WO2010120322A1

WO2010120322A1 - Power tool including vacuum attachment

Info

Publication number: WO2010120322A1
Application number: PCT/US2009/052798
Authority: WO
Inventors: David Elsea; David M. Smith; Ernest C. Bostic; James Morgan
Original assignee: Techtronic Power Tools Technology Limited
Priority date: 2009-04-14
Filing date: 2009-08-05
Publication date: 2010-10-21

Abstract

A power tool includes a housing defining a cavity, a motor supported by the housing in the cavity, an output shaft extending from the housing and operably coupled to the motor, and a vacuum attachment removably coupled to the housing. The vacuum attachment includes an inlet positioned adjacent and in facing relationship with the output shaft, an outlet, and, a passageway fluidly communicating the inlet and the outlet. The passageway is fluidly isolated from the cavity.

Description

POWER TOOL INCLUDING VACUUM ATTACHMENT

RELATED APPLICATIONS

[0001] This application claims priority to co-pending U.S. Provisional Patent

Application Serial No. 61/169,084 filed on April 14, 2009, the entire contents of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to power tools, and more particularly to power tools including vacuum attachments.

[0003] Cast saws are power tools designed to cut through plaster, fiberglass, or plastic casts to remove the casts from an individual's body. Some cast saws incorporate a vacuum duct in the housing of the saw that is attached to an extraction system for removing dust or debris from the cast as it is being cut.

[0004] While incorporating the vacuum duct in the housing of a cast saw might improve the visibility and handling of the cast saw, such cast saws are often difficult to clean without concern for exposing the electronic components of the cast saw to water or other cleaning fluids.

SUMMARY OF THE INVENTION

[0005] The present invention provides, in one aspect, a power tool including a housing defining a cavity, a motor supported by the housing in the cavity, an output shaft extending from the housing and operably coupled to the motor, and a vacuum attachment removably coupled to the housing. The vacuum attachment includes an inlet positioned adjacent and in facing relationship with the output shaft, an outlet, and a passageway fluidly communicating the inlet and the outlet. The passageway is fluidly isolated from the cavity.

[0006] The present invention provides, in another aspect, a power tool assembly operable with a vacuum device. The power tool assembly includes a power tool having a housing defining a cavity, a motor supported by the housing in the cavity, an output shaft extending from the housing and operably coupled to the motor, and a vacuum attachment removably coupled to the housing. The vacuum attachment includes an inlet positioned adjacent and in facing relationship with the output shaft, an outlet, and a passageway fluidly communicating the inlet and the outlet. The passageway is fluidly isolated from the cavity. The power tool assembly also includes a hose having a first end coupled to the outlet of the vacuum attachment and a second end configured to be coupled to the vacuum device. The power tool assembly further includes a power cord disposed alongside the hose and operable to transfer power from the vacuum device to the motor.

[0007] Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a front perspective view of a power tool assembly according to one embodiment of the invention, illustrating a power tool and a vacuum device.

[0009] FIG. 2 is a rear perspective view of the power tool assembly of FIG. 1.

[0010] FIG. 3 is an enlarged, partial cross-sectional view of the power tool of FIGS. 1 and 2, illustrating a vacuum attachment of the power tool.

[0011] FIG. 4 is an exploded, front perspective view of the power tool of FIGS. 1 and

2.

[0012] FIG. 5 is a front perspective view of the power tool of FIGS. 1 and 2, illustrating the vacuum attachment shown in FIGS. 1-4, an alternative vacuum attachment, and a cover that may be interchangeably coupled to the power tool.

[0013] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. DETAILED DESCRIPTION

[0014] FIGS. 1 and 2 illustrate a power tool assembly 10 including a power tool 14, a suction or vacuum device 18, and a hose 22 interconnecting the power tool 14 and the vacuum device 18. The illustrated power tool 14 is configured as a saw, and specifically as a saw designed for removing plaster, fiberglass, or plastic casts from an individual's body. Such a "cast saw" includes a blade 26 that is driven in an oscillating manner about its axis 30 (FIG. 4). Alternatively, the power tool 14 may be configured as a different type of saw, or may be configured as a different type of power tool altogether.

