GB809889A - Improvements in or relating to contact spring sets for electromagnetic switching devices - Google Patents

Abstract

809,889. Contact members for switches. TELEFONAKTIEBOLAGET L. M. ERICSSON. May 6, 1957 [May 5. 19561, No. 14419/57. Class 38 (5). A contact spring set applicable to an electromagnetic relay 1, 2, 3, has the spring strips or wires 4 mounted on an insulating block 5 and bent against their natural bias so as to engage in either upper or lower notches 11 in a fixed contact plate 10 carried on an insulator bar 9 fixed on brackets 13. The springs 4 pass through slots 16, 17 in an insulating plate 8 which is held against the armature 2 by a spring 14. When the armature is attracted to lift the plate 8 contact tubes 12 on the ends of the lower springs 4 can engage the lower notches 11 and contact is broken between the upper notches and the tubes 12 on the upper springs. The instant of contact make and break depends upon the depth of the slots 17, 16 and certain slots may be of such depth that their contacts remain closed. The plate 10 may be drilled at 19 to make a number of electrically separate parts. This, if the slot for the left-hand contact (Fig. 2), is such that it is always closed and the holes 19 are drilled the next two contacts act as a change-over switch. For the modified arrangement of Fig. 4 the springs are arranged so that there is a movable contact for each notch 11. The fixed contact plate may then be broken at any of the necks 41 ... 43 to give the desired contact combination.