Diaphragm pressure switch with integral stop means for diaphragm sealing

Claim 1

A pressure switch comprising a plastic cup-shaped housing having a rim wall terminating in a radial end wall with a radial face, a metal cup-shaped housing having a rim wall nestingly receiving said radial end wall, the back wall of said metal housing having a radial face aligned with said end wall radial face, a diaphragm located between the faces on said radial wall and the back wall of said metal housing, means for passing fluid under pressure through said metal back wall to one side of said diaphragm for moving said diaphragm towards said plastic housing, means extending an electrical connection from said one side of said diaphragm through said diaphragm and plastic housing and biasing said diaphragm toward said metal housing, said connection being opened in response to the application of said fluid to said diaphragm one side moving said diaphragm toward said plastic housing, and a plurality of circumferentially spaced stops integrally formed on said plastic housing radial face projecting from said plastic housing radial face less than the thickness of said diaphragm and extending through said diaphragm for engaging said metal housing radial face in response to the application of axial pressure to said housings in a direction for moving said radial faces towards each other with said stops terminating said movement to thereby control the pressure clamping said diaphragm between said radial faces, and means integrally formed on said metal housing for clamping said plastic housing against said diaphragm with said stops engaging said metal housing radial face to control the space between said radial faces and the pressure clamping said diaphragm.