Differential pressure switch with pivoted one-piece rigid flat switch-actuating disc member captured between two rolling diaphragms

Claim 1

In a differential pressure switch, the combination of: a. a housing; b. a switch actuating member in said housing in the form of a one piece rigid flat circular disc having a lateral extension; c. means mounting said actuating member in said housing for pivotal movement relative thereto about a pivot Axis spaced radially outwardly from the periphery of said disc in said lateral extension and parallel to the faces of said disc; d. rolling diaphragms respectively carried by said housing on opposite sides of and engaging the opposite faces of said disc; e. said diaphragms respectively having annular ribs encircling said disc and disposed between the periphery of said disc and said housing, said pivot axis being spaced radially outwardly from said annular ribs; f. ports in said housing and respectively communicating with said diaphragms on the opposite sides thereof from said disc; and g. a switch carried by said housing and engageable by said actuating member at a point spaced from said pivot axis.