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:
Feb. 23, 1988
Filed:
Dec. 29, 1986
Akira Tatsumi, Tokyo, JP;
Nobuya Okabe, Tsuchiura, JP;
Mitsuo Kihara, Ibaraki, JP;
Seiji Tamura, Ibaraki, JP;
Abstract
A control system of hydraulic construction machinery includes a prime mover, at least one variable displacement pump driven by the prime mover, at least one actuator hydraulically driven by the pump, maximum revolution number altering device for the prime mover, maximum displacment volume altering device for the pump and an information provider device for providing information on the operation mode of the actuator, whereby the maximum revolution number altering means and maximum displacement volume altering means are controlled by the information provider device to provide a maximum number of revolutions and a maximum displacement volume which suit the operation mode indicated by the output signal. A product of the maximum displacement volume and the number of revolutions becomes at a constant always at the same time when the maximum displacement volume of the pump is varied in response to an output signal of the information provider device, whereby a change in the quantity of pumped fluid can be avoided when the maximum displacement volume of the pump is altered.