[0015] With continued reference to FIG. 4, the power tool 14 includes a two-piece housing 34 defining a cavity 36, a motor 38 supported by the housing 34 in the cavity 36, and an output shaft 42 extending from the housing 34 and operably coupled to the motor 38. In the illustrated construction of the power tool 14, the motor 38 is configured as a 12 volt DC can-style motor that may be electrically connected to a source of power (e.g., AC household line current) via a power cord 46 extending from the housing 34 and a power converter or AC adapter (not shown) that is connectable to the power cord 46. Alternatively, the power tool 14 may include a battery with which to power the motor 38. The motor 38 may also be configured to operate using a voltage greater or less than 12 volts. As a further alternative, the motor 38 may be configured as an AC electric motor and use power (e.g., AC household line current) directly without using a power converter or AC adapter. As yet another alternative, the motor 38 may be configured as a fluid or pneumatic motor operable using compressed fluid or gas. With reference to FIG. 2, the power tool 14 also includes a switch 50 that is electrically connected between the motor 38 and the power cord 46. In the illustrated construction of the power tool 14, the switch 50 is configured as a three-position switch, including respective positions for low-speed operation, high-speed operation, and an "off position. Alternatively, the switch 50 may be configured in any of a number of different ways (e.g., a momentary switch, etc.).

[0016] With reference to FIG. 4, the power tool 14 further includes a transmission 54 coupling the motor 38 and the output shaft 42. As mentioned above, the transmission 54 is configured to convert a continuous, rotational output of the motor 38 to an oscillating output of the output shaft 42 and the attached blade 26 about the axis 30 of the blade 26. The transmission 54 converts the continuous, rotational output of the motor 38 to an oscillating output of the output shaft 42 and the attached blade 26 having an arc length of about 8 degrees (i.e., about 4 degrees side-to-side relative to a "home" or neutral position of the output shaft 42 and the blade 26). The transmission 54 may also be configured to increase or decrease the rotational speed of the output shaft 42 relative to the speed of the rotational output of the motor 38. Alternatively, the transmission 54 may be configured to convert the rotational output of the motor 38 to a continuous, rotational output of the output shaft 42 and the attached blade 26.

[0017] With continued reference to FIG. 4, the power tool 14 also includes a coupling

58 interconnecting an output shaft 62 of the motor 38 with an input shaft 66 of the transmission 54, such that the torque output by the output shaft 62 is directly transferred to the transmission input shaft 66. The coupling 58 may be made of a solid material (e.g., metal), an elastomeric material (e.g., rubber), or a combination thereof. Alternatively, the coupling 58 and the transmission input shaft 66 may be omitted, and the motor output shaft 62 may be directly input to the transmission 54 such that the motor output shaft 62 is shared by the motor 38 and the transmission 54. The power tool 14 further includes a shaft housing 70 interconnecting the motor 38 and the transmission 54 to maintain the alignment of the motor output shaft 62, the coupling 58, and the transmission input shaft 66 and to substantially enclose the coupling 58 and the shafts 62, 66. Although the coupling 58 is shown as a straight, single piece, the coupling 58 may alternatively be configured to compensate for slight misalignment of the motor output shaft 62 and the transmission input shaft 66 (e.g., by incorporating a universal joint or a flexible coupling).

[0018] With continued reference to FIG. 4, the output shaft 42 includes an arbor 74, and the blade 26 includes an aperture 78 through which the arbor 74 is inserted to position the blade 26 on the arbor 74. The blade aperture 78 and the arbor 74 each include a similar non- circular cross-sectional shape (e.g., a hexagonal cross-sectional shape) to rotationally secure the blade 26 to the arbor 74. Other non-circular cross-sectional shapes (e.g., a polygon, an oval, etc.) or features (e.g., a key and keyway arrangement) may be employed to rotationally secure the blade 26 to the arbor 74. The saw blade 26 is positioned adjacent a shoulder 82 on the arbor 74, and a chuck 86 is fastened to the arbor 74 (e.g., using a cap screw 90, etc.) to axially secure the blade 26 between the chuck 86 and shoulder 82. Alternatively, the saw blade 26 may be axially secured to the output shaft 42 in any of a number of different ways.

