GB790371A - Improvements in or relating to electromagnetic switch operating mechanism - Google Patents

Abstract

790,371. Electromagnetic switches. IGRANIC ELECTRIC CO., Ltd. Jan. 20,1955 [Feb. 10, 1954], No. 1745/55. Class 38 (5). Mounting brackets 31 of an armature 3 have split end portions 31a, 31b forming bearing surfaces engaging a pivot pin 23, the armature being releasably held on the pin by a spring- biased plate 51 having knife-edges 52 cooperating with hook-shaped ends of the portions 31b, the biasing spring 59 acting between a depending limb of a bracket 62 and a washer 58 retained on a neck portion 56 of an extension 55 of the plate 51. The plate 51 slides to-and-fro upon normal movement of the armature relative to the core 2 and is guided by the enlarged end of the depending arm 61b of a bracket 61, the arm 61b extending through a cut-out 54 in the plate. During the normal armature movement the sides 54a, 54b of the narrow portion of the cut-out 54 co-operate with a narrow portion of the arm 61b, and to remove the armature the plate 51 is pulled forward so that shoulders 54c of the cut-out may be latched against a wider part of the arm 61b thus permitting lifting of the bearing portions 31a, 31b from the pin 23. To prevent inadvertent release of the armature a further neck portion 57 of the plate extension 55 is normally held by a spring 63 in the vertical limb of an inverted T-shaped slot 62b (Fig. 3, not shown) formed in a further limb of the bracket 62. The arrangement is such that the broader end of the extension 55 abuts the bracket 62 before the arm 61b leaves the narrow part of the cut-out 54, release of the armature requiring movement of the extension 55 against the bias of spring 63 so that the extension enters the horizontal arm of the slot 62b. The switch contacts are not shown in the drawings.