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:
Mar. 12, 2013
Filed:
Feb. 18, 2008
Mitsuhisa Tougasaki, Tsuchiura, JP;
Katsumi Ueno, Tsuchiura, JP;
Mitsuhisa Tougasaki, Tsuchiura, JP;
Katsumi Ueno, Tsuchiura, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A control valve has a pressure chambercausing a pressure to act on a valve elementof a check valvean oil chamberaround the valve, a slotformed in the valve elementand interconnecting the oil chamberand the pressure chamberwith each other and, a control valveconnected directly to a divergence portionand the oil chamberand capable of permitting or cutting off communication between the divergence portionand the oil chamberand changing an opening degree of the communication, an intra-valve-element passage, a slotformed in an outer peripheral wall of the valve elementand communicating the passageand the chamberwith each other, and a spring-return auxiliary check valvefor allowing pressure oil to flow from a supply passageinto the intra-valve-element passage