US3848791A

US3848791A - Apparatus for fabricating wooden frames

Info

Publication number: US3848791A
Application number: US00328605A
Authority: US
Inventors: A Castillo; R Leutwyler; J Jureit; H Cotten
Original assignee: Individual
Current assignee: Gang Nail Systems Inc; Mitek Holdings Inc
Priority date: 1973-02-01
Filing date: 1973-02-01
Publication date: 1974-11-19
Anticipated expiration: 1991-11-19

Abstract

The apparatus includes a pair of spaced conveyors for conveying upper and lower frame plates through a pair of nailing assemblies. Each nailing assembly includes a nailing gun pivotal between upper and lower positions whereby nails can be driven through the plate and into a stud disposed between the plates at positions spaced along the width of the plate. The conveyor includes a drive unit for advancing the plates through the nailing assemblies discrete distances of 1.5, 16 or 24 inches. One of the conveyors and nailing assemblies is movable laterally relative to the other conveyor and nailing assembly whereby adjustments in width of the frame undergoing fabrication is accomplished. In use, a stud is butted against retractable stops upstanding between the nailing assemblies. Upon command, clamps carried by the nailing assemblies clamp the stud and frame plates one to the other and the nailing gun automatically drives a nail through the plate into the stud. If two nails are required, the gun automatically pivots to an elevated position to drive the next nail. Upon completion of nailing, the conveyor advances upon command a selected discrete distance whereupon an additional stud is located between the plates for nailing.

Description

United States Patent [191 Jureit et al.

[ Nov. 19, 1974 APPARATUS FOR FABRICATING WOODEN FRAMES [76] Inventors: John Calvin Jureit, 8901 Arvida Ln., Coral Gables, Fla. 33156; Howell J. Cotten, Rt. 1, Box 280, Keswick, Va. 22947; Adolfo Castillo, 7761 SW. 18th Ter., Miami, Fla. 33155; Roy Leutwyler, 1016 NW. 43rd St., Miami, Fla. 33127 [22] Filed: Feb. 1, 1973 [21] Appl. No.: 328,605

Abernathy 227/152 X Davis 227/100 Primary Examiner-Granville Y. Custer, Jr. Attorney, Agent, or Firm-Le Blanc & Shur 5 7] ABSTRACT The apparatus includes a pair of spaced conveyors for conveying upper and lower frame plates through a pair of nailing assemblies. Each nailing assembly includes a nailing gun pivotal between upper and lower positions whereby nails can be driven through the plate and into a stud disposed between the plates at positions spaced along the width of the plate. The conveyor includes a drive unit for advancing the plates through the nailing assemblies discrete distances of 1.5, 16 or 24 inches. One of the conveyors and nailing assemblies is movable laterally relative to the other conveyor and nailing assembly whereby adjustments in width of the frame undergoing fabrication is accomplished. In use, a stud is butted against retractable stops upstanding between the nailing assemblies. Upon command, clamps carried by the nailing assemblies clamp the stud and frame plates one to the other and the nailing gun automatically drives a nail through the plate into the stud. If two nails are required, the gun automatically pivots to an elevated position to drive the next nail. Upon completion of nailing, the conveyor advances upon command a selected discrete distance whereupon an additional stud is located between the plates for nailing.

32 Claims, 26 Drawing Figures PATENIEL NOV 1 91974 sum 010F 12 QEQ? FIG. 2

PATENIEL HEY I 91974 SHEET 02 [1F 12 FIG. 5

PATENIEL HEY I 9l974 SHEET I 3&1

Illll Ill WHAT!!! PATENTEL HEY I 9 I974 sum 07 0F 1 791 Is" RACK STOP CYL.

004119074 48.791 PATENTE sum 0a or 12 3 8 HG. 20A

2022 LH. NM DROP CYLINDER R.H. NAIL DROP CYLINDER\ k/Tj/ L.H. R.H. 4 W Z NAIL NAIL 442 454 BLAST 0451M W i 1 W 450 l I90 CRIPPLE AND STUD CYLINDERS 462 4w 4.5" RACK. F STOP CYL. I

W :|4|8 L L4|e 4|9 RACK CLUTCH T T\ F IG. 434 1 PATENTEL HUV 1 91914 I SHEET 09 1 12 791 APPARATUS FOR FABRICATING WOODEN FRAMES The present invention relates to apparatus for fabricating wooden frames and particularly relates to apparatus for nailing studs between the upper and lower plates of a wooden building frame.

There has been a long-felt need for an efficient and effective machine for fabricating wooden frames, panels and the like and particularly the interior and exterior wall frames in wooden building construction. Such frames usually include upper and lower plates with studs connecting between such plates and spaced on predetermined centers, usually 16 or 24 inch centers. Exterior or load-bearing frames of this type usually have a pair of lapped upper plates. The exterior and interior frames are of conventional height usually about 8 feet with the studs for the exterior frame about 1.5 inches shorter than the studs for the interior frames to account for the width of the lapped plate.

The present invention provides effective and efficient apparatus for successively nailing studs between upper and lower wooden plates to fonn a completed building frame. To accomplish this, the present invention provides a pair of conveyors for locating the plates in lateral registration with nailing assemblies located on opposite sides of the conveyors. A drive unit for the conveyors includes apparatus for advancing the same selected discrete distances of 1.5, 16 and 24 inches whereby the partially completed frame is stepped through the nailing assemblies with the studs between the plates being successively aligned with the nailing guns carried by the nailing assemblies and nailed. The drive unit for the conveyor includes a rack and pinion. Dogs are selectively insertable in the path of movement of the rack whereby the conveyor longitudinally displaces the plates and studs of the partially completed frame in successive accurate longitudinal increments. The studs are thus nailed on the exact centers desired. The system prevents any inertia from moving the plates and studs beyond the positions aligned with the nailing guns. One of the conveyors and the corresponding nailing assembly on a like side of the apparatus are movable transversely as desired whereby frames of various heights can be fabricated. This width adjustment mechanism includes a discrete width adjusting means for moving the one conveyor and nailing assembly laterally a distance of 1.5 inches relative to the other conveyor and nailing assembly thereby providing for immediate set-up when switching from the fabrication of interior to exterior wall panels. The apparatus also includes a plurality of retractable stops located between the nailing assemblies and against which the studs are butted for alignment with the nailing guns.

Each nailing gun includes a carriage for pivoting the gun between selected elevations whereby either one or two nails can be driven through the plate into the stud. That is, frames can be formed utilizing 2X2s, 2X3s, 2X4s or 2X6s. The frames formed of 2X4s and 2X6s usually require two nails at each side of the frame to secure the plates and studs one to the other rather than the one nail required at each side when frames formed of 2 2s or 2X3s are utilized. Electrical-hydraulic control circuits are utilized for automatically sequencing the gun for driving one or two nails as selected. Nails for the guns are provided from a nail hopper which singulates nails randomly distributed from a nail hopper for successive insertion into the bore of the nail gun.

