Abstract: A pressure responsive switch for changing electrical state in response to a fluid pressure which equals or exceeds a desired pressure threshold level includes a cylindrical conductive casing. The casing defines a central, generally cylindrical cavity and at least one upper fluid inlet orifice. The casing further defines a lower opening communicating with the cavity. A non-conductive elastic membrane extends across the upper portion of the cavity beneath the fluid inlet orifice and is sealingly attached at its periphery to the interior of the casing. A conductive, pressure actuatable plunger in the upper portion of the cavity includes a pressure receiving surface directly beneath the membrane. An electrical connector is mounted by a bushing means centrally in the cavity. The connector is held out of electrical contact with a casing and has a first end extending out of the cavity through the lower opening in the conductive casing and a second end which is positioned in the cavity.

Abstract: An industrial type switch having modular parts which may be assembled so the switch may be used in a wide range of installations. The switch includes a differential module which is easily adjustable to operate over a selected range of pressures, a plug-in snap switch module so the switch may be easily wired and serviced, a range module so the response of the switch to pressures within a range may be readily accomplished, and any one of a plurality of different type actuator modules which are mountable on the exterior of the switch so the switch may be used in a large variety of different type installations.

Abstract: A pneumatic tire pressure monitor for a tandem set of tires has a housing for being affixed to the outboard tire wheel. The housing includes a first and second chamber communicating with the interior pressure of each pneumatic tire of the tandem set of tires. The housing further includes a third chamber containing hydraulic fluid for maintaining a reference level of pressure. A diaphragm is responsive to pressure differentials between the first and second chambers and the third chamber to activate a latch. The latch releases a visual signal member, which moves from a retracted position within the housing to an extended position in order to signal a drop in pressure in either or both of the tires. In an alternate embodiment, the monitor may be used to monitor the pressure of a single pneumatic tire.

Abstract: The invention provides a device for activating a passenger restraining system in a vehicle comprising, a dash-pot assembly arranged to be operatively mounted between the vehicle structure and a bumper on the vehicle, the dash-pot assembly including a cylindrical tube, a closure across the tube and a piston movable in the tube to form with the closure a chamber for pressure fluid in the tube, throttle means in communication with said chamber arranged to control exit of pressure fluid from the chamber and to damp movement of the piston relative to the tube whereby to dissipate energy, and a sensor mounted as an assembly with said tube, the sensor including an electrical switch operable in response to fluid pressure in said chamber.

Abstract: A capsule lamp as a fishing tackle in which an electric circuit connecting a light bulb and a battery across a switching mechanism is opened or closed in response to water pressure acting on a diaphragm adapted to be deformed by the water pressure into pressing engagement with the switching mechanism.

Abstract: A pneumatic indicator device having a housing carrying a movable flag that in one position thereof visually indicates one pneumatic condition of the device and in another position thereof visually indicates another pneumatic condition of the device, the housing also carrying an electrical switch which is operatively associated with the movable flag so that the switch electrically indicates the positions of the flag for remote indication purposes.

Abstract: A pressure sensitive electrical switch has a monostable snap disc which is deformed in response to the application of sufficient force. A pressure reducer transmits a force proportional to the pressure of a fluid. The reducer has an annular force transmitting ring which applies force to the snap disc along a circle which is substantially concentric with the disc. By changing the force reducer in a switch to one having a different diameter ring, the operating characteristics of the switch may be changed.

Abstract: A differential pressure cutout switch including a low pressure operating point assembly and a high pressure operating point assembly which are mechanically linked and are operable to respond to first and second pressures supplied over respective first and second pressure inlets of the switch to control a contactor switch assembly which is movable to a first position to provide an open circuit between outputs of the switch and movable to a second position to connect a resistance of a finite value between the outputs as a function of the difference between the two pressures. The differential pressure cutout switch is described with reference to an application in a protection control system for monitoring lubrication oil pressure for a compressor of a refrigeration system.

Abstract: An oil pressure switch comprising a housing having an inlet end connectable to an oil pressure line to admit oil from the line within the housing. A flexible membrane is secured in the housing and having opposed surfaces. One of these opposed surfaces is in contact with the oil admitted to the housing while the other of the surfaces is in engagement with a spring biased electrical contact. The spring biased electrical contact is in abutting engagement with a stationary electrical contact. Connection means is provided for each of the electrical contacts. The membrane is displaced by pressure in the oil line whereby the spring biased contact is caused to be displaced against its spring biased direction to cause disengagement with the stationary electrical contact.

Abstract: A method and apparatus is disclosed for visually indicating when the pressure of a fluid, such as oil in an automobile, falls below a predetermined value. The improvement resides in a novel pressure switch which is typically connected in series in an electrical circuit with a power source and a visual indicator, such as a so-called "idiot light" in an automotive instrument panel. The pressure switch includes a housing with an internal recess and a fluid passageway extending from the internal recess for communication with a fluid under pressure. A resilient, flexible, elastomeric diaphragm overlies the passageway within the recess and is deflected in response to the fluid pressure. An annular, electrically conductive, stationary contact element is positioned adjacent to the diaphragm; and a spherical, electrically conductive contact element is biased by a coil spring toward the opening in the annular contact element and into engagement with the diaphragm.

Abstract: In a flow switch provided for connection in a fluid pipeline, a metering piston or other flow sensor is provided for placement in a pipe in the path of fluid flow. Fluid pressure above a certain minimum will cause the sensor to move, permitting fluid flow and moving the end of a pivot arm. The pivot arm transmits motion, through a flexible rubber-on-dacron seal, to a mechanical linkage which operates an electric switch. Means are provided to adjust the pressure response of the flow sensor and to vary the travel distance of an actuating plunger relative to the electric switch. Improved bearing means are provided for transferring motion between the pivot arm and the mechanical linkage.

Abstract: A differential pressure module is secured in switching relation to the actuating plunger of an electrical switching mechanism. Comprising the differential pressure module are two piston/cylinder assemblies connected together in back-to-back configuration by secured cross members forming a floating yoke. Each of the assemblies includes a diaphragm in communication with a separate oppositely directed fluid inlet and through which a force differential effective from the separate forces acting in opposition to each other is applied via the yoke against the switch actuator. A cast body intervening between the assemblies defines the fluid inlets while maintaining the pressure of each isolated from the other.

Abstract: A panic stoplight system for automobiles includes a fluid pressure switching device connected through a flasher with signal lights for operation by the automobile braking system. The fluid pressure switching device closes for flashing the signal lights only when the force applied to the actuator of the braking system is representative of panic braking. Time delay means keeps the system energized for a predetermined time after panic braking ceases.