Patent GB-709010-A (GB)
Title: Improvements in or relating to knitting machines
IPC: D04B11/32
Filed: 1950-12-15
Abstract: 709,010. Knitting-machines. MILLER, I. L., MILLER, M. C., MILLER, D. L., CHIPMAN, M. R., BEACHAM, E. B., BEACHAM, F. C., ZULICK, E., and EASTON TRUST CO. Dec. 15, 1950 [Jan. 24, 1950], No. 30641/50. Class 74 (2) Welt mechanism, in a flat full-fashioned type, bearded needle machine, comprises a welt bar having hooks with vertical shanks movable vertically and horizontally with relation to the needles, to engage on the hooks, draw off and top on to the needles a setting-up course, a welt wire take-up to draw off and form a fold of the welt fabric and a welt cam shaft disposed, in addition to the main cam shaft, below the worktable, the welt bar being supported on upwardly extending arms pivoted on horizontally disposed levers for positioning and draw-off movement, a take-up tensioning device acting on the arms and welt bar to move the welt bar forwardly in a draw-off direction, and welt bar positioning cam and follower connections between the welt camshaft and the horizontal levers and vertical arms. A welt camshaft 362, driven from the main camshaft 120, operates the welt bar 352 carried on arms 354 pivoted to levers 358 on a shaft 360, yertical movement being produced by one or other of cams 396, 398 on shaft 362 thereon, or by welt transfer cam 400 thereon; and backward and forward movement by one or other of cams 430, 432, a resilient connection involving spring 442 being embodied in the linkage. The welt bar is positively supported during pressing of alternate needles at setting-up and, thereafter, moved positively forwards over the needle tops by plate 454 borne on arms 452 on a rockshaft 450 and co-operating with adjustable stop screws 456 on the welt bar supporting arms 354. The shaft 450 is rocked by either of cams 462, 464 on shaft 362. By latch 469 the welt bar may be held in a rearmost position to give access to the needles &c. The welt bar ends are shaped as at 472 and are held in correspond. ingly shaped sockets by spring-urged tapered pins 477. A fin 483 enters between screws 484 on a bracket 485 on the pivot bar support shaft 253 to align the welt hooks with the needles. Shaft 362 is driven at the same speed as the shaft 120 through a single revolution clutch 491, 492 which, after each single revolution disengages itself by means of co-operating roller 526 and rock arm 507 and is located by roller 516 engageing notch 514. The shaft 362 revolves once at setting-up and once at welt-transfer, being shogged to left or to right, to bring into action the setting-up cams or welt transfer cams. The clutch is shifted to driving position by movement of a pattern chain-controlled rod 542 acting through linkwork, and the shaft 362 is shogged by movement of a pattern-controlled roller 554 between tracks 562, 564, 566 on cam discs 550, 552. Before use, the welt wires are held in throats 615 of holders 614 by spring clips and are yielded to take-up hooks 626 by a dummy movement of the narrowing machine, the lateral shift mechanism of the pivot bar being rendered inoperative. Take-up tension is produced by a weight acting on a cord 654 wound round a pulley on the take-up shaft 640. Take-up chain driving sprockets 638 have a limited degree of rotation on shaft 640 and a torsion spring 664 provides a yieldable connection. The dummy movement of the narrowing machine removes abutments 674 from the path of a crossbar 652 on the takeup chains and take-up begins. When the hooks reach the dot-and-dash position of Fig. 25, a second cross-bar 653 engages an arm 708 integral with a lever 704 to remove the latter from the path of continuously reciprocating resetting and locking pawls 686, 696 which rewind the take-up to the initial position whilst the lever 704 is held inoperative by a latch lever 718 tripped, when the "reset" position is reached, by a third cross-bar 726 which engages a second arm 724 of the lever 718. The take-up tension can be released by a ratchet 760 and pawl 758 on one arm 762 of a a threearmed lever bearing a roller 770 which can be shifted into alignment with either of cams 772, 774 on shaft 120 or into alignment with a third cam on that shaft when the shaft is shogged for narrowing. When the welt wire take-up has been discontinued, the weight of the welt wire and attached fabric, plus the clearing action of the knockover bits, is relied on to provide take-up. Yarn from the usual clamp to the thread guide is located by a guide 738. A pivoted spring-urged cutter arm 730 is held up by a lever 740, 752, which is tripped by the cross bar 652 when the take-up chain and hooks are given a rearward movement for this purpose through the action of the cam 772 of the take-up tension release. Subsequent forward movement of the hook 626 causes a lug 750 thereon to engage an arm 748 to reset the cutter. At set-up very tight loops are produced on the needles, so that when the yarn given up by the cast-off loops is added to that of the remaining loops, these latter loops are of substantially normal size. The knockover bits 108 are contained in a frame 180 having downwardly-extending arms bearing fulcrum pins 184 held upwardly in slots in rock arms 216 against adjustable stops 218, normally by springs, but, when necessary, by adjustable screws 234. During setting-up and welt-turning the narrowing machine can be raised to a high position by a cam 273 on shaft 120, a post 259 engaging in a notch in a lever 255. The position is maintained by the engagement of the foot treadle lever with a latch 280: the engagement can be automatically terminated.