In operation, the plates are located in nailing position by manual operation of the conveyor. A stud is then butted against the stops extended between the nailing assemblies whereby the studs are aligned with the nailing guns with the plates at right angles thereto between the ends of the studs and the nailing guns. Upon command, clamps engage the stud ends and the respective plates to align the stud and plates in a common horizontal plane. After this clamping action is completed, the guns are automatically extended to butt the respective plates and to clamp them against respective opposite ends of the stud. A nail is then driven through each plate and into the corresponding end of the stud. If only one nail is required to secure each plate to the stud in a particular frame, the nailing guns automatically retract. If two nails are required to secure each plate to the stud, the control circuit causes each nailing gun to be elevated to drive a second nail through the plate into the stud. Upon completion of either the one or two nail nailing cycles, the clamps are automatically released. Also, upon completion of nailing, the stud stops are automatically retracted enabling the partially completed frame to be advanced a discrete selected distance by the conveyors to locate the plates in position for insertion of the next stud on its exact center in line with the nailing guns for the next nailing cycle.

Accordingly, it is a primary object of the present invention to provide novel and improved apparatus for fabricating wooden frames, panels and the like.

It is another object of the present invention to provide novel and improved apparatus for fabricating wooden frames, panels and the like and particularly for nailing the upper and lower plates to studs in a building frame.

It is still another object of the present invention to provide novel and improved apparatus for fabricating wooden frames and the like wherein the apparatus is readily and easily adapted for the fabrication of frames of different heights and frames utilizing a wide variety of differently sized framing members.

It is a further object of the present invention to provide novel and improved apparatus for fabricating wooden frames, panels and the like wherein either one or two nails can be selected for securing each plate to the stud and wherein selection of two nails automatically sequences the machine for driving the two nails.

It is a still further object of the present invention to provide novel and improved apparatus for fabricating wooden frames, panels and the like wherein the partially completed frame is advanced through the fabricating machine in selected incremental distances corresponding to the center to center spacing of the studs in the frame wherby additional studs are successively located on center and in nailing position between the plates.

These and further objects and advantages of the present invention will be more apparent upon reference to the following specification, claims, and appended drawings, wherein:

FIG. 1 is a plan view of a fabricating machine constructed in accordance with the present invention and with parts broken out for ease of illustration;

FIG. 2 is a side elevational view thereof;

FIG. 3 is an enlarged fragmentary plan view of the machine of FIG. 1 and illustrating the drive unit for the conveyor thereof;

FIG. 4 is a fragmentary enlarged side elevational view of the drive unit assembly illustrated in FIG. 3;

FIGS. 5, 6 and 7 are fragmentary enlarged crosssectional views thereof generally taken about on lines 5-5, 6-6 and 7-7, respectively, in FIG. 3;

FIG. 8 is a fragmentary enlarged cross-sectional view of the nail head assembly with parts broken out and in cross section for ease of illustration;

FIG. 9 is a cross-sectional view thereof taken generally about on line 99 in FIG. 8;

FIG. 10 is a view similar to FIG. 8 and illustrating the nail head assembly in an advanced position fully embedding a nail into the frame;

FIG. 1 1 is a fragmentary cross-sectional view thereof;

FIG. 12 is a fragmentary cross-sectional view with parts broken out in cross section of a mechanism for adjusting the width of the conveyor and drive unit assembly;

FIG. 13 is a fragmentary side elevational view of a nail feed assembly for the machine hereof;

whereby the attached conveyor rail 24 L is maintained in a fixed position. Stand 36 includes a base 42 and a pair of upstanding end brackets 44 which mount a shaft 46 received through the side channel members 26 whereby the conveyor rail 24R is slidable along shaft 46 in a lateral direction to obtain selected adjusted positions as set forth hereinafter. The drive sprocket 28 at the forward end of conveyor rail 24 R is splined to the square shaft 33 whereby the conveyor rail 24R and drive sprocket carried thereby are free for transverse movement relative to shaft 33. Treads 30 carry a plurality of longitudinally spaced lumber drive members 31 which project above the treads for engagement with the ends of the plates of the panel undergoing fabrication. The treads 30 carry the frame plates through nailing head assemblies 18 whereat the cross members of the frame, i.e., studs, are nailed to the plates. Guides, not shown, are placed along opposite sides of each of the conveyor treads whereby the plates are retained on the conveyor for movement toward the nail head assemblies 18.

The nailing head assemblies 18 are each carried on a machine base 50 to which is secured, on the side FIG. 14 is an enlarged cross-sectional view thereof taken about on line 14l4 in FIG. 13;

FIG. 15 is a plan view thereof;

FIG. 16 is a vertical transverse sectional view of the conveyor and nailing assemblies and further illustrating the width adjustment mechanism;

FIG. 17 is a cross-sectional view thereof taken about on line 1717 in FIG. 16;

FIGS. 18 and 19 are end and side elevational views respectively, of a lumber hold-down mechanism;

FIGS. 20A, 20B and 20C are schematic illustrations of various pneumatic circuits employed with the present invention;

FIG. 21 is a schematic illustration of a hydraulic circuit for use with the fabricating machine hereof; and

FIGS. 22A, 22B and 22C taken together constitute a schematicillustration of the electrical circuit for use with the fabricating machine hereof, the FIGS. 22A, 22B and 22C being arranged end to end and from left to right, respectively, to complete the electrical circuit.

Referring now to the drawings, particularly to FIGS. 1 and 2, there is illustrated a panel fabricating machine constructed in accordance with the present invention and generally indicated 10. Machine 10 generally includes a conveyor 12, a drive unit 14 for the conveyor, a downstream roller conveyor 16, a nail head assembly 18, a nail feed assembly 20 and a width adjustment assembly 22. Conveyor 12 comprises left-and right-hand laterally spaced

conveyor rails

24L and 24R each formed of laterally spaced elongated channels 26 suitably connected one to the other and having an idler sprocket, not shown, at one end and a drive sprocket 28 (FIGS. 3 and 6) at the opposite end. A conveyor chain 29 engages about the idler and drive sprockets and carries tread 30 which, on the upper surface of the conveyor rails, rides on a pair of bearing surfaces, not shown. Drive

sprockets

28R and 28L are coupled to

shafts

32 and 33 respectively, which are driven by the drive unit assembly 14. Portions of the conveyor rails 24L and 24R are supported by conveyor rail floor stands 34 and 36 respectively. Stand 34 includes a base 38 and diagonally upstanding support brackets 40 thereof remote from the conveyor 12, a support base 52 for the drive unit 14. Base 52 carries a mounting plate 54 carrying an upright 56 to which a hydraulic motor 58 is secured. Forwardly of motor 58 there is mounted a shaft 60 carrying a sprocket 62. Shaft 60 is mounted at one end in a bearing 64 carried by plate 54 and at its other end by an air clutch 66. Motor 58 is drivingly coupled to shaft 60 through a sprocket 68 and chain 70, the chain 70 passing over idler sprocket 72. Air clutch 66 carries a drive sprocket 74 which, via a chain drive including chain 76 and a sprocket 78 carried by shaft 32, drives shaft 32 in opposite directions depending upon the direction of rotation of the output shaft of motor 58. A phasing coupling 80 couples shaft 32 one to the other whereby the rightand left-

hand conveyors

24R and 24L respectively operate in synchronism one with the other.

