Abstract: The invention relates to a level detecting system for a powder container of a powder-coating apparatus. It contains an inductive proximity sensor (22) and an electrically insulating membrane (28) which is displaceable to-and-fro the proximity sensor and which is fitted on its inside surface opposite the proximity sensor with a metallic element (32) affixed to it and affecting the magnetic properties of the proximity sensor. The level detecting system operates regardless of any powder particles adhering to it.

Abstract: A pressure measurement device comprising a housing enclosing an elastic pressure measurement element and a magnet attached to the measurement element. First and second Hall sensors operatively positioned near the magnet are connected to an electrical circuit which processes the sensor outputs to provide first and second output signals. The positions of the Hall sensors can preferably each be adjusted from outside the housing.

Abstract: A load applied to a load cell's load-bearing member (21) causes that member to move against the force applied by springs (28 and 30) and thereby bring a magnet (24) into closer proximity to the ferromagnetic core (12) of a coil (10). Acting across a small gap, the magnet partially saturates a magnetic circuit that encloses the coil. This force-caused magnet motion changes the coil inductance and the magnetic circuit's degree of saturation. By applying to the coil (10) a brief voltage pulse without thereby heating it significantly, and by observing the coil current's resultant steady-state value and the rate at which the coil current approaches that value, an inductance-to-load converter (FIG. 4) calculates the applied load and the coil's temperature and generates outputs that represent them.

Abstract: A pressure responsive mechanically resonant sensor device is provided that comprises a torsion pendulum driven at resonance. The pressure sensor includes a rigid frame to which is affixed a torsion pendulum comprising a hollow tube and a resonant mass as well as optimal means for applying energy to drive the torsion pendulum at resonance. The interior of the hollow tube portion of the torsion pendulum communicates through a pressure port in the rigid frame with the fluid whose pressure is to be sensed. The input pressure affects the torsion constant of the hollow tube and therefor changes the resonant frequency of the torsion pendulum, which frequency is converted into an indication of the sensed pressure.

Abstract: A method and an apparatus for measuring the pressure or other physical quantities of a gas or a liquid in a sealed container without penetrating the container. Two permanent magnets, one located on a sensing unit inside the container and one located on a readout unit located outside the container are used to communicate the magnitude of the pressure sensed inside the container to the readout unit. No power supply is required to implement this system.

Abstract: A differential pressure transducer has a measurement chamber which is divided by a membrane into first and second measurement spaces which can be exposed to first and second pressures whereby differential pressure causes deflection of the membrane from its neutral position. A deflection sensor measures the deflection of the membrane and produces a deflection signal. An electromagnet arrangement produces a magnetic force which compensates for the deflection force which is caused by the differential pressure. The coil current for producing the magnetic compensation force represents a measure of the differential pressure.

Abstract: A pressure sensing apparatus for operative arrangement within an environment, having: a sensor comprising a hermetically-sealed receptacle, at least one side of which has an flexible membrane to which a magnetically hard element is attached. Enclosed within the receptacle is a magnetostrictive element that vibrates in response to a time-varying magnetic field. Also included is a receiver to measure a plurality of successive values for magneto-elastic emission intensity of the sensor taken over an operating range of successive interrogation frequencies to identify a resonant frequency value for the sensor.

Abstract: A pressure measurement device comprises an elastic measurement element (12), which can be acted upon by the pressure to be measured, a measurement element housing (2), on which the measurement element is attached, and a magnet (18), which is attached to the measurement element and which is moved by the measurement element in reaction to a change of the pressure acting upon the measurement element along a substantially rectilinear path of movement. The pressure measurement device further comprises a first Hall sensor (38), which is arranged to the side near the magnet outside its path of movement, an electronic circuit, to which the Hall sensor is electrically connected and which processes the sensor output voltage of the first Hall sensor into a first output signal of the pressure measurement device, and a sensor carrier (22), which supports the Hall sensor and is attached to the measurement element housing.

