US2884637A - Multiple fastener driving machine - Google Patents

Description

May 5, 1959 o. A. WANDEL 2,834,637

MULTIPLE FASTENER DRIVING MACHINE I Filed Aug. 1, 1956 7 Sheets-Sheet}.

' Jun e/4236 040a M nnc/e/ May 5, 1959 o. A. WANDEL 2,884,637

MULTIPLE FASTENER DRIVING MACHINE Filed Aug. 1, 1956 I '7 Sheets-Sheet 5 I 22 2 4 v I 21% @274 FIG. 3

May 5, 1959 o. A. WANDEL 2,384,637

I MULTIPLE FASTENER DRIVING MACHINE Filed Aug. 1, 1956 7 Sheets-Sheet 4 25: a: ./55 32 A57 /99 190 o May 5,' 1959 o. A. WANDEL 2,834,637

MULTIPLE FASTENER DRIVING MACHINE I Filed Aug. 1, 1956 7 Sheets-Sheet 5 "III May 5, .1959 o, A, WANDEL 2,884,637

MULTIPLE FASTENER DRIVING MACHINE FiledAug. 1, 1956 '7 Sheets-Sheet e' FIG. 10

I Jn l/e'nfoz Fla/3 04cm: d. Qlm/l (W F W We May 5, 1959 A. WANDEL 6 MULTIPLE FASTENER muvmc MACHINE Filed Aug. 1 1956 7 Sheet s-Sheet 7 Jaknzaz United States Patent C) MULTIPLE FASTENER DRIVING MACHINE Oscar A. Wandel, Mundelein, Ill., assignor to Fastener Corporation, Chicago, 111., a corporation of Illinois Application August 1, 1956, Serial -No.'601,419

22 Claims. ((11-106) The present invention relates to an automatic multiple fastener driving machine, .and, in particular, to a machine for automatically driving a selected number of fasteners into spaced portions of workpieces supplied to the machine.

Fastening apparatus having a plurality of means for driving or setting various types of fasteners such as nails, staples or the like are commonly used in fabricating operations, and many of these prior devices utilize motor means for moving the fastener driving means and the articles into and out of juxtaposition to effect the fastener setting operations. Frequently the article or workpiece must be manually placed on .andremoved from the machine with its attendant increase in the timerequired for assembly operations. Furthermore, the prior machines generally use manually operated means for controlling the motor means which provide the relative movement of the fastening means and the workpiece and for controlling operation of the fastener drivingmeans.

An object of the present invention is to provide new and improved automatically operated means for driving a plurality of fasteners.

Another object of the present invention is to provide an automatically operated machine for simultaneously driving a plurality of fasteners into a workpiece in a preselected pattern.

Another object is to provide a multiple fastener driving machine including new and improved means whereby a workpiece is supplied to and discharged from a fastener driving position in synchronism with operation of the fastener driving means.

A further object is to provide a multiple fastener driving apparatus including new and improved means for automatically controlling.cyclicoperation of the apparatus.

Another object of the present invention is to provide a multiple fastener driving apparatus including a plurality of independently controllable fastener driving devices which are variably positioned relative to a workpiece to permit different selected patterns of fasteners to be driven into the workpiece.

Still another object is to provide a multiple fastener driving apparatus having means for positioning a workpiece -on the apparatus and for initiating cyclic operation of said apparatus in accordance with this positioning of the workpiece.

A further object of the present invention is to provide a multiple fastener driving apparatus wherein a workpiece is automatically ejected from the apparatus subsequent to a fastener driving operation.

Another object is to provide a fastener driving apparatus having workpiece locating means which are automatically moved between effective and ineffective positions during cyclic operations of the apparatus.

Another object of the present invention is to provide a multiple fastener driving apparatus in which engagement and movement ofstructure associated with fastener 2,884,637 a e ted May 19 driving means by a workpiece initiates operation of the fastener driving means.

Briefly, the above and other objects are realized in accordance with the present invention by providing an automatic multiple fastener driving machine comprising a movable platform assembly on which a workpiece is manually positioned. A control circuit actuated by positioning a workpiece on the platform assembly against a movable stop assembly initiates operation of a platform driving means so that the platform assembly is elevated to move the workpiece into engagement with a plurality of independent fastener driving means which are pivotally mounted on a supporting frame at spaced positions selected in accordance with the locations at which staples are to be driven into the workpiece. Engagement of the workpiece with the fastener driving means operates each of these means to drive a plurality of fasteners, such as staples, into the workpiece at spaced positions. Following the fastener driving operation, the control circuit operates the platform driving means to lower the movable platform assembly to move the workpiece out of engagement with the fastener driving means, and thereafter displaces the movable stop assembly and initiates operation of an ejecting mechanism for displacing the finished workpiece from the platform assembly. The control circuit also returns the ejection mechanism, the movable stop assembly and the movable platform to its normal position in which the platform is capable of receiving a subsequent workpiece.

The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be-understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which:

Fig. 1 is a front elevational view illustrating a multiple fastener driving apparatus embodying the present invention and which is shown with a number of the independent fastener driving means removed;

Fig. 2 is a cross sectional view taken along line 22 in Fig. 1, assuming that the complete driving apparatus is shown therein;

Fig. 3 is a cross sectional view taken along line 3-3 in Fig. 1, again assuming that the complete driving apparatus is shown therein;

Fig. 4 is a cross sectional View taken along line 4-4 in Fig. 1, illustrating a workpiece supporting platform assembly;

Fig. 5 is a fragmentary cross sectional view similar to Fig. 2 but showing the apparatus in a fastener driving position;

Fig. 6 is a fragmentary cross sectional view similar to Fig. 2 but illustrating the apparatus in a workpiece ejecting position;

Fig. 7 is an enlarged side elevational view in partial section illustrating one of the independent fastener driving means forming a part of the apparatus in its normal position;

Fig. 8 is an enlarged side elevational view similar to Fig. 7 showing the fastener driving means in a fastener driving position;

Fig. 9 is a cross sectional view taken along line 99 in Fig. 7 showing a magazine for the fastener driving means in dot-dash outline;

Fig. 10 is an enlarged fragmentary perspective view of one portion of the platform assembly showing both a portion of the movable stop assembly and a switch means for controlling lifting movement of the platform assembly; Fig. 11 is an enlarged fragmentary perspective view of a pneumatic control device for initiating operation of an ejection mechanism; Fig. 12 is an enlarged fragmentary perspective view of a portion of the platform assembly illustrating a switch means for initiating return movement of the e ection mechanism;

Fig. 13 is a plan view of a workpiece, such as a chair seat, illustrating the pattern of fasteners or staples provided by the fastener driving apparatus of the present invention; and

Fig. 14 is a schematic diagram of a control circuit for automatically controlling cyclic operation of the apparatus of the present invention.

