Texas Instruments Corporation

Carlton E Sanford

Leo Marcoux

Lawrence E Cooper

Douglas B Strott

Laurence P Kleven

Paul A Lesser

George J Lombardo

Benjamin A Barber

An automotive transmission control is shown having pressure switches to sense the state of actuation of solenoid valves to provide logic signals to a microprocessor type of transmission control. The pressure switches, which sense the pressure of hydraulic fluid controlled by the solenoid valves, use a dished shaped metallic diaphragm characterized in that the pressure-deflection curve of the center of the diaphragm has minimal hysteresis and reflects that the diaphragm is relatively stiff having a positive coefficient of pressure with increasing deflection up to and above a selected pressure level at which level the center accelerates between d.sub.1 and d.sub.2. The diaphragm is loosely held on a conductor at 0 psig with the fluid pressure when it increases forcing the diaphragm into sealing and electrical engagement with the conductor.

Pressure switch apparatus having improved longevity and widened

A fluid pressure switch is shown including first and second discs each having convex-concave surface configurations on opposite sides thereof adapted to invert its configuration upon being subjected to selected pressure levels. A slidably disposed plural stage pressure converter having a flexible membrane on one side thereof is operatively coupled to the discs to transfer force from fluid pressure received by the membrane. A motion transfer member extends from the second disc to an electric switch. At a first range of pressures the first disc prevents actuation of the switch, at a second range of pressures the curvature of the first disc has inverted allowing actuation of the switch while at a third range of pressures the curvature of the second disc has inverted resulting in deacuation of the switch.

Fluid pressure responsive electrical switch

An automotive transmission control is shown having pressure switches to sense the state of actuation of solenoid valves to provide logic signals to a microprocessor type of transmission control. The pressure switches, which sense the pressure of hydraulic fluid used to actuate the solenoid valves, use a dished shaped metallic diaphragm characterized in that the pressure-deflection curve of the center of the diaphragm has minimal hysteresis and reflects that the diaphragm is relatively stiff having a positive coefficient of pressure with increasing deflection up to and above a range of set point pressures within which the effective spring rate of the diaphragm changes with the diaphragm being relatively supple but having little or no negative coefficient of pressure. In a first embodiment a housing is shown in which a conductive lead pattern is molded in the housing with a plurality of switching stations. Each switching station has a circular diaphragm formed with an annular flat berm portion which lies on a portion of the conductive lead pattern and is sealed by an 'O' ring biased against the berm by a sleeve which interfaces with the hydraulic fluid. An electrically conductive rivet is placed beneath the diaphragm within a specific distance from a plane on which the berm lies so that a circuit will be closed upon sufficient deflection of the diaphragm. The housing mounts electrical contacts for energizing the solenoid valves and a pin connector coupled to the conductive lead pattern. Other embodiments are shown using diaphragms having the same pressure-deflection curve.

Automotive transmission control system and improved longevity therefor

A dual condition responsive switch is shown including first and second discs each having convex-concave surface configurations on opposite sides thereof adapted to invert its configuration upon being subjected to selected conditions. A motion transfer member extends from the second disc to an electric switch. At a first range of conditions the first disc prevents actuation of the switch, at a second range of conditions the curvature of the first disc has inverted allowing actuation of the switch while at a third range of conditions the curvature of the second disc has inverted resulting in deactuation of the switch.

Dual condition responsive electrical switch

A thermal or pressure responsive switch has a base mounting a set of electrical contacts. A metallic snap acting disc support, placed on the base is provided with a bore which receives a pin to transfer motion from a disc mounted on the support to the set of electrical contacts upon snapping of the disc. A first embodiment has a pressure converter received on the disc support. The peripheral edge of the snap acting disc is received on a seat formed in the converter with an annular reaction ridge formed on the support. A second embodiment has a pressure converter with the peripheral edge of the snap acting disc received on a seat formed in the disc support and an annular force ridge on the converter is adapted to contact the upper surface of the disc. In either embodiment a layer of low friction plastic can be placed on both faces of the disc. A third embodiment has a flat metallic disc support with a recessed portion for receiving the disc and a continuous stop surface. In all embodiments a cup shaped shell has a gasket received in a channel formed in a top end wall of the shell with the outer wall portion of the shell crimped over to compress the gasket and provide a gas tight seal. The top end wall of the shell can be formed with a portion displaced from the wall to serve as an automatic valve deflator which can be used with any of the embodiments.

Features of a condition responsive switch

A compact, low cost, pressure responsive electrical switch of improved reliability has simple and easily assembled contacts movable on a base between open and closed circuit positions. A dished metal disc is operably connected with a diaphragm to move with snap action between original and inverted dished configurations for moving the contacts sharply between such circuit positions when selected pressures are applied to the diaphragm. The contacts are biased to open the circuit; a first, convex side of the disc engages and holds the contacts firmly in closed circuit position against the noted bias when the disc is in its original dished configuration; a selected diameter portion of that first side of the metal disc engages an annular ridge on the base; and a motion transfer member is located between the diaphragm and the opposite side of the disc, the member having an annular ridge of relatively larger diameter than the ridge on the base engaging a correspondingly larger diameter portion on the opposite side of the disc near the disc periphery. The member moves in response to application of a selected pressure to the diaphragm to press the disc against the annular base ridge to snap the disc to its inverted configuration and to withdraw the originally convex disc side away from the contacts for permitting the contacts to follow the disc movement to fully and reliably open the device circuit.

Normally closed pressure responsive switch with improved compact

A push-button switch having an electrically conductive body forming a chamber, having a fixed contact supported in the chamber, having a passage communicating with the chamber, having a flexible diaphragm sealing said chamber from said passage, and having an operating member slidably movable in said passage for depressing the diaphragm, has a flat spiral spring disposed within the chamber with the perimeter of the spring in electrical engagement with the body and with a central portion of the spring disposed in selected spaced relation to the fixed contact between the fixed contact and the diaphragm for permitting movement of the operating member to depress the central portion of the flat spiral spring through the flexible diaphragm into electrical engagement with the fixed contact to close an electrical circuit between the fixed contact and the body.

Push-button switch

A push-button switch particularly adapted for use in a digital watch has an open-ended chamber formed at one end of an electrically conductive body and has a passage communicating with the chamber from the opposite end of the body, has electrically insulating spacer means secured in sealing relation to the open-chamber end supporting at fixed contact extending from the chamber through the open chamber end, has a resilient electrical contact supported on the spacer means within the chamber with the perimeter of the resilient contact in electrical engagement with the body and with a central portion of the electrical contact disposed in selected spaced relation to the fixed contact, has a flexible diaphragm secured between the resilient electrical contact and said body passage sealing the chamber opposite the open chamber end, and has a push-button operating member slidable in the body passage for selectively depressing the central portion of the resilient contact through the flexible diaphragm into electrical engagement with the fixed contact to close an electrical circuit, the body being adapted to be secured to a watch case by press-fitting into a watch case aperture.

Growing community of inventors

East Providence, RI, United States of America

Carlton E Sanford