Patents by Inventor Stephen M. Sturhahn

Stephen M. Sturhahn 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).

  • Low RPM switching tachometer
    Patent number: 6182634
    Abstract: The present invention includes preventing an engine from stalling at a preselected low idle range during operation of a work machine. To accomplish this, a controller is located within a tachometer and disposed on the work machine. The controller is responsive to a first specified low idle RPM signal from the engine. The controller converts the RPM signal to an electrical signal that is directed to a relay. The relay is responsive to the electrical signal to automatically switch at least one device operating on the work machine from a first power output level to a second power output level lower than the first power output level. The controller is responsive to a second specified low idle RPM signal from the engine and converts it to another electrical signal.
    Type: Grant
    Filed: October 13, 1999
    Date of Patent: February 6, 2001
    Assignee: Caterpillar Inc.
    Inventors: Sarah D. Caldwell, Robert Q. Elliott, John E. Francis, W. Frank Landon, David M. Smith, Stephen M. Sturhahn