US3705609A

US3705609A - Manufacture of springs

Info

Publication number: US3705609A
Application number: US68677A
Authority: US
Inventors: George A Matts; Robert C Quarmby
Original assignee: USM Corp
Current assignee: Emhart Industries Inc
Priority date: 1970-09-01
Filing date: 1970-09-01
Publication date: 1972-12-12
Anticipated expiration: 1989-12-12

Abstract

The invention relates to improvements in machines and methods for forming attached loops in generally longitudinal orientation at or from end portions of coil springs. A coil spring to be provided with a loop as indicated is supported by support means of a machine with an end portion of the spring to be looped, projecting therefrom. The projecting portion is operated on by a plurality of coordinated tools to bend the portion away from the remainder of the spring and impart a permanent set to a portion of the wire of the spring whereby a loop of the desired orientation is permanently provided on the spring. The improvement involves a plurality of fluid pressure operated motors and connecting means for actuating the tools in cooperative manner.

Description

[54] MANUFACTURE OF SPRINGS [72] Inventors: George A. Mutts; Robert C. Quarmby, both of Leicester, England Assignee: USM Corporation, Boston, Mass.

Filed: Sept. 1, 1970 Appl. No.: 68,677

us. Cl. ..140/103 rm; Cl. .321: 35/02 Field of Search ..140/103; 92/138 References Cited UNITED STATES PATENTS 3,205,917 9/1965 Vanhulen "140/103 3,246,58l 4/1966 Carr ..92/138 ns] 3,705,609 [4 1 Dec. 12,1972

Primary Examiner-Lowell A. Larson Attorney-Richard A. Wise, Richard B. Megley and Cornelius A. Cleary [57] ABSTRACT The invention relates to improvements in machines and methods for forming attached loops in generally longitudinal orientation at or from end portions of coil springs. A coil spring to be provided with a loop as indicated is supported by support means of a machine with an end portion of the spring to be looped, projecting therefrom. The projecting portion is operated on by a plurality of coordinated tools to bend the portion away from the remainder of the spring and impart a permanent set to a portion of the wire of the spring whereby a loop of the desired orientation is permanently provided on the spring. The improvement involves a plurality of fluid pressure operated motors and connecting means for actuating the tools in cooperative manner.

C eim D i F u Jigsaw 11.4

m 2 7 I "all PATENTED DEC 12 I972 SHEET 1 OF 3 In 1/9 12 f0 r5 George Art/2 [If/ '70 its n3 QM PATENTED DEC 12 1972 SHEET 2 OF 3 PATENTED um: 12 1912 SHEET 3 BF 3 1 MANUFACTURE OF SPRINGS BACKGROUND OF THE INVENTION In the manufacture of coil springs it is often necessary to provide them with attaching loops at their ends. This is generally done by bending an end portion comprising one or more coils away from the remainder of the spring and form in this portion a loop in generally longitudinal orientation from the remainder of the spring.

Because of the large variety of coil springs in demand, involving wide variation in diameter and material specifications of wire used, it has proved difficult to provide a machine capable of forming loops both conveniently and effectively. As a result in many cases the use of highly skilled labor had been necessary to form loops in coil springs of consistently high quality. Recently, however, such a machine, capable of providing loops in coil springs in consistently high quality without the necessity of employing skilled labor, has been developed. That machine together with amethod for loop forming is disclosed in copending application Ser. No. 33,271, filed Apr. 30, 1970, now US. Pat. No. 3,662,788 and that disclosure is incorporated herein by reference. That disclosed machine, while being compact in size and simple in its operation is hand operated SUMMARY OF THE INVENTION The present invention is directed to a poweroperated spring looping machine which may bearranged to operate in a manner similar to that described in the previously identified patent application. In that respect the machine includes a frame and base plate carrying a spring supporting means including a spring holder for supporting a coil spring with an end portion of the spring projecting from the support means and tool assemblies for operating on the projecting end of the spring to provide a permanently set, longitudinally oriented loop at or on that end. The machine includes as one of the tool assemblies a loop bending means which is motor actuated to move the operating instrumentalities transversely of the support means. The first bending means includes a pair of tool portions, the lead portion of which is adapted to be inserted between the coils to initially separate them away from the remainder of the spring, and a following or loop bending portion which is adapted to bend the separated coil or coils further in longitudinal orientation. The first bending means includes mounting means for the tool portions, motor connecting means and fluid drive motors for actuating the tool portions in the prescribed manner. The machine includes a second tool assembly having a loop setting means which is also motor actuated to move transversely of the support means and operates to impart a permanent set to the wire whereby the loop retains the desired orientation. The loop setting means includes an assembly for mounting a setting tool, motor connecting means and a fluid drive motor for actuating the setting tool in the prescribed manner;

