US3504840A - Fastener driving tool - Google Patents

Description

April 7, 1970 Filed Feb. 28. 1968 5 Sheets-Sheet 2 rroeA/EYS.

April 7, 1970 o. A. WANDEL. ETAL 3,504,840

FASTENER DRIVING TOOL 5 Sheets-Sheet 3 Filed Feb. 28, 1968 Ir if" /A/l/E/s/rozs M w AWM@ 0 EE @T D/ r ME 44 www A. .//M/ ef@ mwa Oqw u/ua4 /Um/ u W April 7, 1970 o. A. wANDl-:L ETAI- 3,504,340'

FASTENER DRIVING TOOL Filed Feb. 28, 196e 5 sheets-sheet 4 /M /40 fm y w W 7 /60 /504 /az /aa 35; 361.1 'VZ/7g4 I n .L -W i-1T Y Um w /60 j 2564 54 f90 /l Y 5a 5a 236 Wa 256.6 257 /Zc i, /m zi, 4':

p54 /m i 0564@ A. MMA/DEL AWD 550w/5 W 55m-er April 7, 1970 o. A. wANDEL ETAL 3,504,840

FSTENER DRIVING TOOL Filed Feb. 2s, 196e 5 sheets-sheet s Arroz/JE Ys United States Patent Of 3,504,840 FASTENER DRIVING TOL Oscar A. Wandel, Mundelein, and George W. Seifert,

Chicago, Ill., assiguors to Fastener Corporation, Franklin Park, Ill., a corporation of Illinois Filed Feb. 28, 1968, Ser. No. 709,029 Int. Cl. Bc J/04 U.S. Cl. 227-130 21 Claims ABSTRACT OF THE DISCLOSURE A fastener driving tool comprising a drive track and a driver slidatble in said track. A magazine assembly for supplying fasteners to said drive track including support means for holding a row of fasteners disposed with their Shanks in spaced apart relation and a helical worm with a portion thereof disposed between a pair of adjacent fasteners in said row. Rotor means for tuning said worm to advance fasteners toward said drive track in synchronism with the power and return strokes of said driver in said drive track.

The present invention relates to a new and improved fastener driving tool and, more particularly, to a tool having a new and improved magazine for holding a supply of fasteners and feeding them into the drive track of the tool.

With the advent of a new electrically and pneumatically powered fastener driving tool having the capability of driving relatively large fasteners, such as common nails and the like, it has been a problem to provide an automatic magazine assembly for the tool capable of holding a relatively large supply of fasteners and capable of positively feeding the large fasteners, one at a time, into the drive track in synchronism with the power and return strokes of the driver. Many prior magazine assemblies do not have the capability of holding a large enough supply of fasteners and oftentimes are so large and heavy as to inhibit the portability and ease with which the tool can be handled and positioned for driving fasteners. In many instances fasteners would fail to feed properly into the drive track, and frequently jams or other malfunctions would occur in operation.

It is therefore an object of the present invention to provide a new and improved fastener driving tool.

Another object of the invention is the provision of a new and improved fastener driving tool which eliminates the aforementioned difficulties encountered in prior art tools.

More specifically, it is an object of the present invention to provide a power driving fastener driving tool having a new and improved magazine assembly.

Still another object of the invention is the provision of a new and improved magazine assembly of the character described having the capability of holding a quantity of relatively large fasteners, such as common nails and the like, yet remaining relatively small in size and light in weight so as not to reduce or limit the ease with which the tool may be handled and oriented for driving fasteners.

Still another object of the present invention is the provision of a new and improved magazine assembly of the character described employing operatively reliable and positive means for feeding the fasteners into the drive track of the tool in synchronism with the movements of the driver.

Yet another object of the invention is the provision of a new and improved magazine assembly of the character described which is completely automatic in operation, easy to load with a large number of fasteners, and more reliable in operation.

Another object of the invention is the provision of a ICC new and improved magazine assembly of the character described employing novel worm gear means for positively and reliably feeding 'the fasteners into the drive track of the tool.

A further object of the invention is the provision of a new and improved magazine of the character described in the preceding paragraph which is capable of handling several different types of fasteners with a minimal amount of adjustment being required to change from one type or size fastener to another.

Another object of the present invention is to provide a new and improved magazine assembly having novel means for adjusting the worm gear feeding mechanism to accommodate different types Vand sizes of fasteners.

Yet another object of the invention is the provision of a new and improved magazine assembly of the type described capable of holding multiple rows of fasteners and employing novel means for automatically shifting each row into feeding alignment with the drive track until the supply of fasteners is exhausted.

Still another object of the invention is the provision of a new and improved magazine assembly of the character described employing worm gear feeding means and novel means for driving the worm to advance fasteners toward the drive track in selected synchronism with the movements of the driver of the tool.

Brieily, the foregoing and other objects and advantages of the present invention are accomplished in one embodiment thereof comprising a tool having a drive track, a driver slidable in the track, and a magazine assembly for holding a supply of fasteners and feeding them one at a time into the drive track. The magazine assembly includes means for supporting at least one ro-w of fasteners in alignment with the drive track and arranged with their Shanks in spaced apart relation. A helical worm is disposed -adjacent the row of fasteners and a portion of the worm extends between at least one pair of adjacent fasteners for advancing the fasteners toward the drive track upon rotation of the worm. Means are provided for rotating the `worm to advance fasteners toward the drive track in synchronism with the movements of the driver of the tool.

