Abstract: A torque sensor comprises a magnetoelastically active element, and a magnetic sensor, such as a Hall effect sensor, responsive to the field of the magnetoelastically active portion. In one embodiment, the magnetoelastically active portion comprises a ring of material endowed with an effective uniaxial magnetic anisotropy such that the circumferential direction is the easy axis, and magnetically polarized in a substantially circumferential direction. The ring is attached to the torqued member, such as a rotating shaft, so that application of a torque to the shaft is transmitted to therting. The torque on the ring reorients the circumferential magnetic orientation of the ring, producing a helical magnetic orientation having both circumferential and axial components. A magnetic field vector sensor is mounted in a fixed position relative to the ring and oriented so that it responds maximally only to the field due to the axial magnetization components of the ring.

Abstract: A torque sensor comprises a magnetoelastically active element, and a magnetic sensor, such as a Hall effect sensor, responsive to the field of the magnetoelastically active portion. In the preferred embodiment, the magnetoelastically active portion comprises a ring of material endowed with an effective uniaxial magnetic anisotropy such that the circumferential direction is the easy axis, and magnetically polarized in a substantially circumferential direction. The ring is attached to the torqued member, such as a rotating shaft, so that application of a torque to the shaft is transmitted to the ring. The torque on the ring reorients the circumferential magnetic orientation of the ring, producing a helical magnetic orientation having both circumferential and axial components. A magnetic field vector sensor is mounted on a flux collector in a fixed position relative to the ring and oriented so that it responds only to axial magnetic field components of the ring.

Abstract: A motion sensor for detecting and providing an indication of the direction of motion along a predetermined line of travel of a smooth, uninterrupted, generally flat or gently curved, ferromagnetic target surface of a movable member includes a permanent magnet, at least one active field sensor for sensing magnetic field intensity and mounting structure for positioning the magnet and sensor along the line of travel in fixed spatial relationship to the target surface and to each other. The magnetic field of the permanent magnet, upon movement of the target surface relative to the permanent magnet along the line of travel, creates asymmetric magnetic fields along the target surface on either side of the axis which are unequal in strength in a way which is dependent upon the relative direction of motion of the target surface. The sensed magnetic intensity permits determination of the direction of motion, where the target surface is ferromagnetic, and velocity, where the target surface is conductive.

Abstract: A torque sensor comprises a magnetoelastically active element, and a magnetic sensor, such as a Hall effect sensor, responsive to the field of the magnetoelastically active portion. In the preferred embodiment, the magnetoelastically active portion comprises a ring of material endowed with an effective uniaxial magnetic anisotropy such that the circumferential direction is the easy axis, and magnetically polarized in a substantially circumferential direction. The ring is attached to the torqued member, such as a rotating shaft, so that application of a torque to the shaft is transmitted to the ring. The torque on the ring reorients the circumferential magnetic orientation of the ring, producing a helical magnetic orientation having both circumferential and axial components. A magnetic field vector sensor is mounted on a flux collector in a fixed position relative to the ring and oriented so that it responds to the field arising from the axial component of the magnetization within the ring.

Abstract: A force transducer for providing a signal indicative of, and a method for sensing, the magnitude of an external force applied to a ferromagnetic member, the external force causing tensile and/or compressive stresses to arise in the member, comprising a permanent magnet for creating a magnetic field and a sensor, such as a Hall effect or magnetoresistive device, for sensing the magnetic field intensity at the sensor. The member is positioned for conducting a portion of the magnetic flux therethrough, the amount of member-conducted magnetic flux being a function of the stressed condition of the member and of the applied force creating the stressed condition. The sensor senses only a portion of the flux not conducted through the member (leakage flux) and means are provided for converting the sensed leakage flux into a signal proportional to the magnitude of the force applied to the member. In one preferred form the member is positioned between the permanent magnet and the sensor.

Abstract: A magnetoelastic torque transducer for providing an electrical signal indicative of the torque applied to a member, the member including ferromagnetic, magnetostrictive means affixed to, associated with or forming a part of the surface of the torqued member for altering in magnetic permeability in response to the application of torque to the member. The ferromagnetic, magnetostrictive means is advantageously formed of a thermally hardened or iron-nickel martensite hardenable steel alloy characterized by a substantially isotropic magnetostriction having an absolute value of at least 5 ppm and including from 0.05 to 0.75 percent by weight carbon and sufficient of one or more elements selected from Ni, Cr, Co, Ti, Al, Mn, Mo, Cu and B to raise the alloy magnetostriction to at least 5 ppm absolute. Preferably, the ferromagnetic, magnetostrictive means is formed of nickel maraging steel.

