Patent ID: 7404777

Claim:
A power transmission comprising: an endless, flexible, traveling transmission medium arranged to transmit rotational power from a driving sprocket to at least one driven sprocket; a main tensioner lever in sliding engagement with a first part of the length of said transmission medium extending from said driving sprocket to said driven sprocket on the side of said transmission in which the transmission medium moves from the driving sprocket toward said driven sprocket, said lever being elongated along the direction of said length of said transmission medium, having first and second opposite ends, and being pivoted on a pivot axis adjacent one of said first and second opposite ends for movement in a direction to increase tension in said length of said transmission medium; an auxiliary lever having an arc-shaped surface in sliding engagement with a second part of said length of said transmission medium adjacent said one of the first and second ends of the main tensioner lever, said auxiliary lever also being pivoted on said pivot axis, and coaxially pivotable relative to said main tensioner lever; and a spring having a first end bearing against the main tensioner lever, and a second end bearing against the auxiliary lever, and exerting a force urging the arc-shaped surface of the auxiliary lever against said second part of said length of the transmission medium.