 13 O₂ → 8CO₂+ H₂O + energy). As a result, a greater proportion of oxygen gas to fuel is generally required for combustion of butane gas. Utilization of essentially pure oxygen gas as opposed to ambient air therefore decreases the required combustion chamber volume, since the volume of inert materials is significantly decreased. As a result, a smaller combustion chamber than one utilizing ambient air as an oxygen source may be implemented. Oxygen and fuel injection valves may be proportionally connected to enable a user to control the power of a combustion reaction, white maintaining the stoichiometry of the combustion reaction. For example, a user may require more fastener-driving power when working with a denser workpiece or may desire to conserve fuel by reducing power when working with a relatively soft workpiece. As with the above-mentioned multi-point fuel injection valve embodiment, the oxygen and fuel valves may be configured such that turbulence is achieved within the combustion chamber upon gas injection. [0090] In an additional aspect of the disclosure, a power management system is disclosed. Combustion-powered fastening tools using battery power may become a maintenance hassle or a burden if electrical power is inefficiently used, as frequent battery replacement or charging may decrease work efficiency. In the example of Figure 20, a power management system implements a hybrid power management system to offset battery power loss. For instance, in addition to a primary piston-driving combustion reaction that can occur in a combustion chamber 1000, a secondary combustion reaction powers an engine 1002 to turn a DC generator 1004 designed to generate power to charge the battery 1006. The battery 1006 may provide power for valve operation (i.e., solenoid valves), ignition (i.e., spark plug), fans, and other potential combustion tool functionalities (sensors, displays, etc.). Fuel lines 1008 originating from a fuel source 1010 or fuel regulator (not shown) may dispense fuel into a primary and a secondary combustion chamber. A battery-powered fan 1012 disposed in the primary combustion chamber 1000 may mix the dispensed fuel with air introduced through an intake system (some examples previously described). Alternatively, fuel and air may be mixed prior to dispersion into the primary and secondary combustion chambers to ensure proper stoichiometric conditions exist for both combustion reactions. The combustion reaction in the secondary combustion chamber provides power to turn a DC generator to recharge the battery 1006. For example, the pressure derived from the combustion reaction may propel a piston forward (away from the combustion chamber). The piston may be attached to a connecting rod that drives a metal flywheel having a commutator attached thereto. The flywheel may spin through a magnetic field, producing an electric current which may be used to recharge the battery. Implementation of such a system would eliminate the need to recharge a combustion- powered driving tool battery, thereby relieving the user of a recharging or replacement hassle.

[0091] In the example of Figure 20, a power management system implements multiple combustion engines. An object of the disclosure is to reduce or eliminate electrical power usage. For example, a combustion-powered driving tool 1100 may utilize a first combustion engine 1102 in a first combustion engine housing 1104 to provide fastener-driving power via a piston 1106 and driving member 1108, while a second combustion engine 1110 may be used to power a combustion chamber fan 1 1 12. A combustion powered fan 1 112 would not require electrical energy for fuel and air mixing, combustion chamber cooling, or exhaust of combustion waste gases. The first engine 1102 may comprise a combustion chamber 1102a, the piston 1106, a fuel inlet 1120, an air inlet (not shown), an ignition source (not shown), and means for exhaust (not shown). The second engine 1 110 may comprise an air intake and exhaust system (not shown) and an ignition source (not shown). For example, the second engine 1 1 10 may be a Wankel rotary combustion engine. In one embodiment, air for the first combustion engine 1102 may be provided via an intake for the second combustion engine 11 10 and may be propelled into the first combustion engine 1 102 by the combustion chamber fan 1112 powered by the second combustion engine 1110. The first and second combustion engines 1102 and 11 10 may alternately operate such that no combustion reactions occur simultaneously. As a result, one air intake and one exhaust outlet may not be suitable. Therefore, in another embodiment, the first and second combustion engines 1102 and 1110 utilize independent air intake and exhaust systems. The ignition source for both engines may comprise a piezoelectric device or other means not requiring an electrical power source for spark generation. Fuel may be supplied to the first and second combustion engines 1 102 and 1 1 10 via fuel lines 1122 originating from a fuel container 1124 or fuel regulator. A power management system in this manner requires no external electrical power for combustion fan operation or ignition of combustion gases.

[0092] In a further embodiment of the disclosure, a power management system implements environment sensors and a microprocessor for use in combustion event optimization. For example, sensors may be used to monitor temperature, air pressure, humidity, etc. and may relay data to a microprocessor. Control programs may be entered into and stored in a memory system. For example, a control program may be configured such that an iterative process of expanding or contracting a combustion chamber volume and increasing/decreasing dispensed fuel volume is performed to maximize combustion reaction pressure using minimal amounts of fuel. A microprocessor may access control programs stored in the memory and accordingly control combustion-powered driving tool functions to conform to optimization specifications located in the program. For instance, a microprocessor may control operation of an electric motor configured to move a piston and driver assembly (retraction embodiment explained later), thereby controlling combustion chamber volume; and the microprocessor may dictate when and for how long electric currents are passed to a solenoid valve in a combustion chamber inlet fuel line, thereby controlling how much fuel is directed into the combustion chamber (such as via a modulated fuel injector explained above). The microprocessor may constantly (or on a shot-by-shot basis) monitor data received from temperature, pressure, humidity, and other sensors and derive from these values theoretical combustion pressure data stored in the memory. In this manner, the microprocessor may accordingly update combustion chamber volume or fuel injection volume in an attempt to reach theoretical or idealized combustion pressure values. In another embodiment, a microprocessor may control a battery-powered air intake, fuel injection, and ignition spark to control combustion magnitudes and timing. For example, air intake may be controlled via a battery- powered fan, fuel injection may be controlled via a solenoid valve, and ignition may occur via a spark plug. A microprocessor may access a control program from a memory which optimizes timing events and fuel/air ratios. A power optimizer system in one of the above manners (or a combination) may enable high fuel efficiency per shot and may avoid combustion-powered driving tool malfunctions due to poor or no ignition. [0093] In another embodiment, a power management system implements a flywheel battery recharge. A flywheel battery recharge may function similarly to that described above in the hybrid power management system. However, instead of deriving flywheel spinning power from a separate combustion reaction in an individual combustion chamber, the flywheel battery recharge of this embodiment may spin via frictional forces upon the driving member. For example, a brushed DC electric motor may be positioned such that wheels frictionally contact the driving member, whereby the wheels may be connected to the flywheel which spins to generate an electric current. The spinning force derives from a driving stroke of the piston, following a combustion reaction in the combustion chamber. In this manner, a simpler system is utilized, rather than depending on multiple combustion reactions.