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

FIG. 1 is a sectional View of a new and improved fastener driving tool in accordance with the invention taken on a longitudinal plane;

FIG. 2 is a sectional view similar to FIG. l but illustrating the piston and drive in another operative position approaching a rest position at the ends of a return stroke;

FIG. 3 is a sectional view taken substantially along line 3-3 of FIG. l and illustrating in detail the magazine assembly of the tool in accordance with the present invention;

FIG. 4 is a transverse cross-sectional view through the magazine assembly taken substantially along line 4-4 of FIG. l;

FIG. 5 is a transverse cross-sectional view through the drive track of the tool taken substantially along line 5 5 of FIG. 2;

FIG. 6 is a transverse longitudinal cross-sectional view through the magazine assembly taken substantially along line 6-6 of FIG. l;

FIG. 7 is a transverse longitudinal sectional view through the magazine assembly taken substantially along line 7 7 of FIG. 2;

FIG. 8 is a transverse cross-sectional view taken substantially along line 8- 8 of FIG. l;

FIG. 9 is a transverse cross sectional View taken substantially along line 9-9 of FIG. 2;

FIG. l is a fragmentary top plan view of the rear and portion of a modified form of magazine assembly in accordance with the invention;

FIG. l1 is a transverse cross-sectional view taken substantially along line 11-11 of FIG. l0;

FIG. 12 is a transverse cross-sectional view of yet another embodiment of a magazine assembly in accordance with the present invention;

FIG. 13 is a fragmentary top plan view of a modified magazine feeding assembly in accordance with the invention;

FIG. i4 is a fragmentary top plan view of the assembly of FIG. 13 but illustrating the assembly adjusted for accommodating a different size nail strip; and

FIG. 15 is a longitudinal cross-sectional view taken substantially along line 15-15 of FIG. 14.

Referring now more specifically to FIGS. 1 and 2 of the drawings, thererin is illustrated a fastener driving tool which embodies the present invention and which is indidated generally as 10. The tool comprises a housing 12 including a generally vertically extending head or forward portion 12a, a rearwardly extending hollow handle portion 12b, and a short, downwardly extending handle butt portion 12C at the rear end of the handle. The interior of the head portion 12a, handle 12b, and handle butt portion 12C provides a reservoir 16 for holding pressurized uid, such as compressed air, which is supplied to the tool by a flexible line connected to an inlet fitting 14.

The drive system for the tool 10 includes a cylinder y18 movably mounted within the head portion 12a and having an open upper end that is adapted to be selectively connected to the reservoir 16. The cylinder 18 is normally biased to place its open upper end in engagement with a main valve assembly 20 under the control of a safety or touch-trip valve assembly 22 and a manual trigger valve assembly 24. A fastener driving assembly including a piston 26 slidably mounted within the cylinder 18 and having a depending driver element or rod 28 secured thereto is normally Ibiased to a position adjacent the main valve 20 under the control of a piston return valve assembly indicated generally as 30. An exhaust valve assembly indicated generally as 32 for controlling the selective connection of the upper end of the cylinder 18 to the atmosphere is disposed on the housing 12 offset from the axis of the cylinder 18 to reduce the overall height of the tool 10.

When the tool 10 is to be operated, the safety valve assembly 22 and the manual valve assembly 24 both are operated to move the cylinder 18 downwardly away from the main valve assembly 20. As the cylinder 18 moves downwardly, the exhaust valve assembly 32 is closed (FIG. 1) and compressed air from the reservoir 16 enters the upper end of the cylinder 18 and drives the piston 26 and the connected driver 28 downwardly to engage and set a fastener or nail 34 supplied to a drive track 36 in a nosepiece or nosepiece structure 38 by a magazine assembly indicated generally as 40. When the cylinder 18 moves downwardly, a venting assembly indicated generally as 42 places the lower end of the cylinder 18 in communication with the atmosphere so that the air disposed below the piston 26 can be discharged to the atmosphere to prevent pneumatic damping of the downward movement of the piston.

When the valve assemblies 22 and 24 are released (FIG. 2), the cylinder 18 is moved upwardly to engage the main valve assembly 20 and ciose off communication between the reservoir 16 and the upper end of the interior of the cylinder 18. When the cylinder 18 moves to a position engaging the main valve assembly 20, the exhaust valve assembly 32 is actuated to place the upper end of the interior of the cylinder 18 in communication with the atmosphere'. This discharges the entrapped air above the piston 26 and controls the piston return valve assembly 30 so that compressed air is supplied below the piston 26, the vent assembly 42 being closed by the upward movement of the cylinder he Compressed air supplied by the valve assembly 30 retracts the piston 26 and the driving element 28 upwardly to a rest position to complete a cycle of operation of the tool 10.

Referring now more specifically to the drive system embodied in the tool 10, this system is of the same general type as that shown and described in detail in United States Patents No. 2,979,725, No. 3,253,760, and No. 3,190,187. This drive system includes a pair of cylindrical portions 44 and 46 in the head portion 12a in which are slidably received two different diameter portions of the cylinder 18. The larger diameter or upper portion of the cylinder 18 is sealed by two O-rings 48 which slidably engage the cylinder portion 44, and a lower or smaller diameter portion of the cylinder 18 is sealed by an O-ring 50 engaging the cylindrical portion 46.

An intervening space or cavity 52 (FIG. 2) defined between the O- rings 48 and 50 is selectively supplied with compressed air or connected to the atmosphere by the control valve assemblies 22 and 24. In the normal condition of the tool 10, one or both of the valve assemblies 22 and 24 supply compressed air to the space 52 which acts on the downwardly facing surfaces on the cylinder 1S within the space 52 which are greater in area than the upwardly facing surfaces acted on by the compressed air within the reservoir 16 to provide an upwardly directed component of force biasing the open upper end of the cylinder 18 upwardly against the main valve assembly 20 to prevent communication between the upper end of the cylinder 18 and the reservoir 16.

The interior of the cylinder 18 is fitted with a replaceable inner cylinder liner 54 preferably formed of a selflubricating material or metal, and a portion of the outer wall of the cylinder liner 54 is spaced from the inner wall of the cylinder 18 to provide an air conveying space 57 forming a part of the piston return system controlled by the piston return valve assembly 30. The piston 26 includes a greater diameter upper portion 26a carrying a pair of O-rings S8 which slidably engage the inner wall of the cylindrical liner 54.

