GB744371A - Improvements in or relating to clockwork controlled electric switch mechanism - Google Patents

Abstract

744,371. Clockwork actuation of switches; snap-action switches. PULLARS INSTRUMENTS, Ltd. Jan. 6, 1954 [Dec. 12, 1952], No. 31601/52. Class 38(5) A switch comprises a cam adjustable to a selected position from which it is returned by clockwork, a first, manually-operable, lever having a snap-spring and connected to contacts, a second lever also having a snap-spring and connected to further series-connected contacts and operable by the cam, and a third lever controlling the clockwork and having parts engageable by the first and second levers. In one form, Fig. 1, the first lever 19 has a blade spring 14 connected to a movable contact 10, which is opened by anticlockwise tilting of lever 19, such movement also causing clockwise movement of the third lever 31 to the position shown where a wiper 32 thereon engages and stops the clockwork balance wheel 26. The cam 25 is set by anticlockwise rotation, during which the second lever 22 is tilted clockwise to close contacts 12, 13 with a snap action given by spring strip 15. If contacts 10, 11 are closed, the circuit through 16, 17 is completed. If they are open, they are subsequently closed, when desired, by depression of a button 35 which also tilts the lever 31 anti-clockwise-to release the wheel 26. The cam 25 is thereby returned to its original position where a pin 24 on lever 22 drops into a depression 28 in the cam to open the contacts 12, 13. At the same time, a projection 30 on lever 22 tilts lever 31 to stop the clockwork again. In a modification, Fig. 5, both springs 14, 15 act through rods 36, 37 on a single spring contact blade 38 so that both springs must be in their upper positions before the contacts 38, 39 can close. Specification 730,663 is referred to.