Referring now to Figs. 1 and 2 of the drawings, an automatic multiple fastener driving machine 20 embodying the present invention includes a frame 21 on which a platform assembly 22 for supporting a workpiece 23, such as a chair seat, is movably mounted. A drive means 24 connected to the platform assembly 22 is placed in operation by a control circuit 25 (Fig. 14) in response to positioning the workpiece 23 on the platform assembly 22 and against a movable stop assembly 26, whereby the assembly 22 is elevated to move the workpiece 23 into engagement with a resiliently biased clamping means 27 which is movably mounted on the frame 21 and which holds the workpiece 23 on the platform assembly 22 during a fastener driving operation. The elevation of the platform assembly 22 also moves spaced portions of the upper surface of the workpiece 23 into engagement with a plurality of separate fastener driving means, such as pneumatically operated staplers or tackers 28, which are pivotally mounted on the frame 21 at positions spaced above the workpiece 23. The staplers 28 are adjustably secured to the frame 21 to permit them to be disposed in any selected arrangement which will provide a desirable disposition of staples 29 (Fig. 13) or similar fasteners in the workpiece 23. The staplers 28 are operated to drive the staples 29 into the workpiece 23 in response to a predetermined amount of pivotal movement of each of the staplers 28 relative to the frame 21 under the control of continuing upward movement of the platform assembly 22 and the workpiece 23.

The platform assembly 22 and the workpiece 23 are lowered out of engagement with the staplers 28 by operation of the drive means 24 under the control of a lowering control unit 30 which forms a part of the control circuit 25 (Fig. 14) and which is actuated in response to the completion of a predetermined elevation of the workpiece 23. As the platform assembly 22 approaches its lowered normal position, an operator unit 31 in the control circuit 25 is actuated to cause the circuit 25 to displace the movable stop assembly 26 and to operate an ejection mechanism 32 for elevating and discharging the workpiece 23. When the workpiece 23 is discharged from the machine 20, a switch device 33 in the control circuit 25 is actuated to return the ejection mechanism 32 and the stop assembly 26 to their normal positions in which the apparatus 20 is capable of receiving the next workpiece 23 to be stapled. In this manner, the manual disposition of a workpiece on the platform assembly 22 automatically initiates a cycle of operation of the machine 20 in which the workpiece 23 is stapled and discharged under the control of the control circuit 25 without additional manual control intervention of any sort. Further, since the individual staplers 28 are operated by engagement with the workpiece 23, the staplers 28 are actuated to drive fasteners in the workpiece in proper timed sequence without requiring readjustment of the control circuit 25 for workpieces of varying sizes.

The frame 21 on which the various components of the machine 20 are mounted includes a pair of spaced vertically extending side channel irons 35 and 36 which are secured to a pair of angle iron base members 37 and 38 adapted to engage a supporting surface, such as a floor, by a pair of bars 39 and 4'9, respectively. The side channels 35 and 36 are joined together and held in a spaced parallel relationship by a pair of vertically spaced cross members 41 and 42, each of which comprises a pair of outwardly facing channel irons welded at then end portions to the flanged sides of the channel irons 35 and 36. The upper ends of the vertical channels 35 and 36 are secured together in a spaced parallel relationship by a pair of angle irons 43. A generally rectangular panel 44 for supporting some of the components of the control circuit 25 is secured to and spaced outwardly from one side of the frame 21 by a plurality of bolts 44a which engage the vertical channels 35 and 36, a plurality of sleeves 45 being interposed between these channels and the inner surface of the panel 44.

The platform assembly 22 (Figs. 1, 2 and 4), which elevates the workpiece 23 into engagement with the staplers 28 and then lowers the workpiece 23 to its ejecting position under the control of the circuit 25, includes a base plate 50 disposed between and spaced from the channels 35 and 36 of the frame 21, which plate provides a movable support for both the movable stop assembly 26 and the ejecting mechanism 32. The workpiece 23 is supported on the plate 50 by a panel 60 formed of a material such as wood which is secured to and spaced above the upper surface of the plate 50 by a pair of elongated blocks 61. In order to accurately position the workpiece 23 on the panel 60 relative to the width thereof, a pair of guide and positioning assemblies are provided comprising a pair of oppositely located guide blocks 62, each of which is secured to one end of a pair of supporting rods 63. The rods are slidably mounted, by bushings 64, on upstanding legs 65 of a pair of angle irons 66 having horizontal legs 67 mounted on the edges of the base plate 50 directly opposite each other. A compression spring 68 encircling each of the rods 63 is interposed between the outer surface of the block 62 and the inner surface of the leg 65 to resiliently bias the blocks inwardly toward each other, the rods 63 including stop means engaging the legs 65 to limit inward movement of the guide blocks 62. I

A workpiece 23, such as a chair seat whose covering is to be stapled thereto, is manually positioned on the panel 60 to be engaged along its side edges by the blocks 62 by insertion from the right as shown in Fig. 2. Accordingly, the movable stop assembly 26 is provided for limiting inward movement of the workpiece 23 to insure that the workpiece is properly positioned on the panel 60 for subsequent engagement with the staplers 28. During the ejection of the workpiece 23, the movable stop assembly 26 is displaced to an ineffective position under the control of the circuit 25. This assembly includes an arm 76 (Figs. 2 and 10) secured to a rod 77 which is threadedly secured within a supporting plate 78, a stop nut 79 bearing against the upper surface of the plate 78 being provided on the rod 77 to permit the arm 76 to be locked at various heights relative to the plate 78. To limit inward movement of the workpiece 23, the leading edge thereof is adapted to be engaged by the head of a bolt 80 which is threadedly carried by an upper extremity of the arm 76, the bolt 80 being locked in any selected position relative to the arm 76 by a lock nut 81. Since the vertical position of the arm 76 and the horizontal position of the stop bolt 80 are subject to fine adjustment, as set forth above, the movable stop assembly 26 can be accurately adjusted to correctly locate the workpiece 23 on the panel 60.

To movably support the plate 78 on the base plate 50, the plate 78 is carried on a pair of parallel arms 83 pivotally mounted at one end on a pin 84 which is fastened to the base plate 50 adjacent a cutaway portion 50a by a pair of bearing blocks 85 secured to the plate 50 by suitable fastening means 86. A spacer member 87 is also mounted on the shaft 84 between the arms 83 to maintain them in a spaced relationship. The plate 78 is adjustably positioned on the upper edges of the arms 83 by means Of a pair of spaced bolts 88 (Figs.

and 6) which extend downwardly through the plate 78 and between the arms '83 to be threadedly received within a locking plate 89 engaging the lower edges of the arms 83. By loosening the bolts 88, and, accordingly, the clamping engagement of the plates 78 and 89 with the arms 83, the arm 76 and the bolt 80 carried thereon can be adjusted to a variety of widely spaced positions relative to the workpiece supporting panel 60, thereby to permit the machine to be used with workpieces of different sizes.