A smaller diameter lower portion 26h of the piston 26 is adapted to engage a resilient bumper 60 (FIG. l) disposed within a cylindrical retaining sleeve 62 which rests on the upper wall of the nosepiece structure 38, which nosepiece structure is fastened to the lower end of the head portion 12a of the housing 12 by a plurality of machine screws to close the lower end of the head portion 12a. The driver 28, which is secured to the piston 26, passes through an opening 66 in the resilient bumper 60 to enter the upper end of the drive track 36 formed in the nosepiece structure 38.

The venting assembly 42 for controlling the selective connection of the lower end of the interior of the cylinder 18 to the atmosphere comprises an integral cylindrical sleeve portion or annular valve element 68 at the lower end of the cylinder 18 that is slidably mounted in a lower cylindrical portion 70 of the head portion 12a with the interface between the cylindrical portion 70 and the sleeve 68 being sealed by an O-ring 72 carried on the sleeve 68. A compression spring 74 interposed between a ange 62a of the retaining element 62 and the lower end of the sleeve 68 normally biases a resilient O-ring 76 carried on the sleeve 68 into engagement with an inclined wall surface connecting the cylindrical portions 46 and 70 to close the lower end of the interior of the cylinder 18.

When the cylinder 18 moves downwardly, its lower end engages the upper end of the sleeve 68 and moves this sleeve downwardly against the force of the compression spring 74 to move the valve element 76 out of engagement with the inclined wall. This places the lower end of the interior of the cylinder 18 in communication with the atmosphere through one of a plurality of exhaust ports 78. When the cylinder 18 is restored to its normal position at the end of the driving stroke, the compression spring 74 slides the sleeve 68 upwardly so that the valve element 76 again engages the inclined wall surface to close communication between the lower portion of the interior of the cylinder 18 and the atmosphere.

The piston return valve assembly 30 is shown and described in detail in the above-identified Patent No. 3,190,- 187. As set forth therein, the piston return valve assembly 30 is automatically responsive to the pressure within the upper end of the cylinder 18 or the position of the piston 26 to selectively supply compressed air from the reservoir 16 to the lower end of the interior of the cylinder 18 to return the piston 26 to its normal position engaging the main valve assembly 20. The piston return valve assembly 30 is mounted in a protuberance or projection 18a formed on the cylinder 18 and includes a valve element 80 having a piston portion 82 slidably mounted within a two diameter cylinder formed in the portion 18a. The upper end of the larger diameter portion of the cylinder is closed by a member 84 having a passageway 86 through which compressed air from the reservoir 16 is continuously supplied. This air acts on the piston portion 82 to provide a downwardly directed component of force that seats the valve 80 on a resilient valve element provided by an O-ring 88. This closes off communication through a passageway 90 and a port 92 between the reservoir 16 and the air conveying space 57 which is defined between the cylinder 18 and the cylindrical 4insert 54 and which communicates with the lower end of the interior of the cylinder 18 below the piston 26,

Whenever the tool is actuated to move the cylinder 18 downwardly, the piston 26 is driven downwardly to engage the bumper 60 and remains in this position when the cylinder 18 is returned t0 its normal position engaging the main valve assembly by the release of the control valve assemblies 22 and 24. When the exhaust valve assembly 32 is operated to connect the upper end of the interior of the cylinder 18 to the atmosphere, the compressed air interposed between the piston portion 82 and the member 84 is largely exhausted to the atmosphere through a passageway 94, the upper end of the cylinder 18, and the exhaust valve assembly 32. The compressed air acting on the lower end of the piston portion S2 lifts the -valve element 80 out of engagement with the valve seat 88 so that compressed air enters the lower end of the cylinder 18 below the piston 26. This compressed air moves the piston 26 upwardly to engage the main valve 20. In this position, the port terminating the inner end of the passageway 94 is sealed by the O-rings 58. The compressed air entering through the passageway 86 now accumulates above the piston portion 82 and overcomes the upwardly directed force due to the compressed air supplied from the reservoir 16. At this time, the exhaust valve 80 moves downwardly to engage the resilient O-ring 88 and terminates the supply of pressurized fluid to the lower end of the interior of the cylinder 18 below the piston 26. The piston 26 is retained in its upper position by the frictional engagement of the O-rings 58 with the inner wall of the cylindrical insert 54.

The main valve assembly 20 is carried on a closure cap 100 which is secured to the head portion 12a of the housing by a plurality of machine bolts with a resilient sealing gasket 104 interposed between the head portion 12a and the closure cap 100 so as to close the open upper end 106 of the head portion 12a. The main valve assembly 20 includes a resilient element 108 of a diameter slightly larger than the upper end opening in the cylinder 18. The resilient element 108 is vulcanized or otherwise rigidly and permanently secured to a plate 110 that is secured to the lower surface of the closure cap 100 by a plurality of machine screws 112. In prior constructions, the resilient element 108 of the main valve assembly has been mounted in such a manner that it can be deected or pulled downwardfy by the compressed air acting thereon when the cylinder 18 is lowered.

The exhaust valve assembly 32 is selectively responsive to the position of the cylinder 18 either to connect the upper end of the interior of this cylinder to the atmosphere, in the normal condition of the tool 10 (FIG. 2), or to close the exhaust connection whenever the tool 10 is operated. The exhaust valve assembly 32, which is completely carried on the closure cap 100, is offset radially from the center or axis of the cylinder 18 to permit a reduction in the overall height of the head portion 12a of the tool 10. The exhaust system controlled by the valve assembly 32 includes a vertically extending passageway 114 passing through the resilient valve element 108, the plate 110, and the closure cap in a position generally aligned with the axis of the cylinder 18. A transverse passageway 116 in the closure cap 100 connects the passageway 114 with a small diameter cylinder 118 forming a part of the housing for the control valve 32. An additional passageway 120 communicating with the atmosphere at one end is connected to the cylindrical chamber 118 by a larger diameter cylinder 122 also forming a part of the exhaust valve assembly 32.

