GB868007A - Improvements in and relating to fluid-pressure operated electric switches - Google Patents

Abstract

868,007. Fluid actuation of switches. PAL. NARODNI PODNIK. Jan. 28, 1959 [Jan. 31, 1958], No. 3095/59. Class 38 (5). A metal housing 10 is divided into two chambers by a rigid metal insert 30 having a central aperture for a pin 40, the head of which abuts a diaphragm 20, for example of rubber, in the lower chamber which has an inlet 13 for fluid under pressure; the diaphragm 20 has a self-sealing projecting edge 21. The other end of the pin 40 contacts an insulating plate 50 in the upper chamber which also contains an insulating core 70 carrying terminals 80 and 90, the end 81 of terminal 80 being lower than end 91 of terminal 90. The plate 50 carries a contact-spring 60 against which bears a spring 100 whose pressure is adjustable by a set-screw 110. The core 70 has a metallic casing 120 to ensure mechanical strength and dimensional stability and the edge 14 of the housing 10 is tightly flared over the margin of easing 120. On the application of pressure in the lower chamber the diaphragm 20 (via pin 40) causes the spring 60 to first engage contact point 81, then the point 91, and then to flex slightly at the centre; the final pressure on contacts 81 and 91 being determined by the abutment of the head of pin 40 against the insert 30.