[0094] With reference to Figures 22A through 22D, a retraction system 1200 implements a dual piston-dual housing assembly 1202 to compress a fuel/air charge. A dual piston-dual housing retraction system may comprise two piston housings 1204a, 1204b, each comprising separate piston and driving member assembly 1206a, 1206b, respectively. For example, the piston housings 1204a and 1204b may share a common section or portion such that a single wall separates the two piston housings 1204a, 1204b. A vent or aperture 1208 may exist in the common section allowing fluid communication between the forward or leading chambers 1210a, 1210b of the piston housings 1204a, 1204b, respectively, while preventing contact between combustion chambers 1212a, 1212b, respectively, or between any combustion chamber 1212a, 1212b and any leading chamber 1210a, 1210b. At the origin of a combustion/ retraction cycle, a first piston and driving member assembly (e.g., piston and driving member assembly 1206a) may be in a firing position, white a second piston and driving member assembly (e.g., piston and driving member assembly 1206b) may be at the end of its driving stroke (i.e., piston and driving member assemblies 1206a and 1206b are constantly alternating positions relative to one another). A combustion event in the combustion chamber of the first piston housing (e.g., piston housing 1204a) propels the first piston and driving member assembly toward the nose or tip of the first piston housing. Air in the leading chamber (e.g., leading chamber 1210a) of the first piston housing may become compressed by the first piston and travel through the vent or aperture 1208 in the common section of the piston housings 1204a, 1204b. The compressed air flowing through the vent or aperture 1208 passes into the leading chamber (e.g., leading chamber 1210b) of the second piston housing, thereby applying a force on the second piston and driving member assembly and pushing the second piston and driving member assembly to a firing position. A vent (not shown) in the combustion chamber 1212a, 1212b of each piston housing 1204a, 1204b may exhaust waste gases from the subsequent combustion reaction (in that particular housing) during the retraction of the piston and driving member assembly. When the second piston and driving member assembly reaches its firing position, the second half of a combustion/ retraction cycle may proceed. A fuel/air mixture may be dispensed into the combustion chamber (e.g., combustion chamber 1212b) of the second piston housing (e.g., piston housing 1204b) prior to complete retraction of the second piston and driving member assembly, whereupon retraction, the fuel/air mixture is compressed. The compressed fuel/air mixture may be ignited, propelling the second piston and driving member assembly toward the nose or tip of the second piston housing. Air ahead of the second piston assembly (i.e., in the leading chamber) may be compressed and pushed into the leading chamber of the first piston housing via the vent or aperture 1208 in the common section of the piston housings 1204a, 1204b. The compressed air then accordingly pushes the first piston assembly back to its firing position, thereby completing a combustion/ retraction cycle. The dual piston-dual housing assembly may require a mechanism to shift a fastener magazine relative to the dual piston housings. For example, a fastener magazine is first aligned such that the driving member of the first piston assembly drives a fastener upon combustion in the combustion chamber of the first piston housing. The fastener magazine then moves relative to the piston housings to align with the driving member of the second piston assembly. After the driving member of the second piston assembly drives a fastener, the fastener magazine returns to align with the driving member of the first piston assembly, thereby instituting a new cycle. A retraction system of this manner provides means for rapid fastening cycles, energy efficient retraction, and potential fuel/air charge compression. [0095] With reference to Figure 23, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion powered driving tool 1300 can include a motor assembly 1318 that can have a fan assembly 1320 that can be mounted to a piston housing 1322. The fan assembly 1320 can include a housing member 1324, which can define an intake port 1326 and an exhaust port 1328, and a fan 1330 that can be received in the intake port 1326. Valves (not shown) can be employed to selective open or close the intake port 1326 and the exhaust port 1328. In the particular example provided, the fan 1330 is driven by an electric motor 1332. It will be appreciated that the motor 1332 may be energized at a desired time, such as when the piston 1334 is positioned in a fully returned position. In the example provided, air moved by the fan 1330 contacts the piston 1334 and is deflected toward the exhaust port 1328. [0096] With reference to Figure 24, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion powered driving tool 1350 can also include a motor assembly 1352 that can have a fan assembly 1320' that can be mounted to a piston housing 1322'. In the particular example provided, the fan assembly 1320' includes a first fan 1360, which is received in the intake port 1326', and second fan 1362 that is received in the exhaust port 1328'. The first and second fans 1360 and 1362 can be constructed such that a pinion 1364 is rotatably coupled to a fan member 1366. First and second racks 1368 and 1370 can be formed on a linkage 1372 that is associated with the contact trip 1374 of the tool 1350. The first and second racks 1368 and 1370 can meshingly engage the pinions 1364 associated with the first and second fans 1360 and 1362, respectively. Movement of the contact trip 1374 against or away from a workpiece (not shown) can rotate the first and second fans 1360 and 1362 to drive air into or out of the combustion chamber 1378. [0097] With reference to Figure 25, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion powered driving tool 1400 can include a motor assembly 1402 that can have a piston housing 1404, a piston 1406 and an air intake system 1408. The air intake system 1408 can include a cylinder 1410, a piston 1412 that is received in the cylinder 1410, a rod 1414, a vent valve 1416 and a conduit 1418. The rod 1414 can be fixedly coupled to the piston 1412 at a first end and can be fixedly coupled to a contact trip 1420 at an opposite end. It will be appreciated that movement of the contact trip 1420 against a workpiece will cause corresponding translation of the piston 1412 to compress the air that is received in the cylinder 1410. The vent valve 1416 can be any appropriate type of valve, such as a reed valve, and can open to permit air to be drawn into the cylinder 1410 when the contact trip 1420 returns to its normally extended position. The conduit 1418 can couple the cylinder 1410 and the piston housing 1404 in fluid communication; a valve 1422, such as a reed valve, can be employed to selectively inhibit fluid communication between the cylinder 1410 and the piston housing 1404. When the contact trip 1420 is pressed against a workpiece, the air in the cylinder 1410 can be compressed and can pass through the valve 1422 into the piston housing 1404. This incoming air may be used to purge exhaust gases, provide additional air in the combustion chamber of the piston housing 1404 and/or help mix the air and fuel in the combustion chamber. When the contact trip 1420 is removed from the workpiece, the piston 1412 can retract within the cylinder 1410 and the valve 1416 can be opened to permit fresh air to be drawn into the cylinder 1410

