Abstract: The load cell for measuring a force in both push and pull includes a body assembly having a body element defining a measurement chamber with a closed end and an opposite open end, a protruding member positioned within the measurement chamber and extending from the closed end toward the open end. The load cell also includes a base assembly secured at the open end of the body element, including a base element; and a sense die attached to the base element and aligned with the protruding member, where a top surface of the sense die supports a Wheatstone bridge circuit configured to generate a signal based on a force exerted by the protruding member on the sense die. The body element, the protruding member and the base element are integrally formed from a common material which has a CTE close to the CTE of the sense die.

Abstract: The invention prevents a pressure receiving space of a pressure sensor from being electrically charged. In a pressure sensor, a diaphragm is attached to a base which is fixed within a cover and a pressure receiving space in which an oil is sealed is formed. A semiconductor type pressure detecting device is connected to a plurality of terminal pins by a bonding wire. A neutralization plate attached to a periphery of the semiconductor type pressure detecting device or a part of the periphery thereof is connected to an earth terminal pin by an earth bonding wire, or is connected to the earth terminal pin by a soldering so as to prevent an insulative medium sealed within the pressure receiving space from being electrically charged.

Abstract: A pressure sensor header for a pressure transducer includes a header shell having a sensor cavity formed therein, a sensor element disposed in the sensor cavity, a fluid medium disposed in the sensor cavity, an isolation diaphragm closing the sensor cavity, and a joining arrangement disposed at an interface of the isolation diaphragm and the header shell, the joining arrangement joining the isolation diaphragm with the header shell. The isolation diaphragm is an integral unit comprising a thin membrane surrounded by a thicker outer ring. The joining arrangement has a recessed female joining element formed in one of the outer ring of the isolation diaphragm and the header shell, and a protruding male joining element formed on the other one of the outer ring of the isolation diaphragm and the header shell, the male joining element received in the female joining element.

Abstract: A pressure transducer assembly including: a pressure sensor header; a transducer assembly member; and a joining arrangement disposed at an interface of the header and the transducer assembly member, for joining the header with the transducer assembly member, the joining arrangement including: a recessed female joining element formed in one of the header and the transducer assembly member; and a protruding male joining element formed on the other of the header and the transducer assembly member, the male joining element received in the female joining element.

Abstract: Techniques are disclosed for improving pressure sensor shock robustness in fluid containment devices by providing a mechanical filter configured to prevent high-frequency pressure shocks from damaging the pressure sensor. One approach includes a body of elastomeric material disposed on an external surface of the sensor. Another approach is a porous plug in a fluid pathway leading to the sensor. Yet another approach is to provide a seal structure with a labyrinth fluid path.

Abstract: A motion transducer having a user moveable plunger which compresses a spring for generating a force proportional to plunger displacement and applying the generated force to an actuator telescoped onto the plunger. The actuator has an elastomeric pad on the surface which contacts and reacts the generated force onto a force/pressure sensitive resistive strip which varies its resistance with the changing force applied by the elastomeric pad. The changes in resistance may be electrically detected to give an indication of plunger travel.

Abstract: A pressure sensor die is provided with a flexible membrane and a plunger which combine to amplify a low pressure signal while also providing media isolation between a fluid being measured and the internal components of a pressure sensor. One embodiment of the pressure sensor disposes an end of the plunger in direct contact with a pressure sensor die while another embodiment disposes an elastomeric diaphragm between the plunger and the pressure sensor die. This second embodiment creates a chamber between the plunger and the pressure sensor die in which a fluid is captured by movement of the plunger. The captured fluid is decreased in volume by movement of the plunger and the resulting increase in pressure in transmitted to a pressure sensitive portion of a pressure sensor die. The device is particularly useful in conjunction with applications where media isolation is required between the fluid being measured and the components of the pressure sensor, such as kidney dialysis machines.

Abstract: A variable resistor that utilizes, as its resistive component, an extension type conductive elastomer such as a conductive silicone rubber cross-linked and then impregnated with a silicone oil, that will experience a change in electrical resistance responsive to an extension thereof. The elastomer is interposed as a sheet between a pair of electrodes and a pushing member that is capable of movement so as to press the elastomer against the ends of electrodes, creating an extension of that elastomer between the electrodes. The magnitude of which elastomer extension corresponds to the force exerted on the pushing member, and in proportion to the change in electrical resistance of that elastomer as measured across the electrodes.

Abstract: A positioning cylinder assembly for subterranean mining applications has a rotary potentiometer connected through a friction wheel transmission with the spindle of the cylinder which is rotated when the piston is axially displaced therein. The friction wheel assembly comprises a pinion wheel connected to the spindle and a hollow wheel connected to the rotary potentiometer, that not only matches the pitch of the spindle to the rotary spring of the potentiometer but also functions as a slip clutch for zero setting of the potentionmeter and the piston.

Abstract: A hydraulic actuating apparatus for sensing hydraulic pressure and producing an output signal representative of the sensed hydraulic pressure includes a base portion, a case, and a variable resistor unit. A slider is movably connected to the variable resistor unit, and the variable resistor unit is connected to the base, the slider being movable relative to the variable resistor unit by an amount proportional to the hydraulic pressure applied to the slider. The variable resistor unit has a resistance which changes in response to movement of the slider. A resilient member is provided which is resiliently deformable by movement of the slider relative to the variable resistor unit, the resilient means exerting a restoring force on the slider opposing the movement of the slider caused by the hydraulic pressure. An adjusting mechanism is provided for setting an initial resistance value of the variable resistor unit, the variable resistor unit having a portion which is in contact with the adjusting mechanism.

