Patents by Inventor Derrick C. Richfield

Derrick C. Richfield 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).

  • Retractable marine thrust motor
    Patent number: D298631
    Type: Grant
    Filed: October 23, 1985
    Date of Patent: November 22, 1988
    Assignee: Richfield Marine Thrusters Limited
    Inventor: Derrick C. Richfield