Patents by Inventor William D. Riggs

William D. Riggs has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5359288
    Abstract: A magnetic position sensor system including a magnetic medium divided into a plurality of areas of magnetization for producing a magnetic field with a variable intensity. The magnetic medium includes a first side, a second side and a longitudinal axis. A Hall cell is used for detecting the intensity of the magnetic field produced by the magnetic medium and for producing an electric signal which corresponds to the intensity detected. The magnetic medium is movable with respect to the Hall cell so that the Hall cell scans along the first side of the medium along the longitudinal axis and detects the intensity of the magnetic field at any given point along the longitudinal axis of the medium.
    Type: Grant
    Filed: December 1, 1993
    Date of Patent: October 25, 1994
    Assignee: North American Philips Corporation
    Inventors: William D. Riggs, Hermann Rosshirt
  • Patent number: 5089730
    Abstract: A DC electric motor, which is much quieter than previous DC motors, is disclosed. The inventive motor includes a rotor and a stator, and either the rotor or the stator includes tynes bearing windings. Significantly, the tynes are interconnected, which reduces vibration and noise.
    Type: Grant
    Filed: May 18, 1990
    Date of Patent: February 18, 1992
    Assignee: North American Philips Corporation
    Inventors: Edward M. O'Connor, William D. Riggs
  • Patent number: 4311933
    Abstract: A brushless D.C. motor has electrical power switched between the phase windings by means of a circuit which includes a plurality of hall effect switches. The hall effect switches are operated by a plurality of arcuate commutating magnets which are radially polarized and are disposed axially adjacent to field magnets which are also radially polarized. Ordinarily, the direction of radial polarization of the commutating magnets and the field magnets will be opposite.
    Type: Grant
    Filed: August 27, 1979
    Date of Patent: January 19, 1982
    Assignee: North American Philips Corporation
    Inventors: William D. Riggs, Joseph J. Schegan
  • Patent number: D301574
    Type: Grant
    Filed: October 24, 1986
    Date of Patent: June 13, 1989
    Assignee: North American Philips Corp.
    Inventor: William D. Riggs