Abstract: A magnetostrictive stress and torque sensor using the component of the output signal in-phase with the drive voltage to monitor stress or torque. In some embodiments, it may use the quadrature or out-of-phase component, or some combination of the in-phase and out-of-phase components. Such phase component monitoring has several advantages over magnitude detection, including a response which is a more linear function of torque, and which is not subject to overmodulation problems.

Abstract: A method and apparatus detects degradation in performance of an engine by comparing signals such as those obtained from magnetostrictive sensors which are related to, but not necessarily accurately correlated with, stress/strain states of a torque/load transmitting member. A first signal is obtained relating to the stress in the member produced by a first loading event or series of events, typically from the firings of a cylinder in an internal combustion engine. A second signal is obtained which relates to the stress in the member produced by a second loading event or series of events from the same or other cylinder in which the torque/load was intentionally inhibited. The first and second signals are then compared to detect degradation in output of the engine.

Abstract: A magnetochemical sensor for continuous and in-situ sensing of a given chemical species/stimuli includes two magnetically-soft magnetic film layers and a chemical transduction layer that shrinks or swells in the presence of that given chemical species/stimuli. The magnetic switching characteristics of the sensor are dependent upon the thickness of the chemical transduction layer. A method for remotely interrogating the magnetic switching characteristics of the sensor is also provided. In the method, magnetic flux detecting coils are utilized to monitor the sensor.

Abstract: A method for non-invasively monitoring a pressure of a compressed gas inside a closed container includes: forming a magnetic circuit through a portion of the outside wall of the container; detecting magnetic flux amplitude changes in the magnetic circuit created by a transient stress in the outside wall of the container; producing data representing the magnetic flux amplitude changes; and monitoring pressure changes from a nominal pressure by evaluating the data representing the magnetic flux amplitude changes.

Abstract: A solid state triode employs the Hall effect to asymmetrically proportion flow of current through different branches of a number of cascaded bifurcated N- charge carrier channels (10,18,20), thereby providing an indication of strength and direction of an applied magnetic field by measuring magnitude and sense of the difference between currents flowing in the two channel branches (14,16,24,26,30,32). The solid state triode is formed on an silicon-on-insulator (SOI) substrate (47,48,49) in which an N+ source region (54) and at least two end N+ drain regions (56,58) are interconnected by an N- charge carrier channel (60) that is defined by a plurality of P+ regions (64a,64b,64c,64d) in a thin single crystal silicon substrate (49) between the source and drain regions (54,56,58). A polysilicon gate (52) overlies the N- channel and acts as a self-aligning mask during manufacture of the triode to precisely align the N+ and P+ doping to the polysilicon gate configuration.

Abstract: A magnetostrictive force sensor in which magnetically conductive support members are interposed between magnetically conductive end plates. The support members have magnetic properties which vary in accordance with the compressive or tensile load applied to them. The support members and end plates magnetically cooperate to create a magnetic circuit in which magnetic flux is induced by applying an alternating-current signal to a coil wound around one of the support members or by placing a permanent magnet into the magnetic circuit. When a load is applied to the magnetically conductive end plates, the magnetic properties of the support members vary to cause a change in the flux established in the magnetic circuit. The flux is detected by a second coil wound around the second support member, and the output signal detected by the detection coil is decoded to determine the load applied to the force sensor.

Abstract: A method of measuring strain in material by(1) selecting a metallic glass ribbon of the compositionFe.sub.w B.sub.x Si.sub.y C.sub.zwherein0.70.ltoreq.w.ltoreq.0.83,0.10.ltoreq.x.ltoreq.0.20,0.03.ltoreq.y.ltoreq.0.10,0.ltoreq.z.ltoreq.0.03, andw+x+y+z=1.00wherein the metallic glass ribbon is essentially strain free and has easy xes of magnetization which are in the plane of the ribbon transverse (at 90.degree.) to the long axis of the ribbon;(2) bonding the metallic glass ribbon to material to be measured by means of a homogeneous viscous organic liquid having a viscosity greater than 10.sup.5 cp at 25.degree. C.;(3) allowing the viscous liquid to relax until the metallic glass ribbon is not stressed by the viscous liquid and is in a state of constant strain within it magnetostrictive dynamic range; and(4) measuring the susceptibility of the metallic glass ribbon which is directly proportional to strain within the material being measured.

