US3874425A

US3874425A - Wire bender

Info

Publication number: US3874425A
Authority: US
Inventors: Arthur William Edward Guenther
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-07-03
Filing date: 1973-07-03
Publication date: 1975-04-01
Anticipated expiration: 1992-04-01
Also published as: GB1465640A; DE2429308C2; DE2429308A1; JPS5038669A

Abstract

A method and apparatus for bending a straight wire to form a hook, in which the wire is bent by moving an arbor into lateral contact with the wire, moving at least one bending head laterally to bend the wire about the arbor, and withdrawing the arbor and the bending head from the vicinity of the hook. The wire is preferably held against a further arbor, cut to a predetermined length, and bent about the further arbor into a predetermined axis relative to the bending apparatus. A cutter for use with the bending apparatus employs a pair of jaws pivotably closable and then releasable whereby the jaws move longitudinally away from the severed wire.

Description

Apr. 1, 1975 United States Patent 1 Guenther 3,672,410 6/1972 Scheckel............................. 140/103 1 1 WIRE BENDER Inventor: Arthur William Edward Guenther, L n A L 2400 St. Frances Dr., Burlington, Pnmary Exammer Owe arson Ontario, Canada July 3, 1973 Appl. No.: 376,182

[57] ABSTRACT A method and apparatus for bending a straight wire to 122] Filed:

[ form a hook, in which the wire is bent by moving an arbor into lateral contact with the wire, moving at least one bending head laterally to bend the wire about the arbor, and withdrawing the arbor and the bending head from the vicinity of the hook. The wire is preferably held against a further arbor, cut to a preand bent about the further arbor into a predetermined axis relative to the bending apparatus. A cutter for use with the bending apparatus employs a pair of jaws pivotably closable and then re- 02 5 60 3 5 6 /5 33 003 6 MR4 00 n .1 0 U 5 4 3 8 "0 m4 mh C "r. a 8 ms l m l wm (e U.mF HUN 555 determined length [56] References Cited UNITED STATES PATENTS 2,809.675 10/1957 140/103 leasable h b h j move longitudinally away 3,195,583 7/1965 140/102 from the Severed wire 3,351,101 11/1967 Haluorsen ct 140/103 24 Claims, 18 Drawing Figures PATENIED sum ClUF 13 3.874.425

O r 5 v PATENTEU APR 1 W5 SHEET U40? 13 FIG. 6

PMENTEUAPR 119. 5 3,874,425

sum user 13 PJJENTEDAPR Hm? SHEET BEEF 13 PATENIEQAPR news Sm 1M 3 3,874,425

com wom vom mom 0mm mam wwm wmm millll PATENTED APR 1 5 SHEET 110? 13 PATENTED APR 1 SHEET 120- 13 mwm Ohm mm @mm Omwm lliv wwm mwm WIRE BENDER This invention relates to a device for forming a hook on the end of a wire, for instance in the manufacture of a tension coil spring.

Wire coils when used as tension springs must have hooked ends on each end or leg for engagement with eyes or other anchoring means. In a standard method of manufacture of such springs a wire is first wound on a mandrel to form a coil. In another method of manufacture a wire is driven axially around a grooved arbor to curl it into coil form. In each method the free ends or legs project at right angles to the centre line of the coil. In the first step of forming a hook the end of each leg is severed or chopped to a given length. In the next step the leg is bent into the centre line of the coil. To form a hook on each leg, either inward or outward with respect to the centre line of the coil, the leg is placed, at a point spaced from its free end, transversely against a cylindrical arbor and the free end of the leg is bent around the arbor by forcing a series of implements against it tangential to the arbor, first in a linear direction at right angles to the centre line of the coil and then in a linear direction parallel to the centre line of the coil. In this operation the leg must be brought to the plurality of bending members carrying out the bending steps. with attendant complexities. Also, the position of the wire cutter in the region of the centre line of the coil limits the flexibility of the apparatus for use in forming hooks having different radii, degrees of bend, directions of turn, and lengths of leg. Again, each time a different type of hook is required it is necessary to replace some or all of the elements forming the apparatus. This makes the apparatus cumbersome, expensive and inadequate for the automated output of varying types of springs.

To overcome these disadvantages the present inventor previously developed an apparatus described and claimed in US. Pat. No. 3,405,772 issued Oct. 15, 1968. In that device a head is mounted on a shaft which slides through a pivotable fulcrum and a grooved follower is moved in an arcuate path in the plane of the shaft. However. the device is restricted to operation in that plane and to form a hook in a spring leg, other than in a preselected direction relative to the body of the spring. it would be necessary to adjust the position of the spring itself by rotating it about its axis since the device as a whole is fixed to a base. Also the hooking arbor is associated with the spring, which makes the device easily operable with pre-wound springs, but difficult to incorporate in a continuous operation with a torsion winding machine where the spring wire is wound by a pin rotating in parallel about a mandrel.

It is an object of the present invention to provide method and a device for bending a wire to form a hook, in which the arbor and the bending mechanism advance to the work position, perform the work of forming a hook. and then withdraw sufficiently to enable the formed hook to be removed.

It is another object of the invention to provide a device for severing the free end ofa wire and enabling the severed wire to be moved laterally away from the cutter.

Another object of the invention is to provide a device for holding a coil spring with a leg of the spring in a predetermined axis adjacent an arbor.

