Patent GB-895653-A (GB)
Title: Improvements in heading machines for bolts, screws, rivets and the like
IPC: B21K1/46
Filed: 1958-09-03
Abstract: 895,653. Heading-machines. GUEST, KEEN & NETTLEFOLDS Ltd., and ACTON BOLT Ltd. Sept. 3, 1958 [Sept. 19, 1957; Feb 11, 1958], No. 28254/58. Addition to 720,131. Class 83 (4). In a modification of the bolt or rivet heading machine described in the parent Specification with reciprocating punch and die heads 1, 2, wire 30 is fed into the die head 2 by a capstan drum 31, which receives one turn of wire, and a pair of feed rolls 34, 35, Fig. 11, having peripheral grooves 35, 36 with grip portions 37 which feed the wire intermittently. Both the capstan drum 31 and the feed rolls 34, 35 are driven continuously through skew gearing from a camshaft 9, Fig. 1, and the amount of feed is varied by adjusting the relative angular positions of the rolls and hence of the grip portions 37 thereby varying the period during which the wire is gripped. The pull exerted by these rolls tightens the wire on to the capstan drum which thus pulls fresh wire from its supply reel. A wire-straightening device may be interposed between the capstan drum and the feed rolls. The wire is fed through a bore in the die head 2, Fig. 5, and a cut-off die 59 to a stop 57, Fig. 1, and the projecting end is then severed by a knife 43, Fig. 6, reciprocable in guides 46 on a base 47 secured to the front of the die head 2; the knife has a disengageable connection 52a with an actuating pusher 52 having two roller followers 53, 54 driven by a cam 55 on the cam-shaft 9. A spring-loaded finger 48 on the knife grips the cut-off blank and feeds it opposite a die 64, Fig. 5, into which it is pushed by a punch 89 on the punch head 1. Three or more dies 64 are mounted in a turret-type die block 60 which is rotated intermittently to bring each die successively opposite each punch whereby the heading is performed in two stages and the blank is finally removed by an ejector rod 66 forming the bottom of the die bore 64a and which, upon retraction of the die head 2, engages an ejector 72 which is mounted on a bearing pedestal 73 and is caused to rotate with the die block by linkage 74, 75 actuated by adjustable stop screws 76, 77 carried by the die head 2. The position of the ejector rods is adjustable to suit different lengths of blank by a threaded sleeve 70. For producing intermittent rotation of the die block 60, a sun gear 23, Fig. 3, driven through gearing 12, 13 and shaft 14 from the cam-shaft 9, meshes with planet gears 24, Fig. 3, which also mesh with an outer fixed gear 25. The planet gears carry crank pins 26a passing into slide blocks 28 slidable in radial slots of a slide plate 29 connected to a shaft 16 which is thus caused to rotate intermittently and is coupled through gearing 17, 19 and shaft 7 with the die block. The angular indexing movement of the die block is varied by altering the ratio of gears 17, 19. Shaft 7 is biased by spring 21 to prevent jamming of the die block 60. During the actual heading the latter is positively fixed by pressing a ball 87, Fig. 5, into a detent 88 by means of a stop pin 85 driven through linkage 84, 81, 80, Fig. 1, by an axial cam 79 on the punch head 1. The stop pin is split, Fig. 15 (not shown), whereby it expands radially under load and positively holds itself in position. At least two of the punches 89 are mounted in bores 91 of punch carriers 90, Fig. 16, adjustably clamped by screws 93 and plates 94 to the face of the punch block 1 and adjustable thereon by a screw 95.