Patents by Inventor Paul A. Dvorak

Paul A. Dvorak 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: 5934406
    Abstract: A jerk control valve adapted for use in a pilot operated steering system has a pilot operated valve biased to an open position by a spring for communicating left steer and right steer pilot lines to a tank through a pair of orifices. The pilot operated valve is moveable to a closed position blocking communication through the first and second orifices when the highest pressure of the left and right steer pilot lines exceeds a predetermined value. The left and right steer pilot lines are continuously communicated with the tank through a pair of orifice devices.
    Type: Grant
    Filed: May 29, 1997
    Date of Patent: August 10, 1999
    Assignee: Caterpillar Inc.
    Inventors: Paul A. Dvorak, Steven R. Wells
  • Patent number: 5897176
    Abstract: A braking apparatus includes a brake cylinder having a first opening and a second opening defined therein. The braking apparatus also includes a movable member located within the brake cylinder which has a channel defined therein. The braking apparatus further includes a brake chamber in fluid communication with the brake cylinder. The brake chamber has a brake member located therein. The movable member is moved to a position which allows fluid communication between the first and second opening through the channel thus creating a subsequent pressure drop in the system. The pressure drop causes a hydrostatic transmission in fluid communication with the brake apparatus to be neutralized by a responsive displacement of a pump and motor which reduces the travel speed of a vehicle. Additionally, the movement of the movable member causes a brake member to be forced against a moving object.
    Type: Grant
    Filed: March 15, 1996
    Date of Patent: April 27, 1999
    Assignee: Caterpillar Inc.
    Inventors: Paul A. Dvorak, Peter R. Hildner, David P. Smith, William C. Swick