GB764165A - Improvements in or relating to electric circuit control means including quick actionswitches - Google Patents

Abstract

764,165. Thermal switches: actuation of switches. COMPAGNIE ELECTRO-MECANIQUE. Feb. 21, 1955 [May 5, 1954], No. 5073/55. Class 38(5) An electric circuit control device comprising a shaft 1, which is actuated by a heat responsive element (not shown) so that it rotates in one direction or the other according to the temperature change, has a disc 2 loosely mounted on it, the disc and shaft being connected by a first frictional coupling comprising a spring-loaded washer 5 acting on the disc against a washer 6. Moving members 15, 17 of the snap action switches 11, 13 carry fingers which are disposed in slots 3 in the disc so that rotation of the disc actuates the switches. Adjustable stops 9 and 10 limit the rotation of the disc to the angle A but slip at the frictional coupling allows the rotation of the shaft to exceed the angle A. A switch 12 which controls a circuit indicating the direction in which the thermal element is moving, has a blade 16 engaging between the ends of a resilient wire 22 located in a groove in the disc 2 to form a second friction coupling and is operated on a very small movement of the disc. This movement is limited by the stops 19 and 20 after which slips between the wire and disc occurs. The first frictional coupling is made adjustable by having in the washer 6 a number of grooves 21 through which the fixing pin passes, the grooves being of different depths (Figs. 4 and 5, not shown).