Patents by Inventor Andrew G. Grundy

Andrew G. Grundy 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).

  • PTC water level sensor and control
    Patent number: 5197329
    Abstract: A PTC resistive strip is mounted on a wall of a washer tub. Water in the tub carries away heat from the energized strip thereby reducing its resistance. The water level in the tub is measured by measuring the voltage drop across the strip. The resistance of the strip can be compared to the resistance across a variable resistance or resistor to indicate that the water has reached a desired level. A comparator output can be used to control the water level and washer motor operation via a control circuit which operates the water supply valves and motor switch. A second PTC resistive element is also provided for sensing overfill.
    Type: Grant
    Filed: May 22, 1992
    Date of Patent: March 30, 1993
    Assignee: White Consolidated Industries, Inc.
    Inventor: Andrew G. Grundy