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:
Sep. 10, 1996
Filed:
Oct. 17, 1994
Thomas A Watts, Ottawa, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
A variable displacement axial piston hydraulic unit includes first and second control pockets individually disposed between first and second arcuate shaped fluid passages, a first electrohydraulic valve for controlling fluid flow between the first control pocket and the first fluid passage and a second electrohydraulic valve for controlling fluid flow between the second passage and the second control pocket. A controller outputs first and second control signals to the first and second electrohydraulic valves in response to receiving a command signal so that the tilt angle of a swashplate is controlled to obtain a desired operating parameter. An angle detector, a pressure detector, and a speed detector provide feedback signals to the controller for determining when the desired operating parameter has been obtained.