Abstract: A sensor assembly including a flexible member having a first end and a second end, a rotating member connected to the second end of the flexible member, a positional element disposed on the rotating member, and a sensor capable of sensing a movement of the positional element. A movement of the second end of the flexible member allows the rotating member and the positional element to rotate.

Abstract: A sensor assembly including a flexible member having a first end and a second end, a rotating member connected to the second end of the flexible member, a positional element disposed on the rotating member, and a sensor capable of sensing a movement of the positional element. A movement of the second end of the flexible member allows the rotating member and the positional element to rotate.

Abstract: A differential pressure sensor has a magnetized piston free to move in a cylinder. Magnetic endcaps seal the ends of the cylinder, forming chambers on either side of the piston. The moveable magnetic piston is constrained by the opposing magnetic fields of the endcaps. The piston is covered with magnetic ferrofluid, providing a low friction gas-tight seal around the piston. The cylinder has two pressure input lines, one being connected to the chamber on either side of the piston. The relative pressures of the input lines cause the piston to move to a position of equilibrium within the cylinder, with the magnetic fields of the endcaps holding the piston in place against the pressure. A magnetic field angle sensor detects flux lines on the outside of the cylinder, and the reading is correlated with the pressure differential between the two input lines.

Abstract: A differential pressure sensor has a magnetized piston free to move in a cylinder. Magnetic endcaps seal the ends of the cylinder, forming chambers on either side of the piston. The moveable magnetic piston is constrained by the opposing magnetic fields of the endcaps. The piston is covered with magnetic ferrofluid, providing a low friction gas-tight seal around the piston. The cylinder has two pressure input lines, one being connected to the chamber on either side of the piston. The relative pressures of the input lines cause the piston to move to a position of equilibrium within the cylinder, with the magnetic fields of the endcaps holding the piston in place against the pressure. A magnetic field angle sensor detects flux lines on the outside of the cylinder, and the reading is correlated with the pressure differential between the two input lines.

Abstract: An apparatus for measuring pressure comprises a housing and an actuator pressure sealed to the housing and having a shaft. The actuator is configured to be in pressure communication with a volume of gas or liquid. Upon a change in pressure, the actuator is displaced at least partially in the axial direction. A sensor detects axial displacement of a magnetically encoded target upon the change in pressure in the volume. A device for measuring pressure in an engine cylinder comprises a valve in pressure communication with an engine cylinder. The valve stem has a magnetic coding located adjacent a sensor. Axial displacement of the stem under cylinder pressure is detected and pressure is obtained.

Abstract: A pressure transmitter comprises a metal wall separating a process pressure chamber from an electronics compartment. The metal wall has a stepped bore with a bore shelf facing the process pressure chamber. A metal header has a stepped outer rim with a header shelf that contacts the bore shelf. The metal header includes at least one electrical feedthrough with a glass-to-metal seal adjacent the stepped outer rim. A welded seal seals the stepped outer rim to the stepped bore.

Abstract: A pressure gauge is composed of two separate components adapted to be assembled and disassembled by hand. The one component is a pressure-motion conversion element (3, 6) for receiving a pressure and effecting a movement of a movable portion (3c, 6c) thereof in response thereto, and the other component is a force measuring element (5) for measuring a force caused due to the movement of the movable portion (3c, 6c). The pressure-motion conversion element (3, 69) is constructed as a disposable component, whereas the force measuring element (5) is intended for re-use.

Abstract: The present invention relates to a vehicle wheel sensor apparatus and a method that determine if a vehicle wheel sensor is active or passive, while efficiently providing the necessary connectivity, power, and communication between the sensor and a controller, without requiring a change in controller hardware. For an active sensor, the apparatus provides power and receives speed signals, high frequency vibration or acceleration signals, or other analog signals. For a passive sensor, the apparatus receives speed signals.

