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. 13, 2007
Filed:
Apr. 22, 2005
Kazuo Takiguchi, Ibaraki-ken, JP;
Masami Ochiai, Atsugi, JP;
Tsutomu Udagawa, Tsukuba, JP;
Katsumi Ueno, Ibaraki-ken, JP;
Takashi Yagyu, Ushiku, JP;
Yukihiko Sugiyama, Tsuchiura, JP;
Mitsuo Aihara, Ibaraki-ken, JP;
Kazuo Takiguchi, Ibaraki-ken, JP;
Masami Ochiai, Atsugi, JP;
Tsutomu Udagawa, Tsukuba, JP;
Katsumi Ueno, Ibaraki-ken, JP;
Takashi Yagyu, Ushiku, JP;
Yukihiko Sugiyama, Tsuchiura, JP;
Mitsuo Aihara, Ibaraki-ken, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
The control valve apparatus holds a seat valve member in a position seated on a valve seat to thereby prevent a backward flow even if the pressure in the inlet chamber side becomes lower than the pressure in the outlet chamber side. With a pilot control valve member is in a closed state, when the pressure in the inlet chamber is higher, a pressurized medium is introduced to the control pressure chamber via a first valve unit and is cut off from the outlet chamber by a second valve unit. When the pressure in the outlet chamber is higher, the pressurized medium is introduced to the control pressure chamber via the second valve unit and is cut off from the outlet chamber by the first valve unit.