HOT ROLL FUSER FOR A XEROGRAPHIC COPIER

摘要

In a hot roll fuser for a xerographic copier, the hot roll 14 is mounted at a fixed axial position and the back-up roll 16 is mounted on pivot arms 36 for pivotal movement about axis 38 to and from the hot roll. A further pivot arm assembly is mounted on an axis 42 positioned between the axes of the rolls. This assembly includes two arms 40, each of which extends round the axis 34 of the back-up roll to a mounting position 60. At each end of the back-up roll, a compression spring 50 is mounted between the roll axis 34 and mounting position 60. Arms 40 each include a cam follower surface 44 which engages the surface of a cam 46. As cam 46 rotates it causes movement of the arms between a position at which back-up roll 16 is separated from roll 14 and a position at which roll 16 is urged into contact with roll 14 by springs 50. At this latter position, the axis 34 of the back-up roll is positioned on a line between pivotal axis 42 and mounting position 60.