Patents by Inventor Douglas S. Hart

Douglas S. Hart 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: 5259692
    Abstract: An earth working apparatus comprising a wheeled vehicle capable of traversing the ground and a ground breaking assembly mounted on the front end of such vehicle, such ground breaking assembly comprising a cylinder mounted for movement with the vehicle and for rotation about its cylinder axis, such cylinder having teeth projecting from its cylinder surface; the ground breaking assembly also having a shield partially surrounding the cylinder and provided on its inner surface close to the cylinder with fracture boards against which large pieces of pavement, frozen earth or stone impact, thereby causing such large pieces to fragment.
    Type: Grant
    Filed: September 4, 1992
    Date of Patent: November 9, 1993
    Inventors: Larry D. Beller, Douglas S. Hart, Robert White
  • Patent number: 5203729
    Abstract: An auger-driven remotely controllable amphibious vehicle is disclosed. The vehicle includes a buoyant hull in the general configuration of a speedboat. An auger is mounted for rotation along each side of the vehicle. The generally cylindrical augers with helical screws are nested closely in approximately quarter-cylinder recesses formed along the lower sides of the hull at the waterline so that a considerable portion of the water moved by the augers is contained in the narrow spaces between the augers and the hull, and is then thrust directly rearward (or forward) for increased efficiency in propulsion. A propulsion mechanism and other components are preferably mounted in the center of the vehicle for balance. The vehicle preferably includes control apparatus and signal receiving apparatus for remote operation.
    Type: Grant
    Filed: January 9, 1992
    Date of Patent: April 20, 1993
    Inventors: Larry D. Beller, Douglas S. Hart, Robert L. White
  • Patent number: 5203274
    Abstract: A buoyant boat hull of an amphibious vehicle has concave, quarter cylinder recesses along the sides down from the waterline, such recesses receiving the upper inboard quadrants of helical augers. The recesses confine water between the screw threads and project it directly to the rear for more efficient forward thrust. The engine and pumps for the hydraulic motors are mounted on a slide to be moved forward and aft as desired to shift the center of gravity and aid in transition between land and water travel.
    Type: Grant
    Filed: April 19, 1990
    Date of Patent: April 20, 1993
    Assignee: Crude Tool Works
    Inventors: Douglas S. Hart, Larry D. Beller, Robert L. White