Abstract: A pressure transducer to measure and indicate fluid pressure levels including a housing in which a diaphragm and piston assembly is movable in response to pressure changes, the piston having a portion extending therefrom to engage a switch contact thereby disengaging the switch when the fluid pressure falls below a desired level.

Abstract: A fluid pressure transducer having a hollow enclosure with an elongated tubular guide supported therein around which a tubular piston moves in response to fluid pressure forces acting on one piston end. A spirally-wound wire resistance coil on the guide is contacted by one end of a conductor carried by the movable piston to effectively charge resistance through the conductor and parts of the coil. The conductor is connected to one end of a metal spring which opposes piston movement due to pressure forces. An opposite end of the metal spring is connected to a terminal to transmit the resistance changes.

Abstract: A pneumatically actuated pressure transducer has a wiper assembly which is movable from an off position through a range of positions wherein the transducer has a varying voltage output. The pressure transducer comprises a high thermal conductivity substrate which forms a base for a potentiometer element and a resistance path coated onto the substrate. The resistance path includes a first area of low resistance material and a second area of high resistance material which meet in a chevron shaped transition zone. An insulating material coated onto the substrate defines the off position for the transducer.

Abstract: A control device and method of making the same are provided, the control device having a housing provided with an actuator chamber separated from a pressure differential chamber by a wall having an opening therethrough receiving an axially movable actuator pin that transmits axial movement of a movable part in the pressure differential chamber to the actuator chamber. A Hall effect transducer is disposed in the actuator chamber and the actuator pin has a magnet unit for operating the transducer as the movable part axially moves the actuator pin relative to the housing, the magnet unit being disposed in offset relation to the axis of the actuator pin and moving in unison therewith relative to the transducer.

Abstract: This pressure sender or transducer comprises a metal housing having a steel cover and containing a rolling diaphragm which is secured over a cavity in the housing to communicate at one side with fluid under pressure, such as the oil in the crankcase of an automobile. Mounted centrally in the opposite side of the diaphragm is a rigid cup, which rotatably supports one end of a reciprocable plunger which in one embodiment carries two sets of equi-angularly spaced, resilient metal wipers or contacts, four of which are slidably engaged with the cylindrical operating surface of a printed resistor, which is mounted in the closed end of the cover, and four others of which are slidably engaged with the inner peripheral surface of the cover itself. The resistor comprises a steel can having a thin layer of porcelain baked on its outer peripheral surface, and a thin, cylindrical layer of resistance material printed and baked onto the porcelain layer with one end in electrical contact with the steel can.

Abstract: The housing has a flexible diaphragm secured over a fluid pressure inlet port in one end thereof, and a cover secured over an opening in the opposite end thereof. A plunger is mounted to reciprocate in the housing between said diaphragm and said cover in response to changes in fluid pressure at the inlet. Secured in the housing beneath the cover is a ceramic chip or substrate, which has a plane surface that extends normal to the axis of the plunger. A spirally shaped resistor element is printed or otherwise formed on the face of the chip, and a conically coiled compression spring is located in the housing between the resistor element and the plunger, and in such manner that its outer convolution at the larger end thereof is engaged with the outer convolution of the spirally shaped resistor element. The smaller end of the spring is connected to the plunger to be reciprocated thereby toward and away from the resistor element.

Abstract: A hydraulic pressure transducer comprises a cylindrical housing having a plurality of circumferential inwardly and outwardly directed ribs which axially position and retain coaxially aligned operative components within the transducer. These components include a hydraulic piston and cylinder, a restoring spring disposed between two centering and retaining stabilizer cups, and a biasing spring which maintains the components in compressed juxtaposition to ensure accurate and immediate response while minimizing axial dimensional stack up. The transducer senses hydraulic pressure in, for example, a brake line and provides a variable resistance output which may be used in an auxiliary electric brake system controller commonly used on recreational trailers and the like.

Abstract: A multi-stage pressure switch (10) transduces partial vacuum pressure levels to corresponding electrical outputs. The switch (10) comprises a vacuum housing (12) having a bore (16) therein and a port (14) at one end. Positioned within the bore (16) and in engagement with one end of a coaxial spring (48), is a rubber piston (50) having an integral lip seal (54) which wipably engages the wall of the bore, the piston (50) also having a socket (56) disposed therein. A U-shaped switch drive arm (38) has a drive arm extension (40) and ball (41) received within the socket (56) of the rubber piston (50). Contactors (42, 43, and 44,45) are mounted on opposite sides of the drive arm (38). A switch housing (28) having two sets of terminals (32, 33, and 34,35) extending into the housing and terminating at different levels is joined with the vacuum housing (12).

Abstract: A hydraulic pressure transducer comprises a cylindrical housing having a plurality of circumferential inwardly and outwardly directed ribs which axially position and retain coaxially aligned operative components within the transducer. These components include a hydraulic piston and cylinder, a restoring spring disposed between two centering and retaining stabilizer cups, and a biasing spring which maintains the components in compressed juxtaposition to ensure accurate and immediate response while minimizing axial dimensional stack up. The transducer senses hydraulic pressure in, for example, a brake line and provides a variable resistance output which may be used in an auxiliary electric brake system controller commonly used on recreational trailers and the like.

Abstract: A device operable in response to an input fluid force includes a housing having an inner surface and a fluid pressure responsive member carried within the housing and having a surface that abuts the inner surface of the housing. The surfaces are curved and their curvatures differ so that the fluid responsive member makes a rocking contact with the housing surface. A first force is exerted on the fluid pressure responsive member at one point and a variable force to be measured is exerted against the fluid pressure responsive member at a second point so that the point of contact of the curved housing surface and the curved surface of the fluid pressure responsive member varies as a function of the two forces.