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 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.