US3491932A - Fastener driving tool - Google Patents

Description

Jan. 27, 1970 E. J. NOVAK 3,491,932

FASTENER DRIVING TOOL Filed April 21. 19 7 2 Sheets-Sheet 1 Janl 27; 1970 E. J. N OVAK FASTENER-DBIVING TOOL 2 Sheets-Shee't .2

' Filed April 31, 1967 a; ff .2.

-III IIIII/IIIIIIIIA Mia/nan 50mm J Nam/z United States Patent 3,491,932 FASTENER DRIVING TOOL Edward J. Novak, Franklin Park, Ill., assignor to Fastener Corporation, Franklin Park, 111., a corporation of Illinois Filed Apr. 21, 1967, Ser. No. 632,575 Int. Cl. Bc 1/04, 3/00 US. Cl. 227-436 16 Claims ABSTRACT OF THE DISCLOSURE A magazine assembly for feeding fasteners from a carrier strip into the drive track of a driving tool, including guideway means for supporting a strip of fasteners for movement toward the drive track, first fastener engaging means movable laterally with respect to one side of said guideway is provided normally preventing rearward movement of the fasteners away from the drive track. Second fastener engaging means, movable laterally with respect to an opposite side of the guideway, is provided for advancing the fasteners toward said drive track. Stop means associated with one of said first and second fastener engaging means is movable inwardly into the guideway into a stop position for preventing further forward advance of the fasteners toward the drive track and means is provided for moving said second fastener engaging means toward and away from said drive track to pick up and advance successive fasteners into a position ready to be driven by the tool.

The present invention relates to fastener driving tools and, more particularly, to power driven tools and their magazines for handling fasteners supplied from carrier strips.

In many power driven fastener driving tools, the fasteners to be driven are relatively large (for example, 6d or 8d common nails) and these fasteners are supplied from carrier strips constructed of plastic material and the like to hold a plurality of such fasteners in spaced relation to the one another. The fastener holding strips may be relatively short in length and hold a number of fasteners (approximately 20 to in relatively small fiat packages for insertion into the magazine of the tool, or the strips may be relatively long and flexible for holding a much larger number of fasteners and, in this case, the strips may be coiled or rolled into a bundle with only the forward end of the strip extending into the magazine. In the latter instance, as the fasteners are driven by the tool, the coil or roll is unwound as the fasteners are moved forwardly through the magazine into the drive track of the tool.

One of the problems associated with power driven tools and magazine assemblies of this type is that of providing means for positively feeding successive fasteners from the strip into the drive track of the tool after a previous fastener has been driven. A closely related problem is that of providing an automatic power driven tool and magazine associated therewith, which is simple in construction and operation, light in weight, small in size, economical to manufacture, and relatively foolproof and reliable in operation.

It is an object of the present invention to provide a new and improved power driven, fastener driving tool and magazine assembly which eliminates and corrects the aforementioned problems and which is capable of handling small or relatively large fasteners.

Another object of the present invention is the provision of a new and improved fastener driving tool and magazine assembly associated therewith in which the feeding Patented Jan. 27, 1970 of fasteners from the magazine into the drive track of the tool is positively effected after the completion of a power stroke of the driver of the tool.

Still another object of the invention is a new and improved fastener driving tool and magazine including automatic means for positively stopping the feeding of fasteners into the tool when the number of fasteners remaining in the magazine reaches a selected minimum number.

Another object of the invention is the provision of a new and improved fastener feeding magazine assembly for use with a power driven, fastener driving tool.

Yet another object of the present invention is the provision of a new and improved magazine assembly for a fastener driving tool including releasable means operable to permit rearward withdrawal of a fastener strip therefrom.

Still another object of the invention is the provision of a new and improved fastener feeding magazine assembly for automatic feeding of fasteners from a carrier strip employing means normally operative to prevent rearward movement or withdrawal of the fastener carrying strip from the magazine during feeding operations after insertion of the fastener strip into the magazine.

Yet another object of the invention is the provision of a new and improved fastener driving tool capable of driving large, headed nails and including new and improved means for guiding the nails in the drive track as they are driven to prevent the nails from cocking or being driven at an angle and thereby eliminating or reducing the possibility of bending the nails while they are driven.

Still another object of the invention is the provision of a new and improved nail guide means as described above which is effective in guiding many different sizes of nails which are driven by the tool without requiring adjustments in the guide means.

