| 摘要 |
PROBLEM TO BE SOLVED: To reduce a tapping sound generated by colliding against an arm, when a ratchet is returned by tension of a ratchet spring. SOLUTION: A turn bracket 34 is placed in a right or left turn direction position, a cancel cam 31 is rotated in the same direction, to engage with a tip end of a ratchet 37, it is turned, a base end part thereof is detached from an approaching arm 35. Further, the cancel cam 31 is rotated in the same direction, to be dislocated from a tip end of the ratchet 37, when it is returned by tension of a ratchet spring 49, by friction force between a curved surface 50 of a case 33 and a slide contact protruded part 46 of the ratchet 37, a turn speed of the ratchet is decelerated, so as to enable a tapping sound to reduce. |
