Patents by Inventor Marc G. Williams

Marc G. Williams 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: 4890818
    Abstract: The door forcing apparatus for forcing a door set in a door jamb comprises two side rails each having a substantially L-shaped cross section engagable with a beveled edge between the door jamb and the door, a plurality of nearly flat drive wedges pivotally mounted on the side rails adjacent their vertices each having a nearly flat foot oriented parallel to the door pivotally mounted adjacent their circular-arc-shaped edge pressible against the door, two adjustable braces each of which comprise a bracing hydraulic cylinder or a turnbuckle which is pivotally attached to each of the two side rails adjacent one end of the apparatus, two U-shaped-cross-sectioned drive rods on each of which the drive wedges connected to the side rails are pivotally mounted and two driving hydraulic cylinders, each of which has a piston rod pivotally attached to an end of one of the drive rods and whose cylinder is pivotally mounted on a support bracket at one end of a side rail.
    Type: Grant
    Filed: December 27, 1988
    Date of Patent: January 2, 1990
    Inventor: Marc G. Williams