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:
Feb. 12, 2013
Filed:
Nov. 05, 2008
Seiji Sato, Iwata, JP;
Tasuku Furukawa, Iwata, JP;
Seiji Sato, Iwata, JP;
Tasuku Furukawa, Iwata, JP;
NTN Corporation, Osaka, JP;
Abstract
A chain tensioner includes a cylindrical cylinder having an open end and a bottom, a cylindrical plunger axially slidably inserted in the cylinder and having a bottom and an open end located in the cylinder, a screw rod mounted in the cylinder and having an external thread on an outer periphery thereof, wherein the plunger has a protrusion on an inner periphery thereof which is in threaded engagement with the external thread of the screw rod, and wherein the external thread has a pressure flank for receiving pressure when a force is applied that tends to push the plunger into the cylinder, and a clearance flank, the pressure flank having a larger flank angle than the clearance flank, whereby the external thread is serration-shaped, and a return spring mounted between the plunger and the screw rod and biasing the plunger in a direction to protrude from the cylinder, thereby pressing a chain with the plunger, wherein the protrusion extends only a limited arcuate range of the inner periphery of the plunger.