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:
May. 11, 2004
Filed:
May. 08, 2002
Applicant:
Inventor:
Keita Nakano, Itami, JP;
Assignee:
Sumitomo (SEI) Brake Systems, Inc., Mie, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16K 1/00 ; B60T 1/500 ;
U.S. Cl.
CPC ...
F16K 1/00 ; B60T 1/500 ;
Abstract
A pressure-responsive type pressure holding valve is proposed which serves to hold the hydraulic pressure in a circuit connected to a spool valve. A piston valve biased by a spring is mounted in a housing formed with a valve chamber, a small-diameter bore and a large-diameter bore. The outer periphery of the small-diameter portion of the piston valve is sealed by a seal member. A first port opened and closed by a valve head at the tip of the piston valve is connected to a circuit that needs pressure holding, a second port to a circuit in which minute leak can occur, and a third port to a source of hydraulic pressure for opening the valve.