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. 12, 2000
Filed:
Aug. 19, 1998
Masao Kashiwagi, Sagamihara, JP;
Masayuki Nakamura, Sagamihara, JP;
Kayaba Industry Co., Ltd., , JP;
Abstract
The present invention is directed to a hydraulic pressure control device which can overcome problems, such as a shock to an actuator or a pressure boost phenomenon involving a rapid increase in pump delivery pressure, conventionally encountered when a directional control valve is switched. The hydraulic pressure control device is constructed such that first and second connecting ports are connected to a tank when a directional control valve is in its neutral position, one of the first and second connecting ports is cut off from the tank and connected to an actuator and the other is cut off from the tank and closed when the directional control valve has been switched, in accordance with a position to which the directional control valve has been switched, and a maximum pilot pressure selectively taken from between a pressure compensating valve and a pair of check valves is introduced into a pilot line.