GB836571A - Improvements in electromagnetic switches - Google Patents

Abstract

836,571. Electromagnetic switches, contactmembers for switches. ARROW ELECTRIC SWITCHES Ltd. May 13, 1957 [June 14, 1956], No. 15076/57. Class 38 (5). An electromagnetic switch has bridging contacts 30 which may be readily changed from the normally open to the normally closed position or vice versa. A contact-carrying cage 40 has two springs 46, 461 which urge saddles 45, 45<SP>1</SP> inward against stops 41s, 42s, formed in the sides of the cage. The saddles 45, 45<SP>1</SP> have bent edges 47 which may be grasped by the fingers to insert the bridge 30 between one of the saddles and the stops. Each cage is bolted to an insulating bar 50 on a carriage 54a, 54b, 54c. The fixed contacts 12, 14 are carried in insulating members 16, 18 which are held by bolts 19 and the member 18 is removable with the fixed contacts 12 to allow access to the movable contact assembly for reversal of the bridge 30, from the Fig. 2 to the Fig. 3 position or vice versa. The carriage 54a ... 54c has a pivot pin 63 which can move in slots 66 in arms 68 of a support-plate 20 which also has loops 57 for adjustably anchoring the ends of tension-springs 55 having their other ends in apertures in the carriage so as to hold it against a strut 58 having knife-edge engagement with leg 54a of the carriage. The spring 55 also biases the carriage to the lower position when an armature 60 carried on the pin 63 is not attracted to the electromagnet 70. The latter is fixed to the plate 20 by screws 71, and when the screws are removed the armatures 60 and electromagnet 70 may be pivoted about the pin 63 to a position where the magnet 70 may be removed. A spring 80 carried on the end 54b of the carriage may be depressed as the carriage moves downward so as to engage a pin 82 and hold the carriage in a position where neither the normally open nor the normally closed contacts engage the fixed contacts so that the bridges 30 may be easily changed. The plate 20 complete with the electromagnet and contact structure may be removed from a base-plate 10 carrying a support insulator and fixed isolating contacts, as described in Specification 836,575. Specifications 836,572 and 836,574 also are referred to.