Differential pressure switch with hinged plate on diaphragm

Claim 1

A differential pressure switch comprising a housing comprising two spaced, opposed plates defining a fluidtight space therebetween, a flexible pressure responsive diaphragm comprising a flexible material and a diaphragm pressure plate bonded to said flexible material separating said space into two compartments, a rigid member having an edge surface in said space opposed to an edge surface of said pressure plate and in close proximity therewith, the edge surfaces jointly defining a hinge for said pressure plate about which the pressure plate pivots, an electrical contact mounted on said housing exteriorly of said space, an actuator for actuating said contact to an operative position comprising a flexible flat spring mounted exteriorly of said casing for flexing to a position to close said contact, an axially displaceable pin in communication with the interior of said housing and extending outwardly thereof for bearing against said float spring to deflect it in a direction for closing said contact, an actuating element mounted on said diaphragm for movement therewith to contact and engage said pin to actuate it in response to a pressure differential in said compartments flexing the diaphragm in a direction for actuating said switch, and connectors for applying a medium to one of said compartments to develop said differential pressure.