An example embodiment of the invention is shown in the accompanying drawings in which:

FIG. 1 is a perspective view of an arbor and a preliminary bender of an apparatus according to the invention;

FIG. 2 is a view in cross-section taken along line 2-2 of FIG. 1;

FIG. 2A is a fragmentary perspective view of the head of the bending tool of FIG. 1;

FIG. 3 is a perspective view of a cutter;

FIG. 4 is a plan view of the cutter of FIG. 3 in association with the arbor, bender and spring of FIG. 2;

FIG. 5 is a view similar to FIG. 4 showing the cutter in released position after the leg of the spring is severed and bent by the bender;

FIG. 6 is a perspective view of the mounting for the hook bender;

FIG. 6A is a perspective view of the base portion of the apparatus of FIGS. 1, 3 and 6;

FIG. 7 is an exploded perspective view of the hook bender carried by the mounting of FIG. 6;

FIG. 7A is aperspective view of the head of one of the bending arms of the hook bender of FIG. 6;

FIG. 8 is a view taken along line 8-8 of FIG. 6, including the hook bender of FIG. 7 in a position of rest and in relation to the leg of a coil spring;

FIG. 9 is an elevational view of the hook bender as shown in FIG. 8;

FIG. 10 is a plan view similar to FIG. 9 showing the hook bender advanced into a working position with respect to the coil spring leg;

FIG. 11 is a plan view similar to FIG. 9 showing the hook bender in the first stage of bending the spring leg to form a hook;

FIG. 12 is a plan view similar to FIG. 11 showing the hook bender in the second stage of bending the spring leg;

FIG. 13 is a view in cross-section taken along line 1313 of FIG. 12;

FIG. 14 is a plan view similar to FIG. 12 showing the hook bender in the third stage of bending the spring leg; and

FIG. 15 is a cross-sectional view similar to FIG. 13 showing the return travel of the hook bender.

The example embodiment shown in the drawings consists of a holder 10 and a preliminary bender 11 (FIGS. 1 and 2), a cutter 12 (FIGS. 3, 4 and 5) and a hook bender 14 (FIGS. 6 to 15 inclusive) all mounted on a base 16 (FIG. 6A). These individual units function in sequence to form a hook on the end of the leg of a wire spring: preliminary bender l0 angles the leg parallel to the axis of the spring, cutter 12 severs the free end of the leg to make the leg the proper length, and hook bender 14 forms a hook on the free end of the spring leg.

Preliminary bender 11 seen in FIGS. 1, 2 and 2a comprises a shaft 20 passing through the bore of a pipe 21 fixed to base 16 (see FIG. 6A) by a strut 22 and a plate 23. A bending tool 24 is keyed on the upper end of shaft 20 and a pinion 25 is fixed on the lower end of the shaft to engage a rack 26 which is driven by a pneumatic jack 28 mounted on a frame 30 fixed to pipe 21. Jack 28 is fixed to a bracket 32 by bolts 34 which slide in pairs of slots 36 in frame 30 and bracket 32 is longitudinally movable horizontally by an adjustment screw 38 mounted on the frame for free rotation and threaded into the bracket. Bending tool 24 consists of a slotted plate 40 slidably mounted on a collar 42 fixed to shaft 20 and slidably adjustable vertically by a locking screw 44. The upper end of collar 42 is notched and bent to form a horizontal finger 46 having a horizontal groove 48 at its tip.

Holder seen in FIGS. 1 and 2 comprises a slotted bracket 50 slidable horizontally on a keyway 51 of plate 23 on an axis X in the direction of pipe 21 and secured by a locking screw 52. A block 54 is slidable horizontally on a keyway 55 on bracket 50 on an axis Y in a direction perpendicular to keyway 51 and the block is clamped on the keyway by a locking screw 56. Block 54 carries at one end a mount 57 which in turn carries a slotted horizontally disposed mandrel base 58 removably fixed to the block and longitudinally adjustable by screws 59. One side of mount 57 has an arcuate recess 60. One end of mandrel base 58 projects into recess 60 and carries. at right angles at its projecting free end, a mandrel 61. A wedge plate 62 with a slot 64 is also mounted on mount 57, parallel to mandrel base 58, by a holding screw 66 passing through the slot to make the wedge plate horizontally slidable. One end of wedge plate 62 is tapered laterally to form a vertically dis posed arcuate knife edge 68 and the other end of the wedge plate is connected by a tension coil spring 70 through a mount 72 to an arm 74 which is integral with block 54. A pneumatic jack 76 is fixed on mount 72 and piston rod 78 of the jack abuts the end of wedge plate 62. Mount 72 is horizontally slidable on arm 74 and adjustable by a screw tightener 82 slidable in a slot (not shown) in the arm. Recess 60 of mount 57 terminates at each end in a flange 84 having a right angled inner face forming two planes A and B. A pair of plungers 88 carried in slots 90 in mount 57 are urged against flanges 84 by screws 89 to hold a removable vertical arbor 92 which abuts the end of mandrel base 58 carrying mandrel 61. The outer face of mandrel base 58 lies in plane A.