Shaft 60 on the drive unit extends through air clutch 66, through a pillow block 82, and drives a second air clutch 84. Clutch 84 mounts one end of an output shaft 86, the other end of which is carried in a bearing 88 mounted on plate 54. Shaft 86 also mounts a drive pinion 90 which meshes with a rack 92 slidable along a recess 94 defined by upstanding elongated side and

end plates

93 and 95 respectively mounted on plate 54. It will thus be appreciated that by actuation of clitch 84, drive pinion 90 rotates in response to rotation of shaft 60 to slide rack 92 along recess 94 in opposite directions depending upon the direction of rotation of motor 58. The rack 92 is illustrated in FIG. 3 in a zero position, that is, its forward end bears against the forward wall of recess 94. Spaced along the recess and from the opposite end of rack 92 at increments of 1.5 inches and 16 inches are

dogs

96 and 98 carried for sliding movement in transversely extending

slides

100 and 102, respectively.

Brackets

101 and 103 project outwardly from a side 93 of recess 94 and mount air-actuated

cylinders

104 and 106, respectively. The pistons of

cylinders

104 and 106 are connected to the

respective dogs

96 and 98. It will be appreciated that actuation of either cylinder causes the corresponding dog to be inserted into the recess 94 and into the path of movement of rack 92 preventing further movement thereof. For reasons to be discussed hereinafter, the end of recess 94 carries a stop pad 108 located precisely 24 inches from the near end of rack 92 when the rack is located in its zero position. At each of the 1.5, 16 and 24 inch positions along the recess 94, there is also mounted

micro-switches

110, 112, and 114 which are engaged by the near end of rack 92 when it obtains the respective longitudinal positions.

Accordingly, it will be appreciated that by actuation of cylinder 104 or cylinder 106, the rack can be stopped after 1.5 or 16 inches of movement, respectively. The rack is, of course, stopped by stop pad 108 after 24 inches of movement. As will become clear from the ensuing description, the

dogs

96 and 98 and stop'pad 108 are utilized because of the inertia of the system and effectively stop the conveyor instantaneously through conveyor clutch 66 when the rack engages the dogs or stop pad, as the case may be. When stopped by the

dogs

96 or 98 or stop pad 108, the corresponding micro-switch is actuated. When the microswitch is actuated, clutch 66 is disengaged whereby the coupling between the drive motor 58 and the conveyor drive shaft is broken and the motor 58 reverses. Clutch 84, however, remains engaged and, with motor 58 reversed, the pinion 90 drives the rack 92 back to its zero position into engagement with a micro-switch 116 which serves to disengage clutch 84. By the foregoing arrangement, it will be appreciated that conveyor drive shaft 32 can be selectively rotated to advance the plates carried on treads discrete distances of 1.5, 16 and 24 inches upon command. It will also be appreciated that slides 100 and 102 can be located at other selected positions along the recess 94 whereby the conveyor can be advanced other selected discrete distances. Also, spacer blocks can be provided at the end of recess 94 to provide a final discrete movement other than 24 inches. It will also be appreciated that additional slides containing air-actuated cylinders and dogs can be provided, as desired, wherein any desired number of discrete movements can be obtained.

The downstream conveyor 16 comprises a pair of spaced

roller conveyors

109L and 109R each including spaced side rails 111 and 112 with longitudinally spaced rollers connected therebetween. Downstream roller conveyor 109L is fixed on suitable supports, not shown, while roller conveyor 109R is mounted for movement in a transverse direction relative to conveyor 109L. Particularly, conveyor 109R is carried by longitudinally spaced uprights 113, the lower ends of which mount rollers 114 for movement along a transversely extending back or base 116. Accordingly, roller conveyor 109R can be selectively transversely spaced from fixed roller conveyor 109L and in accordance with the spacing of conveyor 24R from fixed conveyor 24L whereby

conveyors

24R and 109R are maintained in longitudinal registry one with the other.

Referring now to FIGS. 4, 8, 10 and 11, the base 50 of the machine includes a pair of transversely extending channels 130 spaced one from the other and carried on suitable supports 132 (FIG. 16). The upper ends of the channels each mount inwardly projecting plates 134. Each of the nail head assemblies 18L and 18R comprises a pair of generally longitudinally spaced upstanding C-shaped plates 136 between which is mounted a nailing gun generally indicated 137 and ancillary equipment therefor. The plates 136 are carried on a lower mounting plate 138. Each mounting plate 138 extends inwardly toward the opposite nail head assembly to provide support for a housing 142 described hereinafter. Mounting plate 138L is secured to its mounting plates 134, i.e. by welding or the like. The mounting plate 138R for nail assembly 18R carries a gib 140 whereby the nailing head 18R is slidable on mounting plates 134 transversely along base 50.

Each plate 138 also carries a housing 142 for mounting a pair of retractable fingers or stops 144, the purpose of which is described hereinafter. Each housing 142 is connected by a bracket 146 to the C-shaped plates 136. Between the housing 142 and nail head assembly 18 on the respective opposite sides of the machine and above bracket 146, extends the forward end portion of the drive conveyor. The conveyor channels 26 are suitably secured to the nail head assemblies 18 and housings 142. It will be appreciated from the foregoing that the left-hand nailing assembly 18L, housing 142L, and conveyor 24L are fixedly mounted relative to base 50. However, the nail head assembly 18R, housing 142R and the conveyor 24R carried between housing 142R and nail assembly 18R are carried for transverse sliding movement relative to base 50.

To adjust the position of the nail head assembly 18R, housing 142R and the conveyor rail 24R relative to the corresponding left-hand parts thereof, there is provided a width adjustment assembly 22 including, as best illustrated in FIG. 12, an elongated screw 150 threadedly carrying a mounting bracket 152 secured to the underside of gib 140. Mounted at one end of screw 50 through a self-aligning rod and coupler 154 is a hydraulic cylinder 156 for shifting the screw thread 150 axially a discrete distance equal to 1.5 inches for reasons noted hereinafter. Cylinder 156 is fixed to base 50 between channels 130. The opposite end of screw thread 150 is splined to a drive coupling 158 carried in a bearing 160 mounted in a motor housing 162. Housing 162 is secured to an end plate 163 in turn secured to channels 130. A hydraulic motor 164 is carried on housing 152 and its shaft 166 is splined to drive coupling 158. Accordingly, it will be appreciated that actuation of motor 164 drives shaft 166 and hence screw thread 150 in rotary direction dependent upon the direction of rotation of motor 164 whereby bracket 152 is displaced axially along thread 150. With the foregoing arrangement, the hydraulic cylinder 156 can be actuated to displace the nail head assembly 18R, housing 142R and the right-hand conveyor 24R a distance of 1.5 inches either inwardly or outwardly depending upon its initial position whereas the hydraulic motor can displace these elements relative to the corresponding elements on the opposite side of the machine selected distances as desired and within a range determined by the length of thread 150. The discrete width adjustment of 1.5 inches permits ready adjustment of the machine for handling exterior and interior wall panels which differ in width one from the other by approximately 1.5 inches.

A telescoping lumber support assembly, generally indicated 170 in FIG. 16, is provided between the leftand right-hand nailing assemblies 18L and 18R, respectively, and specifically between housings 142L and 142R. The support assembly 170 includes a pair of laterally spaced channels 172 suitably secured at one end to housing 142R. One end of another pair of channelshaped members 174 are suitably secured to housing 142]... The opposite ends of channel members 174 are received within the ends of channel members 172. Suitable lateral braces 176 are provided between the

channel members

172 and 174 at spaced locations therealong. A tray 178 is releasably mounted on top of the

channel members

172 and 174. Tray 178 includes a flat upper plate 180, elongated bearing surfaces 182 which ride on the upper flanges of the

channels

172 and 174, and side retaining flanges 184. It will be appreciated that tray 178 can be moved along the

channel members

172 and 174 and that when the nail assembly 18R, conveyor 24R and housing 142R are displaced laterally along the base of the machine, the

channel members

172 and 174 telescope one within the other.

