GB1423618A - Electrical switch drive mechanism - Google Patents

Abstract

1423618 Snap-action switches MASCHINENFABRIK REINHAUSEN Gebr SCHEUBECK KG 9 Oct 1973 [13 Oct 1972] 47043/73 Heading H1N A drive mechanism to provide snap action of a rotary switch having a plurality of switch positions comprises an input shaft 4, an output shaft 10, a disc 6 drivingly coupled to the input shaft 4 and provided at its periphery with a plurality of radial slots for engagement therein of drive means 21 for stepwise rotation of the disc 6, the number of slots corresponding to the number of switch positions, first and second levers 11 and 12 which each have two arms 111, 112 and 121, 122 and are rotatable about the axis of shaft 4, two spring means 13, 14 so respectively coupling levers 11 and 12 as to bias the second lever to rotate with the first lever, a first pair of crank arms 81, 82 rotatable with the input shaft 4 to engage and rotate the first lever, a second pair of crank arms 91, 92 rotatable with the output shaft 10 and arranged to be engaged by the second lever so as to rotate the output shaft 10 on rotation of the second lever, and releasable locking means 16 to so prevent rotation of the second lever that on initial rotation of the first lever the levers are mutually relatively rotated, increasing the bias of the spring means 13, 14, and the locking means 16 being released by a further rotation of the first lever to allow the second lever to be abruptly rotated by the spring means. As shown output shaft 10 is integral with a crank member 9 and the locking means is a member 16 slidable thereon. Member 16 is spring urged to engage in recesses 151 in an annular member 15 which is secured between fixed housing parts 1 and 2. Thus the member 9 and arms 91, 92 are held stationary until, after sufficient rotation of shaft 7, arm 81 or arm 82, according to whether the rotation is clockwise or anti-clockwise, impinges on a release lever 19 or 20 to withdraw member 16. This allows compression springs 13, 14 to reassert by rotating the second lever 11 or 12 (according to direction) and arms 91, 92 with a snap action. This turns output shaft 10 which is coupled to the switch contacts (not described) until member 16 enters the next notch in member 15.