Cutter 12 seen in FIGS. 3, 4 and 5 comprises a bracket vertically slidable on a vertical axis Z on a mounting block 102 which is itself slidable horizontally on a horizontal axis X on a rod 104 fixed by end mounts 106 to a frame 108 bolted on base 16. A locking screw 110 slides in a slot 112 in bracket 100 and an adjustment screw 114 is threaded in block 102. A mounting plate 116 is slidable horizontally on an axis Y. perpendicular to axes X and Z, on a keyway 118 in bracket 100 and clamped by a locking screw 120. A pneumatic jack 122 is fixed on plate 116 and its piston rod 124 carries a cam block 126 slidable on a rest 128 fixed to plate 116. Block 126 has a slot 130 positioned at about 45 to the axis of piston 124. A pair of

jaws

132 and 134 are mounted on the end of jack 122 remote from piston 124, jaw 132 being pivotably mounted on a fixed bracket 136 by a pin 138 and the shank 140 ofjaw 134 being pivotably mounted on the shank 142 ofjaw 134 by a pin 144. Shank 140 ofjaw 134 extends around jack 122 to block 126 and terminates in a curved end 146 carrying a pin 148 engaging slot 130. A lever 150 at one side ofjack 122 is pivotably mounted intermediate its

ends

152 and 154. on base 116 beneath shank 140 of jaw 134 by a pin 156 fixed on base 116. End 152 of lever 150 has a notch 153 which normally rests against a block 158 fixed on shank 142 ofjaw 132 and end 152 is urged into that position by a compression spring 160 bearing against the other end 154 of the lever and against jack 122. A rod 162 is pivotably connected at one end with a pin 159 on shank 142 ofjaw 132 while the other end slides in an eye 164 on plate 116 adjacent rest 128. Rod 162 carries a compression spring 166 bearing against eye 164 and against the rod end adjacent pin 159. Shank 140 ofjaw 134 carries a lug 168 with a threaded screw 170 which bears laterally against end 154 of lever 150 when the shank is moved laterally towards jack 122.

Jaws

132 and 134 are movable in shearing relationship, one in advance of the other, as seen in FIG. 4, and they are located to shear in plane A of holder 10.

Hook bender 14 seen in FIG. 6 to 15 inclusive comprises a base plate 200 (see FIG. 6) which is slidably mounted between a pair of

flanges

202 and 203 on a horizontal frame 204 (see FIG. 6A). Plate 200 carries beneath it a rack 206 which engages a pinion 208 journailed in frame 204 between

flanges

202 and 203 and rotated by a knob 210. Flange 203 is slidably adjustable on frame 204 in relation to flange 202 by a knob 212 on a shaft 214 threaded in flange 202 and journalled in flange 203. Frame 204 is fixed at one end to a rocker bar 216 journalled through a pivot rod 217 on base 16 and supported at the other end on a horizontal shaft 218 mounted on a supporting post 220. Shaft 218 is movable axially by a knob 222, laterally in a vertical direction by a knob 224, and is releasably secured in adjusted position by a clamping nut 226.

A collar 230 (see FIG. 6) is fixed on the upper side of base plate 200. A pair of rods 232 extend rearwardly from collar 230 to support a face plate 234 on which a pneumatic jack 236 is fixed. Piston rod 238 ofjack 236 extends through face plate 234 and the free end portion carries a spool 240 (see FIG. 8). Face plate 234 also carries a manually operable mechanism 242 comprising a yoke 244 pivotably mounted on a pair of lugs 246 fixed to the face plate. Yoke 244 carries a lever arm 248 and a rod 250 engagable with spool 240. A clamping nut 251 holds a barrel 252 in collar 230 and a pair of opposed channels 253 are fixed on the inner surface of barrel 252 to provide a horizontal guideway for a slide 254 (see FIG. 7) which is fixed to the free end of piston rod 238 as seen in FIG. 8. Also fixed to the inner surface of barrel 252 are an upper segment 256 and a lower segment 258. Upper segment 256 has a rearwardly extending shoulder 260 carrying a pivotably mounted latch 262 urged downwardly by a compression spring 263. Lower segment 258 carries a forwardly extending fixed lug 264 having a downward rearwardly sloping cam surface 265. As seen in FIG. 10 each

segment

256 and 258 carries a threaded bolt 266 slidable in a smooth bore 267 in the segment, head 268 of bolt projecting rearwardly from the segment and retaining a disc spring 269.

Slide 254 shown in FIG. 7 carries an upper bar 270 and a lower bar 272 joined one to the other at their rearward ends by shaft means comprising a bolt 274 passing through a bushing 276 which bears against the underside of lower bar 272 and into a boss 278 which is thus fixed on lower bar 272 and positioned between the bars. Boss 278 is slidable in a slot 280 located in the rearward portion of the slide and projects through upper bar 270 to terminate in an upper portion 279, upper bar 270 being freely rotatable on bushing 278. The underside of the forward portion of upper bar 270 also carries a roller 282 slidable in an angled slot 284 in the forward portion of slide 254. Between boss 278 and roller 282 the upper side of bar 270 carries a stop 285. The foreward end of upper bar 270 carries a removable arm 286, fixed by a plate 287, which terminates in a bending head 288 shaped as shown more particularly in FIG. 7A with a right angled concave tip 290 and a hroizontal groove 292. Head 288 is adjustable longitudinally on bar 270 by bolts 289 and is adjustable laterally by bolts 291. A clamping head 294 is mounted on the forward end of lower bar 272 by a channel 296 for vertical pivot-able movement about a pin 298 by the action of a compression spring 300. A jaw 302 clamps a vertical arbor 304 on clamping head 294 adjacent bending head 288 and forwardly of it. Lower bar 272 lies in a slot 305 in the underside of guide 254.

