GB591090A - Improvements in and relating to fluid-proof electric switches - Google Patents

Abstract

591,090. Switches held set and freed mechanically. CONCORDIA ELECTRIC SAFETY LAMP CO., Ltd., and CORNISH, J. P. April 27, 1945, No. 10679. [Class 38 (v)] A liquid or gas-proof switch comprises terminal contacts, such as 14, 15, extending into the bore of its casing 1, a circuit-closing element, such as a ball 17, movable to engage the contacts, a spring-pressed plunger 9 acting always to move the element 17 from one limiting position to the other, a flexible diaphragm 20 across the bore of the casing sealing the element 17, contacts 14, 15, and the plunger 9 within the bore, and an operating element 19 adapted to press on the diaphragm to move the element 17 from one position to the other against the action of of the plunger 9. In Fig. 1, the operating element 19 has a helical groove 29 with recesses 28 engaged by a spring detent 27, so that on rotation, the element 19 moves to the left and bears against ball 17 through the diaphragm 20 to bridge contacts 14, 15. In a modification, the ball 17 permanently engages a strip contact 30 and moves between terminal contacts 14, 31. In other modifications, the ball may be replaced by a cylinder and it may be non-conducting with conducting inserts. In Fig. 5, the ball 45 permanently engages a contact 42 and is moved between two contacts 43, 44 by axial movement of part 52 caused by the interaction of faces 50, 51, on rotation of part 47.