Abstract: The apparatus of the invention is a water level probe comprised of a probe body, a sleeve having openings permitting fluid flow and encasing part of a magnetostrictive sensor, and an external housing encasing electronic circuitry for processing and transmitting the electric signal generated by the magnetostrictive sensor and sealing the circuitry from fluids. The sensor comprises a float slidably mounted on a rod, the float designed to float in water but sink in a petroleum product, thereby ensuring that it will float at the interface between the water and the product. The water level probe is used in the method of the invention to measure the depth of the water in a vessel storing hydrocarbon product at predetermined time intervals. The longitudinal angle of inclination of the vessel with respect of the horizon having previously been determined, the volume of water in the vessel is calculated from the depth measurements.

Abstract: The invention relates to a sensor system for measuring e.g. the preloads in screws, bolts or similar. It comprises sensor means (2) comprising a magnetoelastic material (6) sensitive to the preloads to which the object is exposed and a sensing device (3) comprising a contact portion (4) and gripping portion (5). The contact portion is so arranged that it at least partly surrounds the sensor means (2) and the magnetoelastic material (6) is excited with an excitation frequency of at least 300 kHz.

Abstract: A magnetostriction type torque sensor has a magnetostrictive film formed on an outer peripheral surface of a rotary shaft, a coil having a coil centerline extending in a radial direction of the rotary shaft, and a signal processor responsive to coil impedance. Since the coil includes a coil centerline extending in a radial direction of the rotary shaft, magnetic fluxes are formed mainly in a radial direction of the rotary shaft. Accordingly, the magnetic fluxes intruding deep into the rotary shaft are decreased, and the rate of the magnetic fluxes passing through the magnetostrictive film is increased. As a result, the magnetostriction type torque sensor comes to have high sensitivity even when the rotary shaft has high magnetic permeability or high electric conductivity.

Abstract: A pressure sensor in which a magnetostriction effect of an amorphous magnetic alloy is utilized. It is an object of the invention to suppress the thermal sensitivity change of the pressure sensor and to improve the lineality and the hysteresis of sensor output. The pressure sensor comprises a cylindrical columnar hollow body with a pressure introducing opening, a deforming part of which body is distorted by a pressure introduced from the pressure introducing opening, the deforming part being a peripheral wall of the body, and a thin film made of an amorphous magnetic alloy having a magnetostriction property which is fitted around and bonded to the deforming part, wherein the film, which is curved to have a cylindrical shape and annealed before it is provided around the cylindrical columnar deforming part, has a curvature different from a curvature of the cylindrical columnar deforming part.

Abstract: A multicomponent acceleration sensor in which the inertial force of a seismic mass effects a variation in an electromagnetic quantity of a plurality of individual transducers. During acceleration, the seismic mass acts in each individual transducer a magnetoelastic measuring layer, the permeability .mu..sub.r of which influences the inductance of a sensor coil. For each spacial direction in which the acceleration is to be determined, a pair of transducers is mounted on a base member coaxially to, and axially spaced from, each other in such a way that an acceleration of the acceleration sensor perpendicular to the axial direction of the sensor coils of the two individual transducers causes an equidirectional variation in inductances of the sensor coils of the two individual transducers, and a signal representing the acceleration status is obtained in at least one evaluation electronics form the inductances of the sensor coils.

Abstract: Disclosed are a method and apparatus for comparing torsional stress/strain states of a power transmitting member of an internal combustion engine to detect an abnormal combustion condition, including misfire, knock or roughness. Statistical processing steps may be used to detect an abnormal combustion event including: calculating a mean and standard deviation for a set of signals related to the torsional stress induced in the power transmitting member, calculating a difference between a later signal and the mean, calculating a ratio of the difference to the standard deviation, and comparing the ratio to a threshold. The ratio so obtained from a given cylinder may further be compared with one or more other such ratios from other cylinders. A magnetostrictive sensor may preferably be used to obtain the signals relating to the torsional stress in the power transmitting member, such as the engine crankshaft.

Abstract: A fire fighting trainer for use in training fire fighters is provided. The fire fighting trainer includes a structure having one or more chambers having concrete or grating floors. Each chamber contains one or a series of real or simulated items such as furniture and fixtures and equipment. The trainer has a smoke generating system with an outlet for each chamber. The trainer also includes a propane gas flame generating system. The trainer has a main control panel for regulating the flame generating system and the smoke generating system and for controlling the fire, or fires, and smoke in each chamber. The trainer also has a sensor assembly in each chamber, which senses water.

