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. 01, 2008
Filed:
Jan. 10, 2005
Tsutomu Namie, Osaka, JP;
Tsutomu Namie, Osaka, JP;
Tsubakimoto Chain Co., Osaka, JP;
Abstract
A hydraulic tensioner comprises a hollow plunger slidable in a plunger-accommodating hole in a housing, the plunger and housing forming a high pressure oil chamber. A check valve unit, which includes a check ball and a check ball retainer, allows oil to flow into the oil chamber, but prevents reverse flow. A plunger-biasing spring, disposed inside the high-pressure chamber includes a close-wound portion fitting over the retainer of the check valve unit, and a portion having spaced windings, which extends and compresses axially with protruding and retracting movement of the plunger. The outer diameter of the close-wound portion is greater than the outer diameter of the portion having spaced windings.