One embodiment of the machine, which may be used for illustration, comprises a block secured to the base plate between the tool assemblies and a spring holder detachably secured in said block. The spring holder is selected to have a bore of diameter such that a spring to be operated upon is slidingly received therein with the portion at which a loop is to be formed projecting beyond a rear end portion of the holder. The bore is flared outwardly at a front end portion thereof to facilitate introduction by an operator of springs into the bore, especially short springs.

The illustrative machine also includes a gauge member comprising a spring locating head mounted for movement between an operative position in which the locating head is in alignment with the bore of the spring holder of the supporting means to facilitate positioning of a spring longitudinally and in a desired orientation in the spring holder, and, an inoperative position in which the gauge member is clear of the tools on the tool assemblies and out of alignment with the spring holder such that a formed spring may be ejected rearwardly from the spring holder without interference by the gauge member. The locating head of the gauge includes a locating face from which projects a narrow projection which serves to facilitate proper locating of the coil spring, and particularly that portion of the spring which projects from the holder and is to be operated upon to provide a loop. The position of the locating face is adjustable toward and away from the spring support means according to the spring being operated on. The locating head is adapted to be locked in an adjusted position; and, additionally, the angular orientation of the projection may be altered.

The first tool assembly is arranged to support a tool comprising first and second portions movable along parallel paths relative to each other transversely of the support means, the tools preferably being similarto those described in the above identified patent application. Each tool portion is secured to an associated one of two tool holders mounted adjacent and slidable relative to each other in a slideway. Each tool holder is connected to an associated slide member provided by a rack mounted in a slideway for movement along a fixed path of fixed length, the rack being arranged to be moved by a motor in the operation of the illustrative machine. The tool holder is connected to the rack by screw means comprising a screw member rotatable in the rack and threaded into the tool holder such that rotation of the screw member adjusts the position of the tool holder relative to the rack longitudinally of the fixed path.

Each of the racks in the first tool assembly is arranged to be driven by an associated one of two fluid, and more specifically air operated motors comprising a cylinder in which a piston member is movable, the cylinders preferably being bored out of a metal block and lying side by side with their axes parallel. Each piston has a left and right end portion in sealing engagement with the walls of the cylinder in which it is housed. Each motor comprises output means comprising a rack secured to the piston member between the end portions of the piston member and a connecting portion provided by a pinion rotatably mounted in meshing engagement with the rack on the piston member and projecting from the cylinder through an opening in the wall thereof into meshing engagement with the rack in the slideway. The movement of each piston member is restricted in such a manner that the opening in the wall of the cylinder is disposed, throughout the -movement of the piston member, between the left and right end portions of the piston member. The pinion of one of the motors is integral with a shaft rotatably mounted in the block with its axis at right angles to the axis of both cylinders and intersecting both cylinders. The pinion of the other motor is rotatably mounted on the shaft adjacent the integral pinion. This compact arrangement permits the output from one motor to be in an offset portion so that two cylinders of large diameter can be used, which are separated by a wall to drive two members. Furthermore, the taking of output through the side of each cylinder cuts down the overall length of motor necessary for any given travel and length of piston bearing surface because no piston rod projects beyond the end of the cylinder, although for any given diameter of cylinder the motor will take up a greater overall width than would be the case were a piston rod to be used.

