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:
Aug. 07, 2001
Filed:
Oct. 15, 1999
Tokico Ltd., Kawasaki, JP;
Abstract
A pneumatic booster includes a valve mechanism for introducing atmospheric air into a variable-pressure chamber in accordance with the movement of a plunger, propelling a power piston due to differential pressure generated between the variable-pressure chamber and a constant-pressure chamber and transmitting force by which the power piston is propelled through a valve body to an output shaft. The valve mechanism includes a poppet valve mechanism including a seal surface capable of abutting against an annular atmospheric valve seat formed in the plunger and a seal surface capable of abutting against an annular negative pressure valve seat formed on an inner surface of the valve body. The annular atmospheric valve seat of the plunger is located in a position forward in a direction of propelling of the power piston relative to the negative pressure valve seat and is substantially aligned with the negative pressure valve seat in an axial direction. The poppet valve mechanism has a main poppet valve including the seal surface capable of abutting against the negative pressure valve seat and a sub poppet valve including the seal surface capable of abutting against the atmospheric valve seat. The seal surface of the sub poppet valve is spaced apart in the axial direction from the seal surface of the main poppet valve.