[0098] With reference to Figure 26, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion powered driving tool 1450 can include a motor assembly 1452 that can have a piston housing 1454 and piston and driving member 1456. The piston housing 1454 can include a first portion 1458 and a second portion 1460. The first portion 1458 can be relatively larger in diameter than the second portion 1460 and can define a combustion chamber 1462. The second portion 1460 can be relatively longer than the first portion 1458. The piston and driving member 1456 can be received into the second portion 1460 of the piston housing 1454. The piston and driving member 1456 can include a piston 1468, which can be relatively long and guided for sliding movement along the second portion 1460 at two or more axially spaced apart points, and a driver blade 1470 that can be shorter than the second portion 1460 (so as not to extend outwardly of the piston housing 1454 when the piston and driving member 1456 is in the fully returned position). Gases produced during a combustion event in the first portion 1458 can be employed to propel the piston and driving member 1456 within the second portion 1460 of the piston housing 1454. We note that the relatively long length of the second portion 1460 can permit the piston and driving member 1456 to achieve a higher velocity prior to an impact (e.g., the piston and driving member 1456 against a nail (not shown)). [0099] With reference to Figure 27, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion powered driving tool 1500 can include a motor assembly 1502 that can have an exhaust system 1504 with a vent 1506 that can be employed to connect a combustion chamber 1508 in fluid communication with the atmosphere. A valve 1510 can be employed in the vent 1506. The valve 1510 can be selectively opened to permit exhaust gases to be vented to the atmosphere. The valve 1510 can comprise a spring element 1512 that can be coupled to a cylinder 1514 of the motor assembly 1502. The a plurality of vent apertures 1516 can be formed through the spring element 1512 in one or more areas that are not in-line with the vent 1506. The spring element 1512 can be configured to toggle to an opposite orientation upon application of a predetermined force on the convex side of the spring element so that the spring element 1512 will deflect and the convex side 1512a becomes concave. Prior to combustion of a fuel/air mixture in the combustion chamber 1508, the spring element 1512 can be positioned such that fluid flow between the combustion chamber 1508 and the atmosphere is inhibited (i.e., convex side 1512a covers or closes vent 1506 as is illustrated in solid line). When the combustion reaction occurs, the piston and driving member 1518 are propelled (e.g., to perform a fastener-driving stroke and drive a fastener). Upon or near completion of the fastener-driving stroke, a rod 1520 or other sufficient device can apply a force to the convex side 1512a of the spring element 1512, thereby toggling the spring element 1512 to the opposite orientation (illustrated in phantom line) and allowing fluid communication between the combustion chamber 1508 and the atmosphere (i.e., concave side is adjacent the vent 1506). For example, when the piston and driving member 1518 nears completion of the fastener-driving stroke, the piston and driving member 1518 can engage a protrusion (not shown) that extends into the cylinder 1514 such that, upon forward movement of the protrusion, the rod 1520 connected to the protrusion applies a force to the spring element 1512 through the vent 1506 in the combustion chamber 1508. The protrusion may be attached to a spring or other device (not shown) that can be configured to return the rod 1520 to a rest state in which the rod 1520 is not in contact with the spring element 1512 when the piston and driving member 1518 retract. Exhaust gases can be purged from the combustion chamber 1508 via the vent 1506 on the return stroke of the piston and driving member 1518. The piston and driving member 1518 may be configured with an attachment 1522 such that, at the completion of the return stroke, the attachment 1522 applies a force to the convex side 1512b of the spring element 1512, thereby toggling the spring element 1512 into a condition that prevents fluid communication between the combustion chambers and the atmosphere (i.e., the convex side 1512a of the spring element 1512 covers the vent 1506 to prepare the combustion chamber 1508 for the next injection of fuel and air). For instance, the attachment 1522 may be positioned on a face 1524 of the piston and driving member 1518 in order to perpendicularly contact the convex side 1512b of the spring element 1512. An exhaust vent in this manner enables the motion of the piston and driving member 1518 to properly control exhaust valve operation, thereby providing a reliable exhaust method. [00100] With reference to Figures 28A through 28C, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion-powered driving tool 1550 can include a motor assembly 1552 with an exhaust system 1554 that can employ a pressure actuated exhaust valve 1556. The exhaust valve 1556 may be configured such that (a) nominal fluid flow occurs when a first pressure Pi acting on a first side of the motor assembly 1552 and a second pressure P₂ acting on a second side of the motor assembly 1552 are equivalent (valve in equilibrium, which is illustrated in Figure 28B), (b) increased fluid flow occurs when the second pressure P₂ is greater than the first pressure Pi (illustrated in Figure 28C), and no fluid flow occurs when the first pressure Pi is greater than the second pressure P₂ (illustrated in Figure 28A). The first pressure P₁ may be pressure external the tool (i.e., atmospheric pressure) and a second pressure P₂ may be the internal system pressure (i.e., the pressure within the cylinder 1558 of the motor assembly 1552). For example, one or more vents 1560 may be formed in the cylinder 1558 with a slidable seat apparatus 1562 configured to block fluid flow between the vents 1560 and the interior of the cylinder 1558 when external pressure Pi is greater than internal tool pressure P₂. The positioning of the slidable seat apparatus 1562 prevents external gas from entering the interior of the cylinder 1558when a pressure gradient exists. For example, when internal pressure P₂ is greater that the external pressure Pi, such as when combustion waste gas is present, gas flows from the interior to the exterior, and when external pressure Pi is greater that the internal pressure P₂, no fluid transfer exists. An exhaust system in this manner allows internal tool pressure to dictate valve openness.

[00101] With reference to Figure 29, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion-powered driving tool 1600 can include a motor assembly 1602 that can include an adjustable combustion chamber 1604. An isochoric (constant volume) fuel dispensation system may not always be ideal. For example, varying atmospheric pressure may dictate different fuel requirements (e.g., a lower amount of fuel is typically required at a higher elevation / altitude environment). Also, smaller fastener sizes or softer workpiece materials may require less fuel to drive a fastener flush against the workpiece. Therefore, it would be desirable to implement a system to adjust fuel amounts, white maintaining a proper fuel/air stoichiometry. For instance, the adjustable combustion chamber 1604 can be defined by a cylinder 1606 and an end cap 1608. The end cap 1608 can be employed to adjust a length of the combustion chamber 1604 to permit the amount of fresh air that can be received into the combustion chamber 1604 to be changed (i.e., increased or decreased). The cylinder 1606 can include a section of inner threading 1608 opposite or distal the piston 1610 when the piston 1610 is in a rest position (farthest from nose or tip of fastener). The end cap 1608 can include a complimentary outer threaded section 1612 that can be threadably engaged to the section of inner threading 1608 to thereby couple the end cap 1608 and the cylinder 1606. A locking plate 1614 can be disposed adjacent the cylinder 1606 and threadably engaged to the outer threaded section 1612; tigh^'tening of the locking plate 1614 against the cylinder 1606 can seal the connection between the end cap 1608 and the cylinder 1606, as well as prevent the end cap 1608 from being inadvertently repositioned through vibration, etc. It will be appreciated that the end cap 1608 can include pre-calibrated markings or indicia 1620 that can be disposed at predetermined intervals (e.g., every 90 degrees of rotation). For instance, a quarter (1/4) turn of the end cap results in a 2-3% change in the volume of the combustion chamber 1604 and so forth. Fuel and air delivery to the combustion chamber can be proportionally altered as the volume of the combustion chamber 1604 changes. An air/fuel holding chamber (not shown) may be implemented such that when the end cap 1608 moves forward or backward relative to the cylinder 1606, a plunger (not shown) in the holding chamber can decrease or increase the volume of the holding chamber respectively. The holding chamber may be calibrated such that volume changes in the combustion chamber 1604 are proportionally compensated in the holding chamber, thereby containing an appropriate amount of fuel and air for the volume of the combustion chamber 1604. A valve (not shown) may separate the holding chamber and the combustion chamber 1604. For example, a solenoid valve (not shown) may be used to allow fluid flow from the holding chamber to the combustion chamber 1604. The adjustable combustion chamber 1604 can provide the flexibility of varying shot intensity regardless of geographic location, altitude fluctuations, fastener type, or workpiece material composition.

[00102] With reference to Figure 30, another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The tool 1650 can include a retraction system 1652 for returning a piston 1654 from a location at the end of a driving stroke to a firing position. In the example provided, the retraction system 1652 includes a friction roller 1656 and a pinion 1658 that is fixed for rotation with the friction roller 1656. The friction roller 1656 is f rictionally engaged to a driver member 1660 that is fixedly coupled to the piston 1654. The pinion 1658 can be meshingly engaged to a rack 1662 that is formed on a contact trip 1664. The contact trip 1664 can be biased away from the motor assembly 1668 by a spring (not shown). When the contact trip 1664 is engaged to a workpiece (not shown) and pushed inwardly toward the motor assembly 1668, the rack 1662 will move in a corresponding direction and by a corresponding amount. Since the pinion 1658 is meshingly engaged to the rack 1662, the pinion 1658 will rotate by a predetermined amount, causing the friction roller 1656 to rotate by a corresponding amount. As the friction roller 1656 is f rictionally engaged to the driver member 1660, rotation of the friction roller 1656 will cause corresponding translation of the driver member 1660. Preferably, a one-way clutch (not shown) is disposed between the friction roller 1656 and the shaft 1670 onto which the pinion 1658 is formed. The one-way clutch can permit free rotation of the friction roller 1656 in a direction opposite the rotational direction arrow A.