Abstract: Sensors for mounting in fluid chambers respond electrically to low pressures in the fluid, while resisting damage or leakage at high pressures. A flexible diaphragm, mounted at one end of a housing, is sandwiched between first and second annuli, leaving a center portion free to move in response to fluid pressure changes. The diaphragm moves a cylinder, which reciprocates in the second annulus against an adjustable spring bias. Travel of the cylinder away from the fluid is limited by a stop. Once the stop is reached, increased pressure on the diaphragm forces it against a fixed wall composed of a face of the second annulus and a face of the cylinder. The forces on the diaphragm are then all compressive. This enables the use of an easily flexed diaphragm for low pressure sensitivity, while resisting damage from high pressures. The moving cylinder is used to move a magnet that actuates a Hall effect switch, a Hall effect analog output transducer, or a reed switch.

Abstract: A magnetic pressure sensor for sensing a pressure change inside a sealed container. The sensor includes a sealed deformable vessel having a first end attachable to an interior surface of the sealed container, and a second end. A magnet mounted to the vessel second end defining a distance away from the container surface provides an externally detectable magnetic field. A pressure change inside the sealed container causes deformation of the vessel changing the distance of the magnet away from the container surface, and thus the detectable intensity of the magnetic field.

Abstract: A differential pressure switch comprising an enclosure including a peripheral wall and a solid one-piece non-perforate partition wall that is integrally attached to the peripheral wall around the entire perimeter of the partition wall. The enclosure includes a sensor chamber located on a first side of the partition wall and a fluid cavity located on a second side of the partition wall. The partition wall and the integrally attached peripheral wall seal the sensor chamber in fluid-tight leak-proof isolation from the fluid cavity. A flexible diaphragm is located within the fluid cavity and forms a low-pressure fluid chamber on one side and a high-pressure fluid chamber on a second side of the diaphragm. A magnet is located in the fluid cavity and is coupled to the diaphragm such that the magnet changes position in response to movement of the diaphragm. A Hall effect sensor is located in the sensor chamber.

Abstract: In a semiconductor acceleration sensor, a weight and thin beam parts adjacent to the weight are formed on a substrate, a moving electrode is formed on the weight, and a fixed electrode is formed at a position of the other substrate opposed to the moving electrode. Both the electrodes come in contact with each other and conduct as a result of acceleration on the weight, whereby the semiconductor acceleration sensor operates. The fixed electrode or the moving electrode is formed with a projection toward the opposed electrode and the projection and the electrode come in contact with each other and conduct by action of acceleration with a predetermined spacing held between both the electrodes for preventing occurrence of chattering caused by the electrostatic attraction force between both the electrodes.

Abstract: A pressure sensor having structure for generating a magnetic force to balance forces on opposing sides of a flexible diaphragm centered within a pressure chamber allows fluid pressure to be introduced into the chamber on one side of the diaphragm. A first magnetic coil is positioned on another side of the diaphragm and a second coil is mounted to the diaphragm. When fluid pressure is introduced into the pressure chamber, the diaphragm deflects, and the magnitude of current required to generate a recentering magnetic force which causes the diaphragm to be recentered constitutes a measure of the fluid pressure. Since the recentering magnetic force is substantially unaffected by temperature, the fluid pressure measurement obtained is substantially independent of temperature.

Abstract: A differential pressure transducer includes a pair of interior chambers separated by a peripherally supported, nominally planar electrically conductive diaphragm. A magnetic assembly is positioned on at least one chamber wall opposite to a central portion of the diaphragm. The magnetic assembly includes an electrical conductor and preferably a magnetic field permeable electric field shield between the electrical conductor and the chamber so that as the central portion of diaphragm is displaced from its nominal plane in response to an applied pressure differential, the inductance of the magnetic assembly changes. The transducer may be a portion of a tank circuit of an oscillator having a frequency of oscillation that varies with the pressure differential applied across the diaphragm.

Abstract: The present invention is a displacement sensor, which is capable of keeping high sensing resolution even if the amount of displacement of the core and the amount of changing the inductance are small. In the displacement sensor of the present invention, a displacing body is capable of displacing according to external force. An LC resonance circuit includes a magnetic coil and a core made of a magnetizable material, which is capable of moving close to and away from the magnetic coil according to the displacement of the displacing body. An oscillator inputs continuous signals having prescribed frequency to the LC resonance circuit. A detecting circuit detects the amount of the displacement of the displacing body on the basis of amplitude of the continuous signals from the LC resonance circuit.