A further slot 306 in slide 254 accommodates a link 308 which has a lower ledge 310 bearing against the slide and a downwardly depending latch 312 urged rearwardly by a compression spring 313 (see FIG. 13). A rearwardly directed member 314 above slide 254 is pivotably connected to element 308 by a pin 316 and carries a stop 318 on its upper surface and a downwardly directed lug 320 at its free end which moves in a slot 321 in slide 254. A compression spring 322 lies in slot 321, bearing against lug 32 and against the forward end of the slot. A forwardly directed member 326 above slide 254 is pivotably connected to member 308 by a pin 328 and carries an arm 330 adjustably fixed to the member by screws 332. Arm 330 terminates at its free end in a further bending head 334 having a horizontal groove 336 and a lateral tip 338. A cam 340 is pivotably mounted on a pin 342 on the underside of member 326 and lies in a recess 343 on the upper side of the forward end of guide 254. Cam 340 has a pair of followers 344 engaging a pair of arcuate grooves 346 in member 326 on opposite sides of pin 342. A leaf spring 348 fixed to the under side of member 326 urges cam 340 in a counterclockwise direction about pin 342. A spring loaded bullet detent 350 mounted in member 314 urges member 326 in a counterclockwise direction about pivot pin 328.

One lateral side ofslidc 254 has a notch 360 in its forward portion which accommodates a fixed block 362 carrying a threaded adjustment screw 364 bearing against member 326 (see also FIG. 8). Ahead of block 362 lies a roller 366 mounted on an arm 368 which is pivoted for lateral movement about a vertical pin 370 fixed in a bore 372 in slide 254 behind notch 360. An adjustment screw 374 slides in an aperture 376 in arm 368 and is threaded into a boss 378 on slide 254. Lying between

slots

280 and 321 is a rib 380 fixed to the upper side of slide 254 and having an upstanding cam 382 located laterally and forwardly of stop 318 of member 314.

A plate 390 is fixed to the underside of slide 254 beneath lower bar 272 and has a slot 391 through which latch 312 projects. Plate 390 retains lower bar 272 in slot 305. A further bar 392 is located adjacent the underside of plate 390. being fixed at its forward end 393 to channel 296 and sliding at its rearward end 394 in a slot 395 in lower segment 258 (FIG. 6). Bar 392 has a lateral shoulder forming a cam 396 located beneath slot 391. A block 400 is fixed to lower bar 272 by a bolt 402 passing through a spacer 403 and a slot 404 in plate 390. A bar 406 extends forwardly from block 400 and terminates in a guide member 408 L-shaped in cross-section. A bolt 410. threaded into a bore 411 in lower bar 272, carries a bushing 412 on the upper side of bar 406 between block 400 and guide member 408, and the bushing is accommodated in a slot 414 in the underside of channel 296 adjacent clamping head 294. A compression spring 416 is mounted on a rod 418 which is slidable at its forward end in an aperture 419 in block 400 and fixed at its rearward end by a bolt 420 and a bushing 422 to slide 254. One end of spring 416 bears against bushing 422 and the other end bears against block 400.

In the operation of the example embodiment a coil spring 500 is placed axially on mandrel 61 with one of its two legs 502 lying in plane A and extending horizontally in a direction towards

jaws

132 and 134 of cutter 12. Wedge plate 62 is then moved, by the actuation of jack 76, against the spring to wedge knife edge 68 between turns of the coil, as seen in FIG. 4, thus clamping the coil against the mandrel.

Cutter 12 is adjusted on axes X, Y and Z (see FIG. 3) to move

jaws

132 and 134 astride leg 502 of spring 500, as seen in FIG. 4, for severing the leg to a prescribed length. To sever leg 102, jack 122 is actuated to drive block 126 leftward as seen in FIG. 4, which initially moves shank to pivot

jaws

132 and 134 together, shearing leg 102. As seen in FIG. 5, continued movement of block 126 leftward causes pin 148 to slide in block 126, moving shank 140 towards jack 122 which causes screw 170 to bear laterally against end 154 of lever 150. This pivots lever about pin 156 and disengages notch 153, in end 152 of the lever, from block 158, releasing shank 142 and causing jaw 132 to be pivoted away from jaw 134 in a leftward direction, at the same time compressing spring 166 on rod 162. This retracts

jaws

132 and 134 from the vicinity of leg 502 and allows space for the leg to be bent laterally. This is especially important when leg 502 is severed close to the body of spring 500.

The next step is to bend leg 102 into a position parallel to the axis of coil spring 500. To do this, jack 28 of preliminary bender 11 (see FIG. 1) is actuated to rotate bending tool 24 which is adjusted by screw 38 and screw 44 to have finger 46 located adjacent the junction of leg 502 with the coil of spring 500 as seen in FIG. 4. Jack 28 moves rack 26 which rotates shaft 20 by pinion 25 and moves bending tool 24 in an are about arbor 92 as seen in FIG. 5. The

prior movement ofjaws

132 and 134 away from arbor 92 gives clearance for the leg 102 to be moved laterally. After bending leg 102 in an are 90 about arbor 92, bending tool 24 is returned by jack 28 to its original position of rest and block 126 on cutter 12 is ready to be moved to the right by jack 122 to bring jaw 132 back to a position adjacent jaw 134.