The second tool assembly is arranged to support a setting tool movable transversely of the support head and opposing the first tool assembly with the setting tool being similar to that described in the above identified patent application. The tool is secured to a tool holder which is in turn connected to an associated slide member provided by a rack mounted in a slideway for movement along a fixed path of fixed length, the rack being arranged to be moved by a motor in the operation of the machine. The tool holder is connected to the rack by screw means comprising a screw member rotatable in the rack and threaded into the tool holder so that rotation of the screw member adjusts the position of the tool holder relative to the rack longitudinally of the fixed path. The rack then is arranged to be driven by an associated fluid, and more specifically air operated motor, comprising a cylinder carrying a movable piston member. This cylinder is mounted pivotally on the base plate to allow the setting tool to be operated through an are extending generally from front to rear of the machine. The piston member has a left and right end portion in sealing engagement with the walls of the cylinder in which it is housed. A motor out put means comprises a rack secured to the piston member between the end portion of the same and a connecting portion is provided by a pinion rotatably mounted in meshing engagement with the rack carried on the piston. The connecting portion projects from the cylinder through an opening in the wall and then into meshing engagement with the rack in the slideway.

DESCRIPTION OF THE DRAWINGS The foregoing and other features of the invention will now be more particularly described in connection with the accompanying drawings, wherein:

FIG. 1 is a view in front elevation, partly in section and partly broken away of an illustrative embodiment of the spring looping machine which is the subject of the present invention;

FIG. 2 is a view in plan, partly in section and partly broken away, of the same illustrative embodiment of the subject machine; and

FIGS. 3-6 inclusive are detail view in plan, partly in section and with parts broken way, showing progressive stages in the formation of a loop relative to the tools used in the same embodiment of the subject machine.

DESCRIPTION OF THE ILLUSTRATIVE MACHINE The illustrative machine comprises a frame 180 (FIGS. 1 & 2) comprising a base plate 182 supported by legs 184. A left hand tool assembly 186 and a right hand tool assembly 188 are mounted on the base plate 182.

The right hand assembly 188 comprises a cylinder block 190, secured to the base plate 182, in which are bored a cylinder 192 of a front air motor 193 and a cylinder 194 of a rear air motor 195 (see FIG. 2). The ends of the

cylinders

192 and 194 are closed by end plates 196, 198 provided with seals 197. The construction and arrangement of the

air motors

193 and 195 are generally similar and for this reason only the front motor 193 will be described in detail; also, the arrangement in the end plates 196, 198 is similar at both ends of the motor 193 and thus only the construction of the right hand end plates 196 will be described in detail.

Mounted for sliding movement in the cylinder 192 is a double-acting piston member 200 preferably made of synthetic polymer material such as Delrin acetal resin (Delrin is a registered trademark). The piston member 200 comprises a central portion 202 from left and right hand end portions of which project cylindrical portions 204 on which are mounted sealing rings 206 in sealing engagement with the cylinder 192. Cylindrical portions 208 coaxial with but of smaller diameter than the portions 204, project from the portions 204. Sealing rings 210 are mounted on the portions 208 and are of a diameter to be received in sealing engagement in cylindrical bores 212 and 213 in the end plates 196 and 198, coaxial with the cylinder 192. Pipes 214 and i 216 respectively lead to the right and left end plates 196 and 198 and are respectively connected by similar flow paths in the end plates to the cylinder 192, the pipe 214 being connected to the space between the end plate 196 and the piston member 200, and the pipe 216 to the space between the end plate 198 and piston member 200.

The flow path in the end plate 196 comprises a passage 218 (FIG. 1) leading from the position at which the pipe 214 is connected to theplate 196 to a right hand end portion of the bore 212 and a branch passage 220 perpendicular to the passage 218 opening into the cylinder 192 through an end face 199 of the end plate 196 opposite the cylindrical portion 204. A ball check valve 222 is accommodated in the passage 220, arranged to seat on a shoulder 223 in the passage 220 to permit flow of air through the passage 220 from the passage 218 to the cylinder but not in the reverse direction. A passage 225 (FIG. 1) having a needle valve 227 therein connects the right hand portion of the bore 212 with the end face 199 of the end plate 196. This arrangement provides a dash-pot effect as the piston member 200 is moved to the right (viewing FIG. 1) in the operation of the illustrative machine.

