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:
Apr. 13, 2010
Filed:
Aug. 27, 2007
Tomonori Mouri, Kai, JP;
Naganori Koshimizu, Kai, JP;
Tomonori Mouri, Kai, JP;
Naganori Koshimizu, Kai, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A master cylinder that can prevent impairment of a piston seal, and a method of producing the master cylinder are provided. A master cylinder has a circumferential groove () in which a piston seal is provided, the piston seal having an outer circumference which enables operating fluid to be supplied, and a communication groove () which opens into the circumferential groove () and extends from the circumferential groove () toward a bottom portion of a cylinder body () to connect a pressure chamber and the circumferential groove (). The communication groove () is formed with its center made eccentric relative to the center of the circumferential groove (). A chamfered portion () is formed over an entire extent of a corner portion formed by the circumferential groove () and the communication groove (), along a circular path concentric with the communication groove ().