These and other objects and advantages of the present invention are accomplished by the provision of a new and improved power driven tool capable of driving large, headed nails and including a magazine assembly for positively feeding the nails from a carrier strip, one at a time, into the drive track of the tool. The magazine assembly includes a pair of spaced guide rails forming a nail guideway to support the strip of nails by the nail heads for movement along the guideway toward the drive track. A first nail engaging means or pusher is biased laterally inwardly into engagement with the nails in the guideway from one side thereof and a second nail engaging or holding means is biased laterally inwardly into engagement with the nails in the guideway from an opposite side thereof. Each of the nail engaging means includes structure projecting into the nail guideway having a plurality of nail engaging, spaced recesses between adjacent teeth, and the teeth include forwardly facing, lateral leading edges for engaging the rearward edges of the nails. The teeth also include rearwardly and outwardly extending camming surfaces for camming the respective nail engaging means outwardly of the guideway as the nails are advanced forwardly along the guideway toward the drive track relative to the nail engaging teeth. The pusher means is movable longitudinally with respect to the guideway toward and away from the drive track so that on a forward or feeding stroke, the nails engaged in the recesses thereof are moved forwardly by the advancing leading edges of the teeth. On rearward movements or return strokes of the pusher means, the teeth are cammed laterally the camming surfaces thereon against the nails and, after the pusher is moved far enough rearwardly, the teeth are able to move inwardly again behind the next succeeding group of nails in the strip until the nails are seated in the recesses. During the rearward movement of the pusher means, the nails are engaged and held within the recesses of the second nail engaging or holding means and are prevented from moving rearwardly along with the pusher means. On a forward feeding stroke, the advancing nails engage the camming surfaces of the nail holding means and cam the holding means outwardly thereby permitting the nails to be moved forwardly in the guideway until the teeth of the holding means are able to move inwardly behind the next succeeding group of nails in the strip. Operator means are provided for moving the pusher means on feeding and return strokes, and the operator means is actuated by the tool so that a feeding stroke is accomplished after each driving stroke of the driver.

The magazine assembly may also include a guide means having a forward tip or end extending to the rear face of the drive track to help guide the lower end of the nail into the lower end of the drive track to prevent the nail from becoming cocked or jammed in the drive track during a driving stroke. The forward tip of the guide means normally extends upwardly above the lower ends of the fastener centered in the drive track and is momentarily depressed downwardly as each successive fastener is moved into the drive track from the magazine.

For a better understanding of the invention, reference should be had to the following detailed description taken in conjunction with the drawings, in which:

FIG. 1 is a fragmentary side elevational view of a magazine assembly and tool constructed in accordance with the present invention with portions broken away to show interior components thereof;

'FIG. 2 is a sectional view taken substantially along line 22 of FIG. 1;

FIG. 3 is a sectional view taken substantially along line 3-3 of FIG. 2;

FIG. 4 is a transverse sectional view taken substantially along line 44 of FIG. 1 and illustrating the internal components of the assembly in one operating position;

FIG. 5 is a transverse sectional view similar to FIG. 4 but illustrating the components in another operating position;

FIG. 6 is a fragmentary sectional view of the pusher and holding means of the magazine assembly taken substantially along line 66 of FIG. 1 and illustrating these components in one operating position;

FIG. 7 is a view similar to FIG. 6 but illustrating the pusher and holding means of the magazine assembly in another operating position; and

FIG. 8 is also a view similar to FIG. 6 but illustrating the pusher and holding means of the magazine assembly in yet another operating position.

Referring now, more particularly, to the drawings, therein is illustrated a new and improved power driven fastener driving tool, indicated generally by the numeral 10, and constructed in accordance with the features of the present invention. Preferably, the tool is operated by compressed air; however, other means, such as electrical energy, can also be utilized to power the tool for driving fasteners. The tool 10 illustrated is of the type operated by compressed air and includes a pneumatic motor mechanism indicated generally as 12 (FIG. 1) for reciprocally moving a driver 14 on a downward power or driving stroke and subsequently on an upward or return stroke. The driver 14 is slidably disposed in a drive track 16 which is formed in a nosepiece 18 (FIGS. 1, 2, and 3), and the nosepiece 18 depends downwardly fro-m the head portion of the main body or housing 20 which encloses the pneumatic motor mechanism 12. The major portion of the tool housing 20 is not shown in the drawings and can be of a known type, such as that shown in United States Patent No. 3,253,760, which is assigned to the same assignee as the present invention. A power or driving stroke of the driver 14 is initiated by depression of a trigger valve (not shown) which provides for the entry of pressurized air into the upper end of a slida'ble cylinder or sleeve 22 (FIG. 1) comprising part of the motor mechanism 12 of the tool. A piston (not shown) also comprising a part of the motor mechanism is slidably mounted in the sliding sleeve or cylinder 22 and is connected to the upper end of the driver 14. During a power stroke, the sleeve 22 is moved downwardly to open the upper end thereof to compressed fluid which drives the piston and driver 14 rapidly downward. After completion of a power stroke, the sleeve 22 moves upwardly and pressurized fluid within the sleeve moves the piston and driver upwardly on a return stroke, as more completely described in the aforementioned United States patent. Movement of the sleeve 22 is effected by the pressurization or evacuation of an annular chamber 26 formed in the tool housing around the lower end of the sleeve and the sleeve includes an outwardly extending flange 22a which forms an upper wall portion of the chamber 26.

