Patent ID: 7497794

Claim:
A belt tensioner comprising: a) a belt-tensioner arm adapted to support an idler pulley and having a hook portion; b) a belt-tensioner spring case disposed in the arm and having a first spring seat; c) a belt-tensioner coil spring disposed in the spring case and having a longitudinal axis and longitudinally spaced apart first and second end portions; and d) an arm plate rotatable about the longitudinal axis and having a second spring seat, wherein the spring is longitudinally compressed between the arm plate and the spring case, wherein the spring is in torsion, wherein the first end portion is rotationally seated against the first spring seat of the spring case, wherein the second end portion is rotationally seated against the second spring seat of the arm plate, and wherein a portion of the arm plate is rotationally disposed under the hook portion of the arm, thus securing the belt tensioner at least by compressive longitudinal spring force.