[0019] With continued reference to FIG. 4, a support sleeve 92 is inserted over the output shaft 42 and is positioned on the opposite side of the blade 26 as the chuck 86. The support sleeve 92 is stationary with respect to the housing 34 and the transmission 54, and provides additional support to the rear of the blade 26 during oscillation of the blade 26. The support sleeve 92 includes a plurality of axially-extending protrusions 93 defining therebetween respective grooves 95. As shown in FIG. 3, the protrusions 93 slidably engage the rear of the blade 26 to provide a seal between the blade 26 and the respective protrusions 93 during oscillation of the blade 26.

[0020] With reference to FIGS. 1-4, the power tool further includes a vacuum attachment 94 coupled to the housing 34. As shown in FIG. 3, the vacuum attachment 94 includes a head 98 containing an inlet 102 of the vacuum attachment 94 positioned adjacent and in facing relationship with the output shaft 42. The vacuum attachment 94 also includes a connector 106 containing an outlet 110 of the vacuum attachment 94, and a hollow or tubular body 114 interconnecting the head 98 and the connector 106. The body 114 includes a duct or passageway 118 fluidly communicating the inlet 102 and the outlet 110 of the vacuum attachment 94. As shown in FIG. 3, the passageway 118 is fluidly isolated from the cavity 36, and the passageway 118 is disposed entirely outside of the housing 34.

[0021] The vacuum attachment 94 also includes a guard 122 coupled to the head 98 and enclosing a portion of the saw blade 26. In the illustrated construction of the power tool 14, the guard 122 is integrally formed as a single piece with a portion of the head 98, while the remainder of the head 98, the tubular body 114, and the connector 106 of the vacuum attachment 94 are initially formed as separate pieces that are joined together by an ultrasonic welding process. Alternatively, the vacuum attachment 94 may be formed as a single piece including the guard 122, the head 98, the tubular body 114, and the connector 106. As a further alternative, the guard 122 may be a separate and distinct component from the vacuum attachment 94 and coupled to the vacuum attachment 94 in any of a number of different ways (e.g., by fastening, using adhesives, etc.). As yet another alternative, a front wall 124 of the head 98 may be omitted, thereby combining the guard 122 and the head 98 of the vacuum attachment 94 in a single enclosure through which a vacuum may be drawn.

[0022] With continued reference to FIG. 3, the vacuum attachment 94 also includes a plurality of apertures 126 in the head 98 (only one of which is shown) extending in a direction substantially parallel with the axis 30 of the output shaft 42. The apertures 126 receive respective posts or projections 130 extending from the front of the power tool housing 34 (only one of which is shown in FIGS. 3 and 5) to locate the inlet 102 of the vacuum attachment 94 relative to the output shaft 42. An interference or press-fit may be utilized to positively secure the projections 130 within the respective apertures 126, and therefore the head 98 of the vacuum attachment 94 to the power tool housing 34. The inlet 102 of the vacuum attachment 94 is located within a relatively small running clearance (e.g., 2 mm in the illustrated construction) of the output shaft 42. The rear of the vacuum attachment 94 is secured to the power tool housing 34 using a single fastener (e.g., a screw 134). The screw 134 is threaded to an insert 138 within the power tool housing 34, thereby preventing the rear of the vacuum attachment 94 from being inadvertently removed from the power tool housing 34. Alternatively, different structure may be utilized to interconnect the rear of the vacuum attachment 94 with the power tool housing 34 (e.g., quick-disconnect structure, etc.).

[0023] With reference to FIG. 5, the power tool housing 34 includes a recess 142 having a depth sized to receive the tubular body 114 of the vacuum attachment 94 such that the tubular body 114 is sunken into the power tool housing 34 to fill the recess 142. As a result, the passageway 118 is at least partially disposed in the recess 142, and the transition between the outer peripheral surfaces of the housing 34 and the tubular body 114 of the vacuum attachment 94, respectively, is substantially smooth. Alternatively, the recess 142 may include a depth such that only a portion of the tubular body 114 is sunken into the power tool housing 34. As a further alternative, the recess 142 may be omitted and no portion of the vacuum attachment 94 may be sunken into the power tool housing 34.

[0024] With reference to FIGS. 1 and 2, a power cord 146 is incorporated with the hose 22 such that only a single line or tether interconnects the vacuum device 18 and the power tool 14. More particularly, the power cord 146 is incorporated within the wall of the hose 22 for most of the hose length, with the exception of ends of the power cord 146 that protrude from the hose 22 to interconnect with the power cord 46 of the tool 14 and an electrical outlet on the vacuum device 18, respectively. Alternatively, the power cord 146 may be disposed entirely outside of the hose 22 and secured to the hose 22 (e.g., using clamps, tape, etc.) along the length of the hose 22 such that the hose 22 and the power cord 146 substantially simulate a single tether interconnecting the power tool 14 and the vacuum device 18.