As the member 200 is moved to the right, away from the position in which it is shown in FIG. 1, under the influence of air under pressure admitted through the pipe 216, pipe 214 being open to exhaust, the ball 222 seats on the shoulder 223 and closes the passage220. Air escapes through the passage 225 past the needle valve and through the bore 212 and passage 218. When the sealing ring 210 enters the bore 212, air from between the right seal 206 and end face 199 ofthe end plate can only escape by the needle valve which permits only restricted flow. Thus movement of the member 200 to the right (and in a similar manner to the left) is cushioned as the end of its stroke is reached. Air under pressure may be introduced through pipe 214, the pipe 216 being open to exhaust, to move the member 200 to the left to lift the ball 222 and permit air to reach the member 200 to effect its movement.

A recess 224 (FIG. 1) is provided in an upper part of the central portion 202 of the piston member 200, and

an axial steel rack 226 is securedto the piston member 200 at the bottom of the recess 224. As hereinbefore mentioned the

motors

193 and 195 are generally similar and the motor 195 comprises a piston member 2'28 (generally similar to'the'member 200) in a recess 230 in which is secured a rack 232, see FIG. 2). i

A cylindrical bore 234 (FIG; 1) extends through the cylinder block 190 from front to rear thereof and intersects the

cylinders

192 and 194 about halfway along their length and in an upper portion thereof. An axle and pinion member 236 is mounted in the bore 234 for rotation therein, end portions of the member 236 being mounted for rotation in bearings carried in side plates 238 secured to the block 190 and covering the ends of the bore 234. A pinion 240 of the member 236 is in mesh with the rack 232 of the rear motor 195and extends forwardly so that a front end portion lies in a rear portion of the cylinder 192. A pinion 242 is mounted for free rotation on an axle portion of the member 236 in front of the pinion 240 in meshing engagement with the rack 226 of the front motor 193.

A front rack 244 (FIGS. 1 & 2) is mounted for horizontal movement transversely of the illustrative machine in a slideway 243 (also intersected by the bore 234 in the block 190) in meshing engagement with the pinion 242 and has an upward projecting right hand end portion 246. A rear rack 248 is mounted in the slideway adjacent the rack 244 and in mesh with the pinion 240; the rack 248 also has an upwardly projecting right hand end portion 250. Adjacent surfaces of the

racks

244 and 248 are in sliding contact. A top plate 252 is secured to the block 190 above the slideway and upper surfaces 254 of the

end portions

246 and 250 are in sliding contact with the plate. The

racks

244 and 248 are thus mounted side-by-side for sliding movement in the slideway along fixed paths.

A front tool holder 256 (FIGS. 1 & 2) is mounted in the slideway 243 and secured to the rack 244 for horizontal transverse movement in the slideway 243, and a rear tool holder 258 is mounted in the slideway for horizontal transverse movement therein and secured to the rack 248. The mounting of the holders 256 and 258 and their connection to the associated rack is generally similar and will therefore be described with reference to the front holder 256 and rack 244.

The holder 256 comprises a right hand portion 260 which overlies a portion of the front rack 244 to the left of the upstanding right hand end portion 246 thereof. A lefthand portion 262 of the holder slides in the slideway 243. A peg 264 is secured in the portion 260and projects upwardly into a slot 266 across the top plate 252. A screw member 270 is mounted inthe right hand end portion 246 of the rack 244 for free rotation therein and extends leftwardly into a screw-threaded bore 272 in the right hand portion of the tool holder 256. The screw member 270 is held'against left or right movement in the portion 246 by a collar 274 secured to the member 270 and bearing on the portion 246 and a collar 276 held in bearing engagement with the portion 246 by a pin 278 in an end portion of the member 270 projecting to the right beyond the portion 246. A block 280 is secured to the cylinder block to the right of the rack 244 andhas a bore 282'in alignment with the screw member 270. Adjusting means of the illustrative machine comprises a shaft 284 rotatably mounted in the bore 282, having a knurled head 286 secured to a right hand end portion thereof; a spring 288 surrounds the shaft284disposed between the head 286 and block 280 to urge the shaft 284 rightwardly viewing FIG. 1. A pin 290 extending through the shaft 284 to the left of the block 280 prevents theshaft 284 being urged from the bore 282 by the spring 288. A left hand end portion of the shaft 284 has a bore, not shown, therein adapted to receive the right hand end portion of the member 270 and a slot 294 adapted to receive the pin 278. A lip of the block 280 surrounds the left hand end portion of the shaft 284 and abuts right hand end faces of the top plate 252 and cylinder block 190 adjacent the slideway 243.

