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. 24, 1995
Filed:
Jun. 10, 1994
Nobuhiro Odai, Sakado, JP;
Tsubakimoto Chain Co., Osaka, JP;
Abstract
An oil-operated tensioner is constructed with an internal cylinder which receives a rod in such a way that the rod itself serves as a piston, and the diameter of the high pressure chamber formed by the rod and the cylinder is the same as that of the rod. This configuration eliminates changes in the volume of the low pressure oil chamber of the tensioner, maintains substantially constant oil pressure in the low pressure chamber, and substantially reduces the tendency of air to be drawn into the low pressure chamber as a result of flow of oil out of the low pressure chamber when the rod moves in the protruding direction. A piston on the rod in the low pressure chamber, but spaced from the wall of the chamber by a gap, exerts a positive pressure on the oil as the rod moves in the protruding direction to provide further assurance against the entry of air. A valve incorporated into the piston closes as the rod advances and opens when the rod retracts, thereby preventing the piston from causing a negative oil pressure and drawing air past the seal into the low pressure oil chamber.