In the next step in the operation of the device, the free end of leg 502 is hooked in three steps by hook bender 14, as seen in FIGS. 8-15. FIG. 8 shows hook bender 14 positioned adjacent holder 10 with leg 502 of spring 500 directed towards guide member 408 of the hook bender which is initially adjusted to the required position by suitable adjustments of frame 204 (see FIG. 6A) moved on a horizontal axis Y by knob 222 and moved on a vertical axis Z by knob 224, and by knob 210 to move plate 200 along an axis X (see FIG. 6) perpendicular to axes Y and Z.

When hook bender 14 is in a position of rest with piston rod 238 of jack 236 retracted. as seen in FIG. 8, upper arm 270 and lower arm 272 are in an advanced position on slide 254 with boss 278 being located at the forward end of slot 280 and roller 282 being located at the forward end of slot 284. being held in that position by spring 416 on rod 418 (FIGS. 7 and 9) bearing against bushing 422 fixed to slide 254 and block 400 fixed to lower arm 272.

When jack 236 is actuated to move piston rod 238 forward, slide 254 is moved to the right as seen in FIG. 10, carrying all the appurtenances on the slide with it and causing leg 502 of spring 500 to bear against guide member 408 and assume a position tangential to arbor 304. When the end of leg 502 has passed a predetermined distance past arbor 304, bushing 279 on upper arm 270 and bushing 276 on lower arm 272 come into contact with bolt heads 268 on

segments

256 and 258 in barrel 252, arresting the forward movement of the upper and lower arms. The continued forward movement of slide 254 causes boss 278 and roller 282, arrested in their forward movements, to travel rearwardly along

slots

280 and 284 respectively by the forward advancement ofthe slide. Since slot 284 is angled, the relative rearward movement of roller 282 pivots upper arm 270 about boss 278, which moves bending head 288 against leg 502 and bends the free end portion 504 of the leg 90 about arbor 304 as seen in FIG. 11. Leg 502 is centred in groove 292 of the bending head to keep end portion 504 horizontal. Further forward movement of slide 254 causes roller 282 to dwell in the rearward portion of slot 284 and no further pivotal movement of upper arm 270 occurs.

After bushing 276 and 279 come into contact with bolt heads 268, the continued forward movement of slide 254 compresses spring 418 which holds the bushings against the bolt heads.

Continued forward movement of slide-254 moves bending head 334 into contact with end portion 504 of spring leg 502 and bends the end portion a further 90 about arbor 304 as seen in FIG. 12. Again end portion 504 of leg 502 is horizontally maintained by groove 336 in head 334.

As head 334 passes forwardly past arbor 304, roller 366 passes freely over cam 340 which pivots against the action of spring 348. Slide 254 is now in its farthest forward position and latch 262 on segment 256 (FIG. 6) engages stop 318 on member 314.

The return stroke of piston rod 238 carries slide 254 with it, as seen in FIG. 14, but latch 262 prevents

members

314 and 326,jointed by element 308, from returning with the slide. Since roller 366 is returning with slide 254, the roller is met by cam 340. Cam 340 does not rotate in a counterclockwise direction and member 326 is forced by roller 366 to pivot about pin 328 against the action of detent 350 which causes tip 338 of head 334 to bend end portion 504 of spring leg 502 laterally beyond its previous 90 bend. After roller 366 has passed cam 340, bullet detent 350 pivots member 326 counterclockwise until the member meets adjustment screw 364, moving tip 338 of head 334 to move laterally out of contact with spring leg 502.

On the return movement of slide 254, spring 322 is compressed in slot 321 by lug 320 which is held stationary by latch 262, as seen in FIG. 13. Further leftward movement of slide 254 causes cam 382 to raise latch 262 as seen in FIG. 15, which releases spring 322 and moves

members

314 and 326, together with link 308, to the left. The leftward movement of link 308, relative to slide 254, pivots latch 312 against spring 313 and allows head 294 to be pivoted about pin 298 by the action of spring 300 to clear arbor 304 from spring leg 502, leaving the hooked spring leg free to be removed from mandrel 61. Further leftward movement of slide 254 causes shoulder cam 396 on bar 392 to meet cam 265 on lug 264 which is fixed to lower segment 258. Cam 265 forces bar 392 downwardly, allowing latch 312 to be forced back into a vertical position by spring 313 to rest against bar 392 and keep the bar in a horizontal position against the action of spring 300, thus returning arbor 304 to an operative position.

As slide 254 travels back to its original position of rest, roller 282 travels forward in angled slot 284 and moves head 288 laterally out of the line of spring leg 502. Until upper arm 270 is moved laterally, stop 285 bears against shoulder 324 of rearward member 314 and prevents the upper arm from moving back with slide 254 should spring 416 fail.

It will be apparent that all the work elements of the apparatus may be adjusted or changed to accommodate different sizes of wire and spring. To begin with, while mandrel 61 may accommodate springs of over a wide range of inner coil diameters, it may be replaced by a larger size of mandrel for greater strength and stability to mount springs of considerably larger or smaller diameter and wedge plate 62 is adjustable laterally where the wire of the spring is of larger diameter or longitudinally where the spring body is of larger diameter. Arbor 304 is replacable in head 294 to form a larger hook on leg 502 and head 288 is adjustable to alter its position relative to arbor 304. Adjusting screw 364 alters the lateral clearance of head 334 for the same purposes. Adjustment screw 374 governs the degree of overbend of the hook beyond its bend about arbor 304.