Within each housing 142, there is provided a pair of laterally spaced risers 186 (FIG. 11). Pivotally connected at the lower end of each riser is an upstanding cylinder 188, the piston rod 190 of which is secured to a stud stop or finger 144. The fingers 144 project through an opening in the upper wall 192 of each housing 142 and are generally square in cross section. The fingers 144 are transversely aligned one with the other whereby they form abutments for the studs S located between the plates P.

Turning now to FIGS. 8 and 10, nail gun 137 includes a carriage 200 having a longitudinally extending central aperture 202 and a nail-receiving aperture 204 (FIG. 10) for receiving nails from a flexible line 206 from the nail hopper. The carriage 200 is formed of discrete upper and lower parts with such parts held together by a spring in housing 208. Carriage 200 is secured to a gib 210 which is slidably mounted along a bar 212, the gib 210 being T-shaped in cross section and being received within a slot at the end of bar 212. Gib 210 has a slot along a lower portion thereof in which is received a pin 214 carried by bar 212. Gib 210 is biased by a compression spring 218 for movement into the position illustrated in FIG. 10, that is, in a position advanced to butt the plate P.

To drive the nails into the plate P, a hydraulic cylinder 220 is carried on bar 212. Cylinder 220 carries a piston 221 which mounts a bracket 222. Bracket 222 carries a nail driving rod 224 which is received within the central aperture 202 of the nail gun 137. It will be appreciated that actuation of cylinder 220 advances nail driving rod 224 such that the end of rod 224 engages a nail within aperture 202 and drives the nail through the forward end of the gun into the plate and stud S. Further, it will be appreciated that full extension of piston 221 carried by cylinder 220 causes bracket 222 to butt the rear end of gun carriage 200 and advance the latter relative to bar 212 whereby carriage 200 bears against the plate P to clamp it to the stud S. Thus the nail is fully seated only when the plate and stud engage one another. Also carried on bracket 222 is a plate 226 (FIGS. 8 and 9). Plate 226 has a lower aperture 228 which receives a pull rod 230. One end of pull rod 230 is secured to carriage 200 while the other end carries an enlarged head 232. Plate 226 also carries a downwardly projecting tab 234 which engages a micro-switch 793 in response to full seating of the nail in the plate and stud and complete advance of the gun carriage 200 toward the plate and stud. Thus, to drive a nail into the plate and stud, the cylinder 220 is actuated whereby the compression spring 218 advances the carriage 200 against the plate. Drive rod 224 thereafter advances the nail in aperture 202 into the plate and stud. Full extension of the cylinder 220 butts bracket 222 against the rear end of gun carriage 200 to clamp the forward end of carriage 200 against the plate and stud and ensure final seating of the nail with the plate and stud in butting engagement. Upon full seating of the nail and full advancement of carriage 200, tab 234 engages the micro-switch 793 which causes, as explained hereinafter, the cylinder to retract. Upon retraction of piston rod 221, the plate 226 engages the head 232 of pull rod 230 prior to full retraction of piston 221. Thus, rod 230 serves to withdraw or pull the gun carriage 200 back from engagement with the plate, i.e., back to the position illustrated in FIG. 8, in response to full retraction of piston 221.

In order to drive two or more nails into the plate and stud depending upon the size of the panel undergoing the fabrication, nail gun 137 is mounted for pivotal movement whereby it can be shifted vertically to align another nail in the gun carriage with selected positions along the width of the wooden plate. To accomplish this, bar 212 which carries carriage 200 and ancillary equipment including cylinder 220, is pivotally mounted between the C-frame plates 136 at 240. To maintain the gun at a preselected level or elevation and to shift the gun from one elevation to another, there is provided a hydraulic cylinder 242 pivotally mounted at 244 between plates 136 on a bracket 246. The piston rod 247 of cylinder 242 is pivotally connected to a clevis 248 secured on the underside of bar 212. Also carried by bar 212 is a pair of upwardly projecting stops 250 which engage a pin 252 located in selected openings along fixed brackets 254. That is, cylinder 242 when actuated raises bar 212 until brackets 250 engage pins 252 limiting upward movement of the entire nailing gun assembly. Openings for the pins 252 are provided at selected elevations along brackets 254. When the cylinder 242 is fully retracted, the centerline of the nailing gun, that is, a line drawn through the axis of the aperture 202 through which the nail emerges for embedment into the plate and stud, inclines downwardly for inserting a nail into the plate about /8 inch above the lower edge of the plate. The pins 252 are located in selective openings such that when the gun carriage is elevated and stopped by the pin, the next nail will be embedded at the appropriate elevation above the first nail depending upon the size of the lumber being used. For example, when nailing 2X2s, only one nail is utilized and this would be driven into the plate with the gun carriage in its lowermost position with cylinder 242 fully retracted. For a 2X4, two nails are used. The first nail is applied at a location "/8 inch from the lower edge of the plate and the gun carriage is thereafter raised such that the next nail would be located a distance about 2% inches from the lower edge of the plate. For a 2X6, the pin would be located such that the gun carriage would be elevated to embed the second nail a distance about 4% inches from the lower edge of the 2X6 plate. It is a feature hereof that the axis of the nail driving cylinder 220 is located about inches above the tread 30 whereby each nail driven into the various standard sized plates will be driven at an angle. This is advantageous in that the resistance to withdrawal of the nail is increased due to its angled insertion. Also, when two nails are driven, they provide a clinching action in securing the plate and stud one to the other.

Referring now to FIGS. l3, l4 and 15, one of the left and right-hand nail feed assemblies 20 is illustrated. Each assembly comprises a hopper 260 for receiving randomly distributed nails. Hopper 260 is pivoted at its upper end between a pair of main plates 262 by means of brackets 264 and pins 266. Main plates 262 are, of course, secured to the C-frame plates 136 of the nail assembly 18. The hopper has a longitudinally extending slot 268 in which the randomly distributed nails are received with the shank portions of the nails extending through the slots and the nails being held by the heads engaging along the margins of the slot. At the forward end of the hopper 260 there is provided a main gate 270 having a notch 271 along its lower edge for permitting the head of each nail to pass through the notch. Guide tracks 272 are connected to an escapement generally indicated 274. The guide tracks 272 are spaced such that the nails received in the guide tracks are singulated one behind the other with the nails depending from their heads through the slot 276 between the guides.

To distribute the nails from hopper 260 into slot 276, the hopper 260 is continuously oscillated between the illustrated downwardly inclined position and a position wherein the bottom of the hopper forms essentially a continuation of tracks 272. To accomplish this oscillation, there is provided an eccentric including an arm 278 pivoted at one end to the bottom of hopper 260 and at its other end to a crank 280, the crank being rotated by a hydraulic motor not shown in FIG. 13 but schematically represented in FIG. 21 by the motors 181L and 181R for the left and right hand nail hoppers. It will be appreciated that rotation of crank 280 oscillates hopper 260 between the aforementioned positions whereby the nails are singulated along the tracks 272. The nail escapement 274 for each nail feed assembly 20 is per se conventional and forms no part of the present invention. Further description thereof is therefore believed unnecessary, it being sufficient to note that nails are dropped one at a time from each of the left and right-hand escapements 274 through the associated nail feed line 206 by actuation of the corresponding air cylinder 282 which, in turn, respectively operates spring biased nail picks 284. That is, each time the pick is displaced by actuation of a cylinder 282 a nail drops into the corresponding nail feed line 206.