The nails to be driven by the tool 10 are mounted on carrier strips 30 formed of flexible plastic material (FIGS. 1 and 3) which extend transversely across the shanks of the nails and hold the nails in spaced parallel relation to one another. As illustrated, the nails may comprise large, round-headed nails 32 (for example, 8d common nails) and the strips 30 are arranged in parallel relation with each other to maintain a selected spacing between adjacent nail shanks 32b somewhat greater than the shank diameter thereof. As best shown in FIG. 2, the nails 32 are arranged with their heads 32a spaced apart and vertically stacked in relation to one another and, accordingly, the strips 30 extend across the nail shanks 32b at angles of degrees or somewhat less, measured clockwise from the nail shanks. The strips 30 are constructed of plastic material and the like, in accordance generally with strips of the type shown and described in United States Patent No. 3,212,632, dated Oct. 19, 1965, and in United States Patent No, 3,261,526, dated July 19, 1966. In the latter instance, wherein the strips are relatively long, they may be coiled or rolled into a bundle which is uncoiled as the nails are driven by the tool. In the former instance, the nails may be assembled in relatively small flat packages, wherein the carrier strips are fabricated in appropriate lengths designed to hold a selected number of the nails 32. Paper or other backing material 30a may be applied to the outer side faces of the plastic strip material to add strength and facilitate easy handling and sliding of the strips into and along magazine wall surfaces and the like.

In order to support the nails and feed them into the drive track 16, a magazine assembly, generally indicated as 34 (FIGS. 1 and 2), is connected to the nosepiece 18 of the tool in communication with the drive track 16 through a rearwardly opening mouth or entrance 16a, conforming a substantially in cross section to the shape or outline of the nails. The entrance slot 16a is aligned with the longitudinal axis or vertical center plane of the magazine between a pair of rearwardly extending, parallel, inner sidewalls or guide rails 38a and 38b defining a nail guideway 36. The heads of nails are supported on the upper edges of the inner sidewalls for sliding movement along the guideway 36 toward the drive track 16. The inner sidewalls 38a and 38b are supported from a pair of outer, magazine sidewalls 40a and 40b by means of a plurality of short transversely extending cap screws 42 which extend inwardly into the axial, threaded 'bores of aligned spacer sleeves 43, or bosses, which are disposed between pairs of adjacent inner and outer magazine sidewalls and are preferably welded or otherwise affixed permanently to the outer surfaces of the inner sidewalls 38a and 38b.

The magazine assembly 34, as a whole, is connected to and supported from the nosepiece 18 by a pair of forwardly extending mounting brackets 44 which are secured to the respective outer sidewalls 40a and 40b by spot welding or the like. The forward portions of the supporting brackets 44 and similarly shaped, forwardly projecting tabs or lugs 41 (FIG. 2) of the respective outer sidewalls 40a and 40b are welded together and are seated within appropriate recesses or ways 18a (FIG. 1) formed in the narrow sides of the nosepiece. The magazine assembly 34 is readily disconnected from the nosepiece 18 and to this end, the nosepiece is provided with a pair of laterally, outwardly extending, threaded studs 46 which project through forwardly opening, aligned slots 44a and 41a formed in the brackets 44 and projecting lugs 41, respectively. Self-centering nuts 48 are threaded onto the studs 46 to bear inwardly against the brackets 44 and hold the magazine assembly 34 in place. The nuts include annular, conical, centering surfaces 48a on the inner faces thereof which seat within similarly shaped, concave beveled, frustoconical portions formed in the outer surface of the brackets 44 adjacent the inner or closed ends of the slots 44a therein. Accordingly, when the nuts 48 are tightened, the brackets 44 and projecting lugs 41 are firmly held in the ways 18a of the nosepiece and, in addition, exact longitudinal and lateral positioning, of the forward end of the magazine assembly 34 in relation to the nosepiece is established. Once the nuts are loosened, the magazine assembly 34 can be withdrawn rearwardly and completely disconnected from the nosepiece 18.

In order to accurately align the forward end of the magazine assembly 34 with the entrance opening 16a, the nosepiece is formed with a recess 18b (FIG. 1) opening toward a planar back face 180 thereof. The inner sidewalls 38a and 38b are formed with short, forwardly extending projections 39 at the forward ends thereof, which extend into the recess 18b and maintain the magazine guideway 36 in proper vertical alignment with respect to the entrance opening 160 of the drive track.

The spacing between the outer walls 40a and 40b at the forward end of the magazine assembly 34 is maintained by the brackets 44 which are seated in the ways 18a on opposite sides of the nosepiece 18, and the nosepiece 18 thus maintains the correct spacing between the opposite, inner sidewalls 38a and 38b so that the nails 32 slide easily along the guideway 36 between the inner sidewalls. The spacing between the outer walls 40a and 40b at the rearward end of the magazine assembly is maintained by a pair of spacing bolts 50, the upper of which carries a tubular spacer 52 disposed between the outer sidewalls. In addition to the spacing bushings 43 and screws 42, minimum spacing between the inner sidewalls 38a and 38b and the respective adjacent outer walls 40a and 40b is insured by a pair of lower, outwardly extending flanges 35 formed on the respective inner sidewalls (FIGS. 4 and 5) and by a pair of lower spacing brackets 37 of L-shaped cross section having outwardly extendingly flanges 37a and upright flanges 37b spot welded to the outer surfaces of the inner sidewalls. The magazine assembly 34 is constructed to be long enough to hold at least one or more assembled packages of nails and, if needed, additional spacers can be used to maintain the spacing between the outer sidewalls along the length of the magazine when the magazine is longer.

