Patents Represented by Attorney, Agent or Law Firm Wei Wei Jeang
  • Patent number: 4909088
    Abstract: An apparatus is provided for use with non-contacting torque sensors. The accuracy of non-contacting torque sensors depend upon the uniformity of the air gap between a stress detecting member and a stressed member, for instance, an inductive coil structure disposed about a shaft which exhibits changes in magnetic permeability in response to torque on the shaft. Mounting schemes for bulky inductive coil structures do not provide a uniform air gap, and an inaccurate torque sensor results. As a solution, a mounting apparatus uses a tube concentrically disposed about a shaft at a predetermined distance therefrom, and a flexible sensor structure disposed about the tube. The small, efficient tube and sensor structure may be held to strict manufacturing and mounting tolerances. The apparatus is principally used to sense the torque on a shaft, such as that used in an automobile or work vehicle.
    Type: Grant
    Filed: August 4, 1988
    Date of Patent: March 20, 1990
    Assignee: Caterpillar Inc.
    Inventor: Izrail Tsals
  • Patent number: 4887454
    Abstract: Off-highway trucks generally rely on a suspension system which employs a plurality of gas-over-liquid type struts. These struts are critical to proper operation of the vehicle such that a single collapsed strut can have serious manifestations in structural damage, tire wear, and payload monitor accuracy. These consequences can be mitigated by an accurate and reliable strut monitor. Pressure type sensors are disposed on each of the struts and their pressure is monitored during three critical phases of operation. These phases include static, loading, and roading modes and each mode requires a distinct method for detecting a collapsing strut. The presence of a collapsing strut, detected by any of the three methods, is communicated to the vehicle operator whereby operation can be immediately suspended. The system avoids the serious consequences of vehicle operation with a collapsed strut by providing the operator with immediate and positive feedback on the condition of the struts.
    Type: Grant
    Filed: January 9, 1989
    Date of Patent: December 19, 1989
    Assignee: Caterpillar Inc.
    Inventors: Christos T. Kyrtsos, F. Paul Lutgen, Adam J. Gudat
  • Patent number: 4864284
    Abstract: A self guided vehicle employs a highly accurate velocity sensor to determine vehicle speed and position. The velocity sensor includes a resolver connected to and rotatable with a ground engaging wheel. A resolver to digital converter (R/D) provides a highly accurate 8-bit digital signal representative of the angle of wheel rotation. A second less expensive and less accurate velocity sensor also receives the modulated sine and cosine signals from the resolver and produces a series of pulses representative of vehicle speed. The pulses are produced by detecting the zero crossings of the sine, cosine, and combinations of the sine and cosine signals. The velocity information present in the second velocity sensor signal is not used to actually guide the vehicle, but merely to generally validate the information present in the R/D signal.
    Type: Grant
    Filed: December 8, 1987
    Date of Patent: September 5, 1989
    Assignee: Caterpillar Inc.
    Inventors: John W. Crayton, Charles T. Kinas, Scott G. Sinn
  • Patent number: 4858818
    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.
    Type: Grant
    Filed: August 4, 1988
    Date of Patent: August 22, 1989
    Assignee: Caterpillar Inc.
    Inventors: Lawrence D. Knox, Izrail Tsals
  • Patent number: 4845416
    Abstract: Apparatus is provided for mechanically actuating a valve stem in response to signals generated by an electronic control. A signal means and a sensor means send signals to the electronic control in response to a desired valve stem position and a sensed valve stem position, respectively. The electronic control formulates an error signal if the sensed position is not the desired position. A motor receives a control signal in response to the error signal and drives a linkage for moving the valve stem to the desired position.
    Type: Grant
    Filed: February 13, 1987
    Date of Patent: July 4, 1989
    Assignee: Caterpillar Inc.
    Inventors: Rolland D. Scholl, Mike T. Zimmer, William E. Allen