Abstract: A pressure sensor has a recess formed in outer surfaces of a deforming part and a non-deforming part such that a pair of steps are formed at opposite ends of the recess. The deforming part is strained by a pressure whereas the non-deforming part is not strained by the pressure. An amorphous magnetic alloy film is received in and affixed relative to the recess, and extends between the pair of steps. The depth of the recess is larger than the thickness of the film. A pair of permeability detector elements are mounted respectively on the deforming part and the non-deforming part so as to detect a change in permeability of the film.

Abstract: A noncontacting method for sensing stress and torque based on the principle of magnetostriction comprises inducing a magnetic flux in a shaft (20) via such means as a single core/coil(58/60) placed close to the shaft (20) which detects torque by means of voltage or current changes in the coil (60). Another embodiment comprises two single core/coils (58/60 and 59/61) and signal processing circuitry which produces a signal minimally affected by material property inhomogeneities. An additional embodiment employs a plurality of sensors (66A/66B) strategically located around the shaft (20) to eliminate spurious signals which are due to bending stress and shaft misalignment.

Abstract: A magnetic sight gage sensor comprises a sensor for determining the liquid level in a process vessel utilizing a magnetic float on the interior of a tube. The tube is connected at different levels to a process vessel and contains a liquid that is maintained at the same level as the liquid inside the process vessel. A magnetostrictive displacement transducer is coupled to the tube or sight glass on the exterior of such glass, so it is out of the process fluid. The transducer provides signals indicating the position of the float relative to a reference position on the transducer. The tube or sight glass is made of a non-magnetic material in order to allow transmission of the magnetic field from the float to the transducer.

Abstract: The invention relates to a device for non-contact measuring of stresses including bending stresses in a bar-shaped body (1), e.g. a cylindrical bar, shaft or the like. In at least one transverse zone (2, 3) the bar (1) is provided with a number of thin strips (4) of an amorphous magnetoelastic material, distributed along the circumference of the zone, said strips (4) being affixed to the circumferential surface of the zone and extending at a pitch angle therealong, a preferably at a pitch angle of 45.degree.. Means (5) are provided for generating a magnetic field over said zone (2, 3) and a pick up coil (6-13) encircling the bar is provided for each zone (2, 3), said pick up coil being connected to a measuring unit (16, 16A) for indicating signals generated in the coil.

Abstract: A torque detecting device has a measuring shaft, an excitation device and a detector for detecting a magnetostriction passing through said measuring shaft. The device is able to measure the torque with accuracy even if a temperature gradient is produced in the axial direction of the measuring shaft by making the measuring shaft from a material having specified electromagnetic characteristics at least in a part in which said magnetostrictive force is detected.

Abstract: A magneto-strictive torque sensor for electrically contactlessly detecting a torque applied to a rotary shaft on the basis of a resulting change in the magnetic permeability of the surface of the shaft. Fine dents and retainer areas for retaining residual compressive stress due to the fine dents are formed on the surface of the rotary shaft. According to this arrangement, the process of magnetization resulting from the application of an exciting magnetic field and of the torque to the rotary shaft involves less magnetization due to magnetic domain wall displacement and consists principally of reversible magnetic rotation, with the result of reduced hysteresis in the magnetization process. The reduced hysteresis causes less hysteresis involved in torque detection and higher detection sensitivity, thus resulting in high accuracy of torque detection.

Abstract: A strain gage includes a pair of coils printed on one face of a substrate and an amorphous magnetic metallic plate arranged on the other face of said substrate and having magnetostrictive effect. Magnetic flux generated by one of the paired coils passes through the amorphous magnetic metallic plate and links with the other of the coils. When load is added to an object and strain of the object is caused by the load added, therefore, the magnetic permeability of the amorphous magnetic metallic plate is changed, due to the magnetostrictive effect, in response to the load added. The density of the magnetic flux passing through the magnetic metallic plate is also changed responsive to this changing magnetic permeability and composite inductance of the paired coils is then changed responsive to the changing density of the magnetic flux.

