Patent GB-720131-A (GB)
Title: An improved heading machine for bolts, screws, rivets and the like
IPC: B21K1/46
Filed: 1952-10-28
Abstract: 720,131. Bolt &c. heading machines. GUEST, KEEN & NETTLEFOLDS (MIDLANDS), Ltd., and ACTON BOLT, Ltd. Oct. 28, 1952 [Nov. 12, 1951], No. 27008/52. Class 83 (4). A machine for heading bolts, rivets, &c. Figs. 4 and 5, comprises a crosshead 8 carrying a number of heading dies 15, 15a, 15b and a crosshead 9 having an intermittently rotatable dieblock 16 carrying a corresponding number of dies 17, both crossheads being reciprocated in opposite directions by eccentrics 6 and 7, 7a respectively on a drive shaft 2, wire-pieces being fed into the dies 17 which are indexed so that the wire-pieces receive one blow'from each heading die and then the headed blank is ejected from the machine. The heading dies are spaced 120 degrees apart. The indexing mechanism is driven through gears 5, 33, shaft 32 and gears 34, 34a, and comprises a wheel 21 driven by a gear ring 21a and carrying three planet bevel gears 23 in mesh with a fixed crown wheel 25. Each planet gear is secured to a shaft 24 having an inclined crank pin 24a, Fig. 16, carrying a block 28 slidable in an axial slot in an indexing block 27 secured to a shaft 19 carrying the die-block 16. The wheel 21 is rotated continuously, but due to the rotation of the planet shafts 24 and their crank pins 24a. which, for part of their rotation, tend to oppose the rotation of the wheel 21, an intermittent rotation is imparted to the die-block. During the heading operation the latter is locked by a pin 41, Fig. 4, engaging in an indent in the circumference of the die block and which is actuated by a cam 42 on the shaft 2 through levers 43a, 45a, 48. The dies 17 may be split. Ejectors.-The headed blanks 63, Fig. 16, are ejected by pins 18 and during the return stroke of the crossheads the pin 18 of the finished blank only is engaged by an ejector 29c projecting through an arcuate slot 9h and which prevents the pin from following the return stroke of the die-block and thus eject the blank. Wire feeding.-The wire 57, Fig. 18, is fed from a reel through a non return device. 60, having a spring-loaded wedge 62, by a reciprocating gripper 55 having a spring-loaded wedge 58. The gripper 55 is actuated from the crosshead 8, Fig. 4, through connecting links 49, 50, 54, the link 50 being mounted on an adjustable pivot block 51 whereby the stroke of the gripper 55 may be varied. Shearing.-The wire is fed through a bore 69a, Fig. 19, and is sheared by the edge 65c of a blade 65 sliding in a guideway 64a and actuated by a cam 68, on the shaft 32, through a bellcrank lever 66. A spring-loaded plunger 70 having a groove 70b co-operates with the blade. The cut-pieces drop into a magazine 74. Blanks transferring.-The cut pieces 57a are fed through the magazine past a spring-loaded stop 75 by a pusher 73 secured to the blade 65, and then past a further stop 75a, Fig. 22, to the top end of the magazine where they are pushed through an opening 74c by a finger 77a, reciprocating by a cam 79 on the shaft 32, and are held against a finger plate 77b, by a pivoted finger 80 loaded by a spring 82. The pieces are then positioned in alignment with the dies 17 and are pushed therein by the first heading die 15. A fixed guide 84, Fig. 7 (not shown), ensures the correct alignment of the wire pieces and dies and a bracket 86 retains the piece in the die during the rotation of the die-block.