Patents by Inventor David A. Shields

David A. Shields 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).

  • Vacuum system for diesels and high performance vehicles
    Patent number: 5881557
    Abstract: A vacuum back-up system for diesel vehicles, and a primary vacuum system for high performance vehicles, which vacuum system includes a vacuum pump for creating a vacuum in an associated reserve vacuum tank connected to the vacuum booster of the vehicle. A relay is attached to the vacuum pump or to a mount bracket which mounts the vacuum pump and the reserve vacuum tank and the relay is electrically connected to a vacuum switch on the vacuum booster and to the vehicle battery and the vacuum pump to facilitate operation of the vacuum pump and maintaining a vacuum of preselected magnitude in the reserve vacuum tank and the vacuum booster.
    Type: Grant
    Filed: June 16, 1997
    Date of Patent: March 16, 1999
    Inventor: David A. Shields
  • Welding cable reel system
    Patent number: 4584442
    Abstract: A welding cable reel system including an insulated reel mounted on an electrically conducting bearing assembly, the assembly in turn mounted on a hub which is rotatably mounted on a shaft which is connected to an insulated support post. A cable being connected to the hub so as to receive current which is transmitted to the support post and carried through the shaft and hub to the cable.
    Type: Grant
    Filed: October 11, 1983
    Date of Patent: April 22, 1986
    Inventors: David A. Shields, James R. Davis