Patent ID: 8021253

Claim:
A one way isolator to transfer torque between a flexible drive means and a device, comprising: a hub configured for mounting to an input shaft of the device, the hub including at least one stop member; a sheave rotatably mounted to the hub and including at least one stop member; a torsion spring extending longitudinally along a rotational axis of the hub between the hub and the sheave, the torsion spring having a first end engaging the hub and a second end engaging the sheave to elastically couple the hub and sheave; wherein rotary power is transmitted between the at least one stop member of the hub and the at least one stop member of the sheave when torque is transferred in a first rotational direction from the hub to the sheave to drive the flexible drive means and, when torque is transferred from the sheave to the hub in the first rotational direction, the sheave is rotatable with respect to the hub such that the torque is not transmitted between the at least one stop member of the hub and the at least one stop member of the sheave and the torque is transferred from the sheave, through the torsion spring and into the hub.