A strip of nails 32 is inserted into the guideway 36 from the rear end of the magazine and is moved forwardly until the first or lead nail of the strip is positioned in the drive track 16. As nails are driven by the driver 18 of the tool, the strip is moved forward in successive increments to position the succeeding nail at the forward end of the strip into the drive track.

In order to feed nails forwardly along the guideway 36 and prevent rearward movement thereof, the magazine assembly 34 includes a pair of nail engaging members 54 and 56 disposed on opposite sides of the nail guideway 36 between respective adjacent pairs of inner and outer sidewalls 38a and 40a and 38b and 40b of the magazine. The members 54 and 56 are L-shaped in transverse cross section and include laterally inwardly projecting upper flanges 54a and 56a, respectively, and downwardly extending sides or bodies 54b and 56b. The inner sidewall 38a is provided with a longitudinally extending slot 57 spaced below the upper edge thereof to permit the upper flange 54a to project inwardly into the guideway 36. The inner sidewall 38b is provided with a pair of spaced, longitudinally extending slots 58 and 59 for permitting portions of the upper flange 56a to project inwardly into the guideway 36 from the opposite side, as best shown in FIGS. 6, 7, and 8.

The member 56 serves as a holding or latching dog against rearward movement of the nails and is mounted between the inner wall 38b and outer wall 40b in a manner that permits the upper nail engaging flange 56a to move laterally inwardly and outwardly with respect to the guideway 36. To this end, the downwardly extending body 56b is formed with a pair of spaced openings 61 (FIG. 3) to receive a pair of mounting pins 62 which project outwardly from the inner sidewall 38b to support the member 56. The openings 61 are slightly larger in diameter than the pins 62 to permit pivotal movement of the member 56 about an axis longitudinally parallel with the guideway 36 and extending transversely through the mounting pins. The body 56b also includes a pair of laterally inwardly projecting ears 63 extending normal to the body and positioned along opposite edges thereof adjacent the pins 62 (FIG. 3). These ears are rounded on their ends (FIG. 2) and the rounded surfaces bear inwardly against the outer surface of the inner magazine wall 38b and thereby maintain the lower end of the body 56b in outwardly spaced relation from the adjacent wall 38b, as shown in FIGS. 4 and 5. A large central cutout or opening 64 is provided in the body 56b to accommodate a biasing spring 65 which is mounted in the opening and normally biases the upper flange 56a of the member laterally inwardly into the guideway 36, through the openings 58 and 59'. The spring 65 is constructed from a continuous length of spring steel wire formed in a generally U-shaped configuration and including an upper bight or crown portion 65a, a pair of downwardly extending legs 65b having intergrally formed coiled portions 650 at their lower ends, and a pair of upwardly extending outer legs 65d joined with the coiled portions. The outer legs 65d of the spring extend upwardly along opposite side edges of the opening 64, and the upper ends thereof bear inwardly against the upper portion of the body 56b tending to force the upper flange 56a of the member 56 laterally inwardly into the guideway 36. The coiled portions 650 are centered and mounted on a pair of lugs 66 projecting inwardly toward the central portion of the body 56b from opposite the side edges of the opening 64. The bight portion 65a of the spring exerts pressure laterally outwardly with respect to the guideway 36 against an upper shouldered or offset portion 67a of a Z-shaped bracket 67 having a lower leg 67b spot welded or otherwise secured to the outer surface of the sidewall 38b.

The biasing spring 65 thus exerts a biasing force on the member 56, urging the upper, nail engaging flange 56a thereof laterally inwardly into the guideway 36. The member 56 is mounted so that it will pivot freely about a lower axis longitudinally parallel with the guideway 36 and extending through the lower portion of the body 56b adjacent the ears 63, lugs 66, and mounting pins 62. Because of the manner in which the holding member 56 is mounted on the spaced pins 62, the member cannot move longitudinally with respect to the guideway 36 and, accordingly, the member 56 functions as a holding or latching member normally preventing rearward movement of the nails, once they have been inserted into the guideway 36 of the magazine assembly.

In order that the member 56 may engagingly hold the nails 32 in the carrier strip and prevent them from moving rearwardly along the guideway 36, the upper nail engaging flange 56a is formed to include a first segment or portion 59a (FIG, 3) which is movable in and through the rearwardly positioned slot 59 in the sidewall 38b. The segment 59a includes a plurality of longitudinally spaced nail engaging teeth 68 along the edge which faces the guideway 36, as best shown in FIGS. 6, 7, and 8. Each of the teeth includes a laterally extending, forwardly facing leading edge 68a, generally perpendicular to the guideway 36, for engagement against rearwardly facing portions of the nail shanks 32b. Each tooth is formed with a rearwardly and outwardly sloping, trailing edge or camming surface 68b, and the edges 68a and 68b of adjacent teeth form the edge portions or opposite walls of a plurality of nail shank receiving recesses 69 between each pair of adjacent teeth. As the nails are moved forwardly along the guideway 36, the shanks 32b engage the camming edges 68b and move the upper flange 56a of the holding member 56 laterally outward against the biasing force of the spring 65. When nail shanks 32b have advanced forwardly of the leading edges 68a of the teeth, the spring 65 is then free to move the flange 56a laterally inwardly into the position shown in FIGS. 6 and 7 wherein the nail shanks are seated in the recesses 69. In this position, the lateral leading edges 68a of the teeth prevent rearward movement of the nails. As the nails are advanced forwardly during each successive feeding stroke, each nail moves to the next adjacent forward recess 69. When the last nail in a strip has advanced forwardly of the forwardmost tooth 68, the bias spring 65 is then free to move the upper flange 56a of the member 56 further inwardly into the guideway to a stopping position, as shown in FIG. 8.

