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:
Oct. 22, 2002
Filed:
Sep. 18, 2000
Hongliu Du, Dunlap, IL (US);
Noah D. Manring, Columbia, MO (US);
Caterpillar Inc, Peoria, IL (US);
Abstract
An apparatus and method for controlling a discharge pressure of a variable displacement hydraulic pump. The apparatus and method includes a swashplate pivotally attached to the pump, a control servo operable to increase an angle of the swashplate relative to the pump, a biasing servo operable to decrease the angle of the swashplate relative to the pump, a servo valve having an output port hydraulically connected to the control servo, a divertor line having a first end connected to the pump output port and a second end connected to the biasing servo, and means for controlling the servo valve as a function of the discharge pressure of the pump.