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:
Jun. 05, 2001
Filed:
Apr. 20, 1999
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A hose rupture control valve unit includes a housing provided with two input/output ports. One input/output port is directly attached to a bottom port of a hydraulic cylinder, and the other input/output port is connected to one of actuator ports of a control valve via an actuator line. Within the housing, there are provided a poppet valve body serving as a main valve, a spool valve body serving as a pilot valve which is operated with a pilot pressure supplied as an external signal from a manual pilot valve, thereby operating the poppet valve body, and a small spool having the function of an overload relief valve. The above construction reduces the number of components arranged in a flow passage through which a hydraulic fluid passes at a large flow rate, and hence a pressure loss. A further reduction in overall size and production cost of the valve unit is achieved.