Abstract: Force measuring equipment has a magnetoelastic transducer with an excitation winding supplied with alternating current, which generates a primary flux in a magnetic core of the transducer, and a measuring winding in which a signal voltage is induced, the signal voltage giving a measure of the force applied to the transducer core. The signal voltage is supplied to signal processing members which are arranged to form an output signal by phase-sensitive rectification of the signal voltage. Control members sense when the primary flux passes a positive and a negative reference level, and switch polarity reversing members at the times during each period of the AC supply when the primary flux with a certain sign of its time rate of change passes the positive reference level and with the opposite sign of its time rate of change passes the negative reference level.

Abstract: A tension sensor for sensing tension in the magnetic tape by measuring variations in an inductance value which arise as a result of applying stress which has been transformed from tension in the object to be measured to an amorphous magnetic alloy part of an inductance element. The magnetostrictive effect of the amorphous magnetic alloy which is both resilient and magnetostrictive is utilized in sensing the tension in the tape. The magnetic alloy is used for at least a part of a magnetic core of the inductance element.

Abstract: A torque sensor device for sensing the torque applied to a drive shaft and for producing an electrical signal representative of the applied torque. The sensor includes a non-magnetic drive shaft having a magnetic layer affixed to its outer surface. The magnetic permeability of the magnetic layer changes due to torque applied to the shaft. The permeability of the magnetic layer is detected and converted to an electrical signal representative of the torque applied to the drive shaft. The magnetic layer takes the form of one or more elongated ribbons of magnetic material helically wound about the surface of the drive shaft. Alternatively, the magnetic layer is formed from a plurality of segments of magnetic material affixed to the periphery of the shaft. Magnetically soft amorphous metal material is preferably used to form the magnetic layer.

Abstract: Position sensing mechanism, particularly for photographic apparatus controlled by a digital computer, includes a magnetostrictive position sensing device for supplying information on the positions of movable parts of the apparatus to the computer. The magnetostrictive position sensing device comprises a magnetostrictive element, such as a wire, a first electromagnetic transducer disposed with respect to the magnetostrictive element for transducing an acoustic pulse therein, and a second electromagnetic transducer disposed with respect to the magnetostrictive element for transducing the acoustic pulse, the first and second transducers being constructed for relative movement and a timer for measuring the propagation time of the acoustic pulse between the transducers. The measured time represents the relative position of the transducers along the magnetostrictive element.

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: This disclosure is directed to an acoustic Barkhausen stress detector apparatus and a method of obtaining measurements of stress in or determination of the microstructure of ferromagnetic materials. In the preferred and illustrated embodiment, stress or microstructure information in a ferromagnetic specimen is tested and measured through application of a variable magnetic field. A sensitive acoustic detecting device including an input transducer(s) and amplifier(s) forms a signal based on Barkhausen acoustic phenomena which arise from a change in the magnetic field strength. Barkhausen acoustic information is in the form of vibrations produced within the material which occur as magnetic domain walls shift. The domain wall shifts occur at various locations within the material of interest, and the acoustic vibrations are propagated through the material and are observable at the surface by one or more transducers.

Abstract: A magnetic transducer fits over a rotatable shaft and has a multi-pole magnetic core, one primary winding being wound on half of the poles while a second primary winding is wound on the other half. Direct current pulses are alternately supplied to the two primary windings to provide a-c excitation for producing an alternating magnetic flux or field, adjacent to and within the shaft, which changes 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 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 two primary windings.

Abstract: A magnetostrictive device comprises a magnetostrictive component consisting essentially of an amorphous alloy of iron, boron, lanthanum and lanthanide.

Abstract: A force measuring magnetoelastic transducer includes a core of magnetostrictive material with apertures, in which excitation and measuring windings are arranged, and between which a measuring zone is formed, in which the dominating part of the magnetomotive force is consumed and in which the stress therefore determines the output signal of the transducer. The core further includes apertures for controlling the force flux, which are so arranged that some measuring zone portions are substantially subjected to compressive stress and other measuring zone portions are substantially subjected to tensile stress when a force is acting on the transducer. Means are provided for exciting the transducer with an alternating current of such magnitude that the signals generated by said compressive and tensile stresses, within a predetermined range of load, show deviations from linearity with negative sign for compressive stress and positive sign for tensile stress.

Abstract: A printer comprising a carriage which is displaceable along a record carrier and on which a printing head is arranged to be slidable independently of the carriage. The carriage is provided with a sensor for controlling the distance between the printing head and the record carrier.

Abstract: A sensor for engine vibrations at a predetermined frequency characteristic of detonation comprises a housing adapted at one axial end for attachment to an internal combustion engine, a magnetostrictive element axially compressed in said housing with a source of permanent magnetic flux and a pickup coil on a spool around the magnetostrictive element. The spool engages the magnetostrictive element in a force fit characterized by a predetermined push-out force. The sensor housing comprises a first resonant assembly having a first resonant frequency slightly higher than the predetermined frequency. The spool and coil are coupled to the magnetostrictive element by the force fit to comprise a second resonant assembly having a second resonant frequency slightly lower than the predetermined frequency. The overall output characteristic of the sensor thus has a single resonant peak at substantially the predetermined frequency.

