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:
Nov. 21, 1995
Filed:
Mar. 19, 1993
Jun Maruyama, Kawasaki, JP;
Koji Yamashita, Kawasaki, JP;
Kabushiki Kaisha Komatsu Seisakusho, Tokyo, JP;
Abstract
An operating valve device for supplying fluid under pressure to an actuator comprises: a first hole (3) and a second hole (4) for allowing fluid under pressure supplied by a pump (P) into an inlet port (2) connected with the pump to selectively flow into pressure chambers (B.sub.1, B.sub.2) defined on both sides of an actuator (B) through outlet ports (6, 7), respectively; a first communication hole (12) and a second communication hole (13) formed coaxially and in opposed relationship with each other so as to allow the first and second holes, respectively, to communicate with a tank port (10); a first valve hole (14) and a second valve hole (15) formed coaxially in the valve body outside and in succession with these communication holes, respectively; a pair of support shafts (16, 16) inserted in these valve holes, respectively, in opposed relationship with each other; vacuum prevention valves (9, 9) each mounted on the leading end portion of each of the support shafts so as to open and shut the communication hole; and check valves (8, 8) each mounted on the axially intermediate portion of each of the support shafts so as to prevent fluid under pressure from flowing through the first and second holes, respectively, into the inlet port. Since the operating valve device has the vacuum prevention valves and the check valves mounted coaxially on the pair of support shafts, the whole operating valve device becomes compact, and fluid leakage can be reduced substantially.