GB892579A - Improvements in magnetically operated electric switches - Google Patents

Abstract

892,579. Magnetic switches. TANN CORPORATION. July 27, 1960, No. 26109/60. Class 38 (5). In a magnetic switch the contact controlling armature is held adjacent to one end of a pair of magnetized polepieces and is movable away therefrom when magnetic flux is diverted away from said one end by a movable permeable means associated with the other end of the polepieces. In Fig. 2 a ceramic magnet 40 has its poles in engagement with polepieces 37, 38 having faces 36 to which an armature 35 is normally attracted against the bias of a snap-action contact device 29. When a piston 45 or other magnetizable member approaches the faces 43 of the polepieces 37, 38 flux is diverted from the armature, allowing changeover contacts 32, 33, 34 to operate. A number of switches may be mounted side-by-side to be operated by a member sliding across their ends (Figs. 5 and 6, not shown), and the polepieces may be straight in a side projecting magnet assembly as in Fig. 4. In Fig. 7, the pivoted armature 84 is biased by a spring 85 and has two sets of bridging contacts 70, 78 which co-operate with pairs of fixed contacts 69, 71, 72. The magnet assembly may be adjustable with respect to the switch housing and support the switch (Figs. 11, 12, not shown). In Figs. 14 and 15 the faces 43 of the polepieces form parts of specially-shaped surfaces 104, 111 for co-operation with curved and toothed magnetizable members 106, 114. An adjustable screw in the end of the armature may be used to set the minimum gap between the armature and faces 36 (Fig. 16, not shown), and the switch may be filled with an insulating liquid. The switch may be operated at a set speed by the movement of teeth 130 (Fig. 17) on a shaft 126 past the ends 43 of the polepieces. In Fig. 18 the pivoted armature 142 is secured to an insulator 152 which engages a change-over contact spring 56 (not shown) so as to bias the armature end 148 away from the faces 36.