Patent GB-587552-A (GB)
Title: Improvements in and relating to machines for the manufacture of contact springs and like parts
IPC: H01H11/04
Filed: 1944-08-03
Abstract: 587,552. Making electric contact springs. TELEPHONE MANUFACTURING CO., Ltd., and AYLEN, J. F. Aug. 3, 1944, No. 14850. [Classes 83 (ii) and 83 (iv)] Shearing; riveting.-Apparatus for cutting off successive pieces from a length of wire and for securing each of the pieces in an aperture in one of a succession of members, wherein each of said pieces is sheared from the length of wire by passing the wire through holes in two relatively moving shearing elements of which one is formed by one of said members. The invention is described in connection with a machine for making electric contact springs. A table 1 intermittently rotated on a base 2 has around its edge a number of work carriers each comprising a rectangular block 3, Fig. 2, mounted in a radial slot so as to be flush with the upper surface of the table and having upstanding posts 33, 34 adapted to extend through holes in the contact springs 4. At the first station, the springs are fed on to the work carriers from a shoot 6, Fig. 3. The lowermost spring in the shoot rests on ledges 7 and is pushed forward by a bar 9 operated from a cam by means of a rocking lever 18 and rod 17, until it rests at each side on ledges 10 comprising the outer ends of the horizontal limbs of two L- shape levers which are normally prevented from rocking by means of projections 25 abutting the. vertical limbs 11. The locking projections 25 extend forwardly from pivoted arms 22 which, on the backward movement of the pusher bar 9 are rocked by the passage of the ends of the rod 17 along the upper surfaces of pawls 26. This releases the L-shaped levers which move aside against the action of springs 13 as a vertically reciprocating bar (14, not shown) pushes the spring downwardly on to the carrier 3 beneath. A movement of the table now brings the overhanging end of the spring over a die 41, Fig. 5, and on the descent of the press-head 43, a piercing tool 44 punches a hole in the spring. Spring-pressed guide posts 45 descend at each side of the spring into holes in the base 2 and ensure the correct positioning of the work. Another movement of the table brings the punched hole over a fixed die 48 and the end of a wire 5 is fed up through the hole by means of a gripping pad 56 carried by a reciprocating block 76, Fig. 6. On the downward movement of the block 76 the wire is retained by a gripping pad 55 beneath the base. The block 76 and the gripping pads 55 and 56 are all actuated from a cam-shaft 75. A nut 93 co-operating with a rod 92 secured to a stop member 78 limiting the downward movement of the block 76 serves to adjust the length of wire fed through the spring. After the feed of the wire, a cam-operated member 49 descends on to the spring and holds it firmly down. Member 49 is pivoted to an element 61 having a slot engaged by a projection on a slide 60 movable in a slot in the base 2 by a cam-operated lever 71. The slide 60 is now moved to the left in Fig. 6, moving with it the member 49 and also pushing back the work carrier 3 against the action of a spring 36 so that the spring acts as a shear cutter to cut off the wire. A plunger 52 carried in the member 49 is lightly tapped by a descending element (not shown) and forces the lower end of the sheared-off portion of wire against the upper surface of the die 48, enlarging it sufficiently to cause it to tighten in the hole of the spring. The elements then return to the position shown. At the next station the upstanding wire is engaged by an upsetting tool and riveted over as shown at 5b, Fig. 14A. Another upsetting tool co-operating with a recessed die at the next station forms a flattened contact head 5c, Fig. 14B, and a riveted lower portion. At each of these stations the work is correctly positioned by means of spring-pressed plungers similar to the plungers 45 of Fig. 5. A further movement of the table brings the now completed contact spring to an ejector station, Fig. 15, where a descending plunger 106 co-operates with a push rod 102 moving up through registering holes 38, 37 in the table and carrier respectively to move the work clear of the machine and into a container.