Patents by Inventor Richard L. Dufern

Richard L. Dufern 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).

  • Engine filter assembly
    Patent number: 5167209
    Abstract: An air filter arrangement for a gas engine which is used in a dirty environment such as roof removing machines which covers the air inlet to the fan and consists of an annular air filter and a foam air filter which fit over the fan air inlet and which is held in place by a plate that attaches it to the engine.
    Type: Grant
    Filed: March 5, 1992
    Date of Patent: December 1, 1992
    Inventors: Richard L. Dufern, George Riddiford