GB485824A - Improvements relating to electromagnetically-operated switches - Google Patents

Abstract

485,824. Electromagnetic and mercury switches. CIANCHI, A. Aug. 31, 1937, No. 23736. [Class 38 (v)] An electromagnetically operated switch unit includes a plurality of switches having enclosed contacts, operated from outside the enclosing vessels by a single electromagnetic structure with an energizing coil which surrounds the switches. The energizing winding 2 surrounds a number of switches such as 1, each of which is retained in position by sheaths 18 fitting in holes in two caps 5, 5' of magnetic material enclosing the winding 2. Each switch 1 has contacts 13, 13<1> at its ends upon which bear spring terminal contacts 17, 17<1> passing through discs 19, 19<1> of insulating material affixed to the caps 5, 5<1>. Each switch may consist, as shown, of plunger 21 floating in mercury 22 and having an armature 23 of magnetic material by means of which the plunger is drawn down when the electromagnet circuit is completed. Normally, the circuit between contacts 13, 13<1> is broken, but when the plunger moves to its downwardly-displaced position, mercury enters the plunger through a side passage 25 in the plunger and completes the circuit through the switch. Alternatively, the switches may be arranged to break contact on energization of the operating magnet and solid contacts may be used instead of mercury.