To improve the feeling of continuation in operation by releasing the sudden lock state in inputting the torque.
A drum part 1Ab of a first thin member 1A forming an outer ring, has the approximately elliptic shape, rollers 3 are respectively mounted on a center part in the circumferential direction of each cam face 1Aa, and an inscribed line Do inscribed in an inner periphery of each roller 3 has the elliptic shape having a major axis Dx in the X-direction and a minor axis Dy in the Y-direction, when each roller 3 is kept into contact with an inner periphery of the drum part 1Ab in this state. When the input torque is input to the outer ring, the rollers 3 are successively wedged and engaged with wedge gaps from the roller 3 on the minor axis Dy, of the minimum allowance (or free from an allowance) to the roller 3 on the major axis Dx, of the maximum allowance, in accompany with the increase of the rotating quantity from a neutral position of the outer ring.
KAWAI MASAHIRO
Hideka Tanaka
Yoshiyuki Shiraishi
Kunihiko Shiromura
Tsuyoshi Kumano
Hiroaki Yamane