Abstract: A micromechanical sensor, and a method for manufacturing a micromechanical sensor, featuring, in addition to a sensor element, at least a part of an evaluation circuit. In this context, the micromechanical sensor contains at least a first structural element made of a first material. The first structural element houses at least one sensor region and a part of an evaluation circuit, at least one sensor element being located in the sensor region. Moreover, at least one first and one second side are to be distinguished from one another in the first structural element. The first side of the first structural element features at least the sensor element, while the second side of the first structural element features at least a part of the evaluation circuit. At least parts of the sensor region and/or of the evaluation circuit are formed from the first material by micromechanical processing.

Abstract: A position sensor comprises a substrate having an array of pressure sensors and a membrane overlying the substrate. The membrane includes physical parameters which vary with position. The membrane may include discontinuous regions and protrusions which affect the way in which forces on the membrane are distributed to the substrate. A pressure sensor may also include a controller for receiving pressure information from the substrate, with a signal processor being programmed to localize the depressed region or regions of the substrate.

Abstract: A hydraulic pressure sensor for measuring the pressure in a hydraulic pressure chamber 1. A reservoir housing 9 is connected to the pressure chamber, and the interior of the housing is divided by a slideable partition 13 which defines a reservoir chamber 8 which is connected to the pressure chamber and a sensor chamber 7 which is connected to a sensor element 5. The partition 13 is constructed as a piston and extends for sliding movement along the walls of the reservoir housing while exerting a frictional force. A spring 11 supports the partition relative to the reservoir housing against the pressure in the reservoir chamber 8. The partition 13 may be constructed as a differential piston, and consist of two or more piston sections 13.1, 13.2, 13.3, which extend independently of one another in a sliding and sealing manner, and mutually support one another by an intermediate spring 14.

Abstract: A method of determining the accuracy of a pressure sensor in a surgical cassette is disclosed. The method involves displacing a diaphragm of the sensor a pre-defined amount of displacement, and measuring the force exerted on the diaphragm by the displacing step. The accuracy of the pressure sensor is determined by comparing the force measured in the measuring step to a pre-defined force for the pre-defined amount of displacement.

Abstract: A device and procedure for checking the health of a pressure transducer in situ is provided. The procedure includes measuring a fixed change in pressure above ambient pressure and a fixed change in pressure below ambient pressure. This is done by first sealing an enclosed volume around the transducer with a valve. A piston inside the sealed volume is then driven forward, compressing the enclosed gas, thereby increasing the pressure. A fixed pressure below ambient pressure is obtained by opening the valve, driving the piston forward, sealing the valve, and then retracting the piston. The output of the pressure transducer is recorded for both the overpressuring and the underpressuring. By comparing this data with data taken during a preoperative calibration, the health of the transducer is determined from the linearity, the hysteresis, and the repeatability of its output. The further addition of a thermometer allows constant offset error in the transducer output to be determined.

Abstract: A position sensor comprises a substrate having an array of pressure sensors and a membrane overlying the substrate. The membrane includes physical parameters which vary with position. The membrane may include discontinuous regions and protrusions which affect the way in which forces on the membrane are distributed to the substrate. A pressure sensor may also include a controller for receiving pressure information from the substrate, with a signal processor being programmed to localize the depressed region or regions of the substrate.

Abstract: An improved pressure activated control apparatus is provided for sensing fluid pressure and triggering one or more switches in response to the fluid pressure, as desired. The apparatus is designed to be placed within a fluid of a reservoir. The apparatus includes a first resilient member, such as a pliable rolling diaphragm or bellofram, having an outer surface exposed to the fluid and responsive to the fluid pressure. The pressure activated control apparatus includes a second resilient member, such as a spring with a chosen spring constant, k, that provides a biasing force against the diaphragm that is opposite the fluid pressure. A transducer is operative to monitor changes in pressure of gases within the apparatus causes by movement of the diaphragm. A controller is responsive to the transducer and selectable fluid level thresholds to activate pumps and/or valves for adjusting the level of the fluid in the reservoir.

