Patents by Inventor John A. MacFadden

John A. MacFadden 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: 4449094
    Abstract: A temperature compensated magnetic damping assembly for providing a braking torque on an electroconductive disk of an induction device includes a pair of permanent magnets each having an easy axis of magnetization. Each permanent magnet provides two easy flux paths parallel to the easy axis of magnetization and separated by a dead zone. The permanent magnets are juxtaposed about a predetermined space through which the disk rotates such that the easy flux paths are perpendicular to the disk, and are aligned such that the magnetic flux passes twice through the disk in opposite directions. Flux return plates are provided adjacent to each of the permanent magnets so as to provide a flux path parallel to the disk and linking the two easy flux paths of each of the permanent magnets. In this configuration, a highly-efficient, substantially square magnetic flux loop is provided. One of the flux return plates is movable relative to the adjacent permanent magnet so as to provide series adjustment of the damping torque.
    Type: Grant
    Filed: June 10, 1981
    Date of Patent: May 15, 1984
    Assignee: Westinghouse Electric Corp.
    Inventors: John A. MacFadden, Joseph M. Keever, William J. Zisa
  • Patent number: 4238729
    Abstract: A magnetic damping system for induction devices having electroconductive disk armatures includes a low induction, high coercive force magnet that is vertically elongated and has a horizontal direction of magnetization parallel to the disk. Flux concentrating pole pieces adjoin the magnet pole faces for vertically directing two closely spaced braking magnetic fields from a pair of pole tips and into the disk. A temperature compensating arrangement covers the sides of the permanent magnet between the edges of the pole pieces to efficiently compensate for higher reversible temperature coefficients of magnet remanence.
    Type: Grant
    Filed: February 16, 1979
    Date of Patent: December 9, 1980
    Assignee: Westinghouse Electric Corp.
    Inventors: John A. MacFadden, Joseph M. Keever
  • Patent number: 4182984
    Abstract: A watthour meter damping assembly includes a U-shaped magnetic yoke and a pair of highly coercive and anisotropic permanent magnets projecting in facing relationship from the ends of the yoke. Opposing pole faces of the magnets form an air gap receiving a meter disc to be magnetically retarded. A single temperature compensator extends over the pole faces of the permanent magnets to form a compensating shunt flux path around the air gap. The compensator and magnetic yoke extend substantially parallel to each other from the inner and outer pole faces, respectively, of the magnet pair.
    Type: Grant
    Filed: May 5, 1978
    Date of Patent: January 8, 1980
    Assignee: Westinghouse Electric Corp.
    Inventors: John A. MacFadden, James E. Ramsey