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:
Dec. 07, 1993
Filed:
Jan. 13, 1992
Lonnie J Devier, Dunlap, IL (US);
John J Krone, Dunlap, IL (US);
Stephen V Lunzman, Chillicothe, IL (US);
Howard A Marsden, Pekin, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
An apparatus for limiting the power output of a hydraulic system is disclosed. The hydraulic system has a variable displacement pump. The variable displacement pump has a movable swashplate and is driven by a source of motive power. The apparatus includes a memory device for storing a set of power modes. Each power mode has a predetermined power level associated with the hydraulic system and is defined by a plurality of set points. Each set point corresponds to a predetermined flow rate and discharge pressure of the pump. A device senses the speed of the source of motive power and producing a signal representative of the actual speed in response to the sensed speed. A device senses the pressure of the variable displacement pump and produces a signal representative of the actual pressure in response to the sensed pressure. A device senses the swashplate angle of the variable displacement pump and delivers a signal representative of the actual swashplate angle in response to the sensed swashplate angle. A device receives a desired power mode signal having a desired power level. The desired power level is different from the predetermined power levels associated with the set of power modes. A control device receives the actual speed, pressure and swashplate angle signals, and responsively determines a desired flow limit of the pump. The desired flow limit corresponds to the desired power level.