[00103] With reference to Figure 31 , another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The tool 1700 can include a retraction system 1702 that includes a pinion 1704, a rack 1706 and a torsion spring 1708. The rack 1706 can be formed on the driver member 1710 and can be meshingly engaged to the pinion 1704. The torsion spring 1708 can bias the pinion 1704 in a rotational direction with sufficient energy so as to permit the pinion 1704 to rotate and thereby translate the rack 1706 such that the driver member 1710 (and an associated piston 1712) are returned to a firing position. [00104] Various embodiments of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure are illustrated in Figures 32-34. Generally, each of these embodiments employs a motor assembly 1750 that includes a piston 1752, a driver member 1754 that extends from a first side of the piston 1752, and a rod member 1756 that extends from a second side of the piston 1752 through a piston housing 1758. A seal member 1760 can be employed to seal the interface between the piston housing 1758 and the rod member 1756. In the example of Figure 32, a spring 1762 is disposed between the piston housing 1758 and a distal end of the rod member 1756; the spring 1762 is employed to retract the piston 1752 into a firing position. In the example of Figure 33, the spring 1762' is received into a spring housing 1764 that is fixed to an end of the piston housing 1758. The spring 1762' is coupled to the distal end of the rod member 1756 at a first end and to the rod housing 1764 at an opposite end. In the example of Figure 34, the spring 1762" is a flat roll-type spring (of the type that is used in a tape measurer). The spring 1762" is rotatably mounted in a cradle 1770 that extends from the piston housing 1758. A first end of the spring 1762" is coupled to the distal end of the rod member 1756, while an opposite end of the spring 1762" is coupled to an axle 1772 on which the spring 1762" is mounted. [00105] With reference to Figure 35, another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The tool 1800 can include a retraction system 1802 for returning a piston 1804 from a location at the end of a driving stroke to a firing position. The retraction system 1802 can include a double in-line piston configuration (similar to that which is described in conjunction with Figure 12, above) to conform to these requirements. Two pistons 1804 and 1806 may be attached by a rod 1808 which penetrates a dividing wall 1810 that separates a first piston chamber 1812 and a second piston chamber 1814. A retraction air storage chamber 1816 may be fluidly connected to the first and second piston chambers 1812 and 1814 via directional valves 1818 and 1820. A combustion chamber 1812a may be defined by the dividing wall 1810, a piston chamber housing 1822, and the piston 1804. An air intake port 1824 may exist in the second piston chamber 1814 for fluid communication with the atmosphere. The other piston 1806 may sealingly engage the walls of the second piston chamber 1814 such that slidable motion of this piston 1806 may induce a pumping effect, thereby drawing air from the atmosphere into the second piston chamber 1814. Upon ignition of a fuel/air mixture in the combustion chamber 1812a (those of skill in the art appreciate a number of means to charge the chamber with fuel), the pistons 1804 and 1806 are propelled toward the tip or nose of the combustion-powered driving tool 1800 (i.e., to the right in the illustration) and the air drawn into the second piston chamber 1814 is forced through the directional valve 1818 into the retraction air storage chamber 1816. At the end of the driving stroke, compressed air in the retraction air storage chamber 1816 can be released from the retraction air storage chamber 1816 (via the directional valve 1820) to act on a side of the piston 1804 opposite the combustion chamber 1812a; the directional valve 1820 can be a timed or triggered directional valve. The compressed air applies a force on the piston 1804 that pushes the piston 1804 in a direction (i.e., to the left in the illustration) that retracts the piston 1804 to the firing position. A vent (not shown) may exist in the first piston chamber 1812 such that retraction air may be exhausted prior to or after the subsequent combustion reaction.

[00106] With reference to Figure 36, another combustion-powered driving tool is illustrated. The tool 1850 can include a retraction system 1852 with a telescoping cylinder 1854. During a driving stroke of the piston 1856, air located in the leading chamber 1858 of the piston housing 1860 is pushed through a valve 1862 (e.g., reed valve or other check valve) into an air storage chamber 1864, where it is compressed. The telescoping cylinder 1854 may retract within itself during a driving stroke, as the driving member 1866 extends through the telescoping cylinder 1854. A valve 1868, such as a solenoid valve, may control fluid flow between the air storage chamber 1864 and an inlet 1870 to the telescoping cylinder 1854. At the completion of a driving stroke, the valve 1868 between the air storage chamber 1864 and the inlet 1870 may actuate, releasing compressed air from the storage chamber 1864 into the interior of the telescoping cylinder 1854. The pressure of the air entering the telescoping cylinder 1854 may cause the telescoping cylinder 1854 to extend, thereby pushing the piston 1856 into a retracted position. The telescoping pneumatic retraction system may be configured such that the interior empty volume of the fully expanded telescoping cylinder 1854 is less than the volume of the leading chamber 1858 (not including the fully extended telescoping device volume). In this manner, a full piston retraction is possible using only the air compressed by the piston 1856 during the driving stroke. [00107] With reference to Figure 37, another combustion-powered driving tool is illustrated. The tool 1900 can include a retraction system 1902 that can employ a pair of friction rollers 1904 and 1906 and an electric motor 1908 to retract a piston 1910. The rollers 1904 and 1906 can frictionally engage a driver member 1912 that is fixedly coupled to the piston 1910. The electric motor 1908 can be coupled to one of the friction rollers (e.g., friction roller 1904) and can be employed to rotate the friction roller 1904 in a direction that causes the friction roller 1904 to translate the driver member 1912 in a direction opposite the driving direction. Accordingly, the motor 1908 can be employed to translate the piston 1910 to a returned or firing position. It will be appreciated that one-way clutches (not shown) can be disposed between the friction rollers 1904 and 1906 and the axles on which they are supported for rotation. The one- way clutches can be employed to permit the friction rollers 1904 and 1906 to rotate freely when the piston 1910 is translated in a driving direction (i.e., toward the retraction system 1902).

[00108] With reference to Figure 38, another combustion-powered driving tool is illustrated. The tool 1950 can include a motor assembly 1952 having a cylinder 1954, a piston 1956, a driver member 1958 and an impacting spring 1960 that can be disposed between the piston 1956 and the cylinder 1954. A combustion chamber 1962 can be disposed on a side of the piston 1956 opposite the impacting spring 1960. While not specifically shown, the motor assembly 1952 can employ means for intaking air into the combustion chamber 1962, means for introducing fuel into the combustion chamber 1962, means for igniting the fuel in the combustion chamber 1962 and means for exhausting the combustion chamber 1962. When a combustion event occurs in the combustion chamber 1962, the piston 1956 is moved in a direction toward the impacting spring 1960 and thereby compresses the impacting spring 1960. When the combustion reaction has dissipated and the exhaust means has opened to vent exhaust gases to the atmosphere, the impacting spring 1960 can drive the piston 1956 in a driving direction to perform the desired work (e.g., install a fastener). It will be appreciated that the combustion reaction provides energy that moves the piston 1956 to the returned position, while the impacting spring 1960 provides the energy that performs the desired work. [00109] With reference to Figures 39A and 39B, another combustion-powered driving tool is illustrated. The tool 2000 can include a motor assembly 2002 having a cylinder 2004, a piston 2006, and a driver member 2008. The piston 2006 can divide the cylinder 2004 into a first chamber 2010 and a second chamber 2012. Each of the first and second chambers 2010 and 2012 can include means for intaking air into the chamber, means for introducing fuel into the chamber, means for igniting the fuel in the chamber and means for exhausting the chamber. A first combustion reaction 2014 can be employed in the first chamber 2010 to translate the piston 2006 toward a retracted position as shown in Figure 39A and a second, more powerful combustion reaction 2016 can be employed in the second chamber 2012 to translate the piston 2006 toward an extended position as shown in Figure 39B.

