GB979114A - Time switch - Google Patents

Abstract

979,114. Time switches. A. EISEN. Nov. 1, 1962, No. 41383/62. Heading H2B. A cam 6 of synthetic resin material is driven by a clockwork mechanism (not shown) and has a step reinforced by a metal plate 22. A contact-carrying leaf spring 16 overlies an auxiliary spring 20 which carries an insulating distancepiece 21 passing through a slot in spring 16 and normally engaging a leaf-spring 15 to hold it out of contact with spring 16. As cam 6 rotates the end of spring 20 first drops off plate 22 and the contact springs 15 and 16 engage, as shown. After a time interval the spring 16 also drops off the plate 22 and contact between springs 15 and 16 is broken, the distance piece 21 preventing spring 15 from following spring 16. The spring 20 is longitudinally slidable by means of adjusting screw 18 which engages a flange 19 serving as a nut; the overlap of springs 16 and 20 is thus adjustable, and therefore the time for which the circuit between springs 15 and 16 is closed can be controlled. Three cams, respectively on the seconds, minute and hour shafts of the clockwork, are provided (Fig. 1, not shown) and the contact spring assembly may be moved to co-operate with a selected cam by sliding along a fixed rod 13. Backlash in the clockwork is prevented from affecting the switch by means of an auxiliary gear-wheel having a spiral spring brake on its shaft (Fig. 2, not shown). A separate contact spring assembly may be provided for each cam and these may control different circuits or be inserted in series in the same circuit. The cams may be driven by supplementary gearing from a main clock and be manually adjustable in relation to the hands of the main clock.