GB622507A - Improvements relating to snap-acting electric switches - Google Patents

Abstract

622,507. Snap-action switches ; retractive switches. FIRST INDUSTRIAL CORPORATION. Feb. 5, 1947, No. 3482. Convention date, Feb. 6, 1946. [Class 38(v)] In a snap-action switch having a trifurcated blade spring 43, Fig. 1, the spring has a moving contact 20 at the junction of the three blades. The end of the inner compression blade 44 is located in a groove 46 in a terminal member 37, whilst the ends of the outer tension blades 47 are connected by an integral strip 48 which engages in a groove 49 in an actuating member 39 which is pivoted in a groove 42 in the terminal member 37. The depression of a push button 51 which bears on the actuating member, causes the spring to snap over the dead centre position, opening contacts 20, 32 and closing contacts 20, 33, the spring snapping back when the button is released. In a modification, Fig. 7, the end of the compression blade 144 engages the actuating member 139, whilst the strip 148 is engaged in a groove in the terminal 137. In both embodiments the various terminal and contact-carrying strips have projections or lugs such as 57, Fig. 5, which engage recesses in the body 21 and cover 28 so that all the switch components can be held assembled by a single rivet passing through a hole 59, Fig. 1. By altering the relative dispositions of the grooves 46, 49 in both embodiments the switch may be made non-retractive. If a dust or moistureproof enclosure is required, the actuating member 39 may be actuated through a diaphragm or bellows or by a magnet placed outside the switch body.