Patents by Inventor Douglas J. Rollins

Douglas J. Rollins 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: 4990057
    Abstract: The compressor controller includes a timing circuit for timing-out a detected fault in a compressor. Upon the fault existing for longer than a predetermined time limit, the controller removes power from the compressor. If the fault is corrected within the predetermined time limit, even momentarily, the timing process is discontinued and the controller continues to monitor the status of the compressor. The controller also includes a delay timer for delaying the re-energizing of the compressor after an interruption or loss of power occurs. The delay prevents short cycling of the compressor. The controller further includes a status display for indicating compressor functions, connections to an alarm which is initiated in the event of compressor failure, a switch for initiating a self test of the controller, and circuitry for a field applied current sensing relay.
    Type: Grant
    Filed: May 3, 1989
    Date of Patent: February 5, 1991
    Assignee: Johnson Service Company
    Inventor: Douglas J. Rollins