Patent ID: 7506738

Claim:
A sprag type one-way clutch of disengaging type comprising: an outer race having a substantially annular inner peripheral track surface; an inner race spaced apart from said outer race in a radial direction, disposed coaxially with and rotatable relative to said outer race, and having a substantially annular outer peripheral track surface; a plurality of sprags disposed between said outer race and said inner race so as to be able to transmit torque between said inner and outer peripheral track surfaces; and a ribbon spring for applying rising moment to said sprags, wherein an outer diameter side cam surface of each sprag is provided with a mechanism for preventing fluctuation of the sprag during a predetermined rate of rotation of said outer race, said mechanism includes a posture stabilizing area provided at a predetermined position on an idle rotation side of said outer diameter side cam surface of the sprag, and, when said outer race is idly rotated at the predetermined rate of rotation, each sprag is line-contacted with said outer race at two predetermined points spaced apart from each other by a predetermined length in a circumferential direction in said posture stabilizing area and a direction of an action line of a centrifugal force from a gravity center of said sprag is positioned within said posture stabilizing area.