Patent ID: 7985150

Claim:
A pulley for a member for transmitting power by means of a belt at a starting speed and then at a started speed, the torque of said member being a function of angular deformation in said pulley, the pulley including at least one resilient decoupler element operating between a central hub and a rim over which the drive belt is tensioned, wherein the resilient decoupler element is associated with a progressive deflection limiter element to form a resilient decoupling assembly that provides two stiffness values in each of a drive phase and a driven phase of the said member for transmitting power between said central hub and said rim, a first basic stiffness value being provided by the resilient decoupler element that is active at starting speed or at started speed as a result of the rotational deflection angle between said rim and said hub being less than a pre-determined deflection angle, and an additional stiffness value being provided by the progressive deflection limiter as a result of said rotational deflection angle being above said pre-determined rotational deflection angle, the resilient decoupling assembly thus providing a stiffness value greater than said first basic stiffness value.