Mounted on the inside end of the nailing head assemblies are plate and stud clamps generally indicated 300 (FIGS. 8, l and 11). Particularly, a bracket 302 connects between the forward ends of C-frame plates 136. A clamp cylinder bracket 304 is mounted to bracket 302 by bolts 303. Bracket 304 has a pair of vertically elongated slots 305 by which its position relative to bracket 302 can be adjusted as desired. Bracket 304 carries an outwardly projecting plate 306 mounting a hydraulic cylinder 308, the piston of which extends through plate 306 and carries at its lower end a clamp platen 310. Platen 310 carries a guide rod 312 which extends upwardly through an opening in plate 306 whereby the platen is maintained in alignment. The platen face carries a clamp 314 having a serrated or otherwise roughened edge for clamping engagement against the stud S. Clamp 314 is carried in a recess formed in the face of platen 312. The remaining portion of the lower face of platen 312 which bears against the plate P is smooth. Thus, when the cylinder 308 is actuated to engage platen 312 against the plate and stud, the stud is held in fixed position by clamp 314 while the plate is free to move inwardly against the end of the stud along the lower surface of platen 310. That is, the gun carriage 200 can displace the plate P inwardly along the lower face of platen 312 into engagement with the stud end which is held in place by clamp 314.

Carried by housings 142 and adjacent the left and right hand nailing assemblies is a pair of stud sensor micro-switches 720 and 716 respectively, (switch 720 being illustrated in FIG. 10 while both switches are illustrated in FIG. 22B). Each switch includes a head 322 which projects above the upper surface of housing 142 and which head is engaged by a stud located in butting engagement against the fingers 144. When the stud is so located, head 322 is depressed to actuate switch 720 or switch 716 as the case may be.

Referring to FIGS. 18 and 19, frame hold-down mechanisms are provided on opposite sides of the conveyor downstream of the nail head assemblies to maintain the partially completed frame on the roller conveyor assembly. Each hold-down mechanism includes a roller 330 pivotally carried on a shaft disposed within sleeve 332. Sleeve 332 is coupled to a sleeve 334 pivotally mounted between brackets 336 secured the nail head assemblies for example by welding to one of the plates 136, whereby the roller is pivotal about the axis of sleeve 334. An air-actuated cylinder 338 is pivotally secured at one end to a bracket 340 secured to the lower side of the nail head assemblies. The piston rod 342 is secured to a lever arm 344 also carried on sleeve 334. Accordingly, retraction of cylinder 338 locates the clamping roller 330 on top of the plate and stud as they emerge from the nailing head assembly.

Referring now to FIGS. 20A, 20B and 20C, there are illustrated various pneumatic circuits for the machine hereof. As used in the illustration of the circuits, the small circles indicate a source of air under pressure. Referring first to FIG. 20B, the stop cylinders 188 are connected in parallel via

lines

400 and 402 which communicate with a four-way, two-position, springretumed, valve 404 actuated by finger solenoid 413. Air pressure communicates from a source with the valve 404 via a line 406. The cylinders 188 are connected with

lines

400 and 402 via

lines

408 and 410, respectively. A pressure regulator 412 is disposed in line 402. Air is supplied under pressure from the source through valve 404 to maintain the pistons 190 of cylinders 188, i.e., fingers 144 in an extended position.

Referring now to FIG. 20C, the 1.5 inch rack stop cylinder 104 is coupled to the air pressure source via lines 412 and 414 and a four-way, two-position, springreturned valve 416 under control of solenoid 418. The 16 inch rack stop cylinder 106 is connected with the air pressure source via

lines

419 and 422 through a fourway, two-position, spring-retumed valve 424 under' control of solenoid 420. It will be appreciated that both the 1.5 inch and 16 inch

rack stop cylinders

104 and 106, respectively, are normally maintained in a retracted position. Rack clutch 84 lies in communication with the air pressure source via an air line 426 and a four-way, two-position, spring-retumed valve 428 actuated by solenoid 430. Conveyor clutch 66' lies in communication with the air pressure source via an air line 432 and a four-way, two-position, spring-returned valve 434 under control of solenoid 436.

Referring now to FIG. 20A, the left-hand nail drop cylinder 282L lies in communication with an air pressure source via

lines

438 and 440 and a four-way, twoposition, spring-returned valve 442 under control of a solenoid 446, the piston of the cylinder being normally extended. The right-hand nail drop cylinder 282R likewise lies in communication with an air pressure source via

conduits

447 and 448 and a four-way, two-position, spring-returned valve 450 under control of a solenoid 452, the piston being normally extended. The left-hand nail blast lies in communication with the air pressure source via a line 454 and a two-way normally closed spring-return valve 456 operated by solenoid 458. The right-hand nail blast is similarly connected with the air pressure source via a line 460 and a two-way, twoposition, spring-return valve 462 operated by solenoid 464.

Referring now to FIG. 21, there is illustrated a hydraulic circuit schematic including a hydraulic pump 450 driven by electric motor 452 for supplying hydraulic fluid from a source 454 via a main fluid line 456. A shut-off valve 458 and a pressure gauge 460 are connected to line 456 by line 459. Also, a pressure relief valve 462 lies in communication with line 456 via line 464. The left-hand nailing cylinder 220L receives fluid from pump 450 via a line 466, a four-way, two-position, spring-returned valve 468 in communication with line 466 and operated by solenoid 470, and a pair of

fluid lines

472 and 474 in communication with valve 468 and with the opposite ends of cylinder 220L. Similarly, the right-hand nail cylinder 220R receives fluid from motor 450 via a line 476 in communication with main line 456, a four-way, two-position, spring-returned valve 478 in communication vn'th line 476, and a pair of

fluid lines

480 and 482 in communication with valve 478 and opposite ends of cylinder 220R. Valve 478 is operated by solenoid 484. It will be appreciated that the

valves

468 and 478 are normally positioned such that pump 450 supplies hydraulic fluid to the right and left-hand nail cylinders 220L and 220R respectively and the pistons carried thereby are normally retracted.

Connected to fluid line 476 by line 485, is a normally closed four-way, three-position, spring-returned valve 488 operable by

solenoids

490 and 492. A pair of

fluid lines

494 and 496 connect valve 488 with the inlet and outlet ports respectively of a reversible hydraulic motor 164. Motor 164, as will be recalled, provides for adjustment of the width of the drive conveyors and nailing head assemblies. It will be appreciated that actuation of solenoid 492 shifts valve 488 to the left as illustrated whereby fluid is provided motor 164 to rotate screwthread 150 in one direction to adjust the width of the drive conveyors and nailing head assemblies. Deenergization of valve 492 permits the valve to return to its spring-returned normally closed position. Conversely, energization of valve 490 shifts valve 488 to the right as illustrated whereby pressure fluid is supplied via

lines

486 and 496 to motor 164 whereby it is driven in a reverse direction. This rotates screwthread 150 in the reverse direction. Thus selective energization of

solenoids

490 and 492 adjusts the width be: tween the conveyors and nailing head assemblies infinitely over a range permitting fabrication of wall panels of various heights including most standard heights.