To provide means for initiating a cycle of operation of the machine 20 when a workpiece 23 .is correctly posi tioned on the panel 68, as determined by movement of the leading edge of the workpiece 23 into engagement with the bolt 80, a microswitch 95 is provided in the assembly 26. The switch 95 is mounted on a plate 96 which is secured to the plate 78 in substantial transverse alignment with the arm 76 so that, when a workpiece 23 is moved into engagement with the bolt 80, it also engages a roller 97 rotatably mounted between bifurcated and offset ends 98 .of a switch operator spring arm 99 which is mounted on the body of the switch 95. Movement of the arm 99 toward the body .of the switch 95 due to engagement by the workpiece 23 actuates this switch to initiate a cycle of operation of the control circuit during which the workpiece 23 is stapled and ejected. To insure operation of the switch 95, the bolt is adjusted relative to the arm 76, as described above, to permit enough movement of the workpiece 23 toward the stop arm 76 before engaging the head of the bolt 80 to provide the required deflection of the arm 99. Further, since the switch and the arm 76 are secured in fixed positions relative to each other, the position of the movable stop assembly 26 can be adjusted by shifting the plate 78 relative to the arms 83 toaccommodate different sizes of workpieces without requiring a readjustment of the bolt 80.

To normally support the movable stop assembly 26 including the switch 95 in the position shown in Fig. 2 and to provide means for displacing these components during an ejecting operation, a pneumatically operated motor of the piston and cylinder type is provided. The outer ends of the arms 83 are pivotally connected to an interposed link 111 by a pivot pin 113, and the outer end of a piston rod 114, forming a part of the motor 110, is pivotally connected to a bifurcated end portion 112 of the link 111 by a pivot pin 109. The other end of the rod 114 is connected to a piston 115 (Fig. 14) disposed within a cylinder 116 closed at its ends by a pair of end castings 117 and 118, all of which form a part of the motor 110. The lower end of the motor 118 is pivotally mounted on the base plate 50 by a pivot pin 119 which passes through the casting 118 and which is supported at its ends by a pair of arms 120 secured to the base plate 50.

To hold the movable stop assembly 26 in the effective position shown in Fig. 2, compressed air is normally supplied to a lower chamber 121 (Fig. 14) of the cylinder 116 through a conduit 122 and a suitable passageway and port in the end casting 118. The compressed air forces the piston 115 to a position adjacent the end casting 117 to hold the arms 83 in a substantially horizontal position in which the stop 80 and the switch 95 are engaged by the end of an inserted workpiece 23. To displace these components during the ejection of the workpiece, the conduit 122 is vented to atmosphere by the control circuit 25 and compressed air is supplied through a conduit 123 and suitable passageways and ports in the end casting 117 to an upper chamber 124 (Fig. 14) of the cylinder 116. This .air withdraws the piston rod 114 into the cylinder 116 so that the arms 83 are pivoted in a counterclockwise direction about the pin 84 to lower the movable stop assembly 26 to the position shown in Fig. 6, the motor 11.0 concurrently pivoting in a counterclockwise direction about the pin 119 to move to the position shown in Fig. 6. The control circuit 25 returns the movable stop assembly 26 to the normal position shown in Fig. 2 by venting the conduit 123 to atmosphere and by supplying compressed air to the conduit 122 following the ejection of the workpiece 23.

As set forth above, the platform assembly 22 is moved vertically relative to the frame 21 to move the workpiece 23 into engagement with the staplers 28. Accordingly, the base plate 50 on which the platform assembly 22, the movable stop assembly 26 and the ejecting mechanism 32 are mounted is secured to the drive means 24 (Fig. 2,). The drive means 24 comprises a pneumatically operated motor 129 including a cylinder 130 which is closed at its ends by a pair of castings 131 and 132, and within which is slidably disposed a piston 133 (Fig. 14) connected to a piston rod 134. An upper end of the piston rod 134 extends through a centrally disposed opening in the plate 50 and is secured thereto by the collar 135 mounted on the rod 134, which engages the lower surface of the plate 50, and by a nut 136 threaded on the rod 134 to bear against the upper surface of the plate 58. The drive means 24 provides the sole support for the base plate 50 and the components, such as the platform assembly 22 and the ejection mechanism 32, mounted thereon and is secured to the frame 21 by fastening the end casting 132 to a plate 137 which extends between and is secured to the upper legs of the spaced channels 42.

In the normal position of the machine 20, the control circuit 25 vents a lower chamber 138 (Fig. 14) of the motor 129 through a conduit 139 and suitable passageways in the casting 132 and supplies compressed air to an upper chamber 140 (Fig. 14) of the cylinder 130 through a conduit 141 and suitable passageways in the casting 131, thereby to hold the piston 133 (Fig. 14) adjacent the end casting 132 with the piston rod 134 and the base plate 50 in the normal position shown in Fig. 2. To elevate the base plate 50 to move the workpiece 23 into engagement with the staplers 28, the control circuit 25 vents the upper chamber 140 of the cylinder 130 to atmosphere through the conduit 141 and supplies compressed air to the lower chamber 138 of the cylinder 130 through the conduit 139, thereby elevating the base plate 50 and the components carried thereon to the position shown in Fig. 5. The base plate 50 is again lowered following the completion of the fastening operation under the control of the circuit 25 by venting the lower chamber 138 of the cylinder 130 through the conduit 141 and by supplying compressed air to the upper chamber 140 thereof through the conduit 141.

To provide means for guiding vertical movement of the plate 50, two guide roller assemblies 144 are mounted adjacent the side edges of the plate 50 which engage a pair of track elements 145 secured to the inner walls of the side channel irons 39 and 40. Each of the guide roller assemblies 144 includes a supporting plate 146 secured to the leg 65 of the angle iron 66 and bifurcated at each end to receive a guide roller 147 which is rotatably mounted on a pin 143 and which engages a top wall 145a (Fig. 2) of the track 145. Each of the guide roller assemblies 144 is held against lateral displacement relative to the track 145 by two pairs of vertically spaced rollers 148 and 149 which engage opposite side walls 145]) of the track member 145. Hence, the platform assembly 22 and its associated components are maintained in a substantially stable and horizontal position during vertical movement bythe guide roller assemblies 144 and the tracks 145.

The operation of the drive means 24 under the control of the circuit 25 raises the platform assembly 22 to move the workpiece 23 into engagement with the clamping means .27, thereby to hold the workpiece 23 in a fixed position on the elevated panel 60 during the fastening operation. The clamping means 27 comprises a circular plate 162 having a boss 162a secured to a reciprocable rod 163 which is slidably mounted in a pair of bearings 164 and 165 and which is provided with a pair of locking nuts 166 at its upper end for engaging the upper surface of the bearing 165 to hold the plate in an adjusted position relative to the frame 21. These bearings are secured to a pair of plates 167 and 168 which are carried on the channel irons 43 and include apertures 167a and 168a for accommodating the rod 163. To bias the plate 162 into engagement with the workpiece 23, a coil spring 169 is interposed between the boss 162a and the lower end of the bearing 164. To provide means for guiding movement of the plate 162, a pair of guide rods 170 are secured to the plate 162 by two pairs of nuts 171 carried thereon and at their upper ends are slidably received within a pair of openings 172 (Fig. 3) formed in the lower plate 167. The normal position of the plate 162 may be varied to compensate for workpieces 23 of varying height by adjusting the lock nuts 166.