An important feature of the invention is that collar 252 is rotatable in the predetermined axis of leg 502 of spring 500 to allow a hook to be formed in any plane through leg 502 because when the leg is in the position shown in FIG. 10 it is axially aligned with piston rod 238 of jack 236. It will be apparent that hook bender 14 is useful independently of preliminary bender 11 and cutter 12, for instance in a secondary operation associated with a spring winder. Also, a partial hook may be formed by using only head 288 and not head 334.

Preliminary bender 11 and cutter 12 may also find independent use in association with other operations.

After hook bender 14 has been generally aligned by the adjustments associated with frame 204, slide 254 is manually operable by lever arm 248 engagable with spool 240 to affect fine adjustments to the various bending components carried by the slide.

I claim:

1. A method of bending a straight wire to form a hook, comprising:

positioning the wire in a predetermined axis;

moving an arbor in'to lateral contact with the wire,

and moving a first bending head into a position laterally of the free end portion of the wire projecting beyond the arbor;

moving the first bending head laterally against the free end portion of the wire projecting beyond the arbor to bend the wire about the arbor: withdrawing the arbor longitudinally from the formed hook and from the vicinity of the hook; withdrawing the first bending head laterally from the vicinity of the arbor; moving a second bending head into a position laterally of the free end portion of the wire and unobstructive of the movement of the wire bent about the arbor by the first bending head;

subsequent to the movement of the first bending head, moving the second bending head laterally against the free end position of the wire projecting beyond the arbor and in a direction transverse to the direction of movement of the first head, the second head being moved (l) past the arbor in a direction parallel to the straight portion of the wire and then (2) in a direction towards the straight portion of the wire whereby the free end of the wire moves through an are greater than 180; and withdrawing the second bending head from the vicinity of the arbor. 2. A method of bending a straight wire to form a hook, comprising:

positioning the wire in a predetermined axis;

moving an arbor into lateral contact with the wire,

moving the first bending head laterally against the free end portion of the wire projecting beyond the arbor to bend the wire about the arbor; withdrawing the arbor longitudinally from the formed hook and from the vicinity of the hook; withdrawing the first bending head laterally from the vicinity of the arbor;

clamping the wire adjacent a further arbor;

severing the free end portion of the wire to a predetermined length; and

moving the severed free end portion of the wire laterally about the further arbor into said predetermined axis.

3. Apparatus for bending a wire to form a hook, comprising:

means to clamp the wire to present a free end portion positioned in a predetermined axis;

means to sever the free end portion of the wire to a predetermined length;

means to move the severed free end portion of the wire laterally away from the severing means and transversely against an arbor; and

means to bend the free end portion of the wire about the arbor to form said hook, said bending means comprising (a) a first head movable laterally against the free end portion of the wire projecting beyond the arbor. and (b) a second head movable laterally against the free end portion of the wire projecting beyond the arbor in a direction transverse to the direction of movement of the first head and subsequent thereto.

4. Apparatus as claimed in claim 3, in which the sec ond head is movable. after its initial movement, towards the straight portion ofthe wire whereby the free end ofthe wire moves through an are greater than 180.

5. Apparatus as claimed in claim 3, including means to retract the arbor, the first head and the second head away from the formed book.

6. Apparatus as claimed in claim 3, in which the wire is clamped laterally against a further arbor spaced from the free end thereof and the means to move the free end portion of the wire comprises a bending tool movable about a longitudinal axis which is parallel to the further arbor, the bending tool having a lateral member movable in an are about the further arbor to bear laterally against the free end portion of the wire projecting beyond the further arbor.

7. Apparatus as claimed in claim 6, including means to adjust the length of the arc of movement of the lateral member about the further arbor and the position of said are in a predetermined circle about the further 5 arbor.

8. Apparatus for bending the wire leg of a coil spring to form a hook, comprising:

means to clamp the wire to present a free end portion positioned in a predetermined axis, said clamping means comprising a mandrel insertable into the coil of the spring and a wedge means movable at right angles towards the mandrel for insertion between two successive turns of the coil of the spring;

means to sever the free end portion of the wire to a predetermined length;

means to bend the free end portion of the wire about the arbor to form said hook, said bending means comprising a first head movable laterally against the free end portion of the wire projecting beyond the arbor.

9. ln apparatus for bending a wire to form a hook;

an arbor and means carrying the arbor for substantially longitudinal movement of the arbor;

a first head movable in a direction substantially tan-.

gential to the arbor and normal thereto;

a second head movable in a direction substantially tangential to the arbor and normal thereto and transverse to the direction of movement of the first arbor;

means mounting the arbor carrying means, the first head and second head, the mounting means being rotatable about an axis tangential to the arbor and normal thereto;

means to move the first head, the second head and the arbor is sequence; and

means to advance the mounting means to align a fixed straight wire tangential to the arbor and to retract the mounting means therefrom.

10. Apparatus as claimed in claim 9, in which the means carrying the arbor comprises a bar and a clamp pivotably mounted on the bar on an axis normal to the arbor and spaced laterally therefrom, and means to pivot the clamp.

11. Apparatus as claimed in claim 9, in which the first head is fixed on the end of a further bar slidable longitudinally and pivotable laterally.