This assembly includes a valve element 124 having an upper piston portion 124a and an intermediate valve portion 124b which are disposed within the cylinder 122. The upper end of the cylinder 122 is closed by a cap or closure 126 held in position by a cap screw 128. A lower sealing portion 124e` of the member 124 is disposed within a smaller diameter cylinder 130 forming a continuat'on of the cylinder 118. The lower end of the valve member 124 includes an operator portion 124d which is aligned with and adapted to be engaged by the cosure member 84 mounted on the projecting po tion 18a of the cylinder 18. The operator portion 124d does not close the passageway 86 in the closure member 84. In the normal condition of the tool 10, the lower end of the operator 12451 engages the member 84 on the projecting portion 18a of the cylinder 18 to hold the exhaust valve assembly 32 in the open position illustrated in FIG. 2 in which the upper end of the interior of the cylinder 18 is connected to the atmosphere through the passageways 114 and 116, the cylinders 118 and 122, and the passageway 120.

When the tool 10 is operated so that the cylinder 18 moves downwardly, the member 84 0n the projecting portion 18a moves out of engagement with the operator 124d on the exhaust valve member 124. At this time, the compressed air continuously supplied to the upper surface of the piston portion 124rz from the reservoir 16 through an axially extending passageway 132 in the valve member 124 acts on the upper surface of the piston portion 124:1 and provides a greater downwardly directed force than the upwardly direcfed force resu'ting from the compressed air in the reservoir 16 acting on the lower surface of the sealing portion 124C. This net downwardly directed force moves the valve member 124 downwardly until a valve element provided by an O-ring 134 carried on the valve portion 124b seats on the shoulder between the cylinders 118 and 122. This prevents communicat'on between the passages 116 and 120 and closes the connection between the upper end of the cylinder 18 or the reservoir 16 and the atmosphere.

When the cylinder 18 is restored to the normal or rest position at the upper end of the head portion 12a, the member 84 on the projecting portion 18a engages the lower end of the operator 124d and moves the valve member 124 upwardly against the pneumatic bias to the position illustrated in FIG. 2. In moving upwardly, the valve member 124b lifts the O-ring 134 out of engagement with he shoulder between the cylinders 118 and 122 so that the upper end of the interior of the cylinder 18 is connected to the atmosphere over the system of passageways set forth above. This is effective through the passageway 94 to place the upper end of the piston portion 82 at or near atmospheric pressure so that the piston return valve assembly 30 operates in the matter described above. The eX- haust valve assembly 32 remains in this condition until the tool 10 is next operated to lower the cylinder 18.

The safety valve assembly 22 and the manual valve assembly 24 for controlling the operation of the tool 10 are substantially the same as those described in the aboveidentified patents. In general, the safety valve assembly 22 includes a valve stem 140 having a grooved or reduced diameter portion 140a adjacent its upper end which is slidably received within a sleeve 142 carried on the housing 12. The lower end of the valve stem 140 is connected to a collar 144 so that a compression spring 146 interposed between a projection 148 on the head portion 12a and the collar 144 biases the valve stem 14E) to the position shown in FIG. 2 in which compressed air from the reservoir 16 flows into the space 52 through a passageway or port 150. The collar 144 is connected to an operator element (not shown) that is slidably mounted on the nosepiece structure 38. The lower end of the operator element normally projects below the lower end of the nosepiece structure 38 and is adapted to engage a workpiece. Thus, when the tool is moved into engagement with the workpiece, the operator is moved upwardly to produce a corresponding movement of the valve stem 140 against the action of the compression spring 146. When the valve stem 140 moves upwardly, the upper end of the stem closes off direct communication between the passageway 150 and the reservoir 16, and the notched or recessed portion 140g moves into alignment with a passageway 154.

The passageway 154 communicates with the manually controlled trigger valve assembly 24 which includes a ball valve element 155 and a passageway 156 communicating with the reservoir 16. Thus, compressed air from the reservoir 16 normally passes through the passageways 156, 154, and 150 to the space 52.

When the manual valve assembly 24 is actuated by pivoting a trigger 157 in a counterclockwise direction about a pivot pin 158, a uted valve stern 159 moves upwardly to seat the ball valve 155 in a position closing the port terminating the passageway 156. This movement of the ball valve 155 also places the passageway 154 in communication with the atmosphere through the flutes along the stem of the operator pin 159. Thus, the space 52 is placed at atmospheric pressure, and the compressed air within the reservoir 16 acting on the upwardly facing surfaces of the cylinder 18 produces a downwardly directed force which moves the cylinder 18 downwardly to cause the sequential operation of the valve assemblies 32 and 42 in the manner described above. When either or both of the valve assemblies 22 and 24 are released, compressed air from the reservoir 16 enters the space 52 through the passageway 150 or through the passageways 156, 154, and 150 to provide an upwardly directed force acting on the cylinder 18 to move it upwardly into engagement with the main valve assembly 20. This closes the valve assembly 42, opens the valve assembly 32, and causes the operation of the piston return valve assembly 30 for the period of time necessary to return the piston 26 and the driver 28 to the normal or rest position.

The novel magazine assembly 40 constructed in accordance with the features of the present invention is adapted to feed individual nails 34 one at a time into the driver track 36 in synchronism with the movements of the driver 28. The nails are supplied from a plurality of carrier strips loaded into the magazine, and each carrier strip holds a substantial number of nails held together by longitudinal strip members 160 applied transversely across the nail Shanks. Preferably, the carrier strips or nail assemblages are of the type shown and described in U.S. Patent No. 3,212,632, wherein the nails are arranged with their shanks in spaced apart, parallel relation and their heads are in stacked relation, as shown best in FIGS. 1 and 2. In each carrier a pair of parallel strip members 160 are integrally formed to extend transversely across the nail shanks longitudinally of the assemblage, one strip being arranged parallel to the line of nail heads and another strip spaced below and gen- @rally parallel with the pointed ends of the nails.