The shaft 284 is normally urged to the right as hereinbefore mentioned. The rack 244 and tool holder 256 are movable between a left, innermost position and a right, outermost position; the innermost and outermost positions of the holder 256 are determined by the stroke of'the member 200 and the position to which the holder has been adjusted on the rack 244. Engagement of the peg 264 with the top plate 252 at the ends of the slot 266 limits the adjustment of the holder on the rack. The construction and arrangement is such that when the rack 246 and the shaft 284 are in their outermost position the shaft 284 will not be in contact with the member 270. However, when the rack 246 is in its outermost position the shaft may be pushed to the left by an operator, against the action of "the spring 288, such that the right hand end portions of the screw member 270 (also part of the adjusting means) is received in the bore 292 in the shaft 284 and the pin 278 is received in the slot 294. The head 286 may then be turned to rotate the shaft 284 and, through the slot 294 and pin 278, the screw member 270 so that the screw member is screwed further into or out of the bore 272, as required, to move the tool holder 256 leftwardly or rightwardly in relation to the rack 244. Thus the position of the front tool holder 256 on the rack 244 may be adjusted to set the innermost position to which the tool holder moves by means of the head 286 which does not move as the rack 244 and holder 256 are moved in the operation of the illustrative machine. The position of the rear tool holder 258 on the rear rack 248 may also be similarly adjusted by means comprising a shaft 302, FIG. 2, (similar to the shaft 284) having a head 304 and a screw member (not shown in the drawings) similar to the member 270. A coil separating or opening tool 298 (FIGS. 2-6) is secured to a left hand end portion of the tool holder 256 by means of bolts, not shown. A coil bending or anvil tool .512 (FIGS. 2-6) is attached to a left hand end portion of the tool holder 258 by bolts (not shown).

The left hand tool assembly 186 (FIGS. 1 & 2) comprises a cylinder block 306 in which is bored a cylinder 308. A piston member 310, similar to the piston member 200 except that it has no reduced cylindrical end portions corresponding to the portions 208 of the member 200, is mounted in the cylinder 308 and has a rack 314 secured thereto in a recess 316. Thus no cushioning effect is present when the member 310 reaches the end of its stroke. A bore 312, similar to the bore 234, extends from front to rear of the block 306, and a pinion member 318 is mounted with a pinion thereof in meshing engagement with the rack 314, for rotation in bearings carried by end plates 320 secured to the block 306 and covering the ends of the bore 312. Ends of the cylinder 308 are closed by

end plates

322 and 324. A pipe 326 opens into a passage in the left end plate 322 leading to the cylinder 308 to the left of the piston member 310, and a pipe 328 opens into a passage in the right end plate 324, to the right of the piston member 310.

A rack 330 is mounted, in meshing engagement with the pinion of the member 318, in a slideway, not shown, intersected by the bore 312. A tool holder 334 is mounted in the slideway and secured to the rack 330 in a manner similar to that hereinbefore described with reference to the rack 244 and tool holder 256. The rack 330 and holder are retained in the slideway by a top plate 336 secured to the block 306. A coil setting or hammer tool 338 (FIGS. 1-6) comprising a rod having a wire receiving notch 340 at a right hand end portion thereof is mounted on the tool holder 334 with a left hand end portion thereof received in a bore, not shown, in the holder 334 and secured therein by a large grub screw 344.