Abstract: An apparatus is provided for sensing torque applied to a shaft. In the field on contactless torque sensing, magnetic flux is induced into magnetostrictive material on a shaft whose torque is to be measured. The magnetic permeability of the magnetostrictive material changes in response to torque. The change in magnetic permeability alters the magnetic flux in the magnetostrictive material, and can be sensed by non-contacting inductive coils in close proximity to the magnetostrictive material. However, the amount of flux penetration into the shaft effects the sensed magnetic flux, and thus effects the accuracy of the torque measurement. As a solution, a magnetostrictive material sheet is bonded to a nonferromagnetic sheet which is bonded to a shaft. The nonferromagnetic sheet limits the amount of flux penetration into the shaft to produce better torque measurements.

Abstract: A magnetoelastic force transducer which is compensated for sensitivity drift is provided with a measuring transducer and a reference transducer (1) of the same material. In its simplest form the reference transducer may consist of a toroid. The two transducers are arranged in good thermal contact with one another. The reference transducer is arranged with a winding (2) for excitation with a current which at each moment is proportional to the supply current of the measuring transducer, and with a winding (3) for delivering a reference signal (U.sub.r) proportional to its magnetic flux. The output signal of the reference transducer is rectified in a phase-sensitive rectifier, the output signal of which is compared with a constant reference voltage. The deviation controls the phase position of the control voltage of the rectifier in such a way that the output signal of the rectifier is caused to correspond to the reference voltage.

Abstract: A mechanical quantity sensor element making use of stress-magneto effect of noncrystalline magnetic alloy. Compression strain is preliminarily given to a thin belt made of noncrystalline magnetic alloy by carrying out treatment of applying an external force onto a surface of the thin belt. Suitable methods for applying the external force include; surface grinding by means of abrasive cloth or paper, shot-peening in which spherical fine grains are impinged onto a surface of a thin belt, stroking work in which a surface of a thin belt is scrubbed by means of a scrubber piece made of synthetic resin, rubber or other material, and the like.

Abstract: A method is provided for use with non-contacting torque sensors. Many torque sensors use a sheet of magnetostrictive material wrapped about the shaft whose torque is to be measured. The methods used to wrap and affix the sheet of magnetostrictive material induce a prestress into the sheet, which leads to early saturation of the magnetostrictive material. The prestress diminishes the useful range of the torque sensor. As a solution, a method is provided for bonding a magnetostrictive material sheet to a shaft while minimizing stress of the magnetostrictive sheet. By bending a magnetostrictive material sheet and a carrier sheet about the mandrel and bonding the sheets together at a first preselected temperature, cooling them to form a cylinder having a magnetostrictive material outer layer and a carrier inner layer, and bonding the cylinder to a shaft at a second predetermined temperature, the stresses induced in the magnetostrictive sheet are minimized.

Abstract: A magnetoelastic force transducer comprising two identical, cylindrical bodies defining a hollow magnetic core and held together by means of a force-transmitting stud bolt has its measuring and excitation windings located in the core. The interior of the core is constructed such that a thin cylindrical tubular wall is formed opposite to a respective measuring winding in each one of the bodies, whereby when the core is force-loaded via the stud bolt a compressive stress arises in one of these tubular walls and a tensile stress arises in the other. To eliminate a possible measurement signal at zero applied force a magnetically asymmetric center pole in the form of a punched disk of a soft-magnetic material and having the same diameter as the core and having a foil of a similar material secured on one side is located between the bodies. The hickness of the foil determines the magnitude of the signal adjustment.

Abstract: A torque sensor comprising a magnetic member whose magnetostrictive characteristics vary with the amount of torque applied thereto and coils for detecting magnetostrictive variation disposed opposite the magnetic member, and a method of manufacturing the same. The torque sensor is constituted as an independent unit separate from the shaft whose torque is to be measured. The independent unit consists of a cylindrical member having the magnetic member attached thereto and an enclosure member which is provided with the coils and is mounted so as to cover the cylindrical member and be rotatable about the same axis as the cylindrical member.

Abstract: The long-term measurement stability of a magnetostrictive effect strain or stress sensor that uses an amorphous magnetic alloy excited by a magnetic field is improved by generating a magnetic field from an electric current formed from a superposed alternating current waveform and a recurring rectangular current waveform that has a larger amplitude at its start-up and which converges to a smaller amplitude after a predetermined time period or an electric current formed from a superposed direct current component and an alternating current component having constant amplitude and a frequency that varies in a recurring manner between a high frequency and a lower frequency.

