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:
Apr. 16, 2002
Filed:
Feb. 13, 2001
James Donaldson, Puyallup, WA (US);
Nelson Wong, Kirkland, WA (US);
Genie Industries, Inc., Redmond, WA (US);
Abstract
A mobile lift having extendable axes that is capable of switching between front-wheel steer, rear-wheel steer, all-wheel steer, and crab steer without resulting in undesirable tire scrubbing or unfavorable steering geometry. One embodiment provides a mobile personnel lift having a chassis supported by steerable front and rear wheel sets. The steerable wheel sets are mounted on axles that are extendable and retractable. A double-acting hydraulic cylinder is pivotally coupled between each steerable wheel and its corresponding axle for turning the wheel. A microprocessor controls the flow of hydraulic fluid to the hydraulic cylinders. Sensors positioned adjacent to each wheel measure the angular position of each wheel relative to the chassis, and transmit this information to the microprocessor to synchronize the wheels as required to provide the optimum steering geometry for the selected mode.