In order to hold a plurality of carrier strips or nail assemblages in the magazine and thereby provide capacity for a relatively large number of individual nails 34, the magazine 40 includes a movable support member 162 having an arcuate or curved, transverse, cross section (FIGS. 4 and 12) and a plurality of longitudinally extending, spaced apart, parallel grooves 164-1 through 6 are formed in the member, each holding a separate carrier of nails. Each of the grooves 164-1 through 6 is adapted to support the nail heads in a carrier strip and permit the longitudinal movement of the nails along the groove toward the drive track of the tool.

The nail support member 162 is movable laterally with respect to a feeding axis or plane A-A (FIG. 4) extending rearwardly of the longitudinal axis of the drive track 36 so that each of the grooves 164-1 through 6 may be successively aligned with the drive track until all of the nails in the groove lare advanced into a feed slot 38a formed in the nosepiece and extending rearwardly of the drive track (FIGS. 6 and 7). To this end, the forward end of the magazine nail support member 162 includes a forwardly projecting lip or ridge 162g (FIGS. 1 and 2) at the forward end slidably disposed within a transversely curved slot 38h formed in the rearward face of the nosepiece. The rearward end of the support member 162 is provided with a similar rearwardly projecting support lip or ridge 162b laterally slidable within a transversely curved groove or slot 165 dened in a forwardly facing surface portion 166 of the handle butt portion 12C. Accordingly, the member 162 is laterally movable or shiftable as represented by the arrow B (FIG. 3) in relation to the feeding plane A-A so that each of the nail supporting grooves 164-1 through 6 can be successively aligned with the feed opening 38a in the rear of the nosepiece 38 which communicates with the drive track 36.

In order to advance the nails 34 forwardly from the respective grooves 164-1 through 6 into the feed slot 38a toward the drive track 36, the magazine assembly 40 includes a feeding or nail advancing assembly 170 comprising a worm gear 172 mounted adjacent the forward end of a rotatable shaft 174. The worm gear 172 includes a spiral helix or worm 172a having a plurality of convolutions adapted to extend between the spaced Shanks of the nails 34 as best shown in FIGS. 6 and 7. When the worm is rotated in the direction of the arrow C in FIG. 6, the nails are advanced forward with respect to the drive shaft 174. The pitch of the helical worm 172a is chosen to accommodate the spacing between the nail Shanks and provide good contacting engagement between the advancing side face of the worm against the rearward facing surfaces of the nail Shanks.

The forward end of the worm shaft 174 is supported in a cylindrical recess 38C opening rearwardly on the rearward face of the nosepiece member 28. As shown in FIGS. 6 and 7, the shaft 174 is rotatable and, in addition, is slidable longitudinally of the magazine. As best shown in FIG. 4, it will be seen that the shaft 174 is laterally offset from the nail feeding plane A-A and is generally parallel thereto, so that when one of the T-shaped grooves 164-1 through 6 is aligned with the feed slot 38a, the helical worm engages the nail Shanks from one side and advances them forwardly with respect to the shaft as it is rotated, The rearward end of the worm drive shaft 174 is connected by means of a one-way slip clutch assembly 176 to a short, rear, drive Shaft 178 having its rearward end supported in the axial bore 180a of a flanged bushing 180 which is seated in recess or bore 182 formed in the handle butt portion 12C. The bushing 180 includes a radial ange at the forward end thereof which is biased forwardly in the bore 182 by means of a relatively strong compression spring 184, the rearward end of which is seated against an internal shoulder 182:1 formed in the bore. The spring 184 is adapted to permit longitudinal movement of the bushing 180 within the bore 182 should a jam-up of the drive track Qcur, and

thus damage would be minimized. The rear shaft 178, the forward drive shaft 174, and the worm gear 172 are normally biased forwardly to the position shown in FIG. 7 by a loading spring 188 which is seated at the closed end of the bore 180a in the bushing 180.

The slip clutch assembly 176 is operable to drive or rotate the forward shaft 174 in one direction only, as indicated by the arrow C in FIG. 6 when the rearward shaft 178 is rotated in the same direction. When the rear shaft 178 is rotated in the opposite direction, the slip clutch 176 permits the forward shaft 174 to remain stationary when the worm gear is engaging the nails 34.

The rear drive shaft 178 is rotated by means of a gear 190 mounted intermediate the ends of the shaft, and the gear is rotated by a vertically movable rack member 192 forming the lower end portion of a reciprocating plunger 194 having a piston 196 at the upper end (FIGS. 8 and 9).

The piston 196 is mounted for sliding movement in a cylindrical bore 198 formed in the handle butt portion 12e and generally perpendicular to the drive shafts 178 and 174 of the feed assembly 170. The lower end portion of the bore 198 in the handle butt portion 12C is reduced sealed within the bore 198 by means of an O-ring 1960 against which is seated the lower end of a compression spring 200 which normally biases the piston 196 upwardly to the position shown in FIG. 9. The piston 196 is sealed within the bore 198 by means of an -ring 196rz and when pressurized fluid is supplied to the upper end of the bore 198, the piston and rack portion 192 are driven downwardly thereby rotating the gear 190 in the direction of the arrow C (FIG. 6). This rotates the rear drive shaft 178 which drives the worm 172 via the forward drive shaft 174 and slip clutch assembly 176. When pressurized fluid is exhausted from the upper end of the bore 198 above the piston 196, the compression spring 200 causes the piston and rack portion 192 to move upwardly from the position of FIG. 8 to the position of FIG. 9. This causes the shaft 178 to rotate in the opposite direction, and during this time the slip clutch 176 permits the forward drive shaft 174 to remain stationary without rotation. The upper end of the bore 198 in the handle butt portion 12e` is connected to the valve passage 118 associated with the exhaust valve assembly 32 via a fluid line 202. An end fitting 204 connects the lower end of the fluid line to the upper end of the bore 198 and an end fitting 206 connects the upper end of the fluid line to the exhaust passage 116 which is in communication with the Vertical valve passage 118.

