Patents by Inventor Frederick Maltby

Frederick Maltby 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).

  • Remotely calibratable instrument system
    Patent number: 4723122
    Abstract: A two-wire, admittance-responsive instrument system in which a transmitter, receiver and calibrator are connected by a two-wire transmission line is disclosed. The calibrator repetitively transmits a calibration enabling signal causing the transmitter to increment a reference admittance for comparison to a sensed admittance corresponding to a known physical condition. The calibrator monitors the bistable output signals transmitted by the transmitter in the calibration mode, which changes state when the incremented reference admittance bears a predetermined relationship to the sensed admittance. The calibrator may then transmit additional calibration enabling signals causing preload to be established for transmitter operation.
    Type: Grant
    Filed: October 25, 1985
    Date of Patent: February 2, 1988
    Assignee: Drexelbrook Controls, Inc.
    Inventors: Frederick Maltby, Richard G. Hall, Jonathan L. Kramer, Howard S. Hoopes, Steven R. Petersen