| 摘要 |
A system for tracking an endless image copying or recording belt and maintaining it in alignment within a confined area includes at least three rollers with four rollers being preferred. The first roller is a cylindrical drive roller and the second and third rollers are cylindrical driven rollers. The fourth roller is cylindrical along a major central portion and flares outwardly at the end portions. The third roller is mounted on support arms which, in turn, are mounted to pivot about the axis of the second roller and are biased normally to maintain uniform tension in the belt. If the belt creeps toward one end of the flared roller, the climb to the larger diameter displaces the tape which causes the corresponding end of the third roller to dip thereby causing the belt to move laterally back toward a central position. |
