Patents by Inventor David H. Willson

David H. Willson 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: 4693836
    Abstract: A filter apparatus and method is provided wherein a tank is adapted to receive unfiltered liquid. An outlet chamber is located adjacent the bottom wall of the filter tank and is separated therefrom by a perforated plate. A filter media is movable across the rear, bottom and front walls of the filter tank and accordingly, unfiltered liquid must pass through the filter media as well before entering the outlet chamber. A chain flight assembly is provided which is movable across the filter media along the rear, bottom and front walls of the filter tank. As the chain flight assembly is continuous, a return path is across the top of the tank above the unfiltered liquid. A baffle plate is provided near the rear wall within the filter tank.
    Type: Grant
    Filed: April 28, 1986
    Date of Patent: September 15, 1987
    Assignee: AMSTED Industries Incorporated
    Inventor: David H. Willson
  • Patent number: 4571302
    Abstract: A filter system and method are provided utilizing a filter tank separated into an inlet compartment and a filtrate compartment by a filter media. Under normal filter operation, the liquid to be filtered enters the inlet compartment, is passed through the filter media and out the filtrate compartment by a pressure differential created across the filter media by a pump device. When the need arises to move the filter media as a result of the buildup of contaminents on it, it is necessary to alleviate the pressure differential across the filter media. Such pressure differential is alleviated by the controlled flowing of filtered liquid through an orifice in a closed valve into the filtrate compartment.
    Type: Grant
    Filed: December 31, 1984
    Date of Patent: February 18, 1986
    Assignee: AMSTED Industries Incorporated
    Inventor: David H. Willson
  • Patent number: 4396505
    Abstract: A filtering device including a tank partially located below floor level having a filtrate compartment and a filter means interposed therebetween. Reservoir means and an end suction centrifugal pump means both located substantially on floor level wherein conduit means selectively permits the filtrate level in the reservoir to maintain a positive pressure at the inlet of the pump when pump is shut off, and to neutralize the pressure differential between the filtrate compartment and the tank.
    Type: Grant
    Filed: December 10, 1981
    Date of Patent: August 2, 1983
    Assignee: Amsted Industries Incorporated
    Inventors: David H. Willson, Thomas C. Adams