| 摘要 |
PROBLEM TO BE SOLVED: To hold the tension of a polishing belt by retracting a rear guide roll outward of the loop of the belt even though the polishing belt is slackened and depressed inward of the loop when a front guide roll is retracted, so as to simplify the structure, and to enhance the follow-up responsiveness for stretching motion which takes up slacking of the belt. SOLUTION: A front guide roll 14 for guiding the rear surface of a polishing belt on a processing position D side and a rear guide roll 15 for guiding the rear surface of the polishing belt on the side remote from the processing position D, are arranged respectively at both longitudinally ends of a link member 8 which can be extended and retaracted to and from the processing position D by an extending and retracting mechanism 9, and the link member can be pressed toward the processing position D by a pressing mechanism. |