12. Apparatus as claimed in claim 9, in which the second head is fixed on the end of an arm slidable longitudinally.

13. Apparatus as claimed in claim 12, in which the arm is pivotable laterally.

14. In apparatus for bending a wire to form a book;

a first head movable in a direction substantially tangential to the arbor and normal thereto;

means mounting the arbor carrying means, the first head and second head;

means to move the first head, the second head and the arbor in sequence; and

means to advance the mounting means to align a fixed straight wire tangential to the arbor and to retract the mounting means therefrom;

said arbor carrying means comprising a bar and a clamp pivotably mounted on the bar on an axis normal to the arbor and spaced therefrom, the first head being fixed on the end of a further bar, the bars being parallel one to the other and mounted, remote from the clamp and first head respectively, on transverse interconnecting shaft means, the further bar being pivotable about the shaft means, the shaft means being movable between predetermined limits along a slide positioned between the bars, the slide being movably mounted in a circumscribing collar, and reciprocable means to move the slide longitudinally;

means mounting the arbor carrying means, the first head and second head;

means to move the first head, the second head and the arbor in sequence; and

15. Apparatus as claimed in claim 14, in which the second head is fixed on the end of an arm mounted on the slide for longitudinal movement between predetermined limits and pivotable laterally about an axis remote from the head.

16. Apparatus as claimed in claim 15, in which the collar is rotatable about its axis coincident with an axis tangential to the arbor and normal thereto.

17. Apparatus as claimed in claim 15, in which the reciprocable means and the collar are mounted on a base adjustable in three mutually prependicular directions.

18. A cutter for use in severing the free end portion of a wire, comprising:

a first arm and a second arm terminating in opposed cutting jaws, the first arm being pivotably mounted at its end remote from the jaw thereof, the second arm being pivotably mounted intermediate its ends on the first arm;

reciprocable means to move that end of the second arm remote from the jaw thereof laterally to close the jaws; and

means releasable on closure of the jaws to move the jaw of the second arm away from the jaw of the first arm and rearwardly whereby the jaws move away from the severed end of the Wire.

19. A cutter as claimed in claim 18, includingresetting means cooperating with the reciprocable means and the releasable means which, on the return movement of the reciprocable means, re-engages the releasable means.

20. A cutter as claimed in claim 19, in which the arms, the reciprocable means, the releasable means, and the resetting menas are mounted on a base adjustable in three mutually perpendicular directions.

21. In apparatus for bending the leg of a wire coil spring to form a hook, mandrel and arbor means for holding the spring in a position enabling the leg to be bent into a position parallel to the spring axis, said mandrel and arbor means comprising:

an arbor mounting member having a pair of spaced flanges projecting therefrom, the flanges having aligned and right angled inner faces;

a removable arbor bearing against the inner faces of the flanges and means on the mounting member urging the arbor into said bearing position;

an adjustable mandrel plate carried by the member.

and having a mandrel located adjacent the arbor and projecting at right angles thereto and to the mandrel plate; and

holding means mounted on the mounting member and movable against the mandrel at right angles thereto to wedge between adjacent turns of the coil spring.

22. Apparatus as claimed in claim 21, in which the mounting member is adjustable in two mutually perpendicular directions in a plane normal to the axis of the arbor.

23. Apparatus as claimed in claim 21, including bending means movable in an are about the arbor and comprising:

a shaft axially aligned with the arbor;

a collar fixed on the shaft;

a bending tool mounted on the collar and having a member projecting radially towards the arbor; and means to rotate the shaft.

24. Apparatus as claimed in claim 23, in which the means to rotate the shaft comprises a reciprocable rack and a pinion, the rack being adjustable longitudinally with respect to the pinion and having an adjustable

Claims

1. A method of bending a sTraight wire to form a hook, comprising: positioning the wire in a predetermined axis; moving an arbor into lateral contact with the wire, and moving a first bending head into a position laterally of the free end portion of the wire projecting beyond the arbor; moving the first bending head laterally against the free end portion of the wire projecting beyond the arbor to bend the wire about the arbor; withdrawing the arbor longitudinally from the formed hook and from the vicinity of the hook; withdrawing the first bending head laterally from the vicinity of the arbor; moving a second bending head into a position laterally of the free end portion of the wire and unobstructive of the movement of the wire bent about the arbor by the first bending head; subsequent to the movement of the first bending head, moving the second bending head laterally against the free end position of the wire projecting beyond the arbor and in a direction transverse to the direction of movement of the first head, the second head being moved (1) past the arbor in a direction parallel to the straight portion of the wire and then (2) in a direction towards the straight portion of the wire whereby the free end of the wire moves through an arc greater than 180*; and withdrawing the second bending head from the vicinity of the arbor.

2. A method of bending a straight wire to form a hook, comprising: positioning the wire in a predetermined axis; moving an arbor into lateral contact with the wire, and moving a first bending head into a position laterally of the free end portion of the wire projecting beyond the arbor; moving the first bending head laterally against the free end portion of the wire projecting beyond the arbor to bend the wire about the arbor; withdrawing the arbor longitudinally from the formed hook and from the vicinity of the hook; withdrawing the first bending head laterally from the vicinity of the arbor; clamping the wire adjacent a further arbor; severing the free end portion of the wire to a predetermined length; and moving the severed free end portion of the wire laterally about the further arbor into said predetermined axis.

3. Apparatus for bending a wire to form a hook, comprising: means to clamp the wire to present a free end portion positioned in a predetermined axis; means to sever the free end portion of the wire to a predetermined length; means to move the severed free end portion of the wire laterally away from the severing means and transversely against an arbor; and means to bend the free end portion of the wire about the arbor to form said hook, said bending means comprising (a) a first head movable laterally against the free end portion of the wire projecting beyond the arbor, and (b) a second head movable laterally against the free end portion of the wire projecting beyond the arbor in a direction transverse to the direction of movement of the first head and subsequent thereto.