Abstract: A position sensor and method for detecting and providing an indication of the position of a movable member comprising a ferromagnetic element oriented substantially parallel to the path of travel of the movable member, the element including a segment thereof having spaced-apart ends defining the positional limits between which movement of the movable member is to be monitored, the segment comprising a pair of contiguous, oppositely polarized, remanently magnetized regions defining an intersection along the length of the segment; a magnet positioned proximate the intersection and mounted in known spatial relationship to the movable member for movement therewith, and, simultaneously along the ferromagnetic element, the magnet providing a magnetic field presenting a constant polarity to the element and having a strength sufficient to locally polarize the element, whereby movement of the magnet means along the element alters the length of the respective regions; and, means for sensing the position of the intersec

Abstract: A magnetoelastic torque transducer for providing an electrical signal indicative of the torque applied to a member, the member including ferromagnetic, magnetostrictive means affixed to, associated with or forming a part of the surface of the torqued member for altering in magnetic permeability in response to the application of torque to the member. The ferromagnetic, magnetostrictive means is advantageously formed of a thermally hardened or iron-nickel martensite hardenable steel alloy characterized by a substantially isotropic magnetostriction having an absolute value of at least 5 ppm and including from 0.05 to 0.75 percent by weight carbon and sufficient of one or more elements selected from Ni, Cr, Co, Ti, Al, Mn, Mo, Cu and B to raise the alloy magnetostriction to at least 5 ppm absolute. Preferably, the ferromagnetic, magnetostrictive means is formed of nickel maraging steel.

Abstract: A hand tool for applying torque to a fastener includes a portion for engaging the fastener, a handle to which torque is hand-applied and a torque carrying member operatively coupled with the handle and the fastener-engaging portion for transmitting the hand-applied torque to the fastener. The torque carrying member includes a magnetoelastic torque transducer comprising a ferromagnetic, magnetostrictive region affixed to, associated with or forming a part of the surface of the torqued member for altering in magnetic premeability in response to the application of torque to the member.

Abstract: A magnetoelastic torque transducer for providing an electrical signal indicative of the torque applied to a member, the member including ferromagnetic, magnetostrictive means affixed to, associated with or forming a part of the surface of the torqued member for altering in magnetic permeability in response to the application of torque to the member. The ferromagnetic, magnetostrictive means is advantageously formed of nickel maraging steel, desirably 18% Ni maraging steel. Preferably, the transducer comprises a pair of axially spaced-apart annular bands defined within a region of the ferromagnetic, magnetostrictive means, the bands being endowed with residual stress created, respectively symmetrical right and left hand helically directed magnetic anisotropy of sufficiently large magnitude that the contribution to total magnetic anisotropy of any random anisotropy in the member is negligible.

Abstract: A completely submersible pressure-sensing transducer contains an air vent tube for providing a pressure differential relationship between the hydrostatic head and the atmosphere. The transducer contains associated electronic circuitry for providing direct read-out and absolute units.

Abstract: Devices relying on the Inverse Wiedman Effect. Devices include a current conductive, magnetically anisotropic rod, through which an AC current flows. Wound about the rod is a conductive coil having output terminals. By varying the AC current, the anisotropy, or both, variations in the output across coil terminals can be obtained. Devices may be for current sensing, pressure sensing, fluid flow sensing or an electric push button.

Abstract: Devices relying on the Inverse Wiedman Effect. Devices include a current conductive, magnetically anisotropic rod, through which an AC current flows. Wound about the rod is a conductive coil having output terminals. By varying the AC current, the anisotropy, or both, variations in the output across coil terminals can be obtained. Devices may be for current sensing, pressure sensing, fluid flow sensing or an electric push button.

Abstract: Devices relying on the Inverse Wiedman Effect. Devices include a current conductive, magnetically anisotropic rod, through which an AC current flows. Wound about the rod is a conductive coil having output terminals. By varying the AC current, the anisotropy, or both, variations in the output across coil terminals can be obtained. Devices may be for current sensing, pressure sensing, fluid flow sensing or an electric push button.

Abstract: Electromechanical transducer comprising a helically wound, magnetostrictive rod that is circularly magnetized. Surrounding said rod is a conductive coil.

Abstract: Mechanically controllable magnet made of a magnetostrictive, circularly magnetically anisotropic, circularly magnetized rod. There is no apparent magnetism externally. When rod is twisted, circular anisotropy becomes helical and circular magnetization also becomes helical to produce an axial field component and hence externally apparent magnetism. When rod untwists, it restores itself to its apparently non-magnetic condition.

Abstract: Devices relying on the Inverse Wiedemann Effect. In all instances, magnetostrictive rods are circularly magnetized and exhibit hysteresis when plotting axial induction vs. twist. Hysteresis, especially when rectangular, yields high d.phi./dt upon twisting to result in large output voltage across terminals of coil wound about the rod. In other embodiments, rectangular hysteresis gives rise to one-shot electric push button or sequential switch. Hysteretic magnetostrictive circularly magnetized rods also serve as recording devices to detect mechanical movement or shock.