GB1445272A - Electrical switching devices - Google Patents

Abstract

1445272 Fluid actuation of switches; switch contacts GAUER AG ELECTRONIC 18 Jan 1974 [26 Jan 1973] 02451/74 Heading H1N A pressure-actuated switch comprises a thin domed resilient element 11 (or 111, Figure 2, not shown) having a convex surface and being supported at its edge; a pressure-actuated member 9 (109) is movable relative to element 11(111) for exerting a mechanical force against the said convex surface via a confronting surface 9a (109a); either (Figure 1) the element 11 has a central region of insulating material 17 surrounded by conductive material 13, and the confronting surface 9a is completely formed of conductive material, or (Fig. 2, not shown) the element (111) has a completely conductive convex surface (113) and the central region of the confronting surface (109a) comprises insulation (110); the arrangement being such that, when actuated, the member 9 (109) deforms the element 11(111) and the respective conductive materials come into contact. The actuator may be mechanical, but as shown compressed air or hydraulic fluid acting in bellows 8 causes conductive member 9 to engage an annular conductive layer 13 on a spring steel disc 12. As conductive housing halves 1a and 1b are joined by an insulating ring 2 and bellows 8 are conductive, this closes a circuit between respective leads 3 and 4. Threaded member 16 serves toadjust the operating pressure, and ensures connection between the edge of layer 13 and the side walls of recess 15.