Patents by Inventor Douglas J. MacKenzie

Douglas J. MacKenzie 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).

  • Grab hook for attachment to a chain to provide partial link adjustment, and method of use thereof
    Patent number: 5173998
    Abstract: A hook for gripping chain is asymmetrical so that the effective chain length can be adjusted to a part link tightness. The attachment end of the hook is offset from the plane of the hook end, which includes the slot for receiving a link of a chain. If the chain enters from one side of the hook, the chain and hook have a different angle than when the chain enters from the other side of the hook. The resulting change in angle and hence the way the hook interferes with the chain changes the length of chain required for the chain to reach the slot.
    Type: Grant
    Filed: January 28, 1992
    Date of Patent: December 29, 1992
    Inventor: Douglas J. Mackenzie
  • Mounting for an RTD element
    Patent number: 4087775
    Abstract: A temperature measuring probe utilizing an RTD element and an improved mode of assembling the element in a reliable manner which is proof against shock and vibration. Specifically, the invention has its most important applications in connection with miniaturized RTD's.
    Type: Grant
    Filed: August 23, 1976
    Date of Patent: May 2, 1978
    Assignee: ARi Industries, Inc.
    Inventors: Douglas J. MacKenzie, Dennis C. Johnson