High pressure switch apparatus

A pressure responsive electrical switch for use with a high fluid pressure source comprising:

• a body member formed of electrically conductive material having a central portion with a first surface and having first and second end portions, a recess formed in the first surface forming a fluid pressure chamber, an orifice extending between the first end portion and the recess, the first surface forming a shelf around the recess, a generally cylindrical wall extending from the central portion to a distal end at the second end portion forming a switch chamber,
• an annular support plate having a centrally disposed bore therethrough, the bore having a longitudinal axis, the support plate having an outer periphery received on the shelf, a piston member having first and second diameter portions and having first and second ends, the first end and first diameter portion of the piston member slidably received in the support plate bore, the second end of the piston formed with a circular motion transfer rib having a selected diameter,
• a flexible, impervious membrane disposed between the support plate and the shelf,
• an electrically conductive annular disc support member contiguous with the support plate, the distal end of the cylindrical wall being deformed radially inwardly to capture the disc support member and annular support plate, a disc seat formed on the disc support member, a snap acting electrically conductive disc member having a center and being adapted to snap between a convex upward configuration and a concave upward configuration received on the disc seat,
• an elongated electrical terminal member mounted on the disc support member but electrically isolated therefrom, the terminal member having a longitudinal axis coaxial with the longitudinal axis of the support plate bore, the terminal member having a distal end aligned with the disc and spaced a selected distance along the longitudinal axis below the disc seat, and a stationary electrical contact disposed on the distal end of the terminal member, the stationary contact having a circular projection having a selected diameter extending from the distal end so that when the snap acting disc snaps to a concave upward configuration engagement of the disc and the stationary electrical contact will be along a circular line spaced from the center of the disc.