When the control circuit 25 supplies compressed air to the drive means 24, the platform assembly 22 together with the components carried thereby and the workpiece 23 mounted on the panel 60 are elevated so that the upper surface of the workpiece 23 is moved into engagement with the lower surface of the plate 162. Continuing upward movement of the platform assembly 22 lifts the plate 162 and the rod 163 against the force of the coil spring 169 so as to resiliently clamp the workpiece in its predetermined and aligned position on the panel 60. Concurrently with moving into clamping engagement with the plate 162, the upper surface of the workpiece is moved into engagement with the plurality of individual staplers or tackers 28, thereby to initiate the fastener driving operation.

In general, the tackers or staplers 28 are adjustably and pivotally mounted on the frame 21 in such an arrangement as to provide the desired pattern of fasteners in the workpiece 23. Each of the staplers 28 is individually operated by compressed air from a common source in response to a predetermined pivotal movement of the staplers caused by engagement with the workpiece 23 thereby to actuate a single-stroke fastener driver which drives the fastener into the workpiece 23. The tackers 28 remain in their operated state so that only a single fastener is driven until such time as the workpiece 23 is moved out of engagement therewith, thereby to condition the staplers 28 for driving fasteners into the next workpiece supplied to the machine 20.

Each of the individual tackers or staplers 28 may be of the many types well known in the art but preferably is of one of the types shown in the copending application of Oscar A. Wandel, Serial No. 527,697, filed August 11, 1955, or the copending application of Oscar A. Wandel and Richard H. Doyle, Serial No. 546,377, filed November 14, 1955, which copending applications are assigned to the same assignee as the present application. As shown therein and as illustrated in Figs. 7 and 8, the tacker 28 comprises a housing 180 receiving, at one end, a drive cylinder 181 closed by a cap 182 and having a rearwardly extending hollow handle 183 providing a compressed air reservoir Which is supplied with compressed air by a hose 184 and a detachable hose coupling 185. The hoses 184 are connected to a surge tank 301 mounted on the crosspiece 43 of the frame 21. Operation of the tacker 28 is controlled by a valve having an operating member 186 which controls the admission of compressed air from the reservoir into the cylinder 181 to drive a piston (not shown) slidably mounted therein downwardly so that a fastener, such as the staple 29, is driven outwardly through a drive track (not shown) in a nosepiece 187 by a driver blade (not shown) actuated by the piston. The staples or fasteners 29 are supplied to the drive track by a magazine construction 188 which may be of either the type shown in the above-identified copending Wandel application or of one of the types shown in the copending applications of Oscar A. Wandel, Serial No. 546,354, filed November 14, 1955, and Serial No. 574,870, filed March 29, 1956, which copending applications are assigned to the same assignee as the present application. The magazine construction 188 is secured to the nosepiece 187 and to the handle 183 by a bracket 189.

In order to pivotally support each of the staplers 28 on the frame 21 in accordance with a feature of the present invention, there is provided snap lock means 190' carried by the magazine assembly 188 for pivotally and detachably engaging a pin 191 carried by an inclined arm 192 which is secured by a plurality of fasteners 193 to a horizontal bar 194 adjustably secured to the lower surface of the plate 167. The snap lock means 190 includes a bracket 196 secured to the lower surface of the magazine assembly 188 by a plurality of fasteners 197. The lower edges of the flanges of the bracket 196 are provided with a pair of substantially half round recesses 198 for receiving the pin 191. A reverse bend leaf spring 199 secured at one end to the lower wall of the magazine 188 by a plurality of fasteners 200 includes a rounded portion 199a in its free end for receiving the pin 191 to resiliently bias the pin 191 into seating engagement with the recesses 198 in the bracket 196 to pivotally and removably mount the stapler 28 on the arm 192. A pair of washers 201 mounted on the pin 191 aid in locating the stapler 28 on the pin 191 and prevent the stapler 28 from being inadvertently removed from the machine 20 by lateral displacement along the axis of the pin 191. To bias the tacker 28 to the normal position shown in Fig. 7, a leaf spring 203 secured to a bracket 204 mounted on the bar 194 by a plurality of screws 205 is adapted to slidably engage the cap 182 to deflect the stapler 28 about the axis of the pin 191 so that the lower surface of the housing of the magazine 188 engages a stop pin 206 which limits clockwise pivotal movement (Fig. 7). The leaf spring 203, when the platform assembly 22 and the workpiece 23 are elevated to move the tacker 28 out of engagement with the stop pin 202 (Fig. 8), also resiliently biases the nosepiece 187 of the tacker 28 into engagement with the workpiece 23 and resists upward movement of the tacker 28 due to forces of reaction when the tackers are operated, thereby to insure that the fasteners 29 are fully driven into the workpiece.

The machine 20 is adapted to staple the workpieces 23 with selected staple patterns and, to this end, the staplers or tackers 28 are adjustably positioned on the frame 21. More specifically, each of the bars 194 on which the tackers 28 are mounted is provided with a longitudinal slot 210 to provide for radial adjustment of the tackers 28 relative to the center of the panel 60, and the plate 167 is provided with a pair of parallel slots 211 (Fig. 3) for each of the bars 194. To secure each of the tacker supporting bars 194 in a selected position on the plate 167, a pair of bolts 212 extend through apertures 213 in a clamping plate 214 disposed above the upper surface of the plate and through aligned portions of the slots 210 and 211 to be threadedly received within openings 215 formed in a clamping plate 216 disposed adjacent the lower surface of the bar 194. By suitably adjusting the peripheral position of the bolts 212 relative to the plate 167 and by adjusting the radial positions of the bars 194 relative to these bolts, the bolts 212 can be tightened to clamp the bars 194 on the plate 167 with the tacker 28 carried thereby disposed to provide a staple or fastener pattern corresponding to that required for the particular workpiece 23.

As indicated above, the fastener driving means 28 are individually operated in response to a selected pivotal movement of each of the tackers 28 as the workpiece 23 is elevated into engagement with the nosepieces 187, and, accordingly, the machine 20' includes a control mechanism individual to each of the tackers 28 for actuating its associated valve operating element 186 following a 19 predetermined counterclockwise movement of the 'tacker about the pin 191. This mechanism includes a generally L-shaped operating lever 220 disposed between the arm 192 and a plate 221 secured to the bar 194 and pivotally mounted thereon by a pin 222. A coilspring 223 seated in suitable recesses 224 and 225 in the bar 194 and the lever 220, respectively, biases the lever 220 in a clockwise direction about the pin 222 so that a roller 226 rotatably mounted between the bifurcated ends of the lever 220 bya shaft 226a is positioned immediately above the handle 183 of the tacker 28 adjacent the valve opcrating element 186 in the normal position shown in Fig. 7. This normal position is determined by a threaded stud 227 carried on a projecting portion 220a of the lever 220, a lock nut 228 being provided to hold the stud 227 in any adjusted position relative to the lever 220. By adjusting the length of the stud 227 which projects outwardlyfrom the portion 220a of the lever 220 to engage the end of the bar 194, the clockwise movement of the lever 220 due to the spring 223 and, accordingly, the position of the roller 226 relative to the valve operator 186 is adjusted. To guide relative movement between the lever 220 and the tacker 28, a U-shaped guide 229 is mounted on the lever 220 by a fastener 230 with the arms thereof disposed contiguously to but slightly spaced apart from the sides of the handle 183 of the stapler 28.

