Patent GB-597975-A (GB)
Title: Improvements in the forming of articles from wire and other material
IPC: B21F45/16
Filed: 1945-10-10
Abstract: 597,975. Making fastenings. YATES, G. Oct. 10, 1945, No. 26505. [Classes 83 (ii) and 83 (iv)] A spring fastener for aircraft parts comprising parallel coils joined by a straight wire is made by shearing wire into lengths and by a turret work-holder moving them past stationary crank-operated tools for bending, coiling the ends, shearing the tails, flattening the coils and ejecting the finished articles. An electromotor through a slipping clutch 141, Fig. 25, rotates a shaft 110 actuating workholder indexing mechanism and through bevel gears 217 rotates the crank-shafts 205 operating the tools. Through a worm gear 443 and crank 446, rack 448 and gears 455, 456 it oscillates coiling heads 560 on shafts 437. The wire 19 is fed from a coil by feed rolls 270, 272, Fig. 26, and is sheared by a reciprocating cutter 326 and inserted between fingers 51, 52 of the workholder after fingers 249 have ejected a fastener. Pivoted fingers 51, 52 carried on a sleeve 43, Fig. 56, are pressed together by a spring 60 and urged against a stop 61 by a spring 62. The sleeve 43 carries a notched disc 70 engaged by pawls 86 on a spider 101. The shaft 110 carries a cam 108 which swings a lever 103 about a pin 104 to compress a spring 122. On the working stroke the spring extends to rock the spider 101 carrying a gear 100 meshing with a fixed rack 99 and rotating a pinion 97 on the disc 70. The heel of the pawls 86 releases a locking pawl 74 at the start of the working movement. Feeds.-The wire 19 is fed through a friction device 308 between rolls 270, 272. The roll 270 is rotated continuously from the clutch 141 and carries an adjustable cam 273 which separates the rolls and applies the friction device 308. Shearings-adjuncts.-A cam 358 on the roll 270 reciprocates a blade 326 co-operating with a stationary blade 327. Ejectors.-At station A a cam opens the fingers 51, 52 and trips ejecting fingers 249 which expel the fastener 1 and the sheared length of wire is inserted and gripped centrally by the fingers. In a modification for making clips without joggled portions, the fingers 51, 52 are modified and the ram and ejecting mechanism in the loading stage A is varied. Angular bending.-At station B a double joggle 8 is made in the wire, Fig. 46. A ram 192 reciprocated from the crank-shaft carries a recess 397 and pins 403, 408. On the up-. stroke of the ram a pin 423 abuts the workholder 21 and the pins 403, 408 bend the wire about the worh-holder until limited by pins 417, 418. Coiling.-Stations C, D, Fig. 56. The coiling means for ends 9, 10 are similar. A ram 194 is raised by a cam to lift the work-holder 51, 52 and to lock the fingers by a latch 617 swung by a spring-pressed abutment 440. The wire is positioned between a spiral former 436 and a coiling pin 561 on the shaft 437. The former is lowered during the coiling. On the downstroke of the ram the shaft 437 is reversed and the latch 617 lowers the coil clear of the former. Shearing.-Station E, Fig. 64. A ram 195 raised by a crank 653 carries cutters 648 aligned with fixed cutters 646. On the ascent of the ram, fingers 51, 52 are raised to position the tails against cutters 646 and the cutters 648 co-operate to shear and also open a fluid valve, not shown, which emits pressure through orifices 677 to expel the trimming. Flattening coils.-At stage F, Fig. 71, the coils 9a, 10a are flattened. A ram 196 carries spring-pressed dies 700, 701 with guide pins 686, 687 co-operating with holes in stationary upper discs 680, 681. On ascent of the ram fingers 51, 52 of the work-holder 21 are positioned in a slot and the pins 686, 687 locate the coils which are flattened to form screw seats between dies 700, 701, 680, 681. Lubricatingmachines.-A pump 730 feeds oil from sumps 38, 740 to the gear housing 453.