| 摘要 |
A mechanism with an inner race, which has cams, an outer race and rollers between the cams and the outer race. The inner race has a first notch while the outer race has a second notch with a narrow portion and a wider portion. A member is disposed in the first and second notches. Positioning of the member in the first notch and the narrow portion of the second notch inhibits relative rotation between the inner and outer races and power is not transmitted between the outer race and a power transmitting member, such as a gear. Positioning of the member in the first notch and the wider portion of the second notch permits some relative rotation between the inner and outer races to cause the cams to urge the rollers outwardly so that the outer race frictionally engages the power transmitting member to facilitate transmission of rotary power therebetween. |