[0025] With reference to FIG. 3, the hose 22 includes a detent mechanism 150 that secures the hose 22 to the connector 106 of the vacuum attachment 94. The detent mechanism 150 includes a detent 154 that is selectively received within an aperture 158 in the connector 106 and a biasing element (e.g., a compression spring 162) that biases the detent 154 into the aperture 158. To remove the hose 22 from the connector 106, the user of the power tool 14 would first depress the detent 154 against the bias of the spring 162, and then pull the hose 22 away from the connector 106 to disengage the hose 22 from the connector 106. To reattach the hose 22 to the connector 106, the user would depress the detent 154 against the bias of the spring 162, and then push the hose 22 onto the connector 106 until the detent 154 is aligned with the aperture 158, at which time the spring 162 is allowed to rebound or expand to push the detent 154 at least partially into the aperture 158 in the connector 106. The detent mechanism 150 then prevents the hose 22 from being inadvertently removed from the connector 106 of the vacuum attachment 94. Alternatively, the hose 22 may be secured to the connector 106 in any of a number of different ways (e.g., using interference or press-fit, using fasteners, etc.).

[0026] To operate the power tool 14 with the vacuum attachment 94, the user would first attach the vacuum attachment 94 to the power tool 14 (if it is not already attached) by inserting the projections 130 on the front of the power tool housing 34 within the respective apertures 126 in the head 98 and fastening the rear of the vacuum attachment 94 to the housing 34. Then, the user would attach the hose 22 using the detent mechanism 150 according to the procedure discussed above, and electrically connect the power cords 146, 46 incorporated within the hose 22 and extending from the power tool 14, respectively. Finally, the user would activate the vacuum device 18 to initiate suction through the hose 22 and the vacuum attachment 94.

[0027] While cutting a cast or another object, the debris generated by the oscillating saw blade 26 is suctioned through a plurality of openings defined by the rear of the blade 26 and the grooves 95 in the support sleeve 92, around the output shaft 42, and into the inlet 102 of the vacuum attachment 94 (along flow path F). Such debris is subsequently drawn through the passageway 118, the outlet 110 of the vacuum attachment 94, and the hose 22 before being collected within the vacuum device 18. Should any accumulation of debris form an obstruction within the vacuum attachment 94 and reduce the amount of suction available at the inlet 102, the user of the power tool 14 may remove the vacuum attachment 94 for cleaning by removing the single screw 134, lifting the rear of the vacuum attachment 94 from the power tool housing 34, and then pushing the head 98 of the vacuum attachment 94 away from the front of the power tool housing 34 to remove the projections 130 from the respective apertures 126. The detached vacuum attachment 94 may then be cleaned (e.g., using a fluid or a pressurized gas, etc.) to remove the obstruction and reattached to the power tool housing 34 using the procedure discussed above. By allowing the vacuum attachment 94 to be removed from the power tool housing 34 for cleaning, any concern of exposing the electronic components of the power tool 14 within the power tool housing 34 to cleaning fluid or pressurized gas is substantially alleviated.

[0028] With reference to FIG. 5, an alternative vacuum attachment 166 may omit the blade guard 122 for applications in which it is desirable to have access to the entirety of the saw blade 26. FIG. 5 also illustrates a cover 170 configured to attach to the power tool housing 34 in a similar manner as the vacuum attachments 94, 166 when the power tool 14 is utilized in applications not necessitating either of the vacuum attachments 94, 166 or the vacuum device 18. When attached to the power tool housing 34, the cover 170 takes up or occupies the recess 142 in the housing 34 such that the user of the power tool 14 is able to grasp the power tool housing 34 without noticing the recess 142.

[0029] Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described. Various features of the invention are set forth in the following claims.

Claims

CLAIMSWhat is claimed is:

1. A power tool comprising: a housing defining a cavity; a motor supported by the housing in the cavity; an output shaft extending from the housing and operably coupled to the motor; a vacuum attachment removably coupled to the housing and including an inlet positioned adjacent and in facing relationship with the output shaft; an outlet; and a passageway fluidly communicating the inlet and the outlet, wherein the passageway is fluidly isolated from the cavity.