Abstract: A method for measuring stresses or forces by measurement of variations of the magnetic properties of ferromagnetic substances under stress conditions. This is carried out by providing a ring of ferromagnetic material between two parallel faces on or between which the stresses are exerted, the ring defining a magnetic circuit, providing an electric coil within and around the ring, passing a current through the coil and measuring changes in the properties of the current to measure variations in the magnetic properties of the ring.

Abstract: A torque transducer for measuring the torque in the outgoing crankshaft of automobile engines comprises two two-pole magnetic cores, arranged perpendicular to each other, with coils around the poles. The coils of one core are adapted to be supplied with alternating current for generation of an alternating field in the surface of the shaft. The second core with its coils is adapted to sense the changes in the alternating field which are caused by the torque of the engine. The poles of the primary core are located opposite to diametrically opposed points on the crankshaft.

Abstract: A system for indicating torque and/or speed of a rotatable shaft includes a transducer positioned adjacent the shaft. The transducer has two primary windings wound in a bifilar arrangement on the same magnetic core structure. The primary windings are connected in a manner to facilitate driving of the transducer primary windings with a simple switching circuit.

Abstract: A transducer is provided for fitting over a rotating shaft to produce a magnetic field about the adjacent area of the shaft when the transducer is energized with an a-c voltage. The transducer includes secondary coils which provide an output signal that varies as a function of stresses developed by the loading of the rotating shaft. The transducer output signals are received by a signal processor which in turn provides output signals for indicating the torque, and/or speed of the shaft. In addition the sense of the torque and speed signals can be shown, and the torque and speed signals can be combined to indicate horsepower.

Abstract: A transducer for magneto-elastic stress measurement is formed of a holder and a core of magneto-elastic material provided with coils to generate a flux in and sense flux alterations produced by stresses of the core. The core is formed of one or more plates firmly attached to the holder and designed to be attached to the measuring object. The core may consist of a single plate attached to the holder at four symmetrical points, or of a cross having four arms the ends of which are welded to a frame of magnetic material which is secured to the holder. The holder may also be in the form of a casing of magnetic material which protects the core and coils and serves as a magnetic return path for the fluxes. For applications where disturbing magnetic fields may occur in the measuring object, the casing is preferably made of non-magnetic material and provided with a frame of magnetic material as a return path for the flux.

Abstract: In ordr to measure deformations of magnetic material which is being cold-rolled a plurality of magnetoelastic stress-sensing transducers are used, each of which has two U-shaped magnetic cores provided with windings and crossing each other perpendicularly. The cores are mounted with their pole surfaces spaced from the strip being rolled and with the cores making an angle of 45.degree. with the longitudinal direction of the strip. The individual transducers are screened from each other by a screen of magnetic material positioned axially symmetrically around each transducer, so as to prevent adjacent transducers from magnetically affecting each other except through the field in the measuring object and the leakage field in the air gap between the measuring device and the object. The transducers are mutually displaceably arranged along a line crosswise of the strip. Between the transducers and the measuring object there is a protective plate of non-magnetic material with very high resistivity.

Abstract: An apparatus and method for measuring stresses or forces by measurement of variations of the magnetic properties of ferromagnetic substances under stress conditions. This is carried out by providing a ring of ferromagnetic material between two parallel faces on or between which the stresses are exerted, the ring defining a magnetic circuit, providing an electric coil within and around the ring, passing a current through the coil and measuring changes in the properties of the current to measure variations in the magnetic properties of the ring.

Abstract: A magnetostrictive mechanical, variable frequency stress transducer is disclosed in which the frequency of the output signal is proportional to the applied stress. This device consists of a magnetic stress actuating member, to which the stress is applied, and a transistor-magnetic oscillator constructed so the stress sensitive magnetic characteristic of the stress actuating member is the principal frequency determining element of the oscillator.

Abstract: A transducer including four pins arranged at the corners of a square and provided with exciting and sensing windings are fixed either to the surface of a body of magnetic material to measure stresses therein or to a plate of magnetic material fixed to the body where the body is of non-magnetic material or has undesirable magnetic characteristics.

Abstract: In measuring mechanical stresses in an object of hardened and tempered steel with a magnetic transducer of the type which comprises a magnetizing circuit for generating a magnetic field in the object and a measuring circuit for sensing the changes in the magnetic field which occur in the object when it is subjected to mechanical forces, in order to reduce the creep of the measuring signal which occurs in the case of continuous feeding, the magnetizing circuit is energize with energy in the form of AC pulses of a pulse length between 20 and 120 milliseconds.

Abstract: An electronic differential-pressure transmitter responsive to a difference between two pressure values to generate an output signal proportional to differential pressure for transmission to a remote station for acuating indicator or process control equipment. The transmitter is of the open-loop type that includes a pivoted force-beam to the lower end of which is applied an input force dependent on differential pressure, the resultant deflection of the beam being sensed by a motion detector coupled to the upper end thereof to produce the output signal.

Abstract: This invention relates to the measurement of the driving force used for pile driving and, more specifically, to the use of coils for sensing magnetostrictive effects within the pile which develop when the pile is struck or driven into the ground.