| 摘要 |
PROBLEM TO BE SOLVED: To restrict a reduction of brake force for limiting a rotational torque of a shaft member.SOLUTION: There are provided a non-circular rotating member 11 rotated as a shaft 7 rotates, an abutting member 12 abutted against the outer peripheral surface of the rotating member and a biasing member 13 biasing the abutting member in a direction in which it is abutted against the outer peripheral surface of the rotating member. The abutting member intermittently limits the rotational torque of the shaft by abutting the abutting surface against the outer peripheral surface of the rotating member as the shaft rotates. It is preferable that the rotating member is formed such that a distance between the two sides where a plane passing through the rotating central axis and the outer peripheral surface cross to each other is applied as an outer diameter and its sectional shape becomes a non-circular shape around the central axis, and thereby it is divided into a maximum diameter part where the outer diameter value becomes maximum and a small diameter part where the outer diameter value becomes smaller than the maximum diameter part. |
