GB240996A - Improvements in electric contacts - Google Patents

Abstract

240,996. Siemens Bros. & Co., Ltd., and Humphries, H. E. Oct. 1, 1924. Metering systems.-Relay contacts of the make-before-break type are made with a sluggish intermediate spring, so that a circuit is momentarily made during forward but not during backward movement of the armature. As shown in Fig. 1, the armature 2 of an electromagnet J on attraction first causes the spring 3 to contact at 8 with the spring 5, after which contact is broken at 7 between springs 4 and 5. Spring 5 has a weight 6 attached to its end which ensures that during the return movements contacts 3 and 5 disengage at 8 before contacts 4 and 5 re-engage at 7. By this arrangement contacts 3 and 5 are momentarily in contact only during the attraction of the armature, and the fleeting current passing through them may be employed to operate a meter M in a telephone system as shown in Fig. 2, the meter being cut in by contacts Z<1> of a relay Z, the circuit of which is completed between contacts 3 and 4 of any of a number of relays J to which it is connected.