Patent GB-781321-A (GB)
Title: Button sewing machine
IPC: D05B85/00
Filed: 1954-12-06
Abstract: 781,321. Sewing-machines AMERICAN MACHINE & FOUNDRY CO. Dec. 6. 1954 [Jan. 13, 1954], No. 35271/54. Class 112 A button-attaching machine similar to that described in Specification 712.548 is nrovided with means for automatically threading the needle and 'for preventing unwinding of the thread round the shank attaching the button. The work-support is adjustable relatively to the needle. and is movable to a clearly-visible position for insertion of the work. The buttons are fed from a clip and orientated by means adapted to accommodate different sizes of button. Successive operations are controlled by two pedals. Work-holding. The work is folded over the end of a work-holder plate 172. Fig. 5, and clamped by this plate on a plate 174 with curved prongs 176 (also shown in Fig. 23). One of the prongs 176 has within it a rib carrying a pin 552 to compress the material at the stitching point to prevent puckering; this pin also prevents the thread-winding from covering the entire length of the shank. These plates are hinged at their forward end together to a work-support which is slidable in guides on a work-frame 188, Fig. 3A, and is held in operative position relatively to the frame 188 by a locking pin 250 in lugs 248 on the worksupport. The frame 188 is carried at its rear end by a cross-bar 190 engaging fixed guides '192 and at its forward end of a pivot stud 196 on a cross bar 198 which is pivoted at 206 and engages a fixed guide 200. The frame 188. receives back and forth movements by means of a rod 236 adjustably connected to the bar 198 and connected at its other end to a lever 230, Fig. 1. actuated by a cam 226 driven through wormgearing from a motor-driven shaft 96. It receives sideways movement from a second cam 224 through a lever 220, arm 216. and adjustablyconnected rod 210. A spring 242 biases the table against the force of both cams. The operative position of the work-support on the frame 188 is determined by a stop on the support engaging one or other of a series of stop-screws 262 on a turret 264 carried by the frame 188; the screws 262 project from the turret to varying extents and the position of the work support'is readily adjusted by turning the turret, which is latched in the required position. The height of the work above the work-support is adjustable to vary the' length nf the shank by means of a turret-head 276 with vertical stop-screws 278 of different heights, arranged to engage a member on the work-holding plate 174. The locking-pin 250 is withdrawn against a spring 258, to allow the work-support to be moved forward to a loading position by means of a crank 532 carried by the work-support and provided with a depending finger-pin. This crank is also engaged by a lever 542 operated through a flexible cable 538 from a pedal, to release the locking-pin and by continued motion to carry the work-support forward. Presser. A presser-foot 560, Fig. 5, holding the work on the plate 172, is provided with prongs 580 to assist in preventing unwinding of the thread during shankwinding, and with notches 582 to assist in keeping the upper loop of the thread straight during sewing. The presser foot is formed on a stem fixed adjustably to an arm 566, Fig. 1, on a shaft 568 with an arm 570 acted on by a spring 574 on a push-member 572 actuated by a cable 578 from the pedal. Button-holding. The button chuck comprises a bracket 292, Fig. 23, on the work frame 188, with rotatable and slidable shafts 298 carrying blocks 300 with jaws 302. One jaw 302 has a pin 304 sliding in a bore in the other jaw for alignment. 'The inner ends of the jaws are grooved to grip a button. Arms 308, 310 on the jaw shafts carry racks engaging a pinion 318 whereby the movements of the jaws are co-ordinated; the jaws are slid open against a spring by a cable 328 connecting the arm 308 to the pedal mechanism. The button chuck is turned from the vertical to the horizontal position and back as required by a rod 303 connecting an arm on one of the jaw shafts 298 to a lever 305, Fig. 1, operated by a cam 309. Button supply. The buttons are provided in clips, the arrangement and spacing of the holes in the buttons being the same for all sizes. The clip, Fig. 18, comprises a channel 358 holding the buttons side by side, with a spring 360 having upturned ends to prevent the buttons from sliding out. The clip is loaded into a device comprising an inclined plate 374 in a vertical plane with clamping bars 378 slidably and yieldably secured to them (see also Fig. 1), each with a transverse slot to engage one of two headed studs 382 holding a cross-bar 384; the loading end of the plate 374 and bars 378 are flared. A knob 366 near the rear end of the clip 358 engages a slot in the plate 374 and its front end has prongs to embrace a stop-pin 406; its top fianges are cut away at the front end and part of the bottom is cut out at 372. As the clip is inserted, the