GB1213699A - Improvements in or relating to switches - Google Patents

Abstract

1,213,699. Movable magnet switches. STANDARD TELEPHONES & CABLES Ltd. 17 May, 1968, No. 23493/68. Heading H1N. A magnetic switch operable due to movement of its permanent magnet or movable magnetic part has a sealed magnetic contact capsule with one well formed by one or more inner magnetic members sealed through a central aperture in an outer annular magnetic member and a magnetic contact lamina normal to the axis of the outer magnetic member. The contact capsules may be similar to those used in the relays of Specifications 1,021,047, 1,026,564, 1,026,565, 1,026,566, 1,026,567, 1,098,145, 1,099,081, 1,115,401, 1,119,126, 1,126,869 and 1,131,928, and provide one or more contact sets with normally open or normally closed or changeover contacts (Figs. 1 to 10, not shown). In Fig. 11 the inner magnetic member 108 is surrounded by an insulating washer 107 seating one end of a compression spring 106 which biases a magnetic push-button 101 to a position in which its flanges engage co-operating flanges 102 of a housing 103. When the push-button 101 is depressed it moves a permanent magnet 105 mounted thereon adjacent to the member 108 to effect contact operation. The flanges of the push-button 101 engage the contact capsule 104 to prevent engagement of the magnet 105 and member 108. In alternative arrangements the magnet may have a lost-motion mounting on the magnetic push-button (Fig. 12, not shown), the contact capsule may be resiliently mounted (Fig. 13, not shown) or the contact capsule may be mounted so as to be moved with the push-button relative to a fixed magnet (Fig. 14, not shown). In Fig. 15 the permanent magnet 105 has a magnetic cap 153 and disc 151 so as to attract magnetic washer 156 to bridge the gap between the disc 161 and pushbutton 101. The push-button has a friction reducing nylon liner 154 and when depressed it moves the washer 156 away from the disc 151 to divert flux to the contact capsule 104. When pressure is removed from the push-button the washer 156 and push-button are returned to the position shown by the permanent magnet.