[00110] In a further additional embodiment of the disclosure which is illustrated in

Figure 40, an adaptability system implements combustion/ pneumatic conversion is disclosed. A driving tool 2050 may be configured to function utilizing combustion power or pneumatic power. This may be advantageous to an individual performing a variety of tasks in a short time frame, where in one instance, a pneumatic fastener may be preferred (such as repetitive localized work), and in another instance, a combustion- powered driving tool may be preferred (such as extensive overhead work). A driving tool implementing combustion/ pneumatic conversion rather than purchasing multiple tools may provide a more cost-effective alternative. For example, the handle 2052 a fastening tool 2050 may be configured such that a combustion cartridge 2054 and a pneumatic cartridge 2056 may interchangeably fit within and fixedly but removably couple to the handle 2052. Each cartridge may independently supply energy for fastener-driving power to a piston within a piston housing of the fastener tool. A combustion cartridge may comprise a fuel regulator, fuel metering tube, or shuttle valve, a fuel line connector and seat, and an electrical power source for ignition of a fuel/air mixture in the fastener combustion chamber. A pneumatic cartridge may comprise an external valve for receiving an air supply line. Both cartridges can employ a seal system for sealably connecting the cartridge to the handle. When a combustion cartridge 2054 is inserted and secured into the handle 2052, a fuel regulator within the combustion cartridge becomes fluidly connected to the combustion chamber via a fuel line. When actuated, a trigger in the handle may complete an electric circuit to send a charge from a battery in the combustion cartridge to a spark source in the combustion chamber, or may initiate a piezoelectric device to create an ignition spark. Once the combustion cartridge is removed from the handle, the power and fuel sources are no longer capable of supplying combustion-necessary components to the fastening tool. A pneumatic cartridge 2056 with an air supply connection 2058 may be inserted and secured into the handle 2052, whereby compressed air may flow above and below a valve plunger. Air may flow above the valve plunger via an air line, which may be sealed by trigger actuation. The valve plunger may be biased toward the piston head so that pressure is always greater above the valve plunger, unless the trigger is actuated. Upon trigger actuation, the valve plunger may be pushed away from the piston head, allowing supplied air to force a piston-driving stroke. A different configuration may be utilized without departing from the spirit and scope of combustion/ pneumatic conversion. [00111] With reference to Figures 41-48, a combustion-powered tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion-powered tool 2100 can be configured as described in the discussion associated with Figures 11 and 27. Figure 41 illustrates the tool 2100 at a rest state; Figure 42 illustrates injection of fuel into the combustion chamber of the motor assembly; Figure 43 illustrates the generation of a spark to ignite the fuel; Figure 44 illustrates the power stroke of the piston and charging of air into the second cylinder; Figure 45 illustrates the opening of the exhaust vent; Figure 46 illustrates the return stroke of the piston and the opening of the second valve; Figure 47 illustrates the opening of the third valve; and Figure 48 illustrates the closing of the exhaust valve when the piston is moved to a fully returned position as well as the closing of the second and third valves.

[00112] With reference to Figures 49 through 57, a combustion-powered tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion powered tool 2150 employs an adjustable combustion chamber and a fuel injection system similar to those described above in conjunction with Figure 29, an exhaust system that is with a movable cylinder portion similar to that which is describe in conjunction with Figure 14 above and a retraction system similar to that described above in conjunction with Figure 37.

[00113] The combustion-powered driving tool 2150 may be configured for power optimization by cohesively implementing an adjustable head (end cap), solenoid fuel valve, atmospheric pressure and head positions sensor, and a friction driven motor retraction system. Configuration and operation of such a tool may be as follows: the tool generally comprises a main piston housing or cylinder, a main piston attached with a driving member, a retraction motor (i.e., friction driving motor), a safety and safety spring, an air pump piston, an air pump piston housing, an air intake, a solenoid fuel valve, a fixed head and adjustable head (collectively "head"), and an exhaust valve. The spring biases the safety in an extended position which extends away from the piston housing near the fastener to be driven. The adjustable head may be configured to rotatably seat with the fixed head such as through a threading system. The head may be configured such that, at a rest state, there exists a gap or open section between the main piston housing and the head. When a force is applied to the safety, the head may close the gap or open section such that a seated connection is formed between the main piston housing and the head, thereby creating a combustion chamber. The starting conditions for the tool may include a fully retracted main piston, a head in the rest position (gap between head and main piston housing), and an extended safety. When a user begins to push the safety against a workpiece, the initial force closes the head, forming a combustion chamber. The safety may be connected to the air pump piston such that rearward movement of the safety (relative to the workpiece) moves the air pump piston within the air pump piston housing. A sealable connection between the air pump piston and housing causes air to be pumped from within the housing past the solenoid fuel valve, through the air intake, and into the combustion chamber. As air moves past the solenoid fuel valve, the air flow rate entrains fuel through the solenoid valve and into the combustion chamber. At this stage, the friction driven motor may assist with proper firing positioning of the main piston. For example, head position and atmospheric pressure sensors transmit data to a microprocessor which calculates an exact combustion chamber volume, whereby the main piston is positioned by the motor to achieve this calculated volume (enables fuel/air compression). An ignition system triggers a combustion reaction within the combustion chamber, allowing a fastener to be driven by the main piston and driving member assembly. A portion of exhaust gas may be expelled through the exhaust valve when the piston clears the valve area. Upon exhaust valve closure, the remaining exhaust gas coots, forming a partial vacuum within the combustion chamber, thereby partially retracting the main piston. When a user releases the safety (i.e., pulls tool away from workpiece) the head springs back to a rest position, opening the combustion chamber. The friction driven motor retracts the piston to its starting position, completely purging exhaust gases from the combustion chamber. [00114] Figure 49 illustrates the starting conditions of the tool 2150 wherein the piston is fully retracted, the had is sprung open and the contact trip is extended; Figure 50 illustrates the pushing of the contact trip against a workpiece, which closes the combustion chamber; Figure 51 illustrates further contact of the contact trip against a workpiece wherein air in a pump is compressed, the compressed air entrains fuel into the air flow and the mixture is injected into the combustion chamber; Figure 52 illustrates a charge of fuel and air in the combustion chamber; Figure 53 illustrates ignition of the charge of fuel and air; Figure 54 illustrates the venting of exhaust gases from the combustion chamber when the piston has passed a port in the cylinder; Figure 55 illustrates retraction of the piston while the head is closed; Figure 56 illustrates opening of the head valve and extension of the contact trip; Figure 57 illustrates further retraction of the piston to purge exhaust gases from the combustion chamber. [00115] With reference to Figures 58 through 66, a combustion-powered tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion powered tool 2200 employs two combustion events to reciprocate a piston in a manner that is similar to that which was discussed above in conjunction with Figures 39A and 39B. Figure 58 illustrates the tool 2200 in a starting condition wherein fresh air is disposed on both side of a piston, a solenoid valve is closed, a valve actuated by the contact trip is open and the driver member is partly extended; Figure 59 illustrates the contact trip engaged against a workpiece, which closes the driving chamber valves and causes fuel to be injected into the chambers on both sides of the piston; Figure 60 illustrates the initiation of a combustion event in the leading chamber; Figure 61 illustrates the piston as having been driven to a returned position, which compresses the fuel and air mixture in the primary combustion chamber; Figure 62 illustrates the initiation of a combustion event in the primary combustion chamber; Figure 63 illustrates the piston as located in a fully extended position; Figure 64 illustrates the piston being returned to the starting position via a spring and air being drawn into the leading chamber though the solenoid valve; Figure 65 illustrates the closing of the solenoid valve; and Figure 66 illustrates the opening of the valve and the operation of a fan which exchanges air in the primary combustion chamber. [00116] With regard to Figure 67, another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is provided. The combustion-powered driving tool 2300 can include a motor assembly 2301 with a depth control system 2304. The depth control system 2304 can comprise electronically controlled brakes 2306 that can be operated to control a velocity of the piston 2308 and the distance with which a driving member 2310 has traversed. The electronically controlled brakes 2306 can provide a simple method to control fastener insertion depth, while not altering complex combustion reaction variables. For example, guide wheels 2312 associated with the brakes 2306 may be engaged to the driving member 2310. The brakes 2306 may be electronically controlled and calibrated to reduce driving member velocity and/or limit the distance of travel, within a predetermined range. For instance, a relatively large amount of electricity can be supplied to the braking device for a relatively shallow-driven fastener, while a reduced amount of electricity (e.g., no electricity) can be supplied for a relatively deeper-driven fastener. A user-inputted controller may exist to determine and regulate required electricity flow to the braking device.

