GB751478A - Improvements in or relating to electro-magnetic relays - Google Patents

Abstract

751,478. Electromagnetic relays. ELREMA SOC. ANON PER LO SFUTTAMENTO DI BREVETTI. May 22, 1953 [May 28, 1952], No. 14474/53. Class 38(5) An electromagnetic relay comprises a magnetic core 1 around which is wound an energizing winding 2 which when energized causes two armatures 3, 4 to move to engage the core 1, the core and armatures preferably forming the contact members, the armatures 3, 4 being polarized by the provision of supplementary windings 14, 15 respectively. The polarizing windings 14, 15 may assist or oppose the energizing winding 2 and are designed to be able to maintain the relay operated by themselves but not to be capable of operation of the relay. All three windings must be de-energized to allow the relay to return to its normal position. The polarizing windings may be situated elsewhere in the magnetic circuit; for example around the, armatures themselves or around the air gaps between the core and armatures. A number of such relays may be mounted to form a unit, in which case the polarization windings 14, 15 may be common to all the relays. The armatures may be arranged to operate spring sets instead of forming contact members.