As described above, the workpiece 23 engages the nosepieces 187 of the tackers 28 to pivot them about the axis of the pin 191 against the force of the springs 203. Continuous upward movement of the platform assembly 22 and the workpiece 23 during which the workpiece 23 is clamped on the panel 60 by the means 27, as described above, pivots the tackers 28 so that the rollers 226 engage the upper surfaces of the handles 183 and then depress 'and ride over the valve operating members 186 (Fig. 8) to individually operate the tackers 28 to drive staples into the workpiece 23. During this movement, the counterclockwise rotation of the tacker 28, shown in Fig. 8 for instance, causes a similar counterclockwise movement of the lever 220 against the action of the spring 223. When the platform assembly 22 and the fastened workpiece 23 are lowered under the control of the circuit 25, the levers 220 are rotated to their normal positions by the springs 223 to release the valve operating elements 186 so that the tackers are restored to a normal condition and are pivoted to their normal positions engaging the stop pins 206.

The platform assembly 22 and the workpiece 23 are lowered by operation of the drive means 24 under the control of the control circuit 25 in response to operation of the lowering control unit 30 when the platform assembly 22 has been raised to a predetermined elevation. The unit 30 comprises an exhaust valve 234 (Figs. 1 and 14) having a reciprocable valve stem 235, which valve is supported on and between the channels 41 by a plate 236 with the stem 235 in vertical alignment with the head of a bolt 237 which is threadedly and adjustably mounted within the end of one of the guide rods 170. By varying the position of the bolt 237 relative to the rod 170, the predetermined elevation of the platform assembly 22 at which the stem 235 is engaged and operated can be adjusted in accordance with the various thicknesses of the workpieces 23.

When the platform assembly '22 and the workpiece 23 have been elevated sufficiently to operate the tackers 28, the clamping plate 162 which moves upwardly with the workpiece 23 raises the guide rod 170 to move the head of the bolt 237 to engage and actuate the valve stem 235, thereby causing the control circuit 25 to vent the lower chamber 138 of the motor 129 of the drive means 24 through the conduit 139 and to supply compressed air to the upper chamber 140 of the motor 129 through the conduit 141, thereby lowering the piston 133 and the platform assembly 22. This movement disengages the staplers '28 and the clamping means 27 from the workpiece 23, and, as shown in Figs. 7 and 8, the stapler 28 shown therein is rotated in a clockwise direction by the spring 203 to be returned to its normal position in which the magazine assembly 188 engages the stud 206. Downward movement of the platform assembly 22 continues until the drive means 24 is returned to its normal position, as shown in Figs. 1 and 2, in which the piston 133 is disposed and held adjacent the lower end casting 132.

When the platform assembly 22 approaches its lowered normal position, the ejection operator or control unit 31 is actuated to cause the control circuit 25 to displace or lower the movable stop assembly 26 and to operate the ejection mechanism 32 to discharge the fastened workpiece 23 from the machine 20. More specifically, the operator unit 31 (Figs. 1 and 11) comprises a bracket 249 which is secured to one of a pair of depending arms 250 carried on the plate 50 by a plurality of fasteners 251. The bracket 249 includes a projecting portion 249a to which is pivotally secured, by a pin 252, an arm 253 extending outwardly from the projecting portion 249a. Disposed at the free end of the arm 253 is a roller 254 which is rotatably mounted thereon by a pin 255. A spring 256 having one end secured to the bracket 249 passes around the pin 252 and engages, at its other end, the pin 255 to bias the arm 253 to the normal horizontal position (Fig. l) in which the roller 254 engages the projecting portion 249a of the bracket 249 to limit counterclockwise pivotal movement of the arm 253, as shown in Figs. 1 and 11.

The operator or control unit 31 also includes a valve 257 mounted on the panel 44 and forming a part of the control circuit 25. The valve 257 is actuated by an operator lever 258 which is pivotally mounted on the casing of the valve 257 by a pin 259 and which is slidably received within a bifurcated guide portion 260 of the casing of the valve 257 intermediate its ends. An intermediate portion of the lever 258 is clamped adjacent a valve operating stem 261, and a roller 262, disposed in the vertical path of movement of the roller 254, is rotatably mounted on the free end of the lever 258 by a pivot pin 263.

When the platform assembly 22 is elevated, the rollers 254 and 262 move into engagement but the resistance of the valve stem 261 to displacement exceeds the force applied by the spring 256 so that the arm 253 and the roller 254 carried thereon are pivoted to the clockwise deflected portion shown in Fig. 11 and the valve 257 is not operated. As the roller 254 passes beyond the roller 262 during upward movement, the spring 256 returns the arm 253 to the normal position shown in Fig. 1. However, when the platform assembly 22 is lowered following the fastening operation, the rollers 254 and 262 again move into engagement, and, since the arm 253 is held against counterclockwise rotation (Fig. 11) by engagement with the bracket 249, the lever 258- is pivoted in a clockwise direction to the position shown in dot and dash outline in Fig. 11, thereby to operate the valve 257. When the rollers 254 and 262 move out of engagement, the lever 258 is restored to its normal position by the spring biased valve stem 261 and the valve 257 is restored to its normal position.

Operation of the valve 257 energizes the control circuit 25 to cause simultaneous operation of both the movable stop assembly 26 and the ejection mechanism 32 whereby the assembly 26 and mechanism 32 are moved from the positions illustrated in Fig. 5 to the positions illustrated in Fig. 6 so as to discharge the tacked workpiece 23 from the machine 20. The operation of the valve 257 causes the above-described operation of the movable stop assembly 26 so that it is retracted to the position shown in Fig. 6 to permit the discharge of the workpiece 23 under the control of the ejection mechanism 32.

The ejecting mechanism 32 includes a pair of parallel rails 264 which are pivotally secured by a pair of pins 265 to the outer ends of a pair of projecting arms 266 secured at their other ends to the upper surface of the plate 50. A plurality of spaced rollers 267 are rotatably mounted on each of the rails 264 (Fig. 4) by a plurality of pins 268, but, when the rails 264 are in their normal position (Figs. 1 and 5), the rollers 267 do not engage the lower surface of the workpiece 23 which is supported on the panel 60.

To provide a means for operating the ejection mechanism 32, there is provided a pneumatically operable ntor 269 comprising a cylinder 270 which is closed at its ends by a pair of castings 271 and 272 and Within which are slidably disposed a piston 273 (Fig. 14) and an associated piston rod'274. The motor 269 is pivotally mounted on the platform assembly 22 by a pivot pin 27 which passes through the lower casting 272 and is supported by the arms 250. The upper free end of the piston rod 274 extends upwardly through the casting 271 and through an aperture 276 in the plate 50 to terminate in an eyelet 274a pivotally mounted on a rod 277 connecting the free ends of the rails 264. A pair of sleeves 278 (Fig. 4) secured to the rod 277 adjacent the eyelet 274a limit axial movement of the piston rod 274 along the rod 277.

