Patent ID: 8162787

Claim:
A tensioner comprising: an arm pivotable about a pivot axis in a first direction and a second direction; a stator disposed about said pivot axis of said arm and coupled to said arm for rotation therewith about said pivot axis; a roller clutch frictionally engaged with said stator by a friction contact; the roller clutch comprising: an inner hub; an outer hub concentric about the outer periphery of the inner hub; and a plurality of roller bearing elements retained between the inner hub and the outer hub with each roller bearing element in a bearing pocket in the outer hub; and a biasing element that biases the stator generally along the pivot axis into frictional engagement with the roller clutch; wherein the stator rotates with at least the inner hub or the outer hub when the arm rotates in the first direction and rotates relative to the inner hub and the outer hub when the arm rotates in the second direction; wherein said roller clutch engages only as the arm rotates in the second direction by wedging the roller bearing elements between the inner hub and the outer hub thereby preventing rotation of the inner hub and the outer hub, which activates increased friction resistance at least at the friction contact from the rotation of the stator relative to the inner hub and the outer hub and-results in a friction force applied to the arm that is axially directed generally parallel to the pivot axis.