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:
Apr. 07, 1992
Filed:
Dec. 22, 1989
Kazuhiko Fujii, Hiroshima, JP;
Wataru Kubomoto, Hiroshima, JP;
Hiroshi Shimokakiuchi, Hiroshima, JP;
Sumio Kouchi, Hiroshima, JP;
Kabushiki Kaisha Kobe Seiko Sho, Kobe, JP;
Abstract
An oil hydraulic circuit for a hydraulic shovel with which a composite operation can be performed readily and smoothly without special skill in operation of the hydraulic shovel. The oil hydraulic circuit comprises a first actuator which can operate with pressure oil from a predetermined one or both of a pair of hydraulic directional control valve sets, a second actuator which operates only with pressure oil from the other hydraulic directional control valve set, a proportional changing over device interposed intermediately in a pipe line communicating the other hydraulic directional control valve set with a first actuator for adjusting the maximum meter-in opening value to the first actuator in response to a magnitude of a signal received at a signal receiving portion of the proportional changing over device, and a controller for arbitrarily adjusting the signal to be supplied to the signal receiving portion of the proportional changing over device.