Patents by Inventor David K. Liberty

David K. Liberty 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: 7845443
    Abstract: A low surface impact, skid steered, all terrain vehicle is disclosed which has a rectangular frame from which sets of tandem mounted, independently movable control arms are suspended. A hydraulic motor driven wheel axle is mounted on a lower end of each control arm with at least one pneumatic wheel mounted upon each wheel axle. Separate hydraulic control circuits having separate drive pumps drive the hydraulic motors on each side of the vehicle. Each of these hydraulic control circuits is operable in either a series connected mode or a parallel connected mode.
    Type: Grant
    Filed: September 5, 2008
    Date of Patent: December 7, 2010
    Inventors: David K. Liberty, David W. Murdoch
  • Publication number: 20090078480
    Abstract: A low surface impact, skid steered, all terrain vehicle is disclosed which has a rectangular frame from the opposite sides of which sets of tandem mounted, independently movable control arms are suspended. An hydraulic motor driven wheel axle is mounted on the lower end of each control arm with at least one pneumatic wheel mounted upon each axle. Compressible springs are located between the frame and each control arm so as to bias the control arms and wheels supported therefrom downwardly to a position in which friction plates mounted upon the control arms contact and limit movement of each set of control arms toward one another. Separate hydraulic control circuits having separate drive pumps drive the hydraulic motors on each side of the vehicle. Each of these circuits is operable in either a series connected mode or a parallel connected mode.
    Type: Application
    Filed: September 5, 2008
    Publication date: March 26, 2009
    Inventors: David K. Liberty, David W. Murdoch