Patent ID: 7086359

Claim:
A rotational phase adjusting apparatus for adjusting a difference in rotational phase between a rotating member and a driven member rotationally driven by the rotating member, comprising: a first element capable of being connected to the rotating member so that the first element is rotationally driven by the rotating member, a second element capable of being connected to the first element and the driven member so that the driven member is rotationally driven through the second element by the first element, a third element capable of being set at either of a first condition at which first condition the third element is compressed between the first and second elements to prevent the first and second elements from rotating with respect to each other and a second condition at which second condition the third element is released from at least one of the first and second elements to allow the first and second elements to rotate with respect to each other, and a fourth element rotatable with respect to one of the first and second elements and facing to the third element so that the fourth element is capable of setting the third element at selected one of the first and second conditions, wherein the apparatus further comprises: an elastic member arranged between the fourth element and the one of the first and second elements to enable a rotational positional relationship between the fourth element and the one of the first and second elements to be elastically variable, and a brake for generating a variable braking force to be applied to the fourth element so that the rotational positional relationship between the fourth element and the one of the first and second elements and a value of a force applicable from the fourth element to the third element are elastically variable in accordance with a value of the variable braking force, when the first element is rotationally driven by the rotating member, the fourth element is rotationally driven by the one of the first and second elements through the elastic member and the fourth element is braked by the variable braking force.