Rotational one way clutch chain tensioner with frictional damping

A tensioner for a continuous loop power transmission system of an internal combustion engine, the continuous loop consisting of a chain having a first strand and a second strand, each strand located between a drive sprocket connected to a driveshaft and at least one driven sprocket connected to at least one camshaft, comprising:

• a) a first tensioning arm having a first end, a second end and a chain sliding surface operatively engaging the first strand of chain;
• b) a second tensioning arm having a first end, a second end and a chain sliding surface operatively engaged with the second strand of chain, the second end of the first tensioning arm being mounted to the engine by a pivotal mounting means and the second end of the second tensioning arm being mounted to the engine by a pivotal mounting means;
• c) a one-way clutch including frictional damping means, the one-way clutch pivotally mounted to the engine at a location between the first ends of both tensioning arms, a first linkage connecting the first end of the first tensioning arm to the one-way clutch and a second linkage connecting the first end of the second tensioning arm to the one-way clutch;
• and
• d) a biasing element coupled to the one-way clutch or at least one of the first tensioning arm or the second tensioning arm to bias the first end of the first tensioning arm and the first end of second tensioning arm towards each other;
• wherein, the one-way clutch is alternatively rotatable in a first direction to adjust tension substantially equally on both strands of chain in response to regular fluctuations in the tension of the chain and a second direction, opposite the first direction, to reduce periodic tension overload conditions experienced by the chain only when a pre-determined resistive force in the frictional damping means is overcome by the force of the tension overload.