Abstract: A differential pressure transducer includes a pair of interior chambers separated by a peripherally supported, nominally planar electrically conductive diaphragm. A magnetic assembly is positioned on at least one chamber wall opposite to a central portion of the diaphragm. The magnetic assembly includes an electrical conductor and preferably a magnetic field permeable electric field shield between the electrical conductor and the chamber so that as the central portion of diaphragm is displaced from its nominal plane in response to an applied pressure differential, the inductance of the magnetic assembly changes the transducer may be a portion of a tank circuit of an oscillator having a frequency of oscillation that varies with the pressure differential applied across the diaphragm.

Abstract: A high-temperature, integrated, pressure sensor includes a single crystal semiconductor substrate that is provided with a recess in a first surface thereof, the recess bounded by a rim. A first coil structure is positioned within the recess and a pressure diaphragm, comprising a single-crystal semiconductor wafer is bounded about its periphery to the rim of the semiconductor substrate. The bonding is created by a glass interlayer between the pressure diaphragm and the semiconductor substrate. A second coil structure is positioned on the underside of the pressure diaphragm and is separated from the first coil structure. Electrical circuitry is connected to both coil structures and provides an output indicative of changes in inductive coupling between the coils.

Abstract: A control system for regulating a flow rate of a heat transfer fluid in a heat transfer system, the heat transfer system having a heat transfer fluid flow path, flow control device for creating flow along the path, a fuel source for providing a combustible fuel to the path, an air source for providing combustion air to the path, and an assembly for combusting the fuel and air, the control system comprising a sensor for sensing a measured flow value at the air source, a controller for storing an optimum flow value at the air source and for storing a range of operating control values for the flow control device, the operating control values corresponding to the optimum flow value, a system for calculating a deviation between the measured flow value and the optimum flow value, and a system for varying the operation of the flow control means in accordance with deviation.

Abstract: An inductive pressure transducer senses fluid pressure within a tubular member by passing an alternating current within an inductor coil to generate a magnetic field. The magnetic field passes through a gap between the tubular member and the inductor coil, and into an exterior portion of the tubular member. A detector means senses the net energy transferred from the inductive coil by the magnetic field, which indicates the fluid pressure within the tubular member.

Abstract: A differential pressure transducer for measuring external pressures is disclosed. The pressure transducer uses a ferrofluid contained in two interconnecting chambers, enclosed by two non-magnetic spring diaphragms. In this embodiment, two independent inductance series circuits, each comprising a bar magnet, Hall effect sensor and an iron pole piece, measure variations in the volume of ferrofluid in each of the interconnecting chambers. Changes in pressure displace the non-magnetic spring diaphragms causing the volume in each interconnecting chamber to change in a differential manner. The flux path in the series magnetic circuit is distorted by changes in the volume of the ferrofluid, causing changes in the flux density at the sensing area of the Hall effect sensor, this sensor producing an electrical signal proportional to the flux change.

Abstract: A pressure sensor, such as the type of sensor used in screw-type refrigeration compressors, permits sensing of positive as well as negative pressures and provides an indication of the direction in which the compressor is rotating. Negative pressure leads to system shut-down, while positive pressure verification will allow compressor operation to continue. The pressure sensor includes a pair of adjustable tension springs, on opposite sides of the diaphragm, to vary the position of the diaphragm within its mechanical stroke. By establishing a pressure range of interest, and by employing an electrical sensor, such as a Hall effect sensor, the direction of movement of the diaphragm and sensor can be monitored immediately upon compressor start-up.

Abstract: A sensor or regulator capable of operating at high absolute pressures and for measurement of pressure, especially pressure differential, or liquid level, is disclosed and has a member which moves in response to pressure differential and being coupled directly to a diaphragm via a lever linkage or which is displaceable by a float and which is juxtaposed with an inductive proximity switch responsive to movement of the member where the proximity switch can be mounted directly in a pressure-retentive wall, a sight glass or like pressurizable partition partition need not be provided. In the preferred construction, however, such a glass, sealed in the pressure wall of the housing, is interposed between the inductive proximity switch and the movable member to which that proximity switch responds. A method of controlling oil/refrigerant mixtures in a refrigerating plant is also disclosed.

