Abstract: A pressure switch employs electrical contacts isolated from pressure media. By employing a snap action blade in a snap over center configuration, it is possible to provide a hysteresis effect in which the switch actuates at one pressure and deactuates at a different pressure.

Abstract: A variable analog output pressure switch having a diaphragm attached to a plunger, the plunger controlling the amount of light detected by a photocell or photodetector, the photocell or photodetector outputting voltage roughly proportional to an applied pressure on the diaphragm.

Abstract: A large actuation area switching device includes a housing for holding a switch, means for compression and at least three slotted hinges. The slotted hinges create axes of operation such that a force applied to any point on the surface of the housing actuates the switch.

Abstract: A miniaturized pneumatic snap action switch includes a glass or metallized ceramic body that has a convoluted metal diaphragm closing the open end with a glass to metal seal. The interior of the switch is provided at a desired pressure by a sealable tubulation port and the switch actuation members include a C-spring and a Belleville spring or washer sealed inside the switch housing. The switchable electrical path is from the metal diaphragm, through the C-spring and Belleville spring, to a centrally arranged conductive termination pin embedded in the closed end of the body. The combination of the C-spring and Belleville spring provide the snap action, and the C-spring has two hemispherical engagement portions that centralize the forces through the center line of the switch. The switch is intended for miniature applications and the switch body is less than 0.75 inches in diameter.

Abstract: A differential pressure switch has a main switch body divided into three chambers by means of two diaphragms, thereby sealing the center chamber that contains a snap-action switch. The two diaphragms are mechanically connected by a strut that can move only along a single line of motion, so that movement of one diaphragm is transmitted to the other. Movement of the strut is coupled to an actuator of the snap action to produce the desired switching action.

Abstract: A fluid switch formed of a housing having at least one inlet port to which pressure is applied and at least one outlet port. An inlet conduit disposed within the housing is coupled at one end to an inlet port so that fluid flows therethrough in laminar flow. An outlet conduit is disposed within the housing and is aligned with the inlet conduit. One end of the outlet conduit is coupled to an outlet port. The other ends of the inlet and outlet conduits are spaced from each other by an amount which is less than the critical amount required for the laminar flow to change to turbulent flow. A piston having no fluid sealing means is disposed in the spacing between the conduits and includes a transverse fluid channel which is selectively aligned with the conduits in accordance with the diplacement of the piston. An actuator is provided to exert a force on the piston so as to displace same.

Abstract: A visual indicator for a fluid operated system comprising a housing defining a compartment therein and having a viewing portion. First and second fluid channels are provided in the housing and terminate at respective outputs which discharge to the compartment for applying fluid pressures thereto. A vane is rotatably mounted in the compartment and is responsive to applied fluid pressures so as to rotate between first and second positions. The vane has spaced apart output sealing members for substantially sealing the first and second outlets in accordance with the extreme rotary position assumed by the vane to thereby prevent fluid from flowing through a correspondingly sealed fluid channel. Indicia is provided on the surface of the vane so as to be selectively disposed in an indicating position for viewing through the viewing portion of the housing when the vane rotates to a corresponding one of its extreme positions.