GB619546A - Improvements relating to polarized electric relays and like magnetic devices - Google Patents

Abstract

619,546. Telephone instruments; receivers. CARPENTER, R. E. H. Oct. 2, 1946, No. 29384. [Class 40 (iv)] [Also in Group XXXVII] In a polarized electromagnetic relay, telephone receiver or other instrument for converting electrical into mechanical vibrations or vice versa, the armature 13 oscillates between two parallel polepieces 3 projecting inwardly from legs 4 and spaced apart by distance pieces 12, its axis of oscillation being also parallel to the polepieces. Fig. 4 shows a relay, the magnetic circuit and principle of operation of which is similar to that in Specifications 315,496, [Class 40 (iv)], and 559,047. When the parts are assembled the legs 4 of the polepieces 3 abut against the laminations 23 and a pair of permanent magnets 9, only one of which is shown, project on opposite sides of the armature 13 and overlap in a similar manner to the polepieces 3, similar poles being adjacent. The frame also carries fixed contacts which may be of the kind described in Specification 484,472, [Group XXXVII], and are also arranged on opposite sides of the armature. Fig. 5 shows part of a slight modification in which the magnets 9 are replaced by magnets 34 having unlike poles on their opposite faces and which magnetize respective polepieces 36. Fig. 7 shows a further modification, the magnetic structure of which is a development of that shown in Specification 172,717, [Class 38 (v)]. In this, operating coils 21a, 21b surround the armature 13 which oscillates between poles 45 magnetized by a permanent magnet 40 with poles on its opposite faces. Fig. 9 shows a telephone receiver in which the armature 13 vibrates between two polepieces 37, 38 which are in the form of rectangular frames and are spaced apart by a magnet 40 with poles on its opposite faces. The armature passes through the voice coils 21a, 21b.