4. Apparatus as claimed in claim 3, in which the second head is movable, after its initial movement, towards the straight portion of the wire whereby the free end of the wire moves through an arc greater than 180*.

5. Apparatus as claimed in claim 3, including means to retract the arbor, the first head and the second head away from the formed hook.

6. Apparatus as claimed in claim 3, in which the wire is clamped laterally against a further arbor spaced from the free end thereof and the means to move the free end portion of the wire comprises a bending tool movable about a longitudinal axis which is parallel to the further arbor, the bending tool having a lateral member movable in an arc about the further arbor to bear laterally against the free end portion of the wire projecting beyond the further arbor.

7. Apparatus as claimed in claim 6, including means to adjust the length of the arc of movement of the lateral member about the further arbor and The position of said arc in a predetermined circle about the further arbor.

8. Apparatus for bending the wire leg of a coil spring to form a hook, comprising: means to clamp the wire to present a free end portion positioned in a predetermined axis, said clamping means comprising a mandrel insertable into the coil of the spring and a wedge means movable at right angles towards the mandrel for insertion between two successive turns of the coil of the spring; means to sever the free end portion of the wire to a predetermined length; means to move the severed free end portion of the wire laterally away from the severing means and transversely against an arbor; and means to bend the free end portion of the wire about the arbor to form said hook, said bending means comprising a first head movable laterally against the free end portion of the wire projecting beyond the arbor.

9. In apparatus for bending a wire to form a hook; an arbor and means carrying the arbor for substantially longitudinal movement of the arbor; a first head movable in a direction substantially tangential to the arbor and normal thereto; a second head movable in a direction substantially tangential to the arbor and normal thereto and transverse to the direction of movement of the first arbor; means mounting the arbor carrying means, the first head and second head, the mounting means being rotatable about an axis tangential to the arbor and normal thereto; means to move the first head, the second head and the arbor is sequence; and means to advance the mounting means to align a fixed straight wire tangential to the arbor and to retract the mounting means therefrom.

13. Apparatus as claimed in claim 12, in which the arm is pivotable laterally.

14. In apparatus for bending a wire to form a hook; an arbor and means carrying the arbor for substantially longitudinal movement of the arbor; a first head movable in a direction substantially tangential to the arbor and normal thereto; a second head movable in a direction substantially tangential to the arbor and normal thereto and transverse to the direction of movement of the first arbor; means mounting the arbor carrying means, the first head and second head; means to move the first head, the second head and the arbor in sequence; and means to advance the mounting means to align a fixed straight wire tangential to the arbor and to retract the mounting means therefrom; said arbor carrying means comprising a bar and a clamp pivotably mounted on the bar on an axis normal to the arbor and spaced therefrom, the first head being fixed on the end of a further bar, the bars being parallel one to the other and mounted, remote from the clamp and first head respectively, on transverse interconnecting shaft means, the further bar being pivotable about the shaft means, the shaft means being movable between predetermined limits along a slide positioned between the bars, the slide being movably mounted in a circumscribing collar, and reciprocable means to move the slide longitudinally; a first head movable in a direction substantially tangential to the arbor and normal thereto; a second head movable in a direction substantially tangential to the arbor and normal thereto and transverse to the direction of movement of the first arbor; means mounting the arbor carrying means, the first head and second head; means to move the first head, the second head and the arbor in sequencE; and means to advance the mounting means to align a fixed straight wire tangential to the arbor and to retract the mounting means therefrom.

18. A cutter for use in severing the free end portion of a wire, comprising: a first arm and a second arm terminating in opposed cutting jaws, the first arm being pivotably mounted at its end remote from the jaw thereof, the second arm being pivotably mounted intermediate its ends on the first arm; reciprocable means to move that end of the second arm remote from the jaw thereof laterally to close the jaws; and means releasable on closure of the jaws to move the jaw of the second arm away from the jaw of the first arm and rearwardly whereby the jaws move away from the severed end of the wire.

19. A cutter as claimed in claim 18, including resetting means cooperating with the reciprocable means and the releasable means which, on the return movement of the reciprocable means, re-engages the releasable means.

21. In apparatus for bending the leg of a wire coil spring to form a hook, mandrel and arbor means for holding the spring in a position enabling the leg to be bent into a position parallel to the spring axis, said mandrel and arbor means comprising: an arbor mounting member having a pair of spaced flanges projecting therefrom, the flanges having aligned and right angled inner faces; a removable arbor bearing against the inner faces of the flanges and means on the mounting member urging the arbor into said bearing position; an adjustable mandrel plate carried by the member and having a mandrel located adjacent the arbor and projecting at right angles thereto and to the mandrel plate; and holding means mounted on the mounting member and movable against the mandrel at right angles thereto to wedge between adjacent turns of the coil spring.

23. Apparatus as claimed in claim 21, including bending means movable in an arc about the arbor and comprising: a shaft axially aligned with the arbor; a collar fixed on the shaft; a bending tool mounted on the collar and having a member projecting radially towards the arbor; and means to rotate the shaft.

24. Apparatus as claimed in claim 23, in which the means to rotate the shaft comprises a reciprocable rack and a pinion, the rack being adjustable longitudinally with respect to the pinion and having an adjustable stroke.