Fluid line 486 connects with main fluid line 456 and serves to supply fluid to the 1.5 inch width adjustment cylinder 156, the lift cylinders 242, the clamp cylinders 308, and the motors 281L and 281R for oscillating the nail hoppers. Particularly, the 1.5 width adjustment cylinder 156 communicates with line 486 via a line 488 and a four-way, two-position, spring-returned valve 490 and a fluid line 492. Fluid line 494 connects between the opposite end of cylinder 156 and valve 490. Valve 490 is exhausted via a line 496 in communication with a main exhaust line 498. Valve 490 is under the control of a solenoid 500. It will be appreciated that fluid thus flows from pump 450 through valve 490 via

lines

456, 486, and 488 to one side with fluid line 494 exhausting the fluid. The lower ends to lift cylinders 242L and 242R communicate with the pressure fluid in line 486 via

lines

504, 506, a four-way, two-position, spring-returned valve 508 operated by solenoid 510 and fluid line 512. The opposite sides of the lift cylinders communicate with valve 508 via

fluid lines

514 and 516. A line 518 communicates with valve 508 and exhaust line 498. Thus, it will be appreciated that fluid flows via

lines

486, 512, through valve 508 and

lines

516, 514 into cylinders 242L and 242R whereby the same are normally retracted. Upon energization of solenoid 510, valve 508 is shifted to supply pressure fluid via

lines

486, 512, 506 and 504 to cylinders 242L and 242R to extend the pistons 247 thereof and hence raise the nailing gun carriages as previously described. Deenergization of solenoid 510 permits valve 508 to return to the illustrated position with pressure fluid supplied to cylinders 242L and 242R via

lines

512, 516 and 514 and exhausted therefrom via

lines

504, 506 and 518.

Fluid line 520 communicates with line 486 and a four-way, two-position, spring returned valve 522 operates by solenoid 524. Fluid line 526 communicates with valve 522 and a fluid line 528 which communicates with the upper end of

clamp cylinders

308L and 308R. A pressure-actuated electrical switch 530 lies in communication with line 526. Fluid line 532 communicates with the lower ends of

cylinders

308L and 308R and with valve 522 via line 534. Fluid line 536 communicates between valve 522 and exhaust line 498. Thus, upon energization of solenoid 524 valve 522 shifts to provide pressure fluid to clamp

cylinders

308L and 308R via

lines

486, 520, 526 and 528 while exhausting fluid from the lower ends of the cylinders via

lines

532, 534, 536 and 498 whereby the clamp heads 310 are extended to engage the plates and stud. Upon deenergization of solenoid 524, valve 522 is springreturned to the illustrated position whereby the clamp heads are returned to their retracted positions. Line 542 serially connects the hopper drive motors 281R and 281L. Thus, these motors are on when the hydraulic circuits are actuated.

Pressure fluid also communicates between line 456 and rack and conveyor motor 58 via a four-way, three position, spring returned valve 550 and

fluid lines

552 and 554. Valve 550 is actuated by energization of either solenoid 642 or solenoid 646. Fluid line 556 communicates with line 558 at a juncture between a twoposition, one-way, spring-returned valve 560 and a flow control valve 562. Valve 560 is under the control of the fast conveyor solenoid 688. A fluid line 564 communicates with line 558 beyond valve 562 and via a line 566 to a reservoir. Upon energization of the motor forward solenoid 646, valve 550 is shifted to provide pressure fluid from line 456 to motor 58 via line 552 to advance the conveyor with the fluid exhausting from motor 58 via

lines

554, 556 and 558 through the flow control valve 562 to the reservoir. When the fast conveyor solenoid 688 is energized, valve 560 shifts to exhaust fluid from motor 58 via line 558 whereby motor 58 will speed up. Upon de-energization of

solenoids

646 and 688, the

valves

550 and 560 return to their illustrated positions. Upon energization of solenoid 642, valve 550 is shifted to provide pressure fluid from line 486 to motor 58 via line 554 with fluid exhausting through

lines

552, 556 and 566. This operates motor 58 in the reverse direction to return the rack 92 to its initial position. De-energization of solenoid 642 permits valve 550 to return to its spring-retumed position.

ELECTRICAL CONTROL CIRCUIT Referring now to FIGS. 22A, 22B and 22C which are schematic representations of an electrical control circuit for the machine hereof, the circuit is illustrated in a detached contact mode wherein the various relays represented by circles open and close associated contacts in a manner to be described, and wherein time delay relays represented by squares also open and close associated contacts in a manner to be described, normally open and closed contacts being denoted by pairs of parallel lines and slashed pairs of parallel lines, respectively. The contacts have numeral suffixes corresponding to the numeral suffixes of their actuating relay, the second numeral suffix indicating a particular set of the contacts closed and opened by the particular relay designated by the first numeral suffix. Power is provided across line 600 and a reference potential by a suitable power source, not shown. Connected across the power supply in line 602 are normally closed contacts R9-l and R7-1, a normally open 1.5 inch command switch 604, relay R1, normally closed contacts R3-2 and R2-2. Line 606 is connected to line 602 between contacts R9-1 and R7-1 and serially connects a 1.5 inch movement complete switch 608, normally open contacts Rl-l and relay R4. Line 610 connects with line 602 between relay R1 and switch 604 and with line 606 between contacts Rl-l and relay R4. Line 612 serially connects fuse F1 and a 1.5 inch stop solenoid 418 between line 610 and the reference potential. Line 614 connects with line 602 between switch 604 and contacts R7-1. A normally open 16 inch command switch 616, a relay R2, and normally closed contacts Rl-2 and R3-3 are serially connected in line 618 and between line 614 and the reference potential. Line 620 serially connects a normally open 24 inch command switch 622, relay R3, and normally closed contacts R2-3 and Rl-3 between line 614 and the reference potential. Connected to line 606 across the power supply is line 624 which connects in series a normally closed 16 inch movement complete switch 626, nonnally open contacts R2-1 and a relay R5. Line 628 connects with line 618 between relay R2 and switch 616 and with line 624 between contacts R2-l and relay R5. Connected in series between line 628 and the reference potential and in line 630 in a fuse F2 and a 16 inch stop solenoid 420. Also connected to line 606 across the power supply is a line 632 which serially connects a normally closed 24 inch movement complete switch 634, normally open contacts R3-1, and relay R6. Line 636 connects with line 620 between relay R3 and switch 622 and with line 632 between relay R6 and R3-l. Relay R7 and a normally closed rack zero switch 638 are connected in series in line 639 between line 606 and the reference potential. Line 640 connects between line 606 and the reference potential and serially connects normally open contacts R7-l, normally closed contacts TD2-l and TD3-2, nonnally open contacts TD-4, fuse F3 and a motor reverse solenoid 642. Connected between the reference potential and line 640 between contact TD3-2 and TD-4 is a relay TD4. Normally open contact TD-3, a fuse F4, and a motor forward solenoid 646 are serially connected in line 648 which connects between line 606 and the reference potential. Normally closed contact R11-4 is disposed in line 650 which connects between

lines

600 and 652. Connected in parallel between line 652 and line 654 are normally open contacts R4-2, R5-2, line 654 connecting a relay TDl between such contacts and the reference potential. Line 656 connects

lines

658 and 660 in parallel with line 652.

