GB766009A - Improvements in or relating to electromagnetic unit - Google Patents

Abstract

766,009. Automatic regulation. COHEN, A. M. Jan. 5, 1954 [Jan. 8, 1953], No. 271/54. Class 38 (4). [Also in Group XXXVII] In an electromagnetic unit having, say, thirty contact pairs 42, 44 adapted to be sequentially opened and closed in accordance with the increase or decrease in energization of an electromagnet 84, the magnet 84 is arranged between a magnetic top plate 24 and a non-magnetic bottom plate 20 and the armature 52, Fig. 6, is connected to the plate 20 by means of a leaf spring 76 so that its middle portion pivots about an edge 50 of the plate 20 and a portion 54 extends beneath the magnet so as to be attracted to its poles. The arrangement is designed to be sensitive, independent of position in which it is mounted and shock proof. The notched ends 114 of the armature engage slots in a thin flexible plate 122 secured to an insulating sheet 118 with an inclined lower edge which lifts the contacts 44 successively from the contacts 42 as the magnet is energized. Springs 130 fixed to the plate 122 return it on de-energization. The magnet 84 has two coils and two cores which project through holes in the plate 20 and enter apertures 94 in the armature, the cores and apertures being designed to vary the magnetic pull for different positions of the armature, as required. The armature is held in position, Fig. 4, by means of fixed studs 64 which pass loosely through holes 62 in the armature and by studs 72 on the armature which overhang ledges 66 formed where the studs 64 extend beyond the edge of the plate 20. Specifications 658,869 and 661,972 are referred to.