The left cylinder block 306 of the illustrative machine is mounted on the base plate 182 for pivotal movement on a pivot pin 346 (FIG. 1) passing through the base plate 182 secured in a boss 347 projecting from a left hand portion of the block 306. The block 306 accordingly may be adjusted angularly about the pin 346, to move the notch 340 of the tool 338 in an arc (of relatively large radius) extending generally from front to rear of the illustrative machine by block adjusting means 348.

The block adjusting means 348 comprises a mounting member 349 in which a screw member 350 having a head 351 is mounted for rotational movement. The screw member 350 is threaded into a pin 352 rotatable about a vertical axis in bearings carried by bosses 353 projecting from the block 306. A spring 354 (FIG. 2) carried on the screw member 350 between the pin 352 and mounting member 349 urges the pin 352 and member 349 apart to take up backlash. The screw member 350 is mounted in the member 349 with a slight amount of play so that the screw member 350 can pivot slightly as it is screwed into or out of the pin 352 to adjust the angular position of the block 306.

The block 306 can be locked in a position to which it has been moved by means of a lock bolt 355 threaded into the block 306 and passing through an oversize hole 356 in the base plate 182. A head 357 of the lock bolt is arranged to bear on a washer 358 which in turn bears on the base plate 182 so that tightening of the bolt 355 locks the block 306 to the base plate 182.

Spring supporting means 359 (FIG. 1) of the illustrative machine is mounted on the base plate 182 at a front portion thereof between the

tool assemblies

186 and 188. The spring supporting means 359 comprises a block 360 secured to the base plate 182 and projecting upwardly therefrom. A horizontal bore 362 extends from front to rear of an upper portion of the block 360..

The block 360 has a horizontal cut 364 running from front to rear thereof and extending inwardlyfrom a right hand side of the block 360 into the bore 362. A vertical lockbolt 366 having a knurled head 368 arranged to bear on an upper surface of the block 360 passes through a bore in a portion of the block above the cut 364 and is threaded into the block below the cut 364. A spring holder 370, comprising a head portion 372, a cylindrical shank portion 374 and a springreceiving bore 376 is mounted in the block 360'with the cylindrical shank portion 374 slidingly received in the bore 362 and the head portion 372 in contact with a front face of the block 360. The holder 370 is rotated about the axis of the bore 376 so that flat edge 378 on the head portion 372 is located against a vertical shoulder 380 on the block 360, to correctly orient the holder 370. The spring holder 370 is clamped in place by tightening the lock bolt 366. A front portion of the bore 376 flares outwardly to, inter alia, allow short springs, having only a few coils, to be readily inserted in and removed from the holder by an operator. A notch 377 (FIG. 2) is cut in a rear end portion of the holder and so positioned as to be in alignment with the hammer tool 338 when the holder is correctly inserted in the block 360.

A gauge 382 is mounted on the cylinder block 190 of the left tool assembly 188 of the illustrative machine (see FIG. 2). A bracket 384 projecting from the block 190 supports a pin 386 in bearings, not shown, for rotation about a vertical axis. A bell crank

lever having limbs

390 and 392 is secured to said pin 386 for rotational movement therewith about said vertical axis. An outer end portion of the limb 390 is pivotally secured to an outer end portion of a piston rod 394 of an air motor 396 mounted for pivotal movement about a vertical axis on a pivot pin 398 (FIG. 2) secured to the block 306.

An outer end portion of the limb 392 carries a work clamp member 400 (FIG. 2) having a horizontal, screw threaded bore 402 therethrough and having a horizontal cut, not shown, therein extending for the length of the bore and inwardly from an outer face of the clamp member 400 (opposite where the clamp member 400 joins the limb 392) into the bore. A vertical lock bolt member; the member 410 may belocked in a position to which it has been screwed in the bore 402 by tightening the lock bolt 406 to clamp the clamp member 400 about the screw member 410. A cylindrical bore'414 (FIG. 2) extends longitudinally through the screw member 410. A rod 416 is rotatably mounted in the bore 414. A locating head 418 secured in front of the screw member 414 toan end portion of the rod'416 and a knurled knob 500 secured to an end portion of the rod 416 to the rear of the head 417 prevent longitudinal movement of the rod 416 in the member 410. A leaf spring 502 is secured to the head 412 and extends rearwardly such that a dog, not shown, engages between teeth of atoothed portion 506 on the knob 500. i r

