Patents by Inventor Roger D. Combs

Roger D. Combs 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).

  • Electronic transmission range selection
    Patent number: 6110071
    Abstract: An electro-hydraulic transmission control has a pair of solenoid valves which are energized individually to provide a forward drive or a reverse drive. A mode mechanism downstream of the solenoid valves is actuated to a forward or reverse mode depending on which solenoid is actuated. The hydraulic fluid downstream of the solenoid valves is also effective to actuate one of two disable valves. When the forward solenoid is selected, the reverse disable valve is actuated and vice versa. In the event that hydraulic pressure is inadvertently directed to the forward and reverse drives simultaneously, both disable valves are actuated and the transmission control is placed in neutral.
    Type: Grant
    Filed: April 30, 1999
    Date of Patent: August 29, 2000
    Assignee: General Motors Corporation
    Inventors: Michael Andrew Kozan, Roger D. Combs, Steve P. Gunn