Line 658 serially connects normally open contacts TD-l, fuse F5 and rack clutch solenoid 430 while line 660 serially connects normally open contacts TD-2, fuse F6, and conveyor clutch solenoid 436,

lines

658 and 660 connecting between line 656 and the reference potential. Line 662 connects one contact of nonnally open contacts R7-3 with line 650 between contacts R1 L4 and the parallel connected contacts R4-2, R5-2 and R5-2 and its other contact with line 658 between contacts TD-l and fuse F5. Connected in parallel between line 652 and line 664 are normally open contacts R4-3, R5-3, R6-3, and R9-2. Line 666 connects relay TD2 between line 664 and the reference potential while line 668 connects relay J D3 between line 664 and the reference potential. Line 670 connects between line 664 and the reference potential and serially connects fuse F7 and the finger solenoid 413. Line 672 connects relay R9 and a normally open manual positioning switch 674 in series across line 652 and the reference potential. Line 691 connects through line 606 to line 602 between R9-l and R7-1. Disposed serially in line 691 are the normally closed contacts TDl-2.

Turning back now to FIG. 22A, line 676 serially connects relay R8, a normally closed zero slow switch 680, a normally closed 24 inch slow switch 682 and a normally closed 16 inch slow switch 684. Line 686 connects to line 676 across the power supply and serially connects normally open contacts R8-1, fuse F8 and fast conveyor solenoid 688. Line 690 containing normally open contacts R7-4 connects to line 676 between switches 682 and 684 and to line 604 between contacts R3-2 and R202. Line 692 containing normally open contacts R3-2 also connects to line 675 between switches 682 and 684 and to line 604 between contacts R3-2 and R2-2.

As will be recalled, the foregoing described circuitry relates principally to the manner of advancing the conveyor either automatically in discrete increments of movement or manually. With the circuit energized as illustrated, assume that it is desired to automatically advance the conveyor 16 inches to locate the partially completed frame in position below the nailing heads as more particularly described hereinafter. The operator presses the 16 inch command switch 616 thereby energizing relay R2 via

lines

600, 602, 614 and 618 and relay R5 via

lines

600, 602, 614, 618, 628 and 624. En.- ergization of relay R2 opens normally closed contacts R2-2 and R2-3 to lock out relays R1 and R1 and energize the 16 inch stop solenoid 420. This prevents actuation of the command circuits through the 1.5 inch and 24 inch command switches 604 and 622, respectively. Energization of relay R2 also closes normally open contacts R2-l to complete a holding circuit to relay R2 via

lines

600, 602, 624 and 628 and to relay R5 via

lines

600, 602, 606 and 624. Energization of relay R5 closes

Claims

1. Apparatus for fabricating a wooden frame, panel or the like having a pair of elongated frame members and a plurality of intermediate members spaced one from the other and extending between the elongated frame members comprising: means for supporting the pair of elongated frame members with an intermediate frame member extending therebetween in a generally common horizontal plane, a pair of nailing assemblies along respective opposite sides of said support means, a nailing gun carried by each of said nailing assemblies, means for actuating each of said nailing guns for driving a nail through the corresponding elongated frame member and into the corresponding end of the intermediate frame member, means mounting said nailing guns for movement between discrete positions for driving nails through each elongated member at different elevations, and means for automatically shifting said nailing guns from one elevation to another elevation in response to completion of nailing at said one elevation in order to drive a nail at said other elevation.

2. Apparatus according to claim 1 wherein each of said nailing guns is mounted for pivotal movement about an axis spaced from the end thereof through which the nails are driven into the frame members, said shifting means including means for pivoting said guns about said axis whereby the nails at said different elevations are driven in non-parallel directions relative to one another.

3. Apparatus according to claim 1 including a pair of carriages along respective opposite sides of said support means with each carriage being mounted for linear movement toward and away from the frame members, said nailing guns being carried by said carriage for movement therewith, and means for moving said carriages toward the frame members to engage the ends of said nailing guns against the elongated frame members and clamp the latter against the ends of the intermediate frame member in response to actuation of said nailing machines.

4. Apparatus according to claim 1 wherein said last mentioned means includes means for shifting the nailing guns from said other elevation back to said one elevation in response to completion of nailing at said other elevation.

5. Apparatus according to claim 1 wherein said nailing assemblies are fixed to said support means against longitudinal movement, said support means including a conveyor for moving the frame members longitudinally through and relative to said nailing assemblies, means for advancing said conveyor, and means for automatically stopping said conveyor after said conveyor has advanced a predetermined distance equal to the predetermined spacing between the first mentioned and a second intermediate frame member located between the elongated frame members in the completed frame.

6. Apparatus according to claim 5 including a stop disposed between said nailing assemblies for engagement by an intermediate frame member to transversely align the latter with said nailing guns, and means for moving said stop out of engagement with the intermediate frame member upon completion of nailing thereby enabling the partially completed frame comprised of the elongated frame members and intermediate frame members to be advanced by said conveyor.

7. Apparatus for fabricating a wooden frame, panel or the like having a pair of elongated frame members and a plurality of intermediate members spaced one from the other and extending between the elongated frame members comprising: means for supporting the pair of elongated frame members with an intermediate frame member extending therebetween in a generally common horizontal plane, a pair of nailing assemblies along respective opposite sides of said support means, a nailing gun carried by each of said nailing assemblies, means for actuating each of said nailinG guns for driving a nail through the corresponding elongated frame member and into the corresponding end of the intermediate frame member, means mounting said nailing guns for movement between discrete positions for driving nails through each elongated member at different elevations, means for automatically shifting said nailing guns from one elevation to another elevation in response to completion of nailing at said one elevation in order to drive a nail at said other elevation, said support means including a conveyor for moving the frame members through said nailing assemblies, means for advancing said conveyor, and means for automatically stopping said conveyor after said conveyor has advanced a predetermined distance equal to the predetermined spacing between the first mentioned and a second intermediate frame member located between the elongated frame members in the completed frame, said stop means including a rack and a pinion for moving the rack along a predetermined path from an initial position, a drive shaft for said conveyor coupled to said pinion and means movable into the path of movement of said rack at selected positions along said path to stop said rack and the conveyor shaft coupled thereto.

8. Apparatus according to claim 7 including means for returning said rack to its initial position.

9. Apparatus according to claim 8 wherein said conveyor advance means includes a reversible motor, a first clutch coupling said drive shaft and said reversible motor, a second clutch coupling said drive shaft and said pinion, and means for actuating said clutches to advance said conveyor and said rack when said motor operates in one direction, means for declutching said conveyor drive shaft and said motor when said motor is operated in a reverse direction to return said rack to its initial position.

10. Apparatus according to claim 5 including means responsive to actuation of said nailing guns for disabling said conveyor advancing means.

11. Apparatus according to claim 5 including means responsive to actuation of said conveyor advancing means for disabling said nailing gun actuating means and maintaining the same disabled while said conveyor advancing means is actuated to advance the partially completed frame.

12. Apparatus according to claim 5 including means responsive to actuation of said nailing guns for disabling said conveyor advancing means, means responsive to actuation of said conveyor advancing means for disabling said nailing gun actuating means and maintaining the same disabled while said conveyor advancing means is actuated to advance the partially completed frame.

13. Apparatus according to claim 1 including means for adjusting the distance between said one elevation and said another elevation for each said nailing gun.