' A projection 508 (FIG. 2) extends forwardly from a flat front locating face 510 of the locating head 418 The projection. 508 is in the form of a narrow radial strip ofuniform width and tapering from the periphery of the head418 to merge with the locating face 510 at the center thereof. I

The

bell crank lever

390, 392 may position in which'the rod 416 is in axial alignment with the bore 376 in the spring holder 370 and the locating face 510 is adjacent a rear end of the holder, and an inoperative position in which the gauge is clear of the spring holder 370. The position of the face 510 in relation to the holder 370 may be adjusted by shifting the longitudinal position of the screw'member 410 in the clamp member 400, and'the angular position of the projection 508 may be adjusted by turning the knob 500, it being maintained in the adjusted position by en-. gagement of the dog between teeth of the toothed portion 506, according to the spring to be operated upon, the number of coils desired in the loop, and the position at which the cut end of the wire of the spring is to be located (this being dependent on the form and type of loop to be made).

As indicated previously, the opening tool 398 and the anvil tool .512 are similar to the tools of. the machine described in the specification of copending patent application Ser. No. 33,271. The tool 298 is of T-shaped cross section and comprises a plate portion 514 (FIGS. 3-6), a front face of which is arranged to slide over the rear end portion of the spring holder 370 in the operation of the machine, and a key 516 projecting rearwardly from the rear of the plate portion 514 into a slot 518 (FIG. 3) in the anvil tool 512. A left hand end portion of the plate portion 514 and key 516 taper to a point lying in the plane of the front face of the portion 514. A sloping face 520 of the key 516 tapering to the point provides a lifting face of the tool 298. A left hand face 522 (FIGS. 3 & 4) provides an anvil face of the anvil tool 512.

The operation of the illustrative machine is shown sequentially in FIGS. 36 and is similar to the operation of the machine disclosed in the previously identified application. In FIG. 3 a spring 524 is shown in the spring holder 370 with a rear end portion at which a loop is to be formed projecting therefrom. The spring is first located against the locating face 510 of the locating head 418 with the cut end of the wire abutting the projection 508. The opening tool 298, anvil tool 512 and hammer tool 338 are in their retracted rest posibe pivoted about. the pin 386 by the'air motor 396 between an operative tions. In FIG. 4 the tool 298 has been moved to the left by the air motor 193 and a tapered leading end portion of the tool has been inserted between coils of the spring to separate a loop 526 which has slid up the sloping face 520 to bend it'away from the remainder of the spring; the gauge 382 carrying the locating head 418 has been swung clear of the tools by the air motor 396. In FIG. 5 the loop 526 has been engaged by the anvil face 522 of the setting tool 512 as moved by the motor 195 and bent further. In FIG. 6 the opening tool 298 has been retracted and the hammer tool 338 advanced to engage wire of the spring in the notch 340 and trap it between the hammer tool 338 and :anvil tool 512 to impart a permanent set thereto to maintain the loop 526 in a desired position.

Air is supplied to the

cylinders

192, 194, 308 and motor 396 to operate the tools and gauge in the necessary sequence of each cycle. Suitably the. air may be supplied through valves (not shown) operated in sequence by cams (not shown) mounted on a cam shaft (not shown) driven at a constant speed by an electric motor (not shown). The motor may be arranged to drive the cam shaft continuously to operate the illustrative machine continuously through an indefinite number of cycles or, on an appropriate signal from the operator, todrive the cam shaft for a sufficient period to operate the illustrative machine through one loopforming cycle only. For the purpose of adjusting the machine means are provided to enable each tool and gaugeto be moved independently so that their innermost positions can be adjusted accordingly.

It is envisaged that springs may [be automatically fed into the front of the holder 370 and ejected from the rear thereof: for this reason the gauge is arranged tobe swung well clear of the axis of the bore 376 in the holder.

