Patent attributes
A ratchet tensioner is disclosed for a chain enclosed within a casing that does not have a removable cover. The tensioner including a body for mounting on the exterior of the casing, a plunger slidably mounted in the body and urged in use into the interior of the casing to deflect a run of the chain laterally in order to increase tension in the chain. The plunger is formed with ratchet teeth which interact with a pawl that is pivotably mounted on the body to permit movement of the plunger only in the direction to increase chain tension. In the invention, a pin is provided for inhibiting pivoting movement of the pawl during installation of the tensioner, the pin being retractable from outside the casing in order to free the pawl after the tensioner has been mounted on the casing.