Abstract: A pressure sensor is mounted upon a hydraulic valve body. The sensor has a base which extends into a bore formed in the valve body. The valve body bore is in communication with a pressurized hydraulic fluid. A cover that is removably attached to the valve body encloses the pressure sensor. A circuit substrate is disposed within the cover and electrically connected to the pressure sensor.

Abstract: A fluid pump having a motor operably coupled to a pump assembly, the motor and pump assembly acting cooperatively to pressurize a fluid includes a pressure switch being in communication with the fluid under pressure and being in communication with the motor for sensing the fluid pressure and controlling the operation of the motor to maintain a selected fluid pressure. A method of controlling fluid pressure in a fluid pump, the fluid pressure being generated by activating a pump motor to operate a pump assembly.

Abstract: A force sensor for sensing the weight of a vehicle seat occupant for a vehicle's occupant protection system has a pressure sensor responsive to hydraulic pressure resulting from axial force applied to the force sensor. A constant force spring in the form of a diaphragm with two flanges simultaneous functions as a seal, a constant force bias spring, an armature support resistant to radial forces and a piston for converting force to hydraulic pressure. Two studs receive applied force. An electrical insulator is sealed to the walls of a passage inside of one of the studs to provide electrical communication while sealing against liquid leakage. A pressure sensor is mounted on the electrical insulator and connected to electrical conductors in the insulator by stitch bonding. The diaphragm resists radial movement while allowing axial movement thereby making the sensor insensitive to radial forces. By being a constant force spring the diaphragm makes the sensor insensitive to temperature variations.

Abstract: A pressure detection device for detecting an increase of pressure acting thereon includes an electrically conductive device housing which has an accommodation bore extending inward from one end of the device housing and a slide bare extending between the accommodation bore and the other end of the device housing. A piston is slidably disposed within the slide bore and adopted to receive a pressure, and a terminal serving as one electric contact is fixed to the accommodation bore via an electrical insulator. A disk spring serving as the other electric contact deforms due to a pressing force of the piston and coming in contact with the terminal. The pressure detection device further comprises an electro-functional member attached to either the terminal or the disk spring in which the electro-functional member is changeable its electric resistance due to an impressed pressing force acting thereon.

Abstract: An easily assembled, low cost pressure switch for a hydraulic pump is proposed. An oil pressure introducing hole is provided for leading a discharge pressure to a depression formed in a body which is earthed. A plug supporting an electrically conducting terminal in an insulated state so as to block the depression, comprises a cylindrical part opening into the depression of the body. An electrically conducting sleeve which is pierced by a damping orifice connected to the oil pressure introducing hole, engages with an opening of the cylindrical part. An electrically conducting plunger which comes in contact with and separates from the terminal in response to an oil pressure from the damping orifice, is housed in the sleeve. A spring pushing the plunger against the oil pressure is housed in the cylindrical part of the plug, and the lower end of the sleeve engages with the opening of the oil pressure introducing hole.

Abstract: A double differential pressure indicator has a housing containing two pistons arranged in contiguous bores and biased by a single spring extending between opposed ends of the pistons. The differential pressure is applied across both pistons and as the pressure differential increases to a first predetermined difference one piston moves to operate a first indicator which may, for example, be a reed switch. As the differential pressure further increases, the second piston moves to operate a second indicating device which may be a button. In an alternative arrangement, both indicating devices operate at the same differential pressure.

Abstract: A differential pressure switch particularly suitable for monitoring dirt accumulation on a filter element of an oil-separating air filter comprising a piston which is movable in response to a relative change in pressure between two pressure zones and is biased in one direction by a restoring spring, and a rolling membrane which separates the pressure zones.

Abstract: A sensor for detecting the combustion pressure of an engine, in which an upper fixing member and a casing are fixed while a pre-load is being applied to the upper fixing member, so that a pre-load may be applied to a piezoelectric element. Moreover, a tubular diaphragm for transforming a pressure into a strain and a pressure receiving face for receiving the combustion pressure are connected to each other through a plunger so that they may be kept away from each other.