If desired, indicator means may be provided to indicate the positions to which the left tool assembly, the tool holders and gauge have been adjusted; this may facilitate the setting of the machine to form a particular loop on a spring of a particular diameter and made of a particular wire of such a loop when it has been formed during a previous run, on a similar run of springs.

It will thus be seen that the objects set forth above, including those made apparent from the preceding description, are efliciently attained, and, since certain changes may be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. In a machine adapted for use in deflecting and forming a loop at an end portion of a coil spring having a frame, spring support means for supporting a coil spring with a portion of the said spring projecting beyond the support means, a first tool assembly mounted on the frame having means for mounting coil separating and bending tool portions for movement transversely of the spring support means to separate one or more coils of the projecting portion of the spring and thereby form a loop and bend the said loop away from the remainder of the spring, and a second tool as sembly mounted on the frame having means for mounting a loop setting tool for movement toward and away from the first tool assembly transversely of the support means to engage the wire and press it between the first and second tools to thereby set the loop in position, the means for mounting the tools each comprise: a slide member operatively supporting the tool, movable along a fixed path and connected through motor output means to a fluid pressure operated motor for moving said tools; said motor comprising a cylinder closed at both ends, a piston member therein having end portions in sealing engagement with the walls of the cylinder and having a first portion of said output means mounted on said piston between said end portions which first portion operatively connects with a second portion of said output means which extends through an opening in the cylinder wall and operatively connects with said slide member whereby movement of the piston member is transmitted to said tools; and means restricting the movement of the piston member so that the opening in the cylinder wall is disposed between the end portions of the piston member throughout said piston movement.

2. A machine according to claim 1 wherein each slide member and each firs portion of the output means comprise racks mounted in meshing engagement with a pinion comprising the second portion of the output means.

3. A machine according to claim 1 wherein the second tool assembly is mounted on the frame for pivotable movement such that the tip of the setting tool pivoted thereon is moved in an are extending widthwise of the machine.

4. A machine according to claim 3 wherein there are provided means for adjusting said pivotal movement and means for locking the said assembly in adjusted positions.

5. A machine according to claim 1 wherein the spring support means comprises a spring holder having a bore flared at a front end in which a spring is adapted to be slidingly received 6. A machine according to claim 1 and additionally comprising a holder for each tool wherein each slide member is secured to a tool holder by a screw which is rotatable to adjust the position of the tool holder relative to the slide member.

Claims

1. In a machine adapted for use in deflecting and forming a loop at an end portion of a coil spring having a frame, spring support means for supporting a coil spring with a portion of the said spring projecting beyond the support means, a first tool assembly mounted on the frame having means for mounting coil separating and bending tool portions for movement transversely of the spring support means to separate one or more coils of the projecting portion of the spring and thereby form a loop and bend the said loop away from the remainder of the spring, and a second tool assembly mounted on the frame having means for mounting a loop setting tool for movement toward and away from the first tool assembly transversely of the support means to engage the wire and press it between the first and second tools to thereby set the loop in position, the means for mounting the tools each comprise: a slide member operatively supporting the tool, movable along a fixed path and connected through motor output means to a fluid pressure operated motor for moving said tools; said motor comprising a cylinder closed at both ends, a piston member therein having end portions in sealing engagement with the walls of the cylinder and having a first portion of said output means mounted on said piston between said end portions which first portion operatively connects with a second portion of said output means which extends through an opening in the cylinder wall and operatively connects with said slide member whereby movement of the piston member is transmitted to said tools; and means restricting the movement of the piston member so that the opening in the cylinder wall is disposed between the end portions of the piston member throughout said piston movement.

3. A machine according to claim 1 wherein the second tool assembly is mounted on the frame for pivotable movement such that the tip of the setting tool pivoted thereon is moved in an arc extending widthwise of the machine.

5. A machine according to claim 1 wherein the spring support means comprises a spring holder having a bore flared at a front end in which a spring is adapted to be slidingly received

6. A machine according to claim 1 and additionally comprising a holder for each tool wherein each slide member is secured to a tool holder by a screw which is rotatable to adjust the position of the tool holder relative to the slide member.