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, 2011
Filed:
Mar. 27, 2008
Hiroki Okada, Yokohama, JP;
Naganori Koshimizu, Kai, JP;
Hiroki Okada, Yokohama, JP;
Naganori Koshimizu, Kai, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An object of the present invention is to provide a master cylinder capable of controlling an increase in an intruding amount of a cup seal while relieving a stress concentration therein to thereby prevent the cup seal from being damaged. Provided is a master cylinder in which a piston is moved in slidable contact with an inner circumference of a cup seal held in a cylinder main body so as to pressurize a brake fluid in a pressure chamber formed of the piston and the cylinder main body, wherein an annular wall configured integrally with the cylinder main body is provided behind the cup seal. Further, a chamfered portion having a curved shape in a cross-section taken along a diameter direction of the cylinder main body is provided between the annular wall and a cylinder wall to which the piston is facing. One end of the chamfered portion is formed continuously so that a tangent thereto is in line with the annular wall, and the other end of the chamfered portion is formed to constitute a flexed portion in combination with the cylinder wall.