| 摘要 |
PURPOSE: To ensure the automatic cleaning of an engaging recessed part by providing engaging teeth around a cam plate fitted onto a support shaft or formed integrally thereto, rotating the cam plate to a support member, thereby pushing out dust from the recessed part. CONSTITUTION: A take up 62 is provided to compensate the elongation of cable caused in cables 40, 42. An eccentric cam plate 54 has a number of engaging recessed parts 80 on the circumference, and a support member 56 is engaged with the engaging recessed parts 80 in a ridge part 56' as a rounded engaging part in the radial inside with respect to a support shaft 44. The radius of the rounded ridge part 56' of the support member 56 is set smaller than the radius of the engaging recessed part 80. Thus, when the cam plate 54 gets over a circumferential projection 90 present between the adjacent engaging recessed parts 80, the dust particle adhered to the engaging recessed part 80 is ground down as occasion demands, the pushed out from the engaging recessed part80 by the rounded ridge part 56' of the support member 56. |
