摘要 |
An apparatus which provides for a constant center distance between all drive components in a hot roll fusing assembly during fusing nip opening/closing. This apparatus includes a roll closure device which utilizes a high mechanical advantage toggle mechanism in conjunction with a cam drive. The toggle mechanism is comprised of a pivot arm pinned to the fuser frame and a force-cell attached to the pivot arm and the shaft through the backup roll. The backup roll is constrained to rotate about the cam shaft. When the cam rotates, it rotates the pivot arm, which in turn drives the backup roll either towards or away from the hot roll while maintaining a constant center distance between the backup roll center line and a center line through the cam shaft. The drive means for the backup roll includes a first gear drivingly coupled thereto which rotates on the same axis and which meshes with a second gear rotating on the same shaft as the cam. Thus, with power input at the cam shaft, the backup roll is driven with minimum backlash by gears whose center distance is constant regardless of backup roll position. |