GB498835A - Improvements in or relating to electromagnetic light-current relays - Google Patents

Abstract

498,835. Light current relays. STANDARD TELEPHONES & CABLES, Ltd., and TERRY, R. ST. G. Ju]y 14, 1937, No. 19541. [Class 38 (v)] In a relay which is operated by one coil and latched and later released by energisation of a second coil, the operating and release armatures of the two coils are pivoted on the same axis and have extensions which co-operate with a pivoted latching pawl, the plane of which is perpendicular to the extensions. As shown in Fig. 3, the operating and releasing coils are mounted sideby-side around and are adapted to attract coaxially pivoted armatures 3, 23. The armature 3 carries a latching member comprising a plate 5 formed with a latching extension 27 and the armature 23 carries a latching member 26 having an upright arm 25 from which is offset a lateral latching extension 28. The latching pawl 12, Fig. 4, is pivoted at the top of a pillar 10 and a spiral spring on the stud engages with the arm 30 of the pawl and normally urges the latching arm 29 against the side of the latching projection 27. When the operating armature 3 is attracted by energization of the operating electromagnet 2, the plate 5 is moved away from the pawl 12 so that the latching extension 29 of the pawl is pulled behind the extension 27 so holding the armature 3 in the operated position even though the energizing circuit of the coil 3 is broken by contact springs operated by the armature. The armature 3 is subsequently released by attraction of the releasing armature 23 to the releasing coil 22, the arm 28 of the latching extension engaging the arm 30 of the pawl to rock the latter against its spring so that the pawl 29 is moved from behind the latching extension 27 so releasing the armature. The plate 5 with its extension 27 consists of a main plate backed by a spring plate and the point at which latching takes place may be adjusted by adjustment of the spring plate relatively to the plate 5 by means of a screw 8 passing through the latter and bearing on the spring plate. The coil 2 may be provided with a slug and /or a non-inductive shunt connected in parallel with the winding so that break contacts for the winding circuit may be operated before the armature has completed its stroke in which case the energy stored in the slug and/or shunt winding is sufficient to cause the armature to complete its stroke and allow the latching operation to be completed.