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:
Jan. 11, 1994
Filed:
Oct. 26, 1992
Takayoshi Shinohara, Nagano, JP;
Nissin Kogyo Kabushiki Kaisha, Ueda, JP;
Abstract
In a tandem type vacuum booster, the inner peripheral end of a front booster piston and the inner peripheral bead of a front diaphragm are clamped between a front end of a sleeve fitted over the outer periphery of a piston boss and a flange provided on the piston boss and are thereby fixed to a front portion of the piston boss, while the inner peripheral end of a rear booster piston and the inner peripheral bead of a rear diaphragm are clamped between a stopper member mounted on the piston boss and a rear end of the sleeve and are thereby fixed to a rear portion of the piston boss. A first port for communicating the front and rear working chambers with the control valve, and a second port for communicating the front and rear vacuum chambers with the control valve extend through both the piston boss and the sleeve, and communication between both the ports is inhibited by a single annular sealing member mounted at an axially intermediate portion of a junction surface between the piston boss and the sleeve. A portion of the second port leading to the rear vacuum chamber extends along a front surface of the rear booster piston.