Abstract: Mechanically simple, reliable devices for measuring pressure or detecting pressures above a certain limit are disclosed. A representative device includes a magnet surrounded by one or more bands of a ferrofluid, and which is free to move within a nonmagnetic, generally elongated housing. In operation, the housing is oriented vertically, and the lower aperture exposed to the region of pressure to be sensed. The opposite end, which preferably contains another aperture, is exposed to a reference pressure (ordinarily the atmosphere) that remains isolated from the region of pressure to be sensed. Gravity draws the magnet downward, toward the bottom of the housing, while pressure at the lower aperture tends to force the magnet upward. When the force exerted by the pressure source exceeds the downward force of gravity, the magnet travels upward through the housing; this movement may be detected by an appropriate sensing arrangement, and is used to provide a warning signal or a quantitative pressure measurement.

Abstract: A pressure switch particularly adapted for use with high pressure fluid is shown having a frusto-conical support surface in the form of a protuberance (121, 121') formed at the center of a surface of a piston guide member (12, 12'). A stretchable diaphragm cap member (14, 14') generally in the shape of an inverted V is closely fitted on the protuberance (121, 121') of the piston guide member (12, 12') as well as the head (111b) of a piston member (111, 111') received in and projecting out of bore (120, 120'a) formed centrally through protuberance (121, 121'). The outer thickened peripheral berm (143, 14'a) of the cap member (14, 14') is inserted into a recess (102e, 102'e) in the wall defining an enlarged portion of the bore (102) which in turn opens to a cavity (103, 103') of the upper housing (10, 10') in which piston guide member (12, 12') is disposed. The cap member (14, 14') serves to seal the fluid passage side of the switch from the remainder of the switch.

Abstract: A device for determining a pressure of gas in an evacuated chamber including a cylinder positioned in fluid communication with the evacuated chamber with the cylinder forming a compressed gas chamber, a reciprocating piston received within the cylinder and mounted for reciprocal movement therein, a port or valve for providing selective fluid communication between the compressed gas chamber and the evacuated chamber is disclosed. A drive mechanism is provided for reciprocating the piston between a retracted position, where the compressed gas chamber communicates with the evacuated chamber, and an extended position where communication between the compressed gas chamber and the evacuated chamber is interrupted, the position being a position where a pressure transducer determines that a predetermined pressure differential between the chambers has been reached.

Abstract: A gas-flow sensor features delayed-action response to physical changes in gases as they flow through the sensor, thus avoiding transient flow-metering displacements in response to such change. The delayed-action response is attributable to blind hole and blind-bore configurations within which cylindrical plunger elements must displace in the course of changing gas flow, and the delayed-action response is controlled by provision of predetermined clearances between parts that telescope in the course of sensor operation.

Abstract: A sensor having a wide sensing range is capable of being controll by a small scale processor. The sensor comprises: a plurality of planar zigzag coils being provided on substrates, the planar zigzag coils having the same coil pitch and being formed into zigzag shape in a first direction, the planar zigzag coils being capable of relative movement in the first direction, the planar zigzag coils including a first planar zigzag coil, which is a primary coil, and a second planar zigzag coil, which is a secondary coil; a magnetizing unit for magnetizing the first planar zigzag coil; a first detecting unit for detecting induced electromotive force, which is induced in the second planar zigzag coil by the first magnetized planar zigzag coil; and a second detecting unit for detecting displacement length between the first planar zigzag coil and the second planar zigzag coil on the basis of the induced electromotive force in the second planar zigzag coil.

Abstract: A piezoelectric pressure sensor includes a generally elongated sensor housing, a pressure receiving plate disposed at a first end of the sensor housing with a first surface thereof serving as a pressure receiving surface for receiving a pressure applied from outside of the sensor housing, a pressure transmission member accommodated in the sensor housing with a first end thereof held in contact with a second surface of the pressure receiving plate, and a tubular piezoelectric element accommodated in the sensor housing with a first end thereof held in contact with a second end of the pressure transmission member. A pair of electrodes are formed on the external and internal surfaces of the piezoelectric element, respectively.