Immediately ahead of the forwardmost tooth 68, the flange 56a is formed with a large recess 70 which is deep enough to accommodate at least one or more nails 32 without interference, and when the last nail in the strip has been advanced past the forwardmost tooth 68 into position adjacent the recess 70, there is no engagement between any of the nail shanks 32b and the flange section 59a which can prevent movement of the member 56 from its normal operating position (FIGS. 6 and 7) to the stop position illustrated in FIG. 8. The flange 56a includes a laterally inwardly projecting, forwardly positioned stop tooth or dog 71 which has a laterally extending, rearwardly facing edge 71a, defining the forward end of the recess 70. When the member 56 is in the stopping position, as shown in FIG. 8, the edge 71a engages any of the nails present in the recess 70 and prevents their further forward travel along the guideway. When forward travel of the nail strip is stopped in this manner, the tool operator is alerted that the nail supply in the magazine assembly is getting low and a new strip of nails should be inserted into the guideway 36 from the rear end thereof. During normal operations, when nails are in engagement within the recesses 69 between adjacent teeth 68, the stop tooth 71 is outwardly of the guideway 36 (FIGS. and 6) and does not interfere with forward movement of the nails.

Upon insertion of a nail strip from the rear end of the magazine and subsequent forward movement of the nails toward the drive track 16, engagement between the nails and the camming surfaces 68b of the teeth causes the flange 56a to move laterally outwardly with respect to the guideway 36 and out of stop position (FIG. 8) to the normal operating positions shown in FIGS. 6 and 7. From the foregoing description, it is clear that when the holding member 56 is in a normal operating position, forward feeding of the nails 32 into successive forward positions along the guideway 36 is permitted either during normal feeding strokes or upon initial insertion of a nail strip into the guideway and because of laterally extending leading edges 68a of the teeth rearward travel of the nails is prevented.

When the number of nails in the magazine reaches a selected minimum number and the last or rearwardmost nail in the strip is adjacent the recess 70, the member 56 is moved by the spring 65 laterally inward into the stop position (FIG. 8), and the stop tooth 71 prevents further forward feeding of the nails until the supply is replenished by insertion of another strip of nails.

In the illustrated embodiment, when the last nail in a package or strip of nails engages the stop tooth 71, there are still eight nails remaining in the strip and it has been found in practice that it is desirable that a selected minimum number of around eight is suitable. For example, when there is only one nail remaining in the strip in the magazine, there would be nothing to keep the nail from dropping downwardly as soon as it is advanced into the drive track, and if only two or three nails remain in the strip when the stop tooth 71 is engaged by the last nail it is sometimes possible for the strip to become cocked or jammed in the magazine because of the rearward nails in the strip moving upwardly and the forward nail is driven by the impact of the driver. Accordingly, it has been found that a selected minimum number of eight provides good stability and overcomes the above difficulties because of the added weight of the additional nails.

The nail engaging pusher member 54 is somewhat similar in appearance to the holding member 56 and performs the function of advancing the nails 32 on successive feeding strokes along the guideway 36. The member 54 is mounted on the magazine so that the upper flange 54a will move laterally inwardly and outwardly with respect to the guideway 36 and, in addition, the flange is movable back and forth longitudinally of the guideway toward and away from the drive track. The flange 54a normally extends into the guideway 36 through the longitudinal slot 57 in the sidewall 38a and the body 54b is mounted between the walls 38a and 40a on a single mounting pin 72 which projects outwardly from the inner wall 38a and is secured thereto in a suitable fashion, such as by spot welding. The pin 72 terminates short of the outer wall 40a (FIGS. 4 and 5) and is provided with an annular recess 72a closely adjacent to its outer end in order to receive a removable retaining or C-ring or washer 74 for holding a coiled biasing spring 76 interposed between the outer surface of the body 54b and the washer. The spring 76 exerts an inward biasing force against the body 54b forcing the upper flange 54a laterally inwardly into the guideway 36 through the slot 57. The pin 72 is somewhat smaller in diameter than the diameter of the opening in the body 54b through which the pin projects and, accordingly, the member 54 is pivotable about the pin. When the member 54 pivots about the axis of pin 72 in a counterclockwise direction, as viewed in FIG. 1, the upper flange 54a moves forwardly toward the drive track 16 and, in doing so, accomplishes a forward feeding stroke to move the nails 32 forwardly. In order to move the member 54 about the pin as described, the body 54b includes a forwardly extending actuating arm 540 having a laterally outwardly extending tab 54d adjacent the upper edge of the arm at the outer end thereof. Downward force against the tab 54d causes the upper flange 54a to move on a forward or nail advancing feed stroke, while upward movement of the arm tab permits the member 54 to pivot in a clockwise direction (FIG. 4) and a return stroke toward the rear of the magazine is accomplished. The slot 57 is long enough and wide enough to permit forward and rearward movement of the flange 54a without interference.