[00117] With reference to Figure 68, a portion of another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion-powered driving tool 2330 can include a motor assembly 2332 that can include a retraction system 2334 with a friction driven motor 2336. For instance, an electric motor (i.e., DC motor) may engage spring loaded rollers 2338 resting on a driving member 2340 of a piston assembly 2342. One or both of the rollers 2338 can spin to push the driving member 2340 (and piston assembly 2342) back to a firing position. For example, a first one of the spring loaded rollers 2338 may be positioned opposite another of the spring loaded rollers 2338 such that the rollers 2338 frictionally engage the driving member 2340. Movement of a driving member 2340 relative to the rollers 2338 may induce the rotation of the rollers 2338. The rollers 2338 may be configured such that frictional forces allow the rollers 2338 to control movement of a driving member 2340 upon power supplied by the electric motor 2336. The electric motor 2336 may be powered by a battery 2346, which may comprise a power management system explained above. Retraction by a friction driven motor 2336 outside a piston housing 2344 may leave the combustion stroke unencumbered by retraction energy generation. In the present embodiment, a fuel/air charge may be dispensed into a combustion chamber 2348 of the combustion-powered driving tool 2330 prior to retraction of the driving member 2340. Upon engagement of the electric motor 2336 on the rollers 2338, the piston assembly 2342 can be pushed to firing position, thereby compressing the fuel/air charge. As discussed before, compression of a fuel/air mixture and an unencumbered driving stroke provide increased power and may result in a smaller single cycle combustion-powered driving tool. A retraction system in this manner also alleviates the need for the combustion stroke to generate energy for retraction. It will be appreciated that the rollers 2338 can be engaged to the driving member 2340 at all time and as such, the rollers 2338 can be employed to "back drive" the motor 2336 when the driving member 2340 is propelled by a combustion event in the combustion chamber 2348. Electrical energy can be generated by the motor 2336 when it is back-driven, and such electrical energy can be employed to re- charge the battery 2346.

[00118] With reference to Figure 69, another combustion-powered driving tool constructed in accordance with the teachings of the present disclosure is illustrated. The combustion-powered driving tool 2350 can include a power management system with generator 2352 that is powered by a turbine 2354 that can be driven by exhaust gases generated during a combustion event in the combustion chamber 2358. The turbine 2354 may be positioned adjacent an aperture in a piston housing 2360, whereby, following a combustion reaction, exhaust gases are purged through the aperture to thereby induce rotation of the turbine 2354. The generator 2352 can be coupled for rotation to the shaft 2364 of the turbine 2354 and as such, rotation of the turbine 2354 can cause corresponding rotation of the generator 2352.

[00119] With reference to Figure 70, a combustion-powered driving tool 2400 constructed in accordance with the teachings of the present disclosure can include combustion apparatus 2402 and a remote fastening head 2404. The remote head 2404 may be linked to the combustion apparatus 2402 via a hose link 2408. For example, the combustion apparatus 2402 may comprise the combustion chamber, ignition system, exhaust system, fuel injection system, and piston, while the remote head 2404 may comprise a driving member, trigger, and fastener magazine. The piston may be slidably disposed within the combustion apparatus 2402 such that combustion pressure in the combustion chamber forces the piston toward the hydraulic hose link. Piston movement may increase pressure of air or other fluid ahead of the piston (opposite side of combustion reaction). The pressure increase may translate through the hydraulic hose, and act upon the remote head. A driving member in the remote head 2404 may be attached to a piston or other structure designed to force the driving member forward upon the pressure increase originating from the combustion apparatus 2402, thereby driving a fastener. An adaptability system implemented in this manner reduces the weight of a fastening tool carried by hand and reduces the size of the tool portion that is positioned to fire a fastener. For example, the length of the tool portion manipulated by hand may be significantly reduced, thereby providing increased tool accessibility. [00120] With reference to Figure 71 , a driving tool 2450 constructed in accordance with the teachings of the present disclosure can include a magazine 2452 that can be swiveled about the nose (not shown) of the tool 2450. A detent mechanism 2454 can be employed to lock the magazine 2452 in one of a plurality of predetermined position. [00121] With regard to Figure 72, an LCD display 2500 can be coupled to a driving tool 2502. The LCD display can report information, such as the amount of charge in a battery, the number of fasteners in a magazine, the amount of a gaseous propellant that is available, the number of times the tool has been actuated, etc. [00122] In Figure 73, a driving tool 2600 includes a grip 2602 that is connected to a tool body 2604 via a telescoping intermediate portion 2606. The intermediate portion is extendable and lockable to permit a user to access overhead locations or locations that are near the ground. A trigger 260 can be coupled to the grip 2602. [00123] In Figure 74 a driving tool 2700 is illustrated to be coupled to a tool carrier 2702 having a wheel 2704 and an actuating mechanism (not shown) that can be employed to actuate the driving tool 2700 at predetermined intervals based on a rotational position of the wheel 2704. The carrier 2702 and driving tool 2700 provide a rolling, walk behind unit that can be employed to drive nails into decking at equal distances and in relatively straight lines.

[00124] In a still further aspect of the disclosure, a reliability system is disclosed.

