Patents by Inventor Charles F. Hoffman

Charles F. Hoffman 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).

  • Clutch friction test for motorcycle lubricants
    Patent number: 5932790
    Abstract: A modified SAE No. 2 friction machine is used to evaluate the clutch friction properties of motorcycle lubricants in a process comprising measuring the torque after a break-in period at three temperature points within the ranges 30.degree.-60.degree. C., 70.degree.-90.degree. C. and 110.degree.-150.degree. C. over a 10 second period while the speed of the motor driving the clutch plates varies from 0-300 rpm and the clutch plate pressure is held at 50 psi.
    Type: Grant
    Filed: March 4, 1998
    Date of Patent: August 3, 1999
    Assignee: Exxon Chemical Patents Inc
    Inventors: Charles F. Hoffman, Emil J. Meny, Patrick J. Colby, Roger K. Nibert
  • Two-cycle lubricating oil
    Patent number: 5888948
    Abstract: A two-cycle oil is disclosed comprising a high and low molecular weight polybutene polymer, solvent and mineral oil which has suitable viscosity and exhibits improved smoke performance in the JASO test.
    Type: Grant
    Filed: October 25, 1996
    Date of Patent: March 30, 1999
    Assignee: Exxon Chemical Patents Inc.
    Inventors: Emil Joseph Meny, Charles F. Hoffman