Patent GB-801344-A (GB)
Title: Improvements in or relating to methods and assembly machinery for assembling contactspring sets
IPC: H01H49/00
Filed: 1955-12-15
Abstract: 801,344. Making contact spring sets for telephone relays and the like. TELEFONAKTIEBOLAGET L. M. ERICSSON. Dec. 15, 1955 [Dec. 15, 1954], No. 36006/55. Class 83 (2). In a method of assembling contact spring sets for telephone relays and the like, the elements to be assembled are stored at a number of feeding stations 103-107 in front of which assembly jigs 101 are moved intermittently, the elements are fed into each jig in the required sequence, the assembled set of elements in a jig are secured together, for example by riveting, at a further station 108 and the set is then discharged from the jig at station 109. Each spring set may include different kinds of contact springs such as opening, closing or change-over. The jigs are detachably coupled to an intermittently moving endless chain 102 by means of a control device 110. Each jig comprises a body 210, Fig. 2, with forwardly extending parallel tongues 200 of which alternate tongues are shorter than the other tongues. A comb unit 201 pivoted at 208 has teeth 207 which engage between the longer tongues to space them apart correctly during assembly of the individual contact springs 400, 401 between the tongues. The jigs 101 are slidably guided along a rail 501, Fig. 5, during assembly of the contact springs which takes place at a number of the stations 103. At each station 103 the jig is moved forward in a number of short steps, preferably six, by a cam 508 engaging a follower 202 on the jig. A control roll 510 extends over all of the feeding stations 103, 104, Figs. 1, 5, and has cam projections 509 detachably mounted in its periphery. The contact springs 400 are pre-formed from a continuous metal strip but remain interconnected by bridging pieces; the strip is rolled on a drum with a plastic band between turns. At each or some of the intervals between the steps a projection 509 on roll 510 engages a spring-loaded lever 514 which raises a rod 513 to position a disc 515 between a pair of axial cams 516, 517 on a shaft 518 driven through bevel gearing 503, 504, shaft 525 and slidable coupling 554. The disc 515 causes shaft 518 to move to the right whereby a crank pin 519 is brought into alignment with the slots of a Maltese wheel 520 on a shaft 555 carrying feed wheel 521 for the contact springs 400. The feed wheel 521 is then turned through part of a revolution to feed one spring downwardly and simultaneously a lever 523 operates a coupling bar 522 to move a cutting tool 505, actuated by reciprocating bars 506, 507, into position to sever off the leading spring which is then pushed into the jig by a finger 524, Fig. 6 (not shown). The number and position of the projections 509 on roll 510 thus determines the number and location of the springs. The jig is then moved to another station 103 where contact springs of another kind may be assembled by similar feed mechanism. At station 104, Fig. 1, a return spring 401, Fig. 2, is fed into the jig; at station 105 a bracket 402, Fig. 2, severed from preformed metal strip and bent by a tool 111, Fig. 1, and a lifting bar 403 supplied from a store 112, are fed together into the jig; at station 106 an upper side plate 404, Fig. 2, is fed and thereafter the comb 201 is moved from its guiding position between the jig tongues and at station 107 a lower side plate 404 is fed into the jig. The assembly is then riveted together at station 108 and discharged from the jig by an ejector bar at station 109. A counting device 110, Fig. 1, determines the number of jigs which are to be filled.