| 摘要 |
A first member (1) holding a disc body (16) having a non-circular through hole (23) as to freely rotate around an oscillation axis (C), a non-circular shaft portion (20) to be inserted to the through hole (23), and a second member (2) fixed to an end of the non-circular shaft portion (20), are provided; the first member (1) and the second member (2) are pivoted as to relatively oscillate by insertion of the shaft portion (20) to the through hole (23), a gear portion (4) is formed on a peripheral edge portion of the disc body (16) ; a floating wedge member (6), of which one side is a toothed face (7) engaged to the gear portion (4) and another face is a contact face (9) to contact a wedge face (8) formed on the first member (1) side, is provided; and a recovery means (10), which recovers the floating wedge member (6) from a retreat state to an engaged state with the gear portion (4) by a return action (M 2 ) of a predetermined small angle (¸) in a direction (A) on way of free oscillation (M 1 ) in which the first member (1) and the second member (2) are relatively oscillated in a direction (B) from a lock-releasing position (P 0 ), is provided. |