Abstract: A device for the contactless indirect electrical measurement of the torque at a shaft utilizing the Matteucci effect in which the shaft is located in an induced magnetic direct-axis field. Upon torsion of the shaft, the change in magnetization in the shaft itself is not measured, but rather a measuring layer applied to the shaft is metrologically detected by the device. In order to avoid disturbing influences from the basic magnetization of the shaft on the measuring layer, a further layer is applied to the shaft, which short-circuits the magnetic flux resulting from the basic magnetization of the shaft, the measuring layer being magnetically decoupled from the inner layer by a highly nonmagnetic layer between the inner, further layer and the measuring layer.

Abstract: A torque measuring apparatus including a magnetic detection device for non-contact measuring strains in a rotating shaft of ferromagnetic material which is adapted to transmit torques, the detected strains being used to determine the levels of transmitted torques, the magnetic detection device including an exciting coil device wound around the outer periphery of the rotating shaft and adapted to magnetize the rotating shaft in its axial direction; a detecting core ring device in the form of an integral unit which includes a plurality of detecting cores arranged around the circumferential area of the rotating shaft to be magnetized equidistantly to form a ring, each of the detecting cores forming an independent magnetic circuit between the detecting core and the rotating shaft; and at least one magnetic detecting element for detecting a variable magnetic flux in each of the detecting cores depending on the level of the transmitted torque; whereby the strains in the rotating shaft can be non-contact measured ba

Abstract: A stress-sensitive sensor comprising a means for generating magnetic flux, a thin sheet of an amorphous magnetic alloy which is located in the magnetic flux and which is physically deformed in response to an external force to be measured, and a means for detecting the physical deformation as a variation of the magnetic flux which depends on the external force. The amorphous magnetic alloy consists essentially of Fe.sub.a Cr.sub.b Si.sub.c B.sub.d, in which a is a value of from 69 to 81.5 atomic percent, b is a value of from 2.5 to 6 atomic percent, c is a value of from 10 to 15 atomic percent, and d is a value from 6 to 10 atomic percent provided that a+b+c+d=100. The sensor is particularly suitable for oil pressure or torque detection.

Abstract: A mechanical quantity sensor element making use of a stress-magneto effect of noncrystalline magnetic alloy. This mechanical quantity sensor element is manufactured by coupling a piece of noncrystalline magnetic alloy having positive magnetostriction with another material such as, for example, thermo-setting resin at a temperature exceeding an operating temperature range of the mechanical quantity sensor element, and then cooling them to the operating temperature range. Due to a difference in a coefficient of thermal expansion between the piece and the material, compression strain is preliminarily given to the noncrystalline magnetic alloy piece, and the mechanical quantity sensor element has an excellent linearity and a wide detectable range for mechanical quantities.

Abstract: A torque sensor includes a cylindrical body disposed concentrically around a shaft and having its opposite ends secured to the surface of the shaft through elastic bodies, a layer of soft magnetic alloy having a magnetostriction property and secured to the surface of the cylindrical body, and a coil disposed concentrically around the layer with an air gap between it and the layer. The torque sensor is constructed such that a strain produced on the surface of the cylindrical body by a torque is converted into a change of a relative permeability of the soft magnetic alloy due to a reverse magnetostriction effect which is detected as a change of inductance of the coil. When the shaft thermally expands or deflects, the elastic bodies act to permit only a torque to be transmitted to the cylindrical body, so that a uniform output is provided without the influence of a thermal strain and deflection of the shaft.

Abstract: A lamination type of magnetostrictor incorporated with a mass of plural plates of amorphous metal alloy material laminated by means of a binder wherein the thickness of the plates is equal to or more than 80 .mu.m and the space factor of amorphous metal alloy in the mass is equal to or more than 80% and a manufacturing method thereof.

Abstract: An acoustic transducer for providing large displacements particularly at low acoustic frequencies is formed from a minimum of three curved shells which are attached to each other at their ends. The shells are driven by a ring or corresponding number of attached piezoelectric or magnetostrictive type rod or bar drivers which take the form of a regular polygon. The curved shells are attached to the ends of the driver and vibrate with magnified motion as the rods execute extensional motion. As the polygon expands the curved shells deform and produce additional motional in the same radial direction resulting in a large total displacement and corresponding large acoustic output.

