Patents Assigned to Crude Tool Works
  • Amphibious vehicle
    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