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. 29, 2008
Filed:
Jul. 08, 2005
Yoshinori Ishizawa, Ibaraki, JP;
Hiroki Kitagawa, Ibaraki, JP;
Masashi Nishida, Ibaraki, JP;
Hitachi Koki Co., Ltd., Tokyo, JP;
Abstract
A cylinder is constituted such that the cylinder includes a large diameter portion constituted by forming a portion thereof brought into contact with an O ring by a diameter larger than a diameter of other portion when a piston is disposed at an upper dead center and a small diameter portion formed downward from the large diameter portion, and a fastening margin is provided between an outer periphery of the O ring and an inner periphery of the cylinder even when the piston is disposed at any position from the upper dead center to a lower dead center and a clearance is provided between an inner periphery of the O ring and an outer periphery of a groove.