Abstract: A differential pressure sensor indicating a housing forming a high pressure chamber, a nozzle mounted on the housing at one end of the chamber, a diaphragm mounted in the chamber to form a low pressure chamber in the nozzle, a spring retainer in the high pressure chamber, a spindle connected to the diaphragm, a tension spring connecting the spindle to the spring retainer, a circular magnet mounted on the spindle and a transducer mounted on the housing to sense the position of the magnet.

Abstract: A pressure measurement system comprising a capacitance device whose outer interrelated capacitance plates are maintained in a relatively fixed position relative to one another while an intermediate capacitance plate responds to temperature. The plates are in a restricted enclosure containing a gas dielectric medium. The pressure of the gas dielectric medium (and consequently the density of the gas) is controlled as a function of a pressure to be measured. By measurement of capacitance relationships as a function of the temperature and density of the gas dielectric medium, a pressure measurement is obtained. The system is constructed with like types of materials where the capacitance device is in an enclosure chamber which is immersed in a pressure media. The capacitance device is constructed with a symmetrical arrangement to balance out effects of gravity or vibration. Construction of micro components utilizes an electrostatic bonding system which eliminated arcing during bonding.

Abstract: The pressure sensor has a mechanical pressure receiving member and a mechanical-electrical transducer connected to it. The transducer comprises a permanent magnet attached with a moving portion of the pressure receiving member which cooperates with a locally fixed Hall-effect sensor mounted on the housing. To linearize the characteristic response curve of the transducer the inner surface of the housing wall is shaped like a funnel in a region between the permenent magnet and the Hall-effect sensor and in the vicinity of the permanent magnet. Because of this geometry the field strength lines are bunched increasingly on increasing separation of the permanent magnet from the Hall-effect sensor so that the field strength at the Hall-effect sensor increases and/or decreases approximately linearly with displacement path of the magnet.

Abstract: A medical infusion pump includes a housing (10), a pump assembly (30), a bubble sensor assembly (120), a pressure sensor assembly (140) and a flow control assembly (180). The pump assembly includes a ring (26) with teeth (44) and a wheel (46) mounted for eccentric rotation within the ring. The pumping action is developed by the rotation of the wheel which continuously closes a portion of tubing (36) against one or two teeth as it goes through the pumping cycle. The bubble sensor includes a pair of sensor blocks (124) defining a generally V-shaped trough for cradling a portion of the tubing. The pressure sensor assembly detects pressure variations by movement of a diaphragm (168) coupled to a magnet (162) which is operatively coupled to a Hall effect circuit (160). The flow control assembly includes a thumb wheel (196) having a cam groove (197) interacting with a valve stem (199) for controlling the fluid flow through an orifice and associated valve seat (194).

Abstract: A liquid filled differential pressure detector comprises two pressure sensors. Each sensor is constructed of one or more capsules, which are pairs of diaphragms sealed at their peripheries. The innermost diaphragms are interconnected by a tube which contains a rod assembly. The interior of the sensors and interconnection tube form a sealed volume filled with a incompressible liquid. The rod assembly contacts the outermost diaphragm of the sensors and is displaced by expansion and contraction of the capsules caused by a differential pressure change against the outer surface of the sensors. The motion of the rod assembly is transformed into an electrical signal to indicate the pressure measurement. The apparatus is symmetrical about the center point of the tube to reduce error caused by the fluid's thermal expansion by causing equal and opposite forces to cancel, thereby preventing motion of the rod assembly.

Abstract: A pressure responsive switch including a case having a pressure inlet and an orifice plate, an amorphous diaphragm and a ferrite core arranged in said case, said ferrite core having a pick-up coil housed therein, in which a pressure introduced into the case acts through the orifice plate against a surface of the amorphous diaphragm and a mechanical deformation of said amorphous diaphragm caused by said pressure is detected as a variation of electrical signal by means of the pick-up coil. The characteristic feature resides in that said orifice plate has a larger area at its side facing the ferrite core than at its opposite side facing the pressure inlet.

Abstract: A transducer assembly having a housing provided with an inlet port which is adapted for communication with an exhaust passage of an internal combustion engine. The housing includes at least one pressure chamber to which the inlet port opens and an apparatus for detecting pressure in the chamber. The inlet passage to the chamber being subject to ice blockage when ambient temperatures fall below freezing. As such, an apparatus which extends at least partially through the inlet passage is provided to prevent complete ice blockage of the inlet passage whereby assuring proper performance of the transducer assembly.

