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. 08, 2013
Filed:
Mar. 23, 2009
Applicants:
Takato Ogiwara, Minami-Alps, JP;
Takayuki Kinoshita, Minami-Alps, JP;
Inventors:
Takato Ogiwara, Minami-Alps, JP;
Takayuki Kinoshita, Minami-Alps, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B60T 11/20 (2006.01);
U.S. Cl.
CPC ...
Abstract
A master cylinder includes a bottomed cylindrical cylinder body, a piston formed into a bottomed cylindrical shape by a forging method and slidably disposed in the cylinder body, and a spring assembly including a spring urging the piston toward an opening side of the cylinder body. A length of a spring of the spring assembly is determined by a retainer which can abut against an inner bottom portion of the piston. An annular groove is formed on the outermost side of the inner bottom portion of the piston by the forging method.