Abstract: An speed sensor for a rotating shaft includes a plurality of magnetic portions on the shaft that output a magnetic field from each of the magnetic portions, wherein the magnetic portions are integrally formed in the shaft by magnetically polarizing the shaft material itself. At least one magnetic field sensor is positioned proximate to the shaft for detecting the magnetic field from each of the magnetic portions and for outputting a signal corresponding to the angular speed of the shaft as the shaft rotates. The signal is useful for calculating the angular speed of the shaft, and the calculated angular speed value is useful for things like adjusting the angular speed of the shaft, monitoring the performance of the system in which the shaft is used, and for other purposes.

Abstract: The present invention involves a method and apparatus for canceling the effects of magnetic field noise in a torque sensor by placing three sets of magnetic field sensors around a shaft, the first set of field sensors being placed in the central region of the shaft and the second and third sets of field sensors being placed on the right side and left side of the field sensors placed at the central region, respectively. A torque-induced magnetic field is not cancelled with this arrangement of field sensors but a magnetic near field from a near field source is cancelled.

Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.

Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.

Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.

Abstract: A magnetoelastic torque sensor for providing an output signal indicative of the torque applied to a member, comprising, a first magnetoelstically active region in the member, the region being ferromagnetic, magnetostrictive magnetically polarized in a single circumferential direction and possessing sufficient magnetic anisotropy to return the magnetization in the region to the single circumferential direction when the applied torque is reduced to zero, whereby the ferromagnetic, magnetostrictive region produces a magnetic field varying with the torque. Magnetic field sensors are mounted proximate to the ferromagnetic, magnetostrictive region to sense the magnetic field at the sensors and provide the output signal in response thereto.

Abstract: A magnetoelastic torque sensor for providing an output signal indicative of the torque transmitted between radially separated locations of a disk-shaped member includes a magnetoelastically active, ferromagnetic, magnetostrictive region which is magnetically polarized in a single circumferential direction and possesses sufficient magnetic anisotropy to return the magnetization in the region, following the application of torque to the member, to the single circumferential direction when the applied force is reduced to zero. First and second torque transmitting elements are directly attached to or form a part of the member at its central axis of rotation and its periphery in such a manner that torque is proportionally transmitted between the member and the transmitting elements.

Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.

Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.

Abstract: A magnetoelastic load cell for providing an output signal indicative of a force applied to the load cell comprises a magnetoelastically active, ferromagnetic, magnetostrictive disk-shaped member having upper and lower surfaces and comprising a central hub, an annular rim and at least two slots formed therebetween for defining at least two generally spiral-shaped spokes extending between the upper and lower surfaces, each of the spokes traversing approximately 360° between its origin at the hub and its termination at the rim. The spokes are magnetically polarized in a single circumferential direction and possess sufficient magnetic anisotropy to return the magnetization in the spokes, following the application of a force to the load cell, to the single circumferential direction when the applied force is reduced to zero. Magnetic field sensor means are mounted proximate to the member to sense the magnitude of the magnetic field produced by the member in response to the applied force.

Abstract: A magnetoelastic torque sensor for providing an output signal indicative of the torque applied to a member about an axially extending axis of the member, comprising, a first magnetoelastically active region in the member, the region being magnetically polarized in a single circumferential direction and possessing sufficient magnetic anisotropy to return the magnetization in the region, following the application of torque to the member, to the single cirumferential direction when the applied torque is reduced to zero, whereby the magnetoelastically active region produces a magnetic field varying with the torque. Magnetic field sensors are mounted proximate to the magnetoelastically active region and oriented with respect thereto to sense the magnitude of the magnetic field at the sensors and provide the output signal in response thereto.

Abstract: A magnetoelastic torque sensor for providing an output signal indicative of the torque applied to a member about an axially extending axis of the member, comprising, a member which is unitary and of generally homogeneous chemical composition, the member comprising separate magnetically active and magnetically substantially passive regions. A first magnetoelastically active region in the member is magnetically polarized in a single circumferential direction and possesses sufficient magnetic anisotropy to return the magnetization in the region, following the application of torque to the member, to the single circumferential direction when the applied torque is reduced to zero, whereby the magnetoelastically active region produces a magnetic field varying with the torque. Magnetic field sensors are mounted proximate to the magnetoelastically active region and oriented with respect thereto to sense the magnitude of the magnetic field at the sensors and provide the output signal in response thereto.

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.