| 摘要 |
An expander roller for the wrinkle-free guidance of webs in closed chambers comprises two stationary supporting bodies ( 7, 8 ) which are oriented with respect to one another at an obtuse angle in the proximity of a center plane (E-E). On both sides of the center plane (E-E) on the supporting bodies ( 7, 8 ) are disposed roller sections ( 12 ) with surfaces in the form of truncated cones with shell lines (M 1 , M 2 ) and which during their rotation pass through positions in which said shell lines (M 1 , M 2 ) are aligned with one another. The surfaces ( 12 a) of the rollers are herein steplessly in line one with the other in succession and the rollers are supported via roller bearings in groups ( 10, 11 ) on the two supporting bodies ( 7, 8 ). To reduce speed differences when taking off the webs, to avoid scratches on the webs and to improve the precision of guidance and smoothness of operation, the rollers on both sides of the center plane (E-E) are each comprised of at least two roller sections ( 12 ) rotatable independently of one another. Before aerating the vacuum chamber, in the method for operation a gas is introduced into the bearing region through which solid bodies from the group dust and particles are blown out of the bearing region and solid bodies are prevented from penetrating into the bearing region.
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