It is an object of the disclosure to provide a more reliable combustion-powered driving tool. In a present embodiment, a reliability system implements a sensor system. Sensors may be used for fault analysis and tool operation status. Combustion-powered fastening tools generally require regular maintenance for proper functioning. Frequent combustion reactions may lead to carbon build-up within the tool, fouling of valves and fuel lines, inhibited fan function, seat deformation, etc. Carbon build-up on ignition sources may cause faulty ignitions or misfires, worn seats may result in towered combustion pressures or exhaust blow by, leaky fuel cylinders will decrease the useful life of a fuel cartridge, and the like. A sensor system communicating to a display may provide a user with fault analysis, service recommendations, tool status, etc. For example, a display may present battery life, number of shots taken/remaining (fuel usage/ remaining), remaining nail count, and fault analysis such as carbon build-up, jammed nail in magazine or chamber, ring wear, low colnbustion pressure, open fuel latch, leaky gas cylinder, incorrect nail insertion, and other combustion tool maintenance issues. Pressure sensors, positional sensors, and the like may relay data to a microprocessor, whereby information may be analyzed and transmitted to a display. For instance, a pressure sensor located in the combustion chamber may detect a low pressure during a combustion reaction. The microprocessor may relay this data to the display or may indicate a suggestion (via the display) such as "service piston ring" or "check combustion seats". In another embodiment, a sensor system may be used in conjunction with a sensored power optimization system, such as the one previously mentioned. For instance, in addition to the combustion event optimization, sensors may detect fastener length and communicate with a microprocessor to process the data and adjust depth setting to properly drive the fastener (i.e., adjust combustion event for proper combustion pressure). Additionally, a sensor may track fastener insertion resistance and communicate with the power optimization system to adjust combustion reaction power accordingly. In this manner, the combustion-powered driving tool may automatically adjust combustion conditions when working with varying workpiece materials. For instance, less fuel may be used for a softer workpiece material, while more fuel may be required for a harder workpiece material. In a further embodiment, a sensor system may be used in conjunction with a memory, for use as a more sophisticated reliability system. For example, data recorded by sensors located throughout a combustion-powered driving tool may be stored in a memory such that a user may retrieve past sensor data. In this manner, a user may observe data trends such as peak combustion pressure, combustion chamber temperature, electrical power or fuel usage, number of firings before a fastener jam, etc. Discrepancies in the trends may indicate a servicing need or provide the user with valuable technical insight into tool function.

[00125] In another alternative embodiment of the disclosure, a safety system is disclosed. In a present embodiment, a safety system implements a catalytic converter and sensors to detect and control emissions. Non-ideal combustion conditions may lead to incomplete or altered combustion reactions. For instance, incomplete combustion or combustion of an impure fuel (i.e., a mixture of hydrocarbons) may produce CO (carbon monoxide), nitrogen oxides (if ambient air is used as oxygen source), and volatile organic compounds as combustion by-products, in addition to main products of water vapor and C02 (carbon dioxide). A combustion-powered driving tool comprising a catalytic converter, oxygen and carbon monoxide sensors, and a power optimizer system may function to limit toxic carbon monoxide levels in exhaust gases. For example, a catalytic converter may be used to process waste gas from a combustion reaction prior to expulsion of waste gas from the tool, an oxygen sensor prior to the catalytic converter may be used to determine if enough oxygen is available to the catalytic converter, and a power optimizer system may be used to adjust combustion reaction settings to control exhaust oxygen amounts. An extreme excess of oxygen in the combustion chamber may lead to decreased combustion reaction pressure. However, a catalytic converter may use a portion of oxygen in the exhaust gas with an oxidation catalyst (i.e., platinum or palladium) to convert carbon monoxide to carbon dioxide as follows: 2CO + O₂ → 2CO₂. A carbon monoxide sensor may be configured to monitor CO in the waste gas, whereby the sensor communicates to a microprocessor. A microprocessor may, for example, control an electric motor which manipulates combustion chamber volume or fuel injection to ensure a more complete combustion and therefore minimize toxic levels of carbon monoxide exhaust.

[00126] In an alternative embodiment, a safety system implements a firing logic system. A firing logic system may employ a microprocessor for use vs. transport state determination and voice recognition \ockout. These considerations may help to prevent unintentional firings or accidents thereof. For instance, a microprocessor may selectively activate or deactivate a triggering mechanism based on positional and audio data. Sensors may relay positional data to a microprocessor, which may determine tool orientation and acceleration. The microprocessor may compare orientation and acceleration values with travel profiles stored in a system memory. For example, if tool orientation and acceleration values correlate with data signifying tool transportation, the microprocessor may deactivate the trigger mechanism. Voice recognition hardware may be utilized to lock out and activate a trigger mechanism based on user-provided verbal commands, such as "hold" to lock out and "ready" to activate. In this manner, only the user may lock and unlock the trigger mechanism, providing firing security. For example, once verbally locked out, a fastening tool may not be accidentally fired by a child or during transportation. An exhaust muffler may be implemented to reduce noise, so as to not interfere with voice recognition hardware.

[00127] In an additional embodiment, a safety system implements a remote lockout and identification system. For example, a remote fob may be employed to remotely lock out a trigger and initiate a tool location signal, while an automatic RF ID (radio frequency identification) system may provide tool security and safety. A fastening tool may be equipped with a receiver configured to receive signals from a remote fob and/or a RF ID. For instance, a remote fob may transmit function codes to the receiver, whereby the receiver translates the codes and initiates the respective function, such as trigger lock out, audible/visible location alarm, and the like. An automatic RF ID may be configured to relay a signal to the fastening tool receiver to enable (or maintain) trigger actuation capabilities. In this manner, if the RF ID signal is not received (i.e., RF ID out of range), then the fastener trigger may not actuate. A short-range signal may enable a user-specific security feature. [00128] In an alternative embodiment, an adaptability system implements a fastener magazine swivel. A fastener magazine has great potential for inhibiting fastener accessibility, as most magazines protrude adjacent the tip of the fastener. For instance, a user may not be able to reach a desired fastening location if a fastener magazine contacts a framing stud before the nose or tip of the fastener is positioned to fire. A swiveling fastener magazine may allow a user to reposition the fastener magazine relative to the tip or nose of the fastener, providing multiple orientations that may access a desired firing location. For example, a fastener magazine may be configured to rotate about the firing axis. Means for securing the fastener magazine to the fastener nose may include a toggle and groove system, a ratchet system, a friction system, or other suitable system. In one embodiment, the fastener nose comprises grooves spaced across the circumference into which a protrusion from the magazine fits. The protrusion may be configured such that a user may toggle the protrusion into or out of a groove in order to secure or move the magazine, respectively. In this manner, the magazine may rotate in either direction for increased accessibility. [00129] In an additional embodiment, an adaptability system implements a grip extension. For instance, a grip may include an extendable, lockable, (telescoping) tube that can be used to provide fastener access to above-reach or near-ground areas. The increased range provided by a grip extension may prevent user strain when accessing hard to reach areas. A grip may include a triggering mechanism configured for ignition actuation of a combustion reaction. The trigger may comprise an electronic switch input such as one described earlier in order to avoid a mechanism in the telescoping portion. In one embodiment, the telescoping portion of the grip extension may utilize spring- loaded protrusions configured to engage apertures in the tubing upon movement of the protrusions relative to the tubing. The protrusions may lock the tubing into place and prevent the grip extension from altering length until a predetermined force is provided against the springs.

[00130] In a further embodiment, an adaptability system implements a rotting fastener spacer. A rotting fastener spacer may automatically actuate a combustion- powered driving tool to fire fasteners at equal distances in a line. This functionality may be especially useful in decking projects or other repetitive fastening instances. A rolling fastener spacer may comprise a wheel, a handle, a combustion-powered driving tool, and a mechanism configured to actuate the combustion-powered driving tool. For instance, the wheel axis may have a gear system connected to a combustion triggering device such that, after a designated distance traveled, the gears actuate the triggering device, causing a fastener to be fired. The distance traveled in order to actuate the trigger may be adjustable to better facilitate a user's needs. For example, in one instance a user may require δinch spacing, whereas in another instance, the user may require 12-inch spacing. The wheel may be calibrated such that wheel rotation is easily converted to/from fastener spacing. In another embodiment, the rotting fastener spacer may attach to an existing combustion-powered driving tool. For example, a combustion- powered driving tool may attach to the rolling device, whereby the fastener safety may be actuated in order for the triggering mechanism to function property (i.e., trigger actuation begins ignition). While the diversity of combustion fastening systems may limit the number of fastening tools that one rotting fastener spacer can accommodate (i.e., varying intake, exhaust, and retraction systems), it is possible to allow functionality with a number of fastening tools.