The flange 54a includes a plurality of spaced, laterally, inwardly directed teeth 78 which are spaced apart by a distance equal to the spacing between the nails 32 and the spacing between the teeth 68 in the holding member 56. Each tooth 78 includes a laterally extending, forwardly facing, advancing or leading edge 78a and a rearwardly and outwardly extending trailing edge or camming surface 78b. Fastener receiving recesses 79 are defined between adjacent teeth and these recesses are concavely rounded, as shown, in order to better receive and hold the nails 32. The leading edges 78a of the teeth are somewhat concave, as shown, to reduce the possibility of disengagement between the teeth and the nail shanks 32b during a feeding stroke.

Upon forward movement of the teeth 78 on a feeding stroke, 'the leading edges 78a engage rearwardly facing portions of the nail shanks 32b and advance the engaged nails forwardly until they are seated in the next succeeding recesses 69 of the holding member 56. Upon rearward travel of the teeth 78 on a return stroke, the camming or trailing edges 7 8b engage the nail shanks which are held against rearward travel by the member 56, as previously described, and camming action takes place between the edges 78b and the nail shanks forcing the upper flange 54a of the pusher laterally outwardly against the biasing force of the spring 76. At the completion of a rearward stroke, the leading edges 68a of the teeth are positioned rearwardly of the nails in the strip held by the holding member 56 and the flange 54a moves laterally inwardly because of the force exerted by the spring 76.

The nail shanks 32b are then seated in the recesses 79 and as the feeding stroke proceeds the nails are advanced forwardly along the guideway 36 until seated in the next succeeding recesses 69 in the holding member 56. At the end of each feeding stroke a new nail at the forward end of the strip is positioned in the drive track 16 in preparation for a driving stroke of the driver 14. The flanges 54a and 56a of the pusher and holding members, respectively, are spaced vertically from one another to preclude interference during feeding operations and from the foregoing description it should be noted that on a feeding stroke the pusher flange 54a moves longitudinally forward while the holding member flange 56a is cammed laterally outward. On a return stroke the holding member flange 56a is stationary while the pusher flange 54a moves rearwardly and is cammed laterally outwardly. The two members 54 and 56 thus cooperate to insure positive feeding of successive nails into the drive track and normally prevent the rearward movement of the nails away from the drive track.

In order to permit the nails or strips thereof to be withdrawn or removed from the rear end of the magazine 34, a pair of manual release buttons 80' and 82 are mounted on the respective outer magazine walls 40a and 40b. The release buttons 80 and 82 are identical and each includes an enlarged buttonlike head at the outer end and an integral shank which projects inwardly through an opening in the adjacent outer sidewall. The inner ends of the shanks are adapted to engage the lower body portions of the respective members 54 and 56 when the buttons are depressed and the shanks are mounted for sliding movement with a pair of tubular bosses 84 which are force fitted into the openings provided in the respective sidewalls 40a and 40b, as best shown in FIGS. 4 and 5. The shanks are formed with annular recesses adjacent their inner ends for receiving retaining washers 86 which prevent outward withdrawal of the buttons through the bosses 84 (FIG. 4). The inner end of the release button 80 is adapted to engage a downwardly extending tab or projection 54a on the pusher member 54, and when the button is forced inwardly against the projection 542, the upper flange 54a is moved laterally outwardly with respect to the guideway 36 until the teeth 78 are clear of the nails in the guideway and present no interference to rearward withdrawal of the nails. The inner end of the release button 82 is adapted to engage a lower, downwardly projecting tab 56c (FIGS. 4 and on the holding member 56 to earn the upper flange 56a and teeth 68 thereof laterally outwardly of the guideway 36 until clear of the nails. Accordingly, when the release buttons 80 and 82 are both depressed by an operator, the nails can be withdrawn rearwardly from the guideway 36 without interference, and when the buttons are then released, the bias springs 65 and 76 cause the members 54 and 56 to return to their normal operating positions, as previously described.

