GB446178A - Improvements in cam-operated electric switches particularly for electric cookers - Google Patents

Abstract

446,178. Quick-make switches. DIAMOND H SWITCHES, Ltd., Gunnersbury Avenue, Chiswick, London. Oct. 24, 1934, No. 30516. Convention date, July 3. [Class 38 (v)] A switch for use on an electric cooker comprises an operating lever 10 moulded integrally with a roller 55 having endwardly projecting trunnions 56 resting in slots in partition walls 21 of the base A and held in position by a cover plate B. The roller 55 is formed with three cams 58, 59, 60 which, in certain positions of the lever 10, engage raised portions 39 of three spring contact arms 37 each mounted on a conducting strip 38. The roller 55 also carries a notched plate 63 which works in a slot in a raised web 22 and co-operates with a spring- pressed ball (not shown), to locate the roller in its three positions. The cams 58, 59, 60 are so arranged that in the mid position of the lever 10, all the cams engage the raised portions 39 of the contact springs and all the springs are disengaged from the fixed contacts 30. Movement of the contact springs is limited by stops 61 formed on the base, so as to prevent drawing a long arc. If the lever 10 is moved to one side or the other, the cam 58 and one of the other cams is disengaged to make the corresponding contacts. Switchboards.-A number of switches are mounted side by side on the base A so that all the load terminals 36 are arranged along the rear edge of the base. Three bus bars 11, 12, 13 are arranged in grooves along the underside of the base, the line terminals 43 being arranged at one end. Each strip 38 carrying a contact spring can be connected to any one of the bus-bars by a screw 40 passing through the bus-bars and the base and engaging the corresponding hole 46 in the strip 38. The holes 47 in the base are closed by frangible barriers 48 which are broken as required for admitting a screw 40, the unbroken ones preventing accidental contact.