In the normal position of the ejection mechanism 32, the control circuit 25 vents a lower chamber 279 (Fig. 14) of the cylinder 270 through the line 123 and suitable passageways in the end casting 272 and admits compressed air to an upper chamber 280 (Fig. 14) of the cylinder 270 through the line 122 and suitable passageway in the casting 271, thereby to hold the piston 273 adjacent to the lower casting 272 with the piston rod 274 and the ejection means 32 in the normal position shown in Fig. 2.

In response to the actuation of the valve 257, as described above, the control circuit 25 vents the upper chamber 280 through the line 122 and supplies compressed air to the lower chamber 279 through the line 123, thereby elevating the piston 273 to a position adjacent to the casting 271 and, in doing so, slightly pivoting the cylinder 270 in a counterclockwise direction about the pin 275 (Fig. 6). This movement of the piston 273 and of the piston rod 274 pivots the rails 264 in a counterclockwise direction (Fig. 6) about the pin 265 so that the rollers 267 are moved upwardly into engagement with the lower surface of the workpiece 23. The workpiece 23 is then elevated to move it out of engagement with the guide blocks 62 so that it slides downwardly along the inclined rails 264 in engagement with the rollers 267 and the discharged workpiece 23 can be ejected into a storage bin (not shown) or onto a conveyor belt (not shown) for transportation to another fabricating station.

In order to return the machine 20 to its normal position and, in particular, to return both the movable stop assembly 26 and the ejection mechanism 32 to their normal positions, there is provided the control switch device 33 which forms a part of the control circuit 25. The device 33 (Figs, 4 and 12) comprises a microswitch 290 mounted on a bracket 291 which is mounted at the outer end of one of the arms 266. The microswitch 290 includes a spring switch operator arm 292 having a roller 293 rotatably mounted between the bifurcated ends of the arm 292, the roller 293 being positioned in the path of movement of the discharged workpiece 23 so that the passage of a workpiece thereover depresses the roller 293 to operate the switch, thereby actuating the control circuit 25. The control circuit 25, in response to the operation of the switch 290, vents the upper chamber 124 of the cylinder 116 and the lower chamber 279 of the cylinder 270 and supplies the lower chamber 121 of the cylinder 116 and the upper chamber 280 of the cylinder 270 with compressed air, whereby both the movable stop assembly 26 and the ejection mechanism 32 are returned to their normal positions illustrated in Fig. 2, and the machine 20 is prepared to, receive another workpiece 23.

Referring now to the control circuit 25 illustrated in Fig. 14 of the drawings, the control circuit components are shown in the positions corresponding to the normal position of the machine 20 prior to the initiation of a cycle of operation thereof. The pneumatic fluid for the control circuit 25 is supplied from a line 300 connected to the surge tank 301 through a conventional water trap 302, a pressure regulator 303, and an oil administrator 304. As shown, the surge tank 301 is in fluid communication with the upper chamber 140 of the cylinder 130, the lower chamber 121 of the cylinder 116, and the upper chamber 280 of the cylinder 270 to maintain the drive means 24, the movable stop assembly 26, and the ejection mechanism 32 in their normal positions.

More particularly, the upper chamber 140 of the motor 129 associated with the platform assembly 22 is normally supplied with compressed air from the surge tank 301 through a conduit 305, a central chamber 306 of a spool type control valve 307, another conduit 308, a throttle control valve 309, and the conduit 141. The lower chamber 138 of this motor is vented to atmosphere through the conduit 139, a throttle valve 310, another conduit 311, a lower chamber 312 of the spool valve 307 and a venting port 313 defined in the wall of the valve 307.

The lower chamber 121 of the motor associated with the movable stop assembly 26 and the upper chamber 280 of the motor 269 associated with the ejection mechanism 32 are supplied with compressed air from the surge tank 301 through a conduit 314, a central chamber 315 of a second spool type control valve 316, a conduit 317, a throttle control valve 318, and the conduit 122. In addition, the upper chamber 124 of the motor 110 and the lower chamber 279 of the motor 269 are vented to atmosphere through the conduit 123, a throttle control valve 319, another conduit 320, a lower chamber 321 of the spool valve 316, and a venting port 322 defined in the wall of the valve 316.

In operation, placing the workpiece 23 upon the platform assembly 22 in abutting engagement with the microswitch 95 initiates the cyclic operation of the machine 20 by closing the microswitch 95 to energize a solenoid valve 325 which admits compressed air to the upper end of the spool valve 307 through a conduit 326, a pressure cutout unit 327, and another conduit 328, the pressure cutout unit 327 providing a static compressed air pressure in the conduit 328 but thereafter preventing communication between the conduits 326 and 328. The compressed air admitted to the upper end of the valve 307 displaces a pair of valve spools 330 and 331 connected by a rod 332 downwardly against the force of a return spring 333. In this operated position, a passageway 335 in the spool 330 places the conduit 308 in communication with the atmosphere through a venting port 336 to exhaust the upper chamber of the cylinder 130, and the spool 331 blocks off communication between the chamber 306 and the conduit 308. Further, in its operated position, the spool 331 of the valve 307 closes off communication between the conduit 311 and the venting port 313 and places this conduit in communication with the chamber 306 in the valve 307 so that compressed air is supplied to the lower chamber 138 of the cylinder 130, thereby to elevate the platform assembly 22 to place the workpiece 23 in engagement with both the clamping means 27 and the individual tackers 28. Adjustment of the throttle valves 309 and 310, of course, controls the velocity of vertical movement of the piston 133 and piston rod 134 of the motor 129. As described above, this upward movement clamps the workpiece 23 against the panel 60 and pivots the tackers 28 so that they are individually operated to drive fasteners 29 into the workpiece.

This upward movement of the platform assembly 22 under the control of the drive means 24 continues until the head of the bolt 237 engages the valve stem 235 of the valve 234 to operate this valve. The valve 234 vents the static pressure compressed air in the conduit 328 and the upper end of the valve 307 to atmosphere through a conduit 337 with the result that the coil spring 333 urges the spools 330 and 33.1 upwardly to the position shown in Fig. 14. In response to this displacement of the spools, compressed air is admitted into the upper chamber 141) of the cylinder 13a) and the lower chamber 138 is vented to atmosphere, as described above, to return the piston 133 and the piston rod 134 to their normal position and, accordingly, to lower the platform assembly 22. In lowering the assembly 22, the valve 234 is released to close off the exhaust connection to the conduit 328 but the spool valve 307 is not thereby operated due to the fact that the unit 327 has previously closed off communication between the conduit 328 and the compressed air in the conduit 326.

As the platform assembly approaches its lowered normal position, the lever 258 is pivoted by the arm 253 and the roller 254 to momentarily actuate the valve stem 261 of the valve 257 so that compressed air from the conduit 314 is momentarily supplied to the upper end of the spool valve 316 through a conduit 341), the valve 257, a pressure cutout unit 341, and a conduit 342, the unit 341 providing a static air pressure in the conduit 342. The compressed air in the conduit 342 forces a pair of valve spools 351) and 3551 joined by a rod 332 downwardly against a return spring 353 to a valve operated position in which the spool 350 closes off communication between the conduits 314 and 317 and the conduit 317 is vented to atmosphere through a passageway 354 in the spool 350 and a port 355 in the spool valve 316. Venting the conduit 317 to atmosphere exhausts the upper chamber 280 of the cylinder 271) (ejection motor 269) and the lower chamber 121 of the cylinder 116 (movable stop motor 110). In the operated position of the spool valve 316, the spool 351 closes ofi communication between the conduit 320 and the venting port 322 and supplies the conduit 320 and therefore the lower chamber 279 of the cylinder 270 and the upper chamber 124 of the cylinder 116 with compressed air from the conduit 314 and the central chamber 315 of the spool valve 316.