Abstract: A signal generator for generating an electrical signal which varies in accordance with movement of an actuating member includes a plunger slidable mounted within a housing which carries a pair of permanent magnets for generating a magnetic field to be applied to a hall effect generator. As the plunger is moved relative to the hall effect generator, the magnets are also moved relative to the hall effect generator, thereby varying the magnetic field applied thereto. Accordingly, a variable output signal is generated as a function of the position of the input member.

Abstract: An improved dead weight piston pressure measurement/calibration device includes a cylinder and a dead weight piston assembly that includes a piston rotatable and vertically in the cylinder, bell housing supported by the piston and carrying a number of calibration weights. The weight of the dead weight piston assembly initially is supported by an elastic stop device. Gas from an external source is rapidly forced into the cylinder until the dead weight piston assembly rises in an "elastic" zone defined by the elastic stop device. Such movement is sensed to "proportionally" reduce the rate of flow of gas and stabilize the position of the piston in the second element in a free-floating equilibrium condition, and actuate a drive mechanism that rotates the dead weight piston assembly and maintains the rotation rate in a defined range without producing any sustained vertical or radial displacement forces on the dead weight piston assembly, and thereby avoiding pressure overshoot.

Abstract: A pressure indication device comprises a housing including a bore in which is received a slidable piston. The piston has two end faces, one of which is for connection to a source of fluid at higher pressure and the other of which is for connection to a source of fluid at lower pressure. The device produces an indication when the pressure differential reaches a predetermined value. In an inoperative position of the piston, a portion of the upstream face co-operates with the bore to provide a face seal which reduces leakage between the bore and the piston and which also reduces the effective area of the upstream face. In addition, a labyrinth seal is provided between the bore and the piston. When the predetermined pressure is reached, the piston moves, and as it does so, the effective area of the upstream face is increased.

Abstract: The present invention relates to a compression load cell used to monitor pressure in a diapragm cassette pumping system. A plunger is axially slidable in a linear bearing and has a first end in contact with the cassette and the second end in contact with the load cell. The force signals have a direct relationship with the pressure in the cassette.

Abstract: A pressure switch comprises an electrically conductive housing, a stationary contact stationarily installed in the housing and a movable contact movably received in the housing. The movable contact is movable to contact with the stationary contact. A hydraulically operated moving device is employed for moving the movable contact in accordance with a hydraulic pressure applied thereto. The stationary contact is formed with a blind bore. An end piece to which an end of an electric cable has been connected is press-fitted in the blind bore.

Abstract: An electromagnetic fluid pressure transducer is provided which uses the opposing magnetic fields of a permanent magnet and an electromagnet to sense a change in a differential force. The differential force is the result of a pressure applied to the unequal surface areas of two pistons attached to opposite poles of the permanent magnet. The differential force displaces the permanent magnet which activates a counter whose output controls the field strength of an electromagnet. The magnetic field of the electromagnet is varied by the counter output to counterbalance the differential force by interacting with the field of the permanent magnet. The field strength of the electromagnet is varied until the magnetic force is sufficient to overcome the differential force and return the permanent magnet to its original position which stops the counter. As a result, the counter output which changes in proportion to change in the ambient pressure acting against the pistons can be used to indicate pressure.

Abstract: Holding device for a piston position detector, contained in a casing and being displaceably mounted on the outside of a fluid pressure cylinder. The holding device consists essentially of a U-shaped yoke being displaceable along two mutually parallel guides and being lockable in a desired axial position. The yoke is locked by means of a first fastening screw, whereas the casing is insertable between the shanks of the yoke and is lockable in inserted position by means of a second fastening screw. The casing is protected by the yoke and is detachable from the latter, also when the yoke is located to the guides.

Abstract: A pressure switch for controlling a switching element includes a spring-loaded piston operatively connected to the switching element and acted upon by a pressure fluid. A diaphragm separates the piston from the pressure fluid for providing a leaktight closure of the working parts of the pressure switch from the fluid stream, with a support ring surrounding the piston and being arranged axially between the diaphragm and a bushing by which the piston is guided in an axial direction.

