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.

Date of Patent:
Jun. 24, 2003

Filed:

Mar. 05, 2001
Applicant:
Inventors:

Seiichi Furutate, Tsukuba-gun, JP;

Masao Kajitani, Tsukuba-gun, JP;

Assignee:

SMC Corporation, Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16K 3/700 ; F16K 1/100 ;
U.S. Cl.
CPC ...
F16K 3/700 ; F16K 1/100 ;
Abstract

A main valve mechanism for opening and closing a main flow path between a first port and a second port has a main valve body, a large-diameter first piston for opening the main valve body, a main pressure operating chamber for driving the first piston, and first spring means for closing the first piston. An auxiliary valve mechanism for opening and closing an auxiliary flow path has an auxiliary valve body, a small-diameter second piston for opening the auxiliary valve body, an auxiliary pressure operating chamber for driving the second piston, and second spring means for closing the second piston. The main pressure operating chamber and the auxiliary pressure operating chamber are connected to each other through a connecting hole. There are such relationships between piston diameters of both the pistons and repulsing forces of both the spring means that the second piston is actuated by lower fluid pressure than the first piston.


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