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:
Jan. 12, 1999
Filed:
Nov. 27, 1996
Ronald L Satzler, Princeville, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
A differential steer is provided for use in a machine and includes a variable displacement motor operatively connected to a differential disposed between first and second output members. The variable displacement motor is an over-center type and the displacement thereof is varied from zero to maximum in both directions of movement. Pressurized fluid to drive the steer motor is received from the main system pump. A microprocessor senses the direction and rate of rotation of the steer motor output, the speed of the outputs from the differential, the magnitude of a steer input, and controls the output speed of the steer motor to the differential in response to the magnitude of the steer input. Consequently, the quantity of fluid taken from the main system pump is limited to only that necessary to rotate the steer motor at a rate necessary to satisfy the desired steer input. Since the steer motor is using only the flow necessary to rotate the steer motor output at a desired speed and the steer motor torque is generally proportional to the steer motor displacement, the overall operating efficiency is increased as compared to known differential steer systems.