Patents by Inventor Randall John Griffin

Randall John Griffin 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: 6984908
    Abstract: A rotor for a permanent magnet motor includes a rotor body and a plurality of permanent magnets carried by the rotor body. The rotor body has an outside rotor surface with a plurality of dovetail slots formed on the outside rotor surface. Each magnet is fit within one of the slots, protruding outward of the outside rotor surface in a radial direction. According to another embodiment, a rotor is provided having a rotor body that carries a plurality of magnets on its outside surface, and end caps that are fastened respectively to longitudinal ends of the rotor body. The end caps each have a angled rim surfaces that overhangs an end portion of the outer magnet surface of each of the magnets to retain the magnets onto the rotor body. The angled rim surfaces and the magnets can be configured such that by drawing the end caps tightly against the rotor body by use of fasteners, the magnets are wedged down onto the rotor body by the angled rim surfaces.
    Type: Grant
    Filed: August 26, 2003
    Date of Patent: January 10, 2006
    Assignee: Deere & Company
    Inventors: Brent Gordon Rinholm, Randall John Griffin, Joseph H. Stevenson
  • Patent number: 6946762
    Abstract: The invention provides an electric motor drive for a reel mower. The drive includes an electric motor, a casing, an endless traction member and a secondary output shaft. Preferably the electric motor is a brush-less permanent magnet type electric motor. The electric motor includes a rotor, a stator, and a motor housing that carries the rotor and stator, the rotor having a rotor output shaft extending from the housing. The casing is mounted to the motor housing. The endless traction member is engaged to the rotor output shaft to be circulated by rotation of the rotor output shaft. The secondary output shaft is engaged by the endless traction member to be rotated by circulation of the endless traction member. The secondary output shaft extends from inside the casing to outside the casing to be operatively connected to the reel to rotate the reel.
    Type: Grant
    Filed: August 26, 2003
    Date of Patent: September 20, 2005
    Assignee: Deere & Co.
    Inventors: Brent Gordon Rinholm, Randall John Griffin
  • Publication number: 20050046294
    Abstract: A rotor for a permanent magnet motor includes a rotor body and a plurality of permanent magnets carried by the rotor body. The rotor body has an outside rotor surface with a plurality of dovetail slots formed on the outside rotor surface. Each magnet is fit within one of the slots, protruding outward of the outside rotor surface in a radial direction. According to another embodiment, a rotor is provided having a rotor body that carries a plurality of magnets on its outside surface, and end caps that are fastened respectively to longitudinal ends of the rotor body. The end caps each have a angled rim surfaces that overhangs an end portion of the outer magnet surface of each of the magnets to retain the magnets onto the rotor body. The angled rim surfaces and the magnets can be configured such that by drawing the end caps tightly against the rotor body by use of fasteners, the magnets are wedged down onto the rotor body by the angled rim surfaces.
    Type: Application
    Filed: August 26, 2003
    Publication date: March 3, 2005
    Inventors: Brent Gordon Rinholm, Randall John Griffin, Joseph Stevenson
  • Publication number: 20050044838
    Abstract: The invention provides an electric motor drive for a reel mower. The drive includes an electric motor, a casing, an endless traction member and a secondary output shaft. Preferably the electric motor is a brush-less permanent magnet type electric motor. The electric motor includes a rotor, a stator, and a motor housing that carries the rotor and stator, the rotor having a rotor output shaft extending from the housing. The casing is mounted to the motor housing. The endless traction member is engaged to the rotor output shaft to be circulated by rotation of the rotor output shaft. The secondary output shaft is engaged by the endless traction member to be rotated by circulation of the endless traction member. The secondary output shaft extends from inside the casing to outside the casing to be operatively connected to the reel to rotate the reel.
    Type: Application
    Filed: August 26, 2003
    Publication date: March 3, 2005
    Inventors: Brent Gordon Rinholm, Randall John Griffin
  • Patent number: 6531850
    Abstract: A DC motor control for an electrical implement such as a reel mower includes a regulator having additional inputs connected to a main intelligent control which includes interlock circuitry. The additional inputs provide both an on/off or voltage select function and an interlock function. A low cost and low current field regulator circuit provides switching and load control and eliminates high inrush currents and voltage and current transients. On/off functions and level control functions can be provided from a logic level signal, and the motors can be started smoothly by bringing the voltage up gradually.
    Type: Grant
    Filed: August 20, 2001
    Date of Patent: March 11, 2003
    Assignee: Deere & Company
    Inventors: Randall John Griffin, Brent Rinholm
  • Publication number: 20030034759
    Abstract: A DC motor control for an electrical implement such as a reel mower includes a regulator having additional inputs connected to a main intelligent control which includes interlock circuitry. The additional inputs provide both an on/off or voltage select function and an interlock function. A low cost and low current field regulator circuit provides switching and load control and eliminates high inrush currents and voltage and current transients. On/off functions and level control functions can be provided from a logic level signal, and the motors can be started smoothly by bringing the voltage up gradually.
    Type: Application
    Filed: August 20, 2001
    Publication date: February 20, 2003
    Applicant: Deere & Company, a Delaware Corporation
    Inventors: Randall John Griffin, Brent Rinholm