Abstract: A method and device for measuring combustion knocking in the combustion chamber of an externally-ignited internal combustion engine, the device comprising a magnetostrictive element with a maximum diameter of 2 mm and a length-to-diameter ratio of greater than 100, the device being mounted in the engine so as to be exposed to the combustion chamber. The device can include a coil to which the magnetostrictive element is connected for converting changes in magnetic conductability in the magnetostrictive element, due to pressure increases in the combustion chamber to which it is exposed, into electrical signals. The coil in turn can be connected to an electronic switching system for the engine.

Abstract: A torque sensor for electrically detecting torque, such as the torque of an automobile engine, wherein a strain disk is provided in the path of torque transmission and the torque is magnetically detected in terms of the magnetostriction generated in the strain disk. The torque sensor comprises a magnetic rotating disk and a magnetic sensor disposed in the vicinity of and opposed to the strain disk. The magnetic sensor comprises a detection coil and an excitation coil oriented perpendicularly to each other with the excitation coil ordinarily being disposed outside of the detection coil. Supplying alternating current to the excitation coil causes an alternating field to be produced within the strain disk and the configuration of this alternating magnetic field is varied by the anisotropy of the strain caused within the strain disk by the transmitted torque.

Abstract: A fluid pressure sensor includes a body made of a soft magnetic material with a groove formed therein, and a coil is installed in the body in the groove. One magnetostrictive disc is placed on the body over the groove, and two non-magnetic discs are placed over the magnetostrictive disc. A casing is provided for accommodating the body carrying the coil, the magnetostrictive disc, and the non-magnetic discs, and it is closed by a lid member which has a surface for receiving a fluid pressure. A plurality of through holes are formed in the lid member within the fluid pressure receiving surface such that the through holes extend to the non-magnetic disc at position over the groove, whereby the magnetostrictive plate is partially distorted by the fluid pressure.

Abstract: In a method for testing steam turbine rotors for embrittlement to determine which rotors to retire and which rotors to continue in operation, a varying magnetic field is applied to the rotor in a waveform to produce a detectable Barkhausen effect in the flux density developed in the rotor. The resulting Barkhausen burst of pulses is detected and is displayed on an oscilloscope. In addition, the pulse amplitude distribution of the pulses in the burst is plotted. The oscilloscope display and the pulse height distribution curve are compared with corresponding representations of the Barkhausen effect produced from a test sample known not to be embrittled, or from the rotor itself at a previous time, to make a determination of whether the rotor has become embrittled and whether to continue operation of the rotor.

Abstract: A magnetic amplifier employing a single four-legged ferrite core having orthogonally disposed through holes in the core. Biasing is provided of the magnetic core so as to provide operation in the non-linear parts of the core's hysteresis cycle. A first coil on the ferromagnetic core has an AC excitation signal applied thereto and a second coil on the core is wound orthogonally to the first coil and is adapted to have an output signal derived therefrom. A control or input current in a third coil is used to unbalance the magnetic bridge formed by the four legs, so as to produce a mutual inductance different from zero between the first and second coil. The biasing may be provided by a fourth coil or by permanent magnet means.

Abstract: A stress or strain sensor including a magnetic circuit having at least a part constituted by an amorphous magnetic alloy. For detection of the inductance value of the sensor, a DC magnetic field is superposed on an AC magnetic field so that magnetic domains of the alloy tend to be aligned. The sensor output can be increased significantly over that of the conventional sensor in which only the AC magnetic field is employed, while hysteresis of the output is reduced. The temperature characteristic is also improved.

Abstract: A nonintrusive, or noncontact, shaft torquemeter for use in measuring torque transmission through a rotatable shaft. The torquemeter includes an annular torque-sensing coil structure having an annular excitation coil and a pickup coil magnetically coupled to the excitation coil through an improved magnetostrictive coupling structure carried by the shaft. In the illustrated embodiment, the magnetostrictive coupling portion is provided on a tube coaxially fixed at its ends to the shaft. The invention comprehends the provision of structure for preventing a continuous annular conductive path through the coupling portion or tube. Other structure for improving torque measuring accuracy may be provided, including the use of an outer magnetic stator core, and the provision of annular corrugations in the tube for preventing transmission of nontorque forces, such as bending forces, to the coupling portion.