Abstract: A fluid pressure transmitter suitable for use in potentially explosive atmospheres of the type comprising a measuring transducer provided with inductive, capacitive or resistive sensor means, the transducer having at least one measuring chamber in which electrical or electronic transducing elements are located, the measuring chamber being defined on one side by a measuring diaphragm and carrying on the other side at least one flameproof joint capable to permit passage of a pressure fluid in a direction towards or away from the measuring diaphragm. In order to ensure, at the same time, the compliance with explosion safety regulations, a sufficient pressure fluid flow rate and a great simplicity in structure and in carrying out the contruction, the flameproof joint or joints consist of one or more peripheral grooves provided at the interface that is defined by a small cylinder when force-fitted in a corresponding recess.

Abstract: A magnetic displacement transducer system for measuring the movement of a member includes an elongated permanent magnet which is mechanically coupled to the member so that the magnet moves parallel to its axis. A magnet-position sensor assembly, which includes at least one magnetometer having an elongated ferromagnetic core with a coil wrapped around it, is positioned adjacent the magnet so that the axis of the core and coil intersects the axis of the magnet at right angles. A pair of wires carry a sinusoidal excitation current to the assembly, convey the second harmonic from the assembly, and deliver a DC biasing current to the assembly in order to null the component of the permanent magnet's field that is perpendicular to the axis of the magnet. The value of the DC biasing current is measured to obtain the displacement of the member.

Abstract: A laminar diaphragm (16) for use in a pressure transducer (10) comprised of two or more layers (50, 52, 54). The pressure boundary membrane (50) free of machining defects is supported by one or more support members (52, 54) having a fluid passage therethrough (56, 58). The support members (52, 54) are hermetically sealed around the periphery of fluid passages (56, 58) to the pressure boundary membrane (50) such that when the laminar diaphragm (16) is sealed in the pressure transducer (10) deflection of the pressure boundary membrane (50) within the regions of fluid passage (56, 58) in support members (50, 52) accurately indicates pressure.

Abstract: A measuring diaphragm (1) separates in a pressure-tight manner two half chambers (9, 10) suitable for being respectively subjected to two pressures to be compared. In a central zone of the diaphragm (1) there are two magnetic cores (118, 127) which are disposed on opposite sides of the diaphragm in respective ones of the half chambers and which are displaced with the diaphragm when the faces of the diaphragm are subjected to different pressures. The cores are movable inside respective simple inductors (132, 133 ), thereby varying their impedances. By measuring this impedance variation it is possible to determine the position of the cores in the associated inductors, and consequently to establish the difference between the pressures being applied to respective faces of the measuring diaphragm (1). The above arrangement provides for automatic zero correction in an inductive differential pressure sensor.

Abstract: A differential pressure sensing device is fully implanted in the body of a patient to monitor internal pressure such as intracranial pressure. A movable element in the sensor communicates with the internal pressure of the body to be measured on one side and the atmospheric pressure on the other, the latter communicated through the intact skin and a nearly coplanar membrane. The movable element's differential pressure dependent displacement changes a physical characteristic of the sensor, such as the resonant frequency of a tuned L-C circuit, and the change is detected external to the body by a radiating detector system, such as a frequency swept radio frequency oscillator, by which the internal pressure is read out.

Abstract: A position and motion transducer is described comprising means for providing a permanent magnetic field adjacent an appropriately oriented toroidal transformer, which can be either an isolation transformer or an autotransformer. The means for providing a permanent magnetic field, in an especially useful embodiment is a permanent magnet cobalt disk magnet with its surface pole facing generally radially in the plane of the torus or generally perpendicular the axis thereof. Appropriate excitation of one winding of the toroidal transformer enables readout equipment connected with the other winding to indicate the position and movement of the magnet relative the toroid. Appropriate mounting of the magnet enables various measurands to be indicated. For example, mounting the magnet on or for movement with a diaphragm enables fluid pressures applied thereto to be measured while mounting the magnet on a spring support force plate or piston/cylinder enables the force or weight applied thereto to be measured.

