The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 16, 2011
Filed:
Dec. 21, 2006
Andrew John Smith, Ashbourne, GB;
Andrew John Smith, Ashbourne, GB;
Caterpillar SARL, Geneva, CH;
Abstract
Vehicles with open loop hydraulic steering systems may suffer from jerky steering due to the necessity to have safety valves in the open loop system to prevent uncontrolled vehicle movement. Traditional open loop steering arrangements allow steering by controlling fluid quantities flowing from the pump to the drive motors. The disclosed vehicle has an open loop hydraulic drive system including first and second variable displacement motors for driving ground engaging mechanisms at first and second sides of the vehicle, respectively. The system includes a control mechanism configured for steering the vehicle by changing the displacement of one of the first and second motors. This allows the operator to change the drive motor speed range during travel.