Pressure responsive switch with parallel contact blades bent apart by axial force applied by diaphragm

Claim 1

A switch comprising: first and second end plates; first and second members, each of said members having first and second ends, said first ends being fixed relative to said first plate, said second ends being fixed relative to said second plate, said plates being approximately parallel to each other with one located over the other, said members being approximately parallel to each other and approximately perpendicular to said plates, said plates having approximately parallel facing surfaces, all of said member ends being joined to said plates at said facing surfaces; a first contact fixed to said first member in a position between said members and approximately at the midpoint of said first member; a second contact fixed to said second member in a position between said members and approximately at the midpoint of said second member to engage said first contact when said members are brought toward each other; and releasAble means actuable to push one of said plates toward the other to cause said members to bow outwardly of each other and to move said contacts out of engagement with each other, said members both being made of a spring material which will bring said contacts into engagement with each other when said releasable means is deactuated to allow said members to recover their shapes, said contacts being insulated from each other except when they are brought into mutual engagement as aforesaid; a container having a wall to hold a fluid under an absolute pressure greater than atmospheric, said container having a hole completely through said wall thereof, one end of said hole adjacent the outer surface of said wall being internally threaded, a set screw threaded into the said one end of said hole, a circular diaphragm sealed around the other end of said hole, said diaphragm being made of a flexible spring material, means to vent the space between said screw and said diaphragm to the atmosphere, an electrical lead connected to each contact and extending outwardly of said space, and means to insulate said leads from each other, each of said plates being a solid right cylinder, said cylinders having a common axis, said members being spaced equidistant from said axis on opposite sides thereof, each member being integral with both of said plates, both of said members and both of said plates being made of plastic, said contacts being snap fit through corresponding holes in said members, both said members having the same shape and dimensions, each of said members being a right prism having a rectangular cross section, the heights of said members between said plates being greater than the lengths and widths of said cross sectional rectangles, said lengths being greater than said widths, said members having parallel facing surfaces whose dimensions are said heights and said lengths, said plates, said contacts and said members being located in said space with said first and second plates abutting the facing surfaces of said screw and said diaphragm, respectively.