2. The power tool of claim 1 , further comprising a blade coupled to the output shaft for co-rotation with the output shaft; and a blade guard coupled to the vacuum attachment, wherein at least a portion of the blade is covered by the blade guard, and wherein the blade guard is positioned adjacent the inlet.

3. The power tool of claim 2, wherein the blade guard and at least a portion of the vacuum attachment are integrally formed as a single piece.

4. The power tool of claim 2, wherein the blade guard and a portion of the vacuum attachment at least partially defining the inlet are integrally formed as a single piece.

5. The power tool of claim 1 , wherein the housing includes a recess, and wherein the vacuum attachment is at least partially received within the recess.

6. The power tool of claim 5 , wherein the vacuum attachment substantially fills and occupies the recess in the housing.

7. The power tool of claim 5, wherein the passageway is at least partially disposed in the recess.

8. The power tool of claim 1 , wherein the vacuum attachment is coupled to the housing using a single fastener.

9. The power tool of claim 1 , further comprising a transmission positioned between the motor and the output shaft, wherein the transmission is operable to convert a continuous, rotational output of the motor to an oscillating rotational output of the output shaft.

10. The power tool of claim 1 , further comprising a blade coupled to the output shaft for co-rotation with the output shaft; and a support sleeve slidably engaged with the blade and stationary with respect to the housing, wherein the blade and the support sleeve define therebetween a plurality of openings in fluid communication with the inlet of the vacuum attachment.

11. The power tool of claim 1 , wherein the passageway is disposed entirely outside of the housing.

12. A power tool assembly operable with a vacuum device, the power tool assembly comprising: a power tool including a housing defining a cavity; a motor supported by the housing in the cavity; an output shaft extending from the housing and operably coupled to the motor; a vacuum attachment removably coupled to the housing and having an inlet positioned adjacent and in facing relationship with the output shaft, an outlet, and a passageway fluidly communicating the inlet and the outlet, the passageway fluidly isolated from the cavity; a hose including a first end coupled to the outlet of the vacuum attachment and a second end configured to be coupled to the vacuum device; and a power cord disposed alongside the hose and operable to transfer power from the vacuum device to the motor.

13. The power tool assembly of claim 12, wherein the hose includes a wall, and wherein the power cord is at least partially disposed inside the wall of the hose.

14. The power tool assembly of claim 12, further comprising a detent mechanism coupling the outlet of the vacuum attachment and the first end of the hose.

15. The power tool assembly of claim 12, further comprising further comprising a blade coupled to the output shaft for co-rotation with the output shaft; and a blade guard coupled to the vacuum attachment, wherein at least a portion of the blade is covered by the blade guard, and wherein the blade guard is positioned adjacent the inlet.

16. The power tool assembly of claim 15, wherein the blade guard and at least a portion of the vacuum attachment are integrally formed as a single piece.

17. The power tool assembly of claim 15, wherein the blade guard and a portion of the vacuum attachment at least partially defining the inlet are integrally formed as a single piece.

18. The power tool assembly of claim 12, wherein the housing includes a recess, and wherein the vacuum attachment is at least partially received within the recess.

19. The power tool assembly of claim 18, wherein the vacuum attachment substantially fills and occupies the recess in the housing.

20. The power tool assembly of claim 18, wherein the vacuum attachment includes a passageway fluidly communicating the inlet and the outlet, and wherein the passageway is at least partially disposed in the recess.

21. The power tool assembly of claim 12, wherein the vacuum attachment is coupled to the housing using a single fastener.

22. The power tool assembly of claim 12, further comprising a transmission positioned between the motor and the output shaft, wherein the transmission is operable to convert a continuous, rotational output of the motor to an oscillating rotational output of the output shaft.

23. The power tool assembly of claim 12, further comprising a blade coupled to the output shaft for co-rotation with the output shaft; and a support sleeve slidably engaged with the blade and stationary with respect to the housing, wherein the blade and the support sleeve define therebetween a plurality of openings in fluid communication with the inlet of the vacuum attachment.

24. The power tool assembly of claim 12, wherein the passageway is disposed entirely outside of the housing.