lower end of the button-retaining spring 360 is deflected by a cross-bar 410 so that buttons can slide down to a lip 412 projecting from the cut-out 372. The bars 378 are cut transversely to receive pivoted arms 400 with pins 402 to retain the front button; the arms are spring-pressed, to yield for the passage of the buttons when ejected. The means for orientating the buttons and ejecting them into the button chuck comprises pairs of pins 432, 438 for engaging holes of the button carried by a plug 434, fixed in the forward end of a shaft 410, the pins 432 being spring-pressed by a piston 430, in the shaft 414, to which they are attached. The shaft 414 is slidable and rotatable in the bracket 417 and formed with a cam track 418 engaging a screw 422; it is moved forward by a cable 442 from a second pedal and rotated at the same time by the cam track 418 so that the pins 432 find two holes of the button and orientate it, the pins 438 then enter the other two holes and the plug 434 pushes the button out of engagement with the pins 402 at the bottom of the clip to position it between the jaws of the chuck, which have been opened by the first pedal. Release of the pedals causes the button to be held in the chuck and restores the ejector to the initial position. Running-stitch machines. The upper needle-bar 58, Fig. 1, is adjustably and detachably mounted in a block 62 supported on links 66, from an operating lever 70 actuated by a cam 80, driven by a belt from a shaft 90 bevel-geared to the motordriven shaft 96. The lower needle-bar is carried in a similar block 108 with links 124 to an arm 126 operated by a cam 132 on the shaft 90. Each needle-bar has a bayonet slot engaged by a stud on a sleeve which is adjustably held by nuts in its block 62 or 108; the screws lock the stud in the slot. The needle-bars slide in guide abutments 136, 134. The needle 142, passed from the chuck of one needle-bar to the other, may be sharp at both ends or blunt at one end. A looper arm 144 actuated by a cam 158 through a lever 154 and link 152 is stationary during shank-winding. A thread-puller 168 is provided on an arm 170 on the shaft 90. The loose end of the thread laid by the puller 168 in a trough 700 is also laid across a finger 702, Fig. 32, which is moved upwards and backwards to engage the thread with a fixed guide 712 and a trap 714, assisted by a finger 720 on a stud 722 loose in the member carrying the trap. A spring urges the finger 720 against the member 702, which engages a lug 724 on the former to hold it upright till the latter retreats. To assure the proper formation of a loop while the needle is in the lower needle-bar, gripper fingers (Fig. 34, not shown), pivotally mounted on the member to which the guide 712 is fixed, engage the thread after the needle-bar has moved slightly up from its lowest position to a position in which it dwells. The fingers are geared together and actuated by a rack connected to a cam-operated lever. Shank-winding, To prevent the thread from slipping back during winding, a rod 760, Fig. 1, engages the shank when the needle is in the lower needle-bar and the latter reaches its dwell position. The rod is adjustable on a pivoted arm 762 connected by a spring to a cam-operated arm 770. It is moved quickly for the upward movement of the needle-bar by a bumper on the work frame 188 engaging a'lug on the arm 762. The loose end of the thread is tensioned, to prevent uncoiling, by a finger 789 on the end of a bar 790 which is moved endwise by an arm 794 actuated through a resilient connection 796 by a cam operated lever 800; an extension of the shaft 790 has a threaded end and finger-knob for adjustment of the tension finger. Needles, threading. A threader hook 474, Fig. 23, is carried by an arm 470 on a shaft 472 which is rotated by a rack 480 engaging splines on the shaft. The rack is connected by springs 484 to a member 488 which is operated through a flexible cable by the second pedal. The member 488 also has connected to it a bar 494 slidably carried by the rack and formed with a projection at its end to engage a crank 502 pivoted on the housing 476 to shift the shaft 472 longitudinally against a spring by means of a collar 508. The arm 470 also carries a thread-clamping spring leaf 518 with a hole through which the shank of the hook 474 can project. The ends of the leaf is normally held denressed beneath the end of a plate 522 fixed on the button-guide cross-bar 384. On depression of the pedal, the shaft 472, which is normally held with a lug 512 against a stop-pin 514, is rotated until the lug engages the other side of the pin 514, carrying the leaf 518 clear of the plate 522 to allow it to engage with the bent-up part of the hook 474, which is then exactly in line with the eye of the needle held in the upper needle bar 58. Continued movement of the member 488 actuates the crank 502 to slide the shaft 472 forward carrying the hook through the needle eye, guided by a second fixed pin engaging the