14. Apparatus according to claim 1 including means carried by each nailing assembly for clamping the corresponding elongated frame member and end of the intermediate frame member to said support means to maintain the frame members in a common horizontal plane.

15. Apparatus according to claim 14 including a pair of carriages along respective opposite sides of said support means with each carriage being mounted for movement toward and away from the frame members, said nailing guns being carried by said carriage for movement therewith, means for moving said carriage toward the frame members to engage the ends of said nailing guns against the elongated frame members and clamp the latter against the ends of the intermediate frame members, each of said clamping means including a clamping head having a surface for engaging the frame members, the portion of said surface engageable against the corresponding elongated frame member being smooth thereby facilitating clamping of the elongated frame member against the end of the intermediate frame member in response to movement of the corresponding carriage into engagement with the elongated frame member, the portion of said surface engageable against the intermediate frame membEr being roughened to prevent movement of the intermediate frame member when the elongated frame member is clamped thereagainst.

16. Apparatus according to claim 1 including means for adjustably spacing said nailing assemblies one from the other.

17. Apparatus according to claim 16 wherein said spacing means comprises means for displacing one nailing assembly relative to the other a discrete predetermined distance.

18. Apparatus according to claim 17 wherein said spacing means includes a screw carried by said support means and a follower coupled to said screw and said one nailing assembly, said displacing means including a fluid actuated cylinder connected to said screw for axially displacing the latter and said follower a discrete predetermined distance, and means for rotating said screw thereby to displace said follower and the nailing assembly connected thereto over distances other than said discrete distance.

19. Apparatus for fabricating a wooden frame, panel or the like having a pair of elongated frame members and a plurality of intermediate frame members spaced one from the other and extending between the elongated frame members comprising means for supporting the pair of elongated frame members with an intermediate frame member extending therebetween in a generally common horizontal plane, a pair of nailing assemblies fixed along respective opposite sides of said support means, a nailing gun carried by each nailing assembly, means for actuating each nailing gun for driving a nail through the corresponding elongated frame member and into the corresponding end of the intermediate frame member, a conveyor for moving the frame members relative to and through said nailing assemblies, means for advancing said conveyor and means for automatically stopping said conveyor after said conveyor has advanced a predetermined distance equal to the predetermined spacing between the first mentioned and a second frame member located between the elongated frame members in the completed frame.

20. Apparatus according to claim 19 including a stop disposed between said nailing assemblies for engagement by an intermediate frame member to transversely align the latter with said nailing guns, and means for moving said stop out of engagement with the intermediate frame member upon completion of nailing thereby enabling the partially completed frame comprised of the elongated frame members and intermediate frame members to be advanced by said conveyor.

21. Apparatus for fabricating a wooden frame, panel or the like having a pair of elongated frame members and a plurality of intermediate frame members spaced one from the other and extending between the elongated frame members comprising means for supporting the pair of elongated frame members with an intermediate frame member extending therebetween in a generally common horizontal plane, a pair of nailing assemblies along respective opposite sides of said support means, a nailing gun carried by each nailing assembly, means for actuating each nailing gun for driving a nail through the corresponding elongated frame member and into the corresponding end of the intermediate frame member, a conveyor for moving the frame members through said nailing assemblies, means for advancing said conveyor and means for automatically stopping said conveyor after said conveyor has advanced a predetermined distance equal to the predetermined spacing between the first mentioned and a second frame member located between the elongated frame members in the completed frame, said stop means including a rack and a pinion for moving the rack along a predetermined path from an initial position, a drive shaft for said conveyor coupled to said pinion and means movable into the path of movement of said rack at selected positions along said path to stop said rack and the conveyor shaft coupled thereto.

22. Apparatus accordint to claim 21 including means for returning said rack to its initial position.

23. Apparatus according to claim 22 wherein said conveyor adVance means includes a reversible motor, a first clutch coupling said drive shaft and said reversible motor, a second clutch coupling said drive shaft and said pinion, and means for actuating said clutches to advance said conveyor and said rack when said motor operates in one direction, means for declutching said conveyor drive shaft and said motor when said motor is operated in a reverse direction to return said rack to its initial position.

24. Apparatus according to claim 19 including means responsive to actuation of said nailing guns for disabling said conveyor advancing means.

25. Apparatus according to claim 19 including means responsive to actuation of said conveyor advancing means for disabling said nailing gun actuating means and maintaining the same disabled while said conveyor advancing means is actuated to advance the partially completed frame.

26. Apparatus according to claim 19 including means responsive to actuation of said nailing guns for disabling said conveyor advancing means, means responsive to actuation of said conveyor advancing means for disabling said nailing gun actuating means and maintaining the same disabled while said conveyor advancing means is actuated to advance the partially completed frame.

27. Apparatus according to claim 19 including means, carried by each nailing assembly for clamping the corresponding elongated frame member and end of the intermediate frame member to said support means to maintain the frame members in a common horizontal plane.

28. Apparatus according to claim 27 including a pair of carriages along respective opposite sides of said support means with each carriage being mounted for movement toward and away from the frame members, said nailing guns being carried by said carriage for movement therewith, means for moving said carriages toward the frame members to engage the ends of said nailing guns against the elongated frame members and clamp the latter against the ends of the intermediate frame members, each of said clamping means including a clamping head having a surface for engaging the frame members, the portion of said surface engageable against the corresponding elongated frame member being smooth thereby facilitating clamping of the elongated frame member against the end of the intermediate frame member in response to movement of the corresponding carriage into engagement with the elongated frame member, the portion of said surface engageable against the intermediate frame member being roughened to prevent movement of the intermediate frame member when the elongated frame member is clamped thereagainst.

29. Apparatus according to claim 19 including means for adjustably spacing said nailing assemblies one from the other.

30. Apparatus according to claim 29 wherein said spacing means comprises means for displacing one nailing assembly relative to the other a discrete predetermined distance.

31. Apparatus for fabricating a wooden frame, panel or the like having a pair of elongated frame members and a plurality of intermediate frame members spaced one from the other and extending between the elongated frame members comprising means for supporting the pair of elongated frame members with an intermediate frame member extending therebetween in a generally common horizontal plane, a pair of nailing assemblies along respective opposite sides of said support means, a nailing gun carried by each nailing assembly, means for actuating each nailing gun for driving a nail through the corresponding elongated frame member and into the corresponding end of the intermediate frame member, a conveyor for moving the frame members through said nailing assemblies, means for advancing said conveyor and means for automatically stopping said conveyor after said conveyor has advanced a predetermined distance equal to the predetermined spacing between the first mentioned and a second frame member located between the elongated frame members in the completed frame, means for adjustably spacing said nailing assemblies one from The other, said spacing means comprising means for displacing one nailing assembly relative to the other a discrete predetermined distance, said spacing means including a screw carried by said support means and a follower coupled to said screw and said one nailing assembly, said displacing means including a fluid actuated cylinder connected to said screw for axially displacing the latter and said follower a discrete predetermined distance, and means for rotating said screw thereby to displace said follower and the nailing assembly connected thereto over distances other than said discrete distance.

32. Apparatus according to claim 5 wherein said conveyor advancing means includes means for advancing the conveyor a plurality of discrete distances, means for stopping said conveyor after advancement thereof a distance equal to each of said discrete distances, and means for selectively actuating said stopping means to advance said conveyor one of said plurality of discrete distances.