Abstract: In a double clutch transmission, especially for a motor vehicle, it is necessary for the completely satisfactory shifting sequence to engage and disengage the clutches alternately; in order that such a sequence is assured, differential pressure switches are provided which include a signalling device that indicates end positions of the clutches to an electronic control installation for evaluation purposes.

Abstract: A differential pressure transmitter includes a housing, a first chamber within the housing for receiving an input pressure to be sensed and a second chamber for receiving a transmitter adapted to generate an electrical signal representative of the input pressure. The chambers are separated by a continuously formed, highly resilient diaphragm. A reaction member embodied as a resilient spring is disposed in the second chamber for sensing a position of the diaphragm resulting from the magnitude of the differential pressure thereacross. The reaction member has a magnetized structure mounted thereon which coacts with a Hall effect transducer embodied in the transmitter for detecting the relative position of the magnetized structure and therefore of the diaphragm and responsively generating an electrical signal. The signal may be utilized for positioning actuator controlled dampers within a VAV system duct.

Abstract: An improvement in design of an implantable telemetric differential pressure sensing device enabling thinner, more compact, and simplified construction for the device; increased pressure sensitivity and range of measurement; and a wider class of applications for such pressure sensing devices in diagnostic medicine and clinical monitoring. The implanted device includes a thin, planar, closed, conductive loop which moves with a flexible diaphragm, the diaphragm moving upon changes in the difference of two bodily pressures on its opposite sides. The position of the conductive loop relative to a resonant circuit fixed in the device determines the resonant frequency of the resonant circuit. The resonant frequency is detected telemetrically outside the body, and its value is used to determine the difference in the two bodily pressures.

Abstract: A differential pressure transmitter for process fluids is of the kind having a measuring transducer with a closed cell containing a filling liquid and a measuring diaphragm on both sides of which are arranged resistive, capacitive or inductive elements which are capable of converting a diaphragm deflection induced by differential pressure applied to the cell into electrical quantity changes. Inside the cell is provided at least one pressure sensitive component which is subjected to the pressure (s) of the filling liquid and is capable of providing an electrical output in accordance with the pressure values. This component is preferably a pasted carbon resistor, which permits output processed signal compensations in an electronic processing circuit to be made so as to minimize the effects of static pressure changes.

Abstract: An electronic transmitter for transmitting pressure values of industrial process fluids includes an inductive sensor employing a measuring diaphragm which is movable as a function of the pressure changes in the process fluids so as to produce corresponding changes in inductance and therefore corresponding signals which are suitably processed in an associated electronic circuit. The measuring diaphragm is provided with a rigid center forming or carrying one or more elements of a material exhibiting high magnetic permeability.

Abstract: A pressure or differential pressure detector is hardened to be suitable for use in a hostile environment, for example, under high pressure, temperature, and radiation conditions which could possibly be present in the containment vessel of a nuclear generating plant. A linear variable differential transformer (LVDT) disposed within a detector housing is designed to sustain temperatures up to or exceeding 500.degree. F. A signal detecting and conditioning circuit disposed remote from the detector housing includes demodulator means for producing X and Y demodulated signals respectively from A and B secondary windings of the LVDT, a summing circuit for producing a temperature analog voltage X+Y, a subtractor for providing a differential pressure analog voltage X-Y, and a multiplier for multiplying the differential pressure analog voltage X-Y by a temperature compensation voltage X+Y-Ref based on the temperature analog voltage to provide a resulting temperature-compensated differential pressure analog signal.

Abstract: A pressure receiving element for receiving an external pressure is attached to one end of a body and a temperature compensating diaphragm is attached to the other end of the body. A coupling shaft disposed in the body is fixed at both ends to the pressure receiving element and the diaphragm, respectively. A liquid is sealed in the body and means is provided for detecting displacement or force applied to the coupling shaft in accordance with a pressure received by the pressure receiving element. The diaphragm has corrugations of concentric circles and the crests of a plurality of them are made flat and one of the flat crests is fixed to the body. The effective area of the diaphragm inside of the flat crest that is fixed to the body is selected substantially to be equal to the effective area of the pressure receiving element.

Abstract: A pressure sensitive, toroidal magnetostrictive core wound with primary and secondary coils providing inputs to self-checking circuitry for analyzing operability status and providing redundant pressure measurement options is described. Pressure sensing assemblies are presented which are useful for measuring hydrostatic pressure or concentrated loads.