Abstract: A first belleville spring, having a given preload, controls a translatable, elongate, contact disc assembly, to cause a shunting disc to remove from, and close into contact with a pair of circuit contacts. The assembly is disposed within a translatable carriage, and a second belleville spring having a greater preload controls translation of the carriage, to cause the shunting disc to close into contact with, and remove from, a second pair of circuit contacts. As a consequence dual set points of switching operation is provided. A fluid medium, admitted into a housing for the assembly and carriage, effects translation of the assembly and carriage.

Abstract: A pressure switch for operating a device for increasing the engine speed of an automotive vehicle equipped with a power steering system in order to prevent an engine stall when a high load acts on a power steering pump during parking and at a low vehicle cruising speed. The pressure switch is comprised of a movable terminal which is normally separate from a stationary terminal and contactable with the stationary terminal in response to an oil pressure over a predetermined level, in a hydraulic circuit of the power steering system. The movable terminal is slidably fitted in a pit to be filled with oil so that the response of the movable terminal to the oil pressure is lowered, thus providing a hysteresis effect to prevent chattering of the pressure switch.

Abstract: A pneumatically actuated switching device comprises a pneumatic bulb including a base plate for anchoring the bulb by frictional contact with surfaces in contact therewith. The base plate further having pneumatic seal about an outer periphery thereof, and an actuator dome having a convexly extended pneumatic activation wall supported by an outer peripheral annular rim engaged with the base plate for pneumatic sealing with the seal to define a pneumatic pump chamber. The bulb further including a conduct for conducting a quantity of air pressurized by operation of the dome and, electrically conductive switch responsive to the discharge of a volume of air pressurized by the pneumatic bulb for producing a corresponding electrical signal.

Abstract: A differential pressure control provides a housing having a pair of opposing inlets for accepting lines having different fluid pressures therein. The inlets are sealably connected to a central chamber having a piston by means of diaphragms. The piston is joined to a pivoting lever having a free end that translates as the piston is moved by each of the diaphragms. Upon existence of a pressure inbalance, the free end is moved by the piston, tripping a switch that indicates the pressure imbalance. The lever includes an adjustable spring to vary the gain of the switch and further includes a pair of opposing stops that limit the lever's displacement to substantially match that of the throw of the switch.

Abstract: Differential pressure sensor mechanisms include core members acted upon by pressure sensing plungers at opposite ends of the core members to cause axial movement of the core members relative to a linear variable position sensor when unequal force balances are applied to the respective plungers, and centering springs for centering the core members with respect to the sensor when equal force balances are applied to the respective plungers. The centering springs desirably flex equally in both directions to keep reversing stress levels to a minimum and are essentially unloaded in the null or lower load region of operation to minimize the possibility of induced plunger side loading in the most active and critical region of performance. Carriage members desirably support opposite ends of the core members for coaxial movement relative to the sensor.

Abstract: A flow switch includes a movable shuttle enclosed within a bore having narrower and wider bore sections. The shuttle has a solid cylindrical portion and a vaned portion. When there is no fluid flow from the inlet to the outlet, the shuttle rests on a part-conical portion of the bore. When fluid pressure is applied at the inlet, the shuttle is raised until the vaned portion is partly within the wider bore section. Fluid can then flow through the spaces between the vanes in the vaned portion, and fluid flow is detected by the change in position of the shuttle. The shuttle can be made magnetic, whereupon a magnetic sensing means such as a magnetic reed switch can be used to detect fluid flow. This arrangement has the advantage that resistance to flow and pressure drop are minimal compared to previous designs.

Abstract: An electro-hydraulic servo actuator with function for adjusting rigidity. The electro-hydraulic servo actuator comprises an electro-hydraulic transducer which transduces an electric signal into a hydraulic signal, an actuator of a cylinder type which is operated by the electro-hydraulic transducer, and a position detector which detects a position of an output member of the actuator to emit a positional electric signal. The hydraulic-element transducer is a bias piston which is disposed within a actuator rod of the cylinder type actuator and which floats in response to a differential pressure within the cylinder, and the piston is connected to the position detector.