Because the upper end of the iluid conduit 202 is in communication with the exhaust passage 116 when a power stroke is initiated, as shown in FIG. l, pressurized fluid introduced into the upper end of the cylinder 18 also flows through conduit 202 into the upper end of the bore 198 causing the piston 196 and rack portion 192 to move downwardly. This rotates the worm gear 172 in the direction shown by the arrow C in FIG. 6, but because the driver 28 is occupying the lower end in the drive track 36 during this time, the nails 34 in the groove in feeding alignment with the drive track cannot advance. Accordingly, the worm 172 and shaft 174 move longitudinally rearwardly with respect to the nails, causing compression of the spring 188 (FIG. 6). After a power stroke has been completed, the piston 26 and driver 28 move upwardly on a return stroke. When the lower end of the driver moves above the head of the leading nail in the feed slot opening 38a, the compressed spring 188 forces the feed shaft assembly 170 forwardly to the position of FIG. 7, and the worm helix 172:1 moves, the leading nail into the drive track 36.

During the upward travel of the piston and driver on a return stroke, the exhaust passage 116 is vented to the atmosphere through the exhaust valve assembly 32, as previously described, and accordingly the pressurized fluid in the upper end of the bore 198 above the piston 10 196 is open to exhaust to the atmosphere through the fluid conduit 202, passages 118, 122, and 120. During this time the spring 200 moves the piston 196 upwardly to the position shown in FIG. 9 in preparation for the next cycle of operation.

From the foregoing description it will be seen that the nail feed assembly is operable in synchronism with the movements of the piston 26 and driver 28 to feed a nail 34 into the drive track after each power stroke has been completed as the driver 28 moves upwardly on a return stroke toward the rest position. The worm helix 172a provides for positive advancement of the nails along the grooves 164 through 164-6 :and preferably the worm continuously engages several nails in a strip so that there is little chance of the worm skipping or jumping past the nails without advancing them.

In order to laterally shift the magazine support member 162 to bring each of the nail supporting grooves 164-1 through 6 therein into feeding alignment with the feed slot 38a in the nosepiece, the magazine 40 includes a lateral shifting assembly 210. The shifting assembly 210 includes an axle 212 which is parallel with and spaced above the shafts 174 and 178. The forward end of the axle 212 is seated in a recess 214 in the tool housing 12a, and the rearward end is supported in a recess 216 formed in the face 166 of the handle butt portion 12C. The axle 212 is secured against rotation on the tool housing and a torsion spring 218 is mounted on the axle intermediate its ends with one end of the spring connected to the axle and the opposite end of the spring extending radially outward to engage a tubular sleeve 220. The sleeve is rotatable on the axle 212, and the torsion spring 218 exerts torque on the sleeve, tending to cause rotation of the sleeve in a clockwise direction, as viewed in FIG. 4. The forward end of the sleeve 220 includes a gear portion 222 journaled for rotation on the axle 212, and similarly a gear portion 224 is provided at the rearward end of the sleeve. The gear portions 222 and 224 drivingly engage forward and rearward, toothed, rack portions 226 and 228, respectively (FIG, 3) formed on the upper surface of the magazine support member 162. When the sleeve 220 is rotated on the axle 212 by the spring 218, the gear portions 222 and 224 engage the rack portions 226 and 228 at the forward and rearward ends of the magazine support member 162 and urge the member to shift laterally from right to left (FIG. 4). As the nails 34 in each of the T-shaped grooves 164-1 through 6 are exhausted, the force of the -bias spring 218 automatically shifts the support member 162 laterally to align the next nail support groove in the member on the feeding plane A-A so that the worm gear 172 can engage the nails and advance them forwardly into the feed slot 38a of the nosepiece. The shifting assembly 210 is operable to automatically shift the next succeeding groove in the support member 162 into feeding alignment with the drive track after all of the nails in the preceding groove have been advanced into the feed slot 38a in the nosepiece. This process is repeated until the nails 34 in all of the grooves 164-1 through 6 contained in the magazine support member 162 have been advanced into the feed slot 38a of the nosepiece.

The lateral shifting assembly 210 also serves an important function in continuously biasing the Shanks of the nails 34 against the worm gear 172 so that convolutions of the helical worm 172:1 will seat in the spaces between adjacent nail Shanks and thereby insure positive feeding or advancement of the nails when the worm 172 is rotated, as previously described. Engagement of the nails 34 with the worm gear insures proper alignment of each groove 164-1 through 6 with the drive track and prevents the shifting assembly 210 from skipping any groove which contains nails.

In order to facilitate loading of the carrier strips into the grooves, the upper surface of the magazine support member 162 is provided with an enlarged rectangular opening 230 which extends between the rack portions 225 and 228 and is in communication with all of the grooves in the support member. The nail strips are inserted into the grooves from the top through the opening 230. In order to limit the lateral movement of the support member 162 when empty, a pair of stop members or handles 232 and 234 are formed on opposite sides thereof. When loading the magazine with nails, the support member is laterally shifted manually from left to right (FIG. 4) until the stop 232 is against the sleeve 220 and all of the grooves 164-1 through 6 are open and exposed from the top so that nail strips may be inserted therein without interference. In effecting the manual lateral shifting of the member 162, the handle 234 is grasped and moved from left to right until the handle 232 engages the sleeve 220, and this action winds up the torsion spring 218. After the carrier strips have been loaded into the grooves 164-1 through 6, the handle 234 is released and the torsion spring 218 causes the support member 162 to move laterally from right to left until the nails 34 in the rst groove 164-1 are against the worm gear 172. After all of the nails in the groove 164-1 have been advanced into the feed slot 38a, the torsion spring 218 shifts the support member laterally to align the next groove 164-2 with the drive track, and this process is repeated until all of the nails in the grooves of the magazine have been advanced into the feed slot, `whereupon the spring 218 again shifts the support member to a position wherein the handle 234 is touching the sleeve 220 preventing further lateral movement of' the nail support member. The opening 230 in the top portion of the magazine support member 162 provides an easy and convenient means for inserting the strips of nails downwardly into the T-shaped grooves 164-1 through 6. Because the grooves 164-1 through 6 slope upwardly as they extend rearwardly from the drive track 36, the nail strips, once inserted in the grooves move forwardly in their respective grooves by gravity until the leading nail in the strip is within or closely adjacent to the mouth of the feed slot 38a in the noseipece.