Abstract: Monitoring and signaling device having at least one tape for indicating a measurement value of a measuring unit and for actuating a signal transmitter, the tape having a section thereof stretched over spatially separated guides and having a travel proportional to the measurement value and a coating effecting actuation of the signal transmitter which is displaceable parallel to the section of the tape extending between the guides, including an indicator for indicating a set nominal-value signaling point, the indicator and the signal transmitter being integrated in a signal head, and two bars extending parallel to the section of the tape and carrying the signal head, the section of the tape being displaceable past the signal transmitter in direct vicinity thereof and between the signal transmitter and the indicator.

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: A pressure-sensing transducer which can be used to continuously measure the pressure in the cylinder of an internal combustion engine comprising a pressure-transmitting element which includes a generally tubular seat and a metallic plate which closes off a top end of the seat, an M-shaped force-transmitting member which spans across the top end of the seat, the outer legs of the M-shaped member being connected to opposite portions of the top end of the seat and the inner legs being connected to the center of the metallic plate, and a magnetoelastic force-sensing member connected between the outer legs of the M-shaped member, such that pressure-generated forces applied to the metallic plate from within the generally tubular seat are transformed into a tensile force acting on the force-sensing member in a direction perpendicular to the longitudinal axis through the generally tubular seat.

Abstract: A pressure responsive control device having a housing carrying a flexible diaphragm therein that cooperates with the housing to define a pressure chamber therein that is adapted to receive a variable pressure that acts against the diaphragm to position the diaphragm relative to the housing in relation to the value of the pressure, the diaphragm being operatively interconnected to a plunger that follows movement of the diaphragm. The control device has a transducer operatively associated with the plunger to produce an electrical signal in relation to the position of the plunger, the transducer comprising a core carried by the plunger in axially aligned relation therewith and an induction coil carried by the control device and receiving the core therein. A range spring is carried by the housing and is operatively interconnected to the diaphragm to tend to oppose movement of the diaphragm in one direction of movement thereof.

Abstract: An improvement in fluid pressure transducers having a housing with oppositely facing magnetic blocks (12,14) that form a sealed chamber (20) in which a magnetically permeable diaphragm (24) is disposed for magnetic coupling with electromagnetic coils (30) mounted within the blocks. The coil is mounted on an elongated plug (34) and covered by a non-magnetic, unitary metal cap (36) that is flexibly sealed between the chamber and the coil. The cap has a generally cup-like inner portion (48) for covering the coil and a flat rim portion (46) that is sealingly (58) secured between the mounting plug and shoulder means (50,60) within the block.

Abstract: There is disclosed a hydrostatic leveling system including a pair of indicator heads connected by a liquid hose for equilizing static pressure in the liquid mercury pools of the indicator heads and a gas hose for equalizing the gas or vapor pressure within the heads above the pools of mercury. Each head is a float connected to the stem of a precision measuring gauge with graduations on the order of ten-thousandths of an inch. The indicator heads have identical structures and thus when they are resting on a level surface they may be reversed in location without change in gauge indicator reading; any difference in the reading is a measure of out-of-level condition. The space for the pool is sealed with a very flexible diaphragm between the float and the wall of the pool cavity. A plunger in the cavity is operated by a solenoid in the cavity to periodically thump the float to reduce tendency to stick due to surface tension, friction and hysteresis.

Abstract: A pick-up for the intake pressure of a combustion engine of the type with a flexible membrane and electrical translation of the displacement of the membrane, including a spring acting against the member, an adjustment mechanism for positioning the spring acting against the membrane, a guiding tube for the spring serving as a stop for the membrane, a closed magnetic casing made of ferrite including nested cylinders pierced by a hole at each end of their axes, a central ferrite magnetic core connected to the membrane and penetrating the closed magnetic casing, an insulating bobbin disposed within the casing, a single winding placed on the insulating bobbin around the core and covering a major portion of the core in its deepest position, the bobbin further including cylindrical ends extending beyond the magnetic casing on opposite sides thereof so as to form an air pocket between the core and the casing and guide the core in the casing, and an oscillating electronic circuit connected to the winding which include