Abstract: A pair of electrical switches are operable by a movable lever between a first condition where the first switch is on and the second switch is off, to a second condition where the first switch is off and the second switch is on, by movement of a piston connected to a pressure source via an inlet port. A flange is fixed on the piston shaft, and a compressed spring is mounted over the piston shaft between the flange and a sleeve surrounding the piston bore. A pressure close to ambient moves the flange which in turn moves the lever to the first position, while a pressure substantially less than ambient moves the flange in the direction to move the lever to the second position. The switches are adapted to respond to the pressure of the input manifold of a motor vehicle, actuating the vehicle headlight circuit when the motor is running and the manifold pressure is very high, and actuating the starter/ignition circuit when the motor is not running and the manifold pressure is at ambient.

Abstract: The invention is concerned with switch devices and more particularly with devices to be fitted to piston and cylinder actuators to monitor the position of the piston therein. The device comprises a switch which has two connection or terminal contacts arranged at its axially opposite ends. These terminal contacts are respectively connected with signal conductors which may for instance be in the form of flexible cable wire. The switch is accommodated in a sleeve surrounding it. The two signal conductors are extended as far as a common axial terminal or connection end of the switch. For producing an electrical connection of the one signal conductor with the second terminal contact the current is caused to flow through the sleeve.

Abstract: A proximity switch for signaling the location of a movable member at either of opposite end limits of movement relative to a stationary frame includes a movable member, such as a piston, traveling along a fixed path of movement between a first position and a second position and having an aperture formed within the movable member extending from one end toward another end. A housing encloses a portion of the movable member to form a first fluid chamber between the movable member and a first end of the housing, and to form a second fluid chamber between a second end of the housing and the movable member. Expansion of the first fluid chamber drives the movable member to the first position and expansion of the second fluid chamber drives the movable member to the second position.

Abstract: A device for detecting the position of a movable element of an adjusting member operated by fluid pressure. A cylindrical probe is introduced into the wall of the actuator and extends to near the inner surface of wall. The probe is mounted to be axially displaceable at the holder so that it may be adapted to different wall thicknesses. The holder contains a sealing means for sealing the passage of the cylindrical probe, which is extended by the shaft and is adapted to be rotatable in a thread bore at the rear end of the holder. A circuit box accommodating the electric circuitry is secured to the end of shaft. The position detector, which detects when the piston has approached the probe, may be simply adapted to different cylinder wall thicknesses. This eliminates the requirement of using different types of position detectors whose probes vary by the length of their projection.

Abstract: A tire pressure sensing system for on-board use in an automotive vehicle comprises a transmitter mounted to rotate with each tire and a receiver that is disposed in sensing relationship to each transmitter. Each receiver is a Hall Effect sensor. Each transmitter comprises three magnetic poles that are effective to cause the Hall Effect sensor to develop a bi-directional pulse waveform during passage of the transmitter past the receiver. Electronic circuitry processes the signal waveform that is created by the Hall Effect sensor in response to passage of the magnetic poles. The circuitry develops one rectangular pulse waveform from one magnetic polarity and another rectangular pulse waveform from the other magnetic polarity.

Abstract: A differential pressure switch assembly that includes a conventional snap action switch for controlling the off-on modes of operation of state of the art equipment, which assembly comprises a high pressure plate that defines the high pressure cavity and a high pressure port of restricted size therefor, a low pressure plate that defines a first subchamber of the assembly low pressure cavity and a low pressure port therefor, a diaphragm clamped between the high and low pressure plates and separating the switch assembly high and low pressure cavities, a piston mounted in the low pressure plate for movement perpendicularly of the assembly diaphragm and biased toward the diaphragm by an adjustable range spring device, the range spring of which can be adjusted to provide the set point for the switch assembly, with the range spring device being formed to dispose the range spring in a second low pressure subchamber that is in open communication with the first low pressure subchamber to form a composite low pressure c