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. 14, 1999
Filed:
Jul. 09, 1997
Kevin J Lueschow, Edwards, IL (US);
Stephen V Lunzman, Chillicothe, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
An apparatus for controlling an electrohydraulic system of a work machine having an engine that drives a variable displacement pump is disclosed. The apparatus includes a pump displacement setting device that produces a pump command signal, a pressure sensor that detects the fluid pressure associated with the variable displacement pump and produces a pressure signal, and an engine speed sensor that detects the speed of the engine and produce an engine speed signal. A microprocessor computes the torque demand on the engine in response to the desired pump displacement, determines a torque limit associated with the engine in response to the engine speed, and responsively modifies the pump command signal to limit the engine torque.