Abstract: A torque gauge using magnetoelastic ribbons is presented wherein changes in the magnetic characteristics of these ribbons are detectable in a push-pull mode for determining torque forces applied to the ribbons. Respective tensile and compressive forces applied to the ribbons cause a change in the magnetic qualities of the ribbons and of the inductance of coils wound about the ribbons with the change of inductance being a measure of the torque forces applied to the input of the device.

Abstract: A torque sensor for detecting variation in the drive torque of an automobile comprises an excitation coil wound on an excitation core and a detection coil wound on a detection core. The coils and cores are inserted into a chamber formed within a bearing for supporting a drive shaft and having an opening along the sliding surface of the bearing. The poles of the excitation core and the poles of the detection core are respectively disposed at prescribed clearances from the surface of the drive shaft in such manner that the poles of the detection core intersect the excitation core between its poles, whereby variation in drive torque is detected as magnetostriction.

Abstract: A noncontact torque sensor for measuring torsional loading of a shaft the magnetic permeability of which changes in response to changes in torsion loading of the shaft. The sensor includes an excitation coil for generating a magnetic field passing through the shaft, and sensing coils for detecting changes in the magnetic field caused by changes in the permeability of the shaft. At least one pole is disposed adjacent the shaft, separated by an air gap, for coupling magnetic flux into or out of the shaft. The shaft has a radially extending surface adjacent to which the pole is disposed, and the air gap is represented by the axial spacing between the pole and the radially extending surface. The air gap is thus axial, and does not vary with radial movements of the shaft. In some of the embodiments described, plural poles are arranged symmetrically around the shaft such that other translational movements of the shaft produce offsetting changes in the sizes of various pole air gaps.

Abstract: A force/flash pressure sensor utilizes a stack of annular rings of a magnetoelastic material. One major stack surface is supported at a plurality of points having substantially equal angular displacement therebetween. A member, moving along the axis of the ring stack responsive to an axial force, or pressure, to be measured, presses a different set of points against the opposite stack surface, to distort the ring stack and alter the magnetic flux density saturation magnitude thereof. The plurality of points in abutment with each of the opposite major stack surfaces is advantageously equal; a number of different configurations for applying force (pressure) along the axis of the ring stack are described.

Abstract: A magnetoelastic force transducer with temperature-compensated sensitivity is produced by equally exciting a measuring transducer and a reference transducer having cores of the same material and the same design and in good thermal contact. A spring loads the core of the reference transducer with a constant force. The output signal of the reference transducer is rectified in a phase-sensitive rectifier, the output signal of which is compared with a constant reference voltage. The difference signal resulting from this comparison controls the phase position of the control voltage of the rectifier in such a way that the output signal of the rectifier is brought into agreement with the reference voltage. The output signal of the measuring transducer is also rectified in a phase-sensitive rectifier, which is controlled by said control voltage and the output signal of which constitutes the temperature-compensated measured signal.

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: A magnetic transducer fits over and encompasses a rotatable shaft and has a primary or excitation magnetic assembly having a winding arrangement that is energized to provide a-c excitation for producing an alternating magnetic flux or field, adjacent to and within the shaft, which is modified as the shaft is torsionally stressed when torque is applied thereto. This stressing causes compression and tension in the shaft which alter the shaft permeability and thus vary the magnetic flux pattern in the shaft. The resulting or modified magnetic field is also a function of the shaft speed due to the shaft's armature reaction, eddy currents being generated in the shaft which develop a counter magnetic field that opposes and distorts the field produced by the primary winding arrangement. A pair of secondary or pick-up magnetic assemblies, having secondary windings, respond to the modified magnetic field and provide information signals relative to the torque and speed characteristics of the rotating shaft.

Abstract: A magnetoelastic transducer comprises a plurality of sheets assembled together into a sheet package, the sheet package being provided in known manner with at least one excitation winding and at least one measuring winding. The sheet package comprises first sheets of non-magnetic material of austenitic steel, interleaved with second sheets of compound type, each of the sheets of compound type comprising an inner core layer of magnetic material, for example silicon steel, metallically connected on each of its sides to a respective outer layer of non-magnetic material of austenitic steel.