Referring now to FIGS. 5, 6, and 7 of the drawings, in order to securely hold the nails 34 within the feed throat 38a of the nosepiece, there is provided a U-shaped spring biasing member 236 having one leg 236g which is mounted in the feed throat and bears laterally against the Shanks of the nails 34 therein. The spring member 236 also includes a bight portion 236b which is freely movable within a slotted out portion 38d extending laterally of the drive track 36 and feed throat. The outer leg of the spring member is secured to the side face of the nosepiece 38 by a small cup screw 237. When the number of the nails 34 remaining in a nail strip is low, the spring 236 insures that the nails bear frmiy against one side of the feed throat 38a and prevents cocking of the nails during feeding or as a driving stroke of the driver 28 proceeds.

As best shown in FIGS. 6 and 7, the feed slot 38a is long enough to accommodate a plurality of nails 34, and these nails are firmly held in position within the feed throat by the inner leg 236a of the spring member 236. Each time the lateral shifting mechanism 210 operates to shift the next groove 164 into feeding alignment, the nails remaining in the feed throat 38a are firmly held by the spring 236 and as each new strip of nails in a succeeding groove is moved into alignment, the leading nail in the new strip is positioned properly with respect to the rearwardmost nail in the feed throat 38a in order to provide a continuity of feeding action.

Referring now to FIGS. and 11, there is shown another embodiment of a magazine assembly constructed in accordance with the present invention. This embodiment is similar to the magazine assembly 40 previously described but the piston bore 198 and the piston 196 are located on the left-hand, rather than the right-hand, side of the feeding plane A-A as viewed in FIG. 10. Accordingly, when the piston 196 is moved downwardly by air pressure in the upper end of the bore on the power stroke of the driver, the rack portion 192 engages the gear causing it to rotate in a clockwise direction (FIG. 11). The slip clutch 176 permits the gear shaft 178 to rotate freely in a clockwise direction Without r0- tation of the forward worm drive shaft 172 which remains stationary. During the downward stroke of the piston 196, the spring 200 is compressed to the position shown in FIG. 1l and, after completion of a power stroke of the driver during movement of the piston 26 upwardly on a return stroke, the exhaust valve assembly 32 is open and at this time the spring 200 then operates to move the piston 196 and rack portion 192 upwardly. As this occurs, the gear 190 is rotated in a counterclockwise direction to turn the shaft 178 which drives the worm 172 through the slip clutch 176 and shaft 174 to feed or advance another fastener forwardly into the drive track. In the prior embodiment a feed stroke of the magazine assembly was accomplished by the force exerted longitudinally on the shaft 174 by the previously compressed spring 188, while in the latter embodiment the force for a feeding stroke is supplied by a compressed return spring 200. In the latter embodiment the shafts 174 to 178 do not move longitudinally as in the former lbecause the feeding stroke of the magazine is simultaneous with the upward or return stroke of the driver.

Referring now to FIG. 12, therein is illustrated another embodiment of a magazine employing additional means for insuring positive lateral Contact between the nails 34 being fed and the worm gear member 172. A permanent magnet 240 is mounted with its attractive poles in close proximity adjacent the feeding plane A-A, to the worm gear 172. As each nef strip of naisl in a groove 164 is shifted into feeding position on the plane A-A, the poles of magnet 240 attract the Shanks of the nails 134 and hold them securely in the grooves between adjacent convolutions in the helical worm 172e, thus insuring positive engagement between the worm and the nail Shanks.

Referring now to FIGS. 13 through 15, therein is illustrated a modified form of worm assembly 272 which is adjustable so that different sized nails or carriers with different spacings between adjacent Shanks can be accommodated in the tool without requiring several worm gears of suitable different pitches. For this purpose, the worm feed assembly 272 includes a forward cylindrical sleeve portion 273 fixed on the shaft 274l and a similar sleeve 275 spaced rearwardly thereof but movable longitudinally on the shaft 274 with respect to the forward sleeve 273. A helical worm member 272a is formed of spring steel and at least a portion of the forwardmost turn or convolution is permanently affixed or secured to the forward sleeve 273. At least a portion of the rearwardmost coil or convolution of the worm is likewise fixedly secured to the longitudinally slidable rear sleeve 275. Intermediate the forwardmost and rearwardmost convolutions thereof, the worm is otherwise freely movable on the respective sleeves so that by movement of the rear sleeve forwardly the worm pitch is reduced and, conversely, by rearward movement of the rearward sleeve the worm pitch is increased. FIG. 13 shows the worm adjusted for a short pitch while FIG. 14 shows the worm adjusted for a larger pitch. In order to maintain the selected pitch desired, the shaft 274 is provided with a rectangular diametrically disposed slot 274e therein for receiving a key member 276 inserted therein. The rearward end portion of the rear sleeve 275 is formed with a first pair of relatively long, longitudinally disposed slots 275e which are formed on diametrically opposite sides thereof and, in addition, includes a pair of shorter longitudinally extending slots 275d radially spaced with respect to the longer slots 275er. In FIG. 13 the worm 272a is set for a minimum pitch and, accordingly, the rearward sleeve 275 is rotated so that the shorter sleeve slots 27511 are aligned with the key member 276 inserted in the shaft slot 274a and the shorter sleeve slots 275b. If it is desired to increase the worm pitch, the sleeve 275 is moved forwardly on the shaft until clear of the slots 275b and is turned until the longer slots 275a are aligned with the key members 276. The sleeve is then released and the worm biases the sleeve rearwardly until the key is seated in the slots 275a. More than two pairs of slots can be furnished to provide for any number of on intermediate worm pitches and other means could be employed to provide for holding the worm at selected different pitches without departing from the scope of the present invention.