In order to actuate the pusher member 54 to feed successive nails into the drive track 16 after a driving stroke has been completed, the tool 10 includes an actuator assembly 88 which is preferably mounted on the body of the tool for interconnection with the actuating arm or operator 540 of the pusher member. The actuator assembly 88 includes a chamber 90 formed in the tool body, and a tubular sleeve 92 having an apertured lower end is inserted into the chamber to form a cylinder for sliding movements of a piston member 96 mounted thereon. The upper end of the chamber is in direct communication with the annular chamber 26 around the sleeve 22 by means of a transverse connecting passage 94 and, accordingly, the upper end of the chamber 90 is maintained at a pressure equal to that in the chamber 26. The piston 96 includes a head 96a and a smaller diameter, downwardly extending stern 96b which projects through the lower, internally flanged open end of the sleeve 92. The stem 96b is formed with one or more elongated slots 960 to permit atmospheric air to enter the lower end of the sleeve beneath the piston head 96a. The lower end of the piston member 96 is connected to a roller support bracket 98 having a roller 102 mounted thereon for engagement against the tab 540! on the arm 540 of the pusher member 54. The roller support bracket 98 is slidable between an upper position (FIG. 1, dotted lines) and a lower positiontFlG. 1, full lines) and is guided for vertical reciprocating movement between these positions by a fixed bracket secured to the outer surface of the magazine wall 38a and formed to include an outwardly extending upper guide flange 100a having a slot therein through which the support bracket 98 is guided. Normally, the pusher member 54 is maintained in a rearward position (dotted lines, FIG. 1) by means of a biasing spring 104 having an elongated, forwardly extending leg 104a bearing upwardly against the tab 54d, a coiled portion 10411 mounted on a lower rear spacing sleeve 43, and a short leg 1040 which bears downwardly against the bottom flange 35 between the magazine walls 38a and 40a. The spring 104 exerts a clockwise biasing force on the member 54 about its mounting pin 72 and, accordingly, forces the piston 96 upwardly in the sleeve 92 when the air pressure above the piston is reduced sufliciently. When a power stroke of the driver 14 is initiated the annular chamber 26 is vented to the atmosphere and, accordingly, the roller assembly moves upwardly under the force of the spring 104. When this occurs, the pusher 54 moves in a clockwise direction from the position shown in solid lines in FIG. 1 to the position shown in dotted lines therein on a return stroke. After a driving stroke is completed, the chamber 26 is again filled with pressurized fluid which flows through the pas sage 94 into the upper end of the sleeve 92 forcing the piston 96 downwardly. When this occurs, the pusher member 54 pivots in a counterclockwise direction against the spring 104 on a feeding stroke and moves the next nail 32 into the drive track 16. After the next power stroke of the driver 14, the nail feeding cycle is repeated and the 1pusher member 54 feeds another nail into the drive tr-ac In accordance with another aspect of the invention, the tool 10 includes a nail guiding mechanism to prevent the lower end of the nail being driven from cocking to the rear far enough so that it will not pass smoothly out through the lower end of the drive track as it is driven. To this end, a longitudinally extending nail guiding finger is provided and the finger is pivotally mounted at its rearward end on the lower and rearward spacer bolt 50 between the outer magazine sidewalls 40a and 40b rearwardly remote from the drive track. The rear end of the finger 110 is provided with a laterally extending tubular sleeve 112 which is journaled on the bolt 50 and which additionally serves as a spacer between the outer sidewalls. The finger is biased in a clockwise direction about the bolt 50 by means of a spring 114 having a coiled body mounted on the sleeve 112 and a forwardly extending spring finger 114a which is engaged in a slot 110a formed in the finger (FIGS. 3, 4, and 5). The spring also includes an upwardly extending leg 114b which protrudes upwardly to bear against the outer end of the bottom wall or flange 35 of the magazine.

The forward tip portion of the guide finger 110 includes an outer end surface 11% which is positioned to be even with the rearward wall portion of the drive track 16 and includes a forwardly upwardly sloping upper edge surface 110c intersecting the surface 11012 at a point 110d. In a normal position of the finger 110, the point 110d is above the lower end of the nail 32 positioned in the drive track (as best shown in FIG. 3) and, accordingly, the end surface 11011 prevents the lower end of the nail from cocking rearwardly far enough to move out of the drive track and jamming during a driving stroke. The spring 114 biases the guide finger 110 in a clockwise direction so that an upper edge 110a thereof rearwardly of the tip portion is always in contact against the lower end of the forwardmost nail in the magazine and, as this nail is fed forwardly from the magazine into the drive track, the upwardly sloping surface 1100 of the finger is cammed downwardly momentarily until the nail is forwardly clear of the end surface 11011 and in position in the drive track 16. Because the finger 110 is pivoted rearwardly remote from the drive track and is relatively long, nails of different length can be used in the tool without jamming problems because the forward guiding end surface 110]) of the finger, while movable on a circular arc, is always closely adjacent the rearward portion of the drive track wall. The nail guiding mechanism of the tool eliminates a common problem occurring in a tool capable of driving large round headed nails, and effectively prevents jamming of the nails in the lower end of the drive track because of rearward cocking of the lower end of the nails during a driving stroke.

The present invention thus provides a new and improved fastener driving tool and magazine assembly capable of automatically driving large nails and the like supplied from a carrier strip. Nail feeding action of the magazine is swift and positive after each driving stroke of the driver. In addition, the magazine indicates to the operator when the supply of fasteners is getting low and permits the easy insertion of a new supply. Manual release means are provided for permitting removal of the fasteners from the magazine.

