Patents by Inventor Douglas A. Stiff

Douglas A. Stiff 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).

  • Vehicle mileage interval detector
    Patent number: 4284972
    Abstract: An apparatus for providing a service reminder when a vehicle has accumulated a predetermined mileage comprises a potentiometer operated by the highest order number wheel of the vehicle odometer to provide an output voltage which changes incrementally with each indexing motion of that number wheel. An electrical detector responsive to the potentiometer output energizes a signal lamp when the output reaches a voltage in a predetermined range representing a desired service interval. An electrical connector in circuit with the potentiometer can be disconnected to change the potentiometer voltage to a value outside the predetermined range to allow the service reminder circuit to turn off the indicator lamp when the indicated service has been performed. The apparatus is adapted to operate in conjunction with an electronic engine control module which can be programmed to detect the predetermined value of the potentiometer output and to operate a signal lamp.
    Type: Grant
    Filed: November 9, 1979
    Date of Patent: August 18, 1981
    Assignee: General Motors Corporation
    Inventors: Randolph K. Chiu, Douglas A. Stiff, Francis G. Cox