Although the present invention has been described with reference to several illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this invention.

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

1. A fastener driving tool comprising a drive track, a driver reciprocally slidable in said track on repetitive cycles for driving said fasteners, and a magazine for feeding successive fasteners into said drive track during each cycle of operation of said driver, said magazine including support means for holding a row of fasteners disposed with their shanks in spaced apart relation, a helical worm laterally offset from said row and having a portion thereof disposed to extend across said row between a pair of adjacent fastener shanks therein, said worm engageable against the shanks of successive fasteners in said row for moving the same along said support means toward said drive track, and rotor means for rotating said Worm during each cycle of operation of said driver.

2. The fastener driving tool of claim 1 including motor means for moving said driver in said cycle including a power stroke and a return stroke, and means operatively interconnecting said motor and rotor means to rotate said worm a selected amount during each cycle of operation of said driver.

3. The fastener driving tool of claim 1 wherein said support means comprises means for holding a plurality of rows of said fasteners and shifting means for moving said support means to align a succeeding row of fasteners with said drive track after the fasteners of a preceding row are exhausted.

4. The fastener driving tool of claim 3 wherein said shifting means is operable to bias fasteners laterally toward said helical worm into position wherein a portion of the worm is disposed between a pair of adjacent fasteners.

5. The fastener driving tool of claim 1 including magnet means for attracting said fasteners toward said worm.

6. The fastener driving tool of claim 1 wherein said worm includes a plurality of convolutions and means for adjusting thel pitch of said worm to accommodate a plurality of spacing between adjacent fasteners.

7. The fastener driving tool of claim 2 wherein said worm is rotated to advance said fasteners toward said drive track during a return stroke of said driver.

8. The fastener driving tool of claim 1 wherein said worm is reciprocal toward and away from said drive track to advance fasteners into driving position during forward travel toward said drive track.

9. The fastener driving tool of claim 8 wherein said worm is movable toward and away from said drive track during rotation thereof by said rotor means.

10. A fastener driving tool comprising a drive track, a driver reciprocally slidable in said track on successive operating cycles, and a magazine for feeding fasteners into said drive track, said magazine including support means for holding a plurality of separate rows of fasteners disposed with their shanks in spaced apart relation, said support means including a plurality of spaced apart slots, each slot adapted to hold a row of fasteners, means for laterally shifting said support means to align each of said slots with said drive track after the fasteners in a Ipreceding slot have been exhausted, and feeding means independent of said support means for advancing fasteners in the slot aligned with said drive track toward said drive track, said feeding means including a helical worm engaging the fasteners in the slot aligned with said drive track to advance the same along said slot towards said drive track, and rotor means for turning said worm a selected amount of rotation during each cycle of operation of said driver.

11. The fastener driving tool of claim 10 wherein said support means includes an opening above said slots permitting the insertion of a row of fasteners in each slot from the top thereof.

12. The fastener driving tool of claim 1 wherein said rotor means includes a rst shaft supporting said worm, a second shaft for driving said first shaft, and one-way clutch means interconnecting said shafts to rotate both shafts in one direction to advance fasteners along said aligned slot and permitting the second shaft to rotate in an opposite direction without rotation of said first shaft.

13. The fastener driving tool of claim 12 wherein said shafts are movable longitudinally during rotation and spring means for biasing said shafts toward said drive track.

14. The fastener driving tool of claim 12 including reciprocal rack means engaging said second shaft and piston means for moving said rack means in one direction to rotate said second shaft.

15. The fastener driving tool of claim 14 including spring means for moving said rack means in an opposite direction.

16. The fastener driving tool of claim 14 including means for supplying pressurized fluid to operate said piston means during a power stroke of said driver.

17. The fastener driving tool of claim 15 wherein said piston means is operable to deflect said spring means during a power stroke of said driver, said spring means being operable to move said rack means to rotate said second shaft to advance fasteners in said aligned slot after completion of a power stroke of said driver.

18. A fastener driving tool comprising a drive track, a driver mounted in said track for movement on successive operating cycles comprising a driving stroke and a return stroke, magazine means for holding a supply of fasteners in at least one row disposed with their shanks in spaced relation, a helical worm having at least a portion thereof extending between an adjacent pair of fastener shanks in said magazine and engaged with at least one of said shanks to advance fasteners in said row into said drive track, and rotor means for rotating said worm in one direction during each operating cycle of said driver.

19. The fastener driving tool of claim 18 including motor means for actuating said rotor means to advance a fastener toward said drive track, each operating cycle of said driver.

20. The fastener driving tool of claim 19 wherein said motor means includes a reciprocating rack drivingly engaging said rotor means, said rack movable to rotate said rotor means in one direction on a power stroke of said driver and in an opposite direction on a return stroke of said driver.

21. The fastener driving tool of claim 20 wherein said motor means includes piston means for moving said rack in one direction and spring means for moving said rack in the opposite direction.

References Cited UNITED STATES PATENTS 1,125,411 1/1915 Szemerey. 3,437,249 4/1969 Baum 227-120 GRANVILLE Y. CUSTER, IR., Primary Examiner U.S. Cl. X.R. 227-

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