The admission of air to the chamber 124 retracts the piston rod 114 to pivot the movable stop assembly 26 out of alignment with the workpiece 23 (Fig. 6), and the admission of air to the lower chamber 279 in the cylinder 270 elevates the piston 273 and the piston rod 274 to pivot the rails 264 upwardly so that the rollers 267 engage the lower surface of the workpiece 23. The workpiece slides down the inclined rails 264 in rolling contact with the rollers 267, and, in being discharged from the ends of the rails 264, actuates the microswitch 2% comprising the control unit 33.

The operation of the microswitch 290 returns the ejection mechanism 32 and the movable stop assembly 26 to their normal position. More particularly, operation of the switch 290 energizes a solenoid operated exhaust valve 361) to vent the static pressure in the conduit 342 via a conduit 361 and the valve 360 to atmosphere so that the spring 353 returns the valve spools 350 and 351 to the position shown in Fig. 14 in which the upper chamber 124 of the cylinder 116 (motor 110) and lower chamber 279 of the cylinder 270 (motor 269) are vented to the atmosphere by the conduit 123, the throttle valve 319, the conduit 320, the lower chamber 321 of the spool valve 316 and the port 322. Simultaneously therewith, the spool 350 admits compressed air to the lower chamber 121 of the motor 110 and the upper chamber 280 of the motor 269 through the conduit 317, the throttle valve 318, and the conduit 122 to extend the piston rod 114 so that the movable stop assembly 26 is returned to its normal effective position and to retract the piston rod 274 so that the rails 264 are returned to their normal horizontal position adjacent the base plate 50. By adjustment of the throttle valves 318 and 319 the velocity of vertical movement of the pistons 115' and '14 273 and piston rods 114 and 274 and the speed of operation of the assembly 26 and the ejection mechanism 32 is varied. The control circuit '25 and the machine 219 are now conditioned for another cycle of operation similar to that described above in which fasteners are driven into the workpiece 23.

From the foregoing description it is apparent that there has been provided, in accordance with the present invention, an automatic multiple fastener driving machine embodying a movable platform assembly adapted to carry a workpiece. in response to manual positioning of the workpiece against a movable stop assembly on the platform assembly, a control circuit is actuated to initiate operation of the platform driving means, whereby the platform assembly is elevated to move the workpiece into engagement with a plurality of independent fastener driving means which are detachably and pivotally mounted on a supporting frame to provide a selected fastener pattern and to permit facile and quick interchangeability of the driving means. In response to the movement of the workpiece and the fastener driving means, the driving means are operated to drive a plurality of fasteners into the workpiece following which the control circuit lowers the platform assembly, displaces the movable stop assembly, and actuates a mechanism for ejecting the fabricated workpiece. In response to the completion of the ejection of the workpiece, the control circuit returns both the movable stop assembly and the ejection mechanism to their normal positions in which the machine is conditioned for another cycle of operation.

While a particular embodiment of the invention has been shown, it will be understood, of course, that the invention is not limited thereto, since many modifications may be made, and it is, therefore, contemplated by the appended claims to cover all such modifications as fall within the true spirit and scope of the invention.

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

1. An automatic multiple fastener driving machine comprising a frame, a platform assembly movably mounted on said frame and adapted to receive a workpiece thereon, a plurality of fastener driving means, adjustable means for pivotally mounting said fastener driving means in a spaced relation on said frame, motor means carried on said frame for moving said workpiece and said fastener driving means into engagement to pivot said fastener driving means relative to said frame, and means carried on said frame and responsive to said pivotal movement of said driving means for operating said driving means to drive fasteners into said workpiece.

2. In a fastener driving machine, a plurality of fastener driving means, movable means for supporting a workpiece thereon, means for positioning said workpiece on said supporting means, means for effecting movement of said workpiece relative to said fastener driving means between spaced workpiece discharging and workpiece fastening positions, means for ejecting the workpiece from the machine, motor means for displacing said positioning means to permit ejection of said workpiece, and means for controlling the operation of said ejection means and said motor means in response to movement of said workpiece to said workpiece discharging position.

3. A fastener driving apparatus comprising a frame, means for supporting a workpiece movably mounted on said frame, pneumatically operated fastener driving means movably mounted on said frame, valve means for operating said fastener driving means, said supporting means and driving means being normally spaced apart, motor means for effecting relative movement between said supporting means and said driving means in a first direction to place said driving means and said workpiece in engagement so that said movably mounted driving means are deflected and in a second direction to return said supporting means and driving means to said normally spaced positions, means responsive to said deflection of said driving means during relative movement in said first direction for operating said valve means so that said driving means drive fasteners into said workpiece, and control means positioned adjacent the path of said relative movement and responsive to said relative movement of said supporting means and said driving means in said first direction for operating the motor means to return said supporting means and driving means to said normally spaced positions.

4. A fastener driving machine comprising means for supporting a workpiece, movable locating means for positioning a workpiece on said supporting means, motor means for shifting the portion of said locating means, ejecting means adjacent said supporting means for displacing said workpiece from said supporting means, said ejecting means displacing said workpiece by moving said workpiece along a path normally intercepted by said locating means, and control means for operating said motor means to displace said movable locating means and for operating said ejecting means.

5. A fastener driving machine comprising supporting means for receiving a workpiece movable between spaced positions, movable means for positioning said workpiece on said supporting means, means for ejecting said workpiece from said supporting means, a first fluid motor having a first movable element and a second fluid motor having a second movable element connected to said positioning means and said ejecting means, respectively, first control means including first valve means for admitting fluid under pressure to said first and second motors in response to movement of said supporting means into one of said spaced positions for simultaneously displacing said positioning means and actuating said ejection means, and second control means including second valve means for controlling the supplying of fluid under pressure to said first and second motors to return the said positioning means and ejection means to their normal positions.

6. A fastener driving machine comprising fastener driving means, means for supporting a workpiece, means for moving said workpiece supporting means and said fastener driving means relative to each other to place said workpiece adjacent said driving means, control means disposed adjacent and movable relative to said supporting means for controlling operation of said moving means, and means including motor means for moving said control means to effective and ineffective positions relative to said supporting means in accordance with the relative movement between said workpiece supporting means and said fastener driving means.

7. The machine defined by claim 6 in which the control means includes switch means operable in response to positioning a workpiece on said supporting means when the control means is in said effective position.

8. A fastener driving machine comprising a frame, supporting means for receiving a workpiece and mounted on the frame for movement between a workpiece receiving position and a fastener driving position, stop means movably mounted on the supporting means for movement therewith, motor means carried on the supporting means and connected to the stop meann, and control means responsive to movement of said supporting means from said fastener driving position to said workpiece receiving position for operating said motor means to move said stop means relative to said supporting means.

