Patent ID: 7229374
Filing Date: 2007-06-12
Classification: F16H

Abstract:
1. A tensioner for a power transmission belt that utilizes asymmetric motion control, the tensioner comprising: an arm comprising a belt engaging section and a drum section; a support member for securing the tensioner relative to the belt, the arm pivoting about the support member; a spring that urges the arm to pivot about the support member in a first direction and urges the belt engaging section against the belt with a force to tension the belt; a stator coupled to the support member to form arcuate spaces, the arcuate spaces being circumferentially spaced around the stator between the stator and the drum section; arcuate shaped wedges located in the arcuate spaces; a Belleville spring coupled to the arm for pivoting therewith; and a friction device in sliding contact with the Belleville spring and the wedges; wherein the tensioner is operable in a first condition in which the friction device is engaged with the Belleville spring so as to pivot with the Belleville spring and the arm relative to the stator and a second condition in which the stator, wedges and friction device are locked up together and the Belleville spring and the arm pivot relative to the friction device.