Patents by Inventor Robert S. Graham

Robert S. Graham 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).

  • Control system for eddy current coupling drive for armoured face conveyors
    Patent number: 4477734
    Abstract: A control system for eddy current coupling drive for armoured face conveyors wherein the systems controls a number of eddy current drives via a pair of power supply lines and a single pilot line. A main contactor controlled by a relay is held closed by contact of a pilot relay which is energized only if relay contacts in individual control units for each drive remain closed. These last mentioned contacts open if certain operating conditions are not met.
    Type: Grant
    Filed: May 12, 1983
    Date of Patent: October 16, 1984
    Assignee: Anderson Strathclyde PLC
    Inventor: Robert S. Graham