9. The machine defined by claim 8 in which the motor means comprises a cylinder and a piston connected to said stop means and in which the control means includes a valve arrangement for selectively supplying a medium under pressure to said cylinder to control movement of said piston and said stop means.

10. A fastener driving machine comprising a frame, a first piston motor fixedly mounted on a frame and including a piston rod, means for supporting a workpiece mounted on said piston rod and movable between spaced positions, a second piston motor mounted on said supporting means, a stop assembly on said supporting means movable from an effective to an ineffective position and connected to said second piston motor, said assembly including a stop member for positioning said workpiece on said supporting means, switch means actuatable by the positioning of a workpiece on said supporting means against said stop member for operating said first piston motor, means for ejecting said workpiece, a first control means operable in response to movement of said supporting means into one of said spaced positions for actuating said second fluid motor to displace said stop assembly to its ineffective position, and a second control means carried by said supporting means and responsive to ejection of the workpiece from said machine for actuating said second fluid motor to return said stop assembly to its effective position.

11. In a fastener driving machine having supporting means for receiving a workpiece, a pair of pivotally mounted spaced rails disposed adjacent said supporting means and positioned below said workpiece, motor means connected to said rails, first control means for operating said motor means to raise said rails to engage and lift said workpiece so that the workpiece slides along said rails to be discharged from said machine, and second control means operated incident to discharging the workpiece from said machine to operate said motor means to lower said rails.

12. The combination defined by claim 11 in which the second control means includes a control device located adjacent the ends of said rails and disposed in the path of movement of a workpiece sliding along said rails to be operated thereby.

13. A fastener driving machine comprising a supporting means for receiving a workpiece movable between two spaced positions, means for ejecting said workpiece from said supporting means. a fluid motor having a movable element connected to said ejection means, first control means including first valve means for admitting fluid under pressure to said motor in response to movement of said supporting means from one of said spaced positions to another of. said spaced positions to actuate said ejection means to remove said workpiece from said supporting means, and second control means including second valve means for controlling the supplying of fluid under pressure to said motor to return said ejection means to its normal position.

14. The machine set forth in claim 13 wherein the first control means includes means for supplying fluid under pressure to said first valve means to operate said first valve means, and wherein said second valve means vents the fluid supplied to said first valve means to release said first valve means in response to movement of said workpiece by said ejecting means, thereby to cause the motor to return the ejection means to its normal position.

15. A fastener driving apparatus comprising fastener driving means, supporting means for receiving a workpiece, said fastener driving means and said supporting means normally being spaced apart, motor means for effecting relative movement between said driving means and said supporting means in a first direction to place said workpiece in a driving relationship with said fastener driving means and in a second direction to return said driving means and said supporting means to said normal spaced apart relationship, means for ejecting said workpiece from said supporting means, control means for operating said ejecting means to discharge said workpiece, and an operator element for said control means engaged by said supporting means during said relative movement between said driving means and said supporting means in both said first and second directions and operative to actuate said control means only during relative movement in said second direction.

16. A fastener driving machine comprising a frame, supporting means for receiving a workpiece and movably mounted on the frame, movably mounted stop means for positioning a workpiece on said supporting means, first motor means for moving said stop means, fastener driving means carried on the frame spaced above the supporting means, second motor means for moving said supporting means, means actuated by positioning a workpiece on said supporting means for operating said second motor means to elevate said supporting means to place said workpiece in engagement with said fastener driving means, said fastener driving means being operated when in engagement with said workpiece to drive fasteners into said workpiece, means operative following operation of said fastener driving means for operating said second motor means to lower said supporting means, ejecting means for displacing said workpiece from the machine, third motor means for operating said ejecting means, and means operated incident to lowering said supporting means to actuate said first and third motor means so that said stop means is moved and said ejecting means is operated to displace said workpiece.

17. The machine defined by claim 16 in which are provided means controlled by discharge of said workpiece from said machine for also actuating said first and third motor means.

18. A fastener driving machine comprising a frame, pneumatically actuated fastener driving means pivotally mounted on said frame, valve means for controlling the operation of said driving means and including a valve operator element, a table carried on said frame for supporting a workpiece, valve operating means mounted on said frame adjacent said valve operating element, and means for producing relative movement between said table and said driving means to move said workpiece and said driving means into engagement, movement of said workpiece into engagement with said driving means pivoting said driving means relative to said frame so that said valve operating means actuates said valve operator element to operate said valve means, whereby said driving means drives a fastener into said workpiece.

19. In a fastener driving apparatus, a frame, a pneumatically operated fastener driving tool including an operating cylinder and a rearwardly extending fastener magazine, pivot means for pivotally mounting said magazine on said frame at a point spaced from said cylinder, a control valve carried on said tool for selectively admitting compressed air to said cylinder to operate said tool, and

18 an armmounted on said frame adjacent said control valve so that pivotal movement of said tool relative to said frame in one direction causes said arm to actuate said control valve and pivotal movement of said tool relative to said frame in an opposite direction releases said control valve.

20. The fastener driving apparatus as set forth in claim 19 in which said arm is pivotally mounted on said frame and supports a roller adapted to roll along said tool into and out of engagement with said control valve.

21. The fastener driving apparatus set forth in claim 19 in which said pivot means comprises a pin carried on said frame and a resilient element carried on said magazine for detachably mounting said tool on said pin.

22. A fastener driving apparatus comprising a frame, a table movably mounted on said frame and adapted to support a workpiece, a plurality of pneumatically operaated fastener driving tools movably mounted on said frame above said table and spaced from each other, each of said tools having a compressed air inlet and a control valve for controlling the application of compressed air from said inlet to operate tool, a compressed air tank mounted on said frame above said plurality of fastener driving tools, a plurality of flexible lines each connecting the compressed air inlet on one of said tools to said tank, motor means carried on said frame for producing relative movement between said table and said plurality of tools to place said workpiece in engagement with said tools and to move said tools relative to said frame by virtue of the engagement of said tools by said workpiece, and means carried on said frame and operated by the movement of said tools relative to said frame for actuating said control valves to operate said tools so that fasteners are driven into said workpiece.

References Cited in the file of this patent UNITED STATES PATENTS 200,774 Somers Feb. 26, 1878 1,887,731 Obstfeld et a1 Nov. 15, 1932 1,940,980 Svenson Dec. 26, 1933 2,008,592 Paxton July 16, 1935 2,630,566 Thornton et al Mar. 10, 1953 2,723,393 Verrinder et a1 Nov. 15, 1955 2,743,442 Davies May 1, 1956 2,763,861 Wandel Sept. 25, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,884,637 May 5, 1959 Ots car A, Wendel It is hereby certified that error of the above numbered patent requiring cor patent should read as corrected below faction and that the said Letters 001111111115, line 14, for "portion read mu position line 61, for

"meaml" read means Signed and Sealed this 8th da of September 1959 Attest:

AXLINE ROBERT c. WATSON Attesting; Officer Comissioner of Patents appears in the printed specification

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