While there has been illustrated and described a single embodiment of the present invention, it will be apparent that various changes and modifications thereof will occur to those skilled in the art. It is intended in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the present invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A magazine assembly for feeding fasteners from a carrier strip into the drive track of a driving tool, comprising guideway means for supporting a strip of fasteners from movement toward said drive track, first fastener engaging means movable laterally with respect to said guideway from one side thereof for engagement with said fasteners, second fastener engaging means movable laterally with respect to said guideway from an opposite side thereof for engagement with said fasteners, said first engaging means including structure adapted to project inwardly into said guideway and engage said fasteners to normally prevent rearward movement thereof, said second engaging means including structure adapted to project into said guideway for engagement with fasteners in said strip and movable toward and away from said drive track for 'moving said fasteners toward said drive track, stop means movable laterally inwardly into a stop position in said guideway with one of said first and second fastener engaging means for engaging fasteners in said guideway to prevent further longitudinal movement of said fasteners toward said drive track, and means for moving said second engaging means towards and away from said drive track to advance successive fasteners into said drive track.

2. The magazine assembly of claim 1 including manual means on opposite sides of said guideway for moving said inwardly projecting structures outwardly of said guideway to permit rearward movement of said fasteners therein.

3. The magazine assembly of claim 1 wherein said first and second fastener engaging means are mounted for pivotal movement about axes extending longitudinally of said guideway.

4. The magazine assembly of claim 3 wherein said inwardly projecting structure of said second engaging means reciprocally is movable longitudinally of said guideway and said inwardly projecting structure of said first fastener engaging means is fixed against movement longitudinally of said guideway.

5. The magazine assembly of claim 1 wherein said stop means is movable laterally with respect to said guideway between a first position clear of said guideway and said stop position wherein said guideway is blocked against forward movement of said fasteners therein.

6. In a fastener driving tool including a magazine for holding a supply of fasteners and advancing them into a drive track, said magazine including guideway means for supporting said fasteners, pusher means movable toward and away from said drive track for advancing fasteners along said guideway, holding means independent of said pusher measure for normally preventing rearward movement of said fasteners in said guideway, lateral stop means movable into and out of said guideway means for blocking the advancement of fasteners therein, said stop means including means responsive to the absence of fasteners in a selected position in said guideway means to permit movement of said stop means into a stopping position in said guideway means and means on said tool for reciprocating said pusher means toward and away from said drive track.

7. The tool of claim 6 wherein said pusher means is pivotally mounted on an axis transverse with respect to said guideway means and includes fastener engaging means normally projecting into said guideway means and reciprocally movable toward and away from said drive track to advance fasteners toward said drive track.

8. The tool of claim 7 wherein said holding means is pivotally mounted along an axis parallel with said guideway means and fixed against longitudinal movement with respect thereto, said holding means including fastener engaging means movable laterally into and out of engagement with the fasteners for normally preventing rearward movement thereof.

9. In a power driven tool for driving fasteners of the type including enlarged heads at the upper end of depending shanks having smaller transverse dimensions than said heads, comprising a drive track dimensioned to accommodate said heads as the fasteners are driven therefrom, magazine means communicating with a rearward wall portion of said drive track for feeding successive fasteners forwardly into said drive track to be driven, movable shank guiding means having a guiding surface closely adjacent a wall surface of said drive track for guiding engagement against a lower portion of the shank of a fastener positioned in said guideway, said shank guiding surface normally extending upwardly above the lower end of a fastener in said drive track and movable downwardly therefrom as successive fasteners are advanced forwardly from said magazine means into said drive track.

10. The tool of claim 9 wherein said shank guiding means comprises an elongated finger having said gliding surface at the forward end and a rearward end pivotally mounted on said tool remote from said drive track.

11. The tool of claim 10 including means normally biasing said finger upwardly toward engagement with the lower ends of fasteners in said magazine means.

12. The tool of claim 11 wherein said finger includes a sloping cam surface thereon engageable with the lower end of a fastener next adjacent said drive track for pivoting said finger away from the lower ends of successive nails in said magazine each time a nail is advanced into said drive track.

13. The magazine assembly of claim 5 wherein said inwardly projecting structure of said first and second fastener engaging means includes a plurality of ratchet teeth arranged in rows and spaced longitudinally of said guideway at an interval substantially equal to the spacing between successive fasteners in said carrier strip, said stop means comprising a projection spaced forwardly of a forwardmost ratchet tooth in one row by a distance greater than the spacing between adjacent teeth.

14. The magazine assembly of claim 13 wherein said ratchet teeth in said one row project inwardly into said guideway beyond said stop means whereby, during normal engagement of said teeth in said one row with said fasteners, said stop means is spaced outwardly of said guideway.

15. The magazine assembly of claim 14 wherein said stop means and said one row of ratchet teeth are formed on a common flange portion of said first fastener engaging means, said flange portion extending longitudinally of said guideway and generally normal to said fasteners.

14 16. The magazine assembly of claim 15 wherein said flange portion is formed with slot means between said forwardmost tooth and said stop means permitting movement of said stop means into said stop position when the rearwardmost fastener in said guideway is forward of said forwardmost tooth.

References Cited UNITED STATES PATENTS 248,398 10/1881 Brock 227136 1,162,678 11/1915 Boden 227136 XR 2,078,064 4/1937 Day 227136 2,923,937 2/1960 Laucher 227-135 XR 3,281,046 10/1966 Boulay 227136 XR 3,353,737 11/1967 Howard et al. 227136 GRANVILLE Y. CUSTER, 111., Primary Examiner

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