[00131] INVENTORS: NOTE THAT YOU HAVE NOT PROVIDED SKETCHES

OF THIS EMBODIMENT. In another embodiment, an adaptability system implements an ergonomic grip configuration. A traditional pistol-grip style fastener creates a kickback force on the user. Extended periods of usage may cause ergonomic problems of the wrist resulting from repetitive kickback. An ergonomic grip configuration may place the trigger behind the combustion chamber instead of underneath the combustion chamber. For example, the trigger may be placed near the axis of piston movement. A second hand may be placed near the nose or front housing of the combustion-powered driving tool for better handling. The result of such a configuration is increased stability during firing, while kickback is resisted by a larger portion of the arm and shoulder as opposed to mainly the wrist. Also, by positioning the handle behind the combustion chamber, the fastener may have increased accessibility, as there is no handle protruding perpendicularly from the piston housing. [00132] In a still further embodiment, an adaptability system implements a user customization system. For example, a user customization system may include a heated grip, adjustable grip size/shape, adjustable trigger finger or location, a harness, or any combination of these features. A heated grip may be an extremely useful feature when working in a cold environment, especially for extended periods of time. A grip may be selectively heated such that the grip is heated only when desired, so as to avoid a hot grip on a warm day. Combustion chamber exhaust gas may be directed to the handle (via a passage) following a combustion, whereby the hot gases conductively warm the handle portion. The waste gas may then be purged from a port in the handle. A selectable toggle switch may block the passage from the combustion chamber to the handle, whereby gases may exhaust from a port in the combustion chamber. When a user desires a warmed grip, the selectable toggle switch may be positioned to open the passage accordingly. Grip size or shape may be adjustable to provide better comfort for the user. The grip may incorporate an air pocket designed to expand and contract upon increased or decreased air pressure. Pressure within the pocket may be increased via an onboard compressor, a manual pump, exhaust gases, or other suitable mechanism. A release valve may be incorporated to relieve pressure within the air pocket. The trigger may be adjustable such that a different hand configuration may be utilized to initiate combustion. For example, a user may wish to fire a fastener with the thumb or ring finger, as opposed to traditionally using the index or middle finger. A harness may be implemented to reduce user fatigue while supporting the fastener. The fastener may include harness attachments along a variety of casing positions for user customization and harness comfort. Providing a user customization system allows the user increased comfort and diversified operating conditions, which may especially benefit an individual over an extended work period. In yet another embodiment, an adaptability system implements a user vision enhancing system. Combustion-powered fastening tools may deny a direct tine-of-sight to the desired fastening location, especially just prior to firing, but most combustion-powered fastening tools do not offer a remedy for visual obstructions. It is an object of the disclosure to provide features designed to assist a user with relative positional information and improved tine-of-sight. For example, a user vision enhancing system may comprise a proximity sensor, laser projections, bubble level, stud sensor, metal detector, wood markers, barrel-mounted work lights, or any combination of these features. For instance, a proximity sensor may be used as an alternative to a mechanical safety. A proximity sensor may clear the tine-of-sight between the tip or nose of the combustion-powered driving tool and the workpiece, as the physical mechanical safety would not be present to obstruct vision. The combustion-powered driving tool may be configured to fire only after the proximity sensor detects an object within a predetermined distance and the trigger is actuated. Laser projections, such as a laser crosshair, may provide simple and cost-effective vision enhancement without requiring dramatic design changes. The laser(s) may be calibrated to project an image directly below the nose or tip of the combustion-powered driving tool to guide a user to an exact fastening location. A bubble level may be used to 1 indicate plumb in multiple firing orientations. For example, a user may require an exactly vertical or an angular orientation, with little deviation. A bubble level may be calibrated to fairly precise angular orientations to provide fastening accuracy. A stud sensor may be utilized near the nose or tip of the combustion-powered driving tool to indicate the edges of studs or joists through drywall, plywood, and other common materials. Audible or visual indicia may be implemented to convey location information. The stud sensor may increase productivity since only one tool is required to locate studs or joists and fire a fastener. A metal detector may be implemented near the nose or tip of a combustion-powered driving tool. For instance, a metal detector may locate (and thus help avoid) plumbing, electrical conduit, other fasteners, etc. Wood markers may be utilized to indicate preferred firing locations. For example, markers may be placed on wood after the wood has been cut to a desired size/shape. The markers may include visible or invisible indicia. An embedded gun sensor may be used in conjunction with invisible indicia to provide audio or visual acknowledgment when the nose or tip of the fastener is above the desired location. In one embodiment, the fastener may be configured to automatically fire when an embedded gun sensor indicates a fastener is desirably positioned (above a wood marker). Finally, a user vision enhancing system may utilize barrel-mounted work lights. The lights may comprise ultra bright LEDs (light emitting diodes) to minimize power consumption and space requirements. In one embodiment, light sensors may be used to automatically control light function (i.e., brightness, on/off, etc.).

[00133] In still another embodiment, an adaptability system implements a nail blunter. Pointed nails may induce wood splitting (especially with dry wood), which may require costly repairs or replacement. Blunting a nail point will help prevent wood splits, since a blunt nail will crush, rather than spread, wood fibers. A nailing tool may incorporate a mechanism to blunt a nail upon command. For instance, two angled cutting edges may be pressed together to clip off the pointed nail end, a roughly textured metallic file may be quickly passed onto the nail to shave down the point, or other suitable means may be used. The nail blunter may be motorized via an onboard engine, or may require manual operation from a user. Though blunted nails are not as common for use in combustion and pneumatic nailers, an effective nail blunter on a fastening tool may be ideal for the limited situations demanding these specialized fasteners. [00134] While specific examples have been described in the specification and illustrated in the drawings, it will be understood by those of ordinary skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure as defined in the claims. Furthermore, the mixing and matching of features, elements and/or functions between various examples is expressly contemplated herein so that one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one example may be incorporated into another example as appropriate, unless described otherwise, above. Moreover, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular examples illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out the teachings of the present disclosure, but that the scope of the present disclosure will include any embodiments falling within the foregoing description and the appended claims.

Claims

CLAIMS What is claimed is:

1. A driving tool comprising: a piston housing; a piston received in the piston housing, the piston cooperating with the piston housing to define a combustion chamber; an auxiliary housing coupled in fluid communication with the piston housing; wherein movement of the piston in a predetermined direction compresses air in the piston housing that is vented into the auxiliary housing, the compressed air in the auxiliary housing being discharged into the piston housing to perform at least one of purging exhaust gases from the combustion chamber, mixing air and fuel in the combustion chamber, and moving the piston toward a firing position.

2. A driving tool comprising: a tool housing defining a handle; a piston housing in the tool housing; a piston received in the piston housing, the piston cooperating with the piston housing to define a combustion chamber; a fuel cell and battery that are removably coupled to the handle of the tool housing, the fuel cell and battery providing gaseous fuel and electrical energy for producing a combustion event in the combustion chamber.

3. The driving tool of Claim 2, further comprising a cartridge having a seal member and an air inlet that is adapted to couple the cartridge to a source of compressed air, wherein upon removal of the fuel cell and battery from the handle the cartridge can removably coupled to the handle of the tool, the cartridge being adapted to selectively provide compressed air to the combustion chamber.