Patents by Inventor Charles F. Logston, Jr.

Charles F. Logston, Jr. 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).

  • Patent number: 3997822
    Abstract: A method and apparatus are disclosed for controlling the wheel slip of an electric or diesel electric locomotive such that optimum wheel adhesion may be attained. A certain characteristic of a series traction motor, specifically the back emf per rpm versus motor current (E/n vs. I), forms the basis for a voltage control which limits the voltage (V) supply to each motor to a value which will limit the maximum percentage wheel slip. The selected limit value of wheel slip is great enough to encompass the conditions of maximum adhesion under most rail conditions. By combining the E/n with the motor IR drop, motor current, and a locomotive speed signal, the idealized voltage V for a non-slip condition is derived. This voltage is increased by a factor representing the desired maximum percentage slip to obtain the limiting voltage which may be supplied to the motor.
    Type: Grant
    Filed: December 18, 1974
    Date of Patent: December 14, 1976
    Assignee: General Motors Corporation
    Inventors: Charles F. Logston, Jr., Bruce R. Meyer, Alfred P. DE Buhr, Benjamin C. Liebenthal