GB1303341A - - Google Patents

Abstract

1303341 Manufacturing electromagnetic relays PLESSEY CO Ltd 17 Aug 1971 [20 May 1970] 24341/70 Heading H1N A method of manufacturing a contact stack for an electromagnetic relay in which contact springs 3, 4 are interleaved with insulating spacers 9 and toothed combs 1, 2 are fastened to the contact springs adjacent their free ends to move the springs under the action of an armature of an electromagnet comprises pressing the combs 1, 2 on to the contact springs 3, 4 by a machine instead of by hand. A number of contact stacks (ten in Fig. 3) may be made at the same time. The machine includes a jig 10 having ten recesses 11 each with a pair of guide pins 13. First, base plates are slid down pins 13 into recesses 11, then the stacks are built up on the pins 13 with an assembly of metal spacer bars 15 interlaced with the contact springs 3, 4, one bar between each pair of contacts, the spacer bar assembly running the length of the jig 10 and fitting into slots 16, 17 in blocks 18, 19 at the ends. A block 30 having grooves 39 is then moved towards the front of the machine by handle 31 so that contact springs 3, 4 penetrate grooves 39 to align springs 3, 4. The stacks are then lightly clamped by pivoting clamping bar 40 on top of the stacks by handles 43, 44. An air piston and cylinder 22, Fig. 1 (not shown), is then actuated to move blocks 18, 19, spacer bars 15 and clamping bar 40 rearwards to locate bars 15 close to the front face of block 30, as shown in Fig. 4. Then air piston and cylinder 45 or 46, Fig. 1, is actuated to move the assembly of bars 15 to the extreme right or left hand positions. Assume cylinder 45 is actuated, the assembly of spacer bar 15 is slid to the left in Fig. 3 through a bar 48, block 49, slider 50 and block 51 (all in Fig. 1) whilst a lever 47, Fig. 1, is pivoted to prevent the block on the other side of the machine from restraining the movement of bars 15. When the bars 15 are in the extreme left hand position, combs 1 are dropped in position through recesses 54 in bars 15 and alongside the contact springs 4 and bars 15 are then moved to their extreme right hand position by cylinder 46 so that combs 1 are pressed on to the edges of contact springs 4. Then similarly combs 2 are pressed on to the contact springs 3. Bars 15 are then moved towards the front of the machine by cylinder 22, the stacks are unclamped by lifting bar 40 and bars 15 are withdrawn from the side. Stiff springs 6, 7, Fig. 5 (not shown), are then dropped on top of the stacks, the stacks are clamped together by screws 59, Fig. 5, block 30 is moved to the rear by handle 31 and the stacks are slid up pins 13 and removed from the machine.