Patents by Inventor Mark R. Unger

Mark R. Unger 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: 5740887
    Abstract: A drive system for a vertical mast personnel lift uses a pair of rear wheels that are fixed in an axial direction of a base portion of the personnel lift. When an operator input to make a turn is received, DC motors respectively connected to the right and left rear wheels are rotated at a different rate. Neither the front wheels nor the rear wheels are steered during the turning movement. The front wheels are configured as caster wheels, which are free to turn in any direction. In order to rotate the personnel lift about its central axis, the right rear wheel is rotated at a first rate in a first direction, and the left rear wheel is rotated at the first rate in a second direction opposite the first direction.
    Type: Grant
    Filed: January 18, 1996
    Date of Patent: April 21, 1998
    Assignee: JLG Industries, Inc.
    Inventors: Mark R. Unger, Brian M. Boeckman