Patents by Inventor Frederick P. Fitzgerald

Frederick P. Fitzgerald 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: 4869341
    Abstract: This invention relates to the automatic control of work platforms and in particular to a circuit means that provides a safe operation and automatic relevelling of a work platform that is being raised and lowered by electrically powered hoists. Angle sense means are used to detect out of level orientations of the platform either along the longitudinal or transverse axis of the platform. When the angle sense means signals are interpreted by the circuit means appropriate hoist control signals stop the travel of the platform for a pre-determined period, control the hoists to bring the lowest portion of the platform up into a substantially level position, stop the travel of the platform for a pre-determined period and recommence the direction of travel of the platform.
    Type: Grant
    Filed: September 20, 1988
    Date of Patent: September 26, 1989
    Inventor: Frederick P. Fitzgerald