Abstract: A calendar stack is provided with pneumatic actuators of the expansible bag or bellows type wherein a selected roll has the end bearings thereof carried by a pair of pivoted control arms, the position of a respective control arm being selectively controlled, for upward loading or for downward loading of the stack by a single primary actuator. The selected direction of force application by the primary actuator is determined by a force transmission linkage shiftable by a secondary actuator between a first and a second position, for roll upward loading or roll downward loading.

Abstract: A follower roll or so-called spring roll system for use with a paper machine has a roll about which the paper web passes on its path through the machine, the web having a wrap angle about the roll of about 90.degree., to exert a horizontal force component against the roll, due to web tension. The roll bearings are each supported on a low friction slide, to permit substantially friction free displacement of the roll horizontally. The position of each roll bearing housing is controlled by an air bag acting as a variable rate spring to oppose displacement of the roll under web tension, with a second air bag opposed thereto, acting as a constant rate displacer, to assist the displacing effects of web tension. The two bearing housings are synchronized in their displacement under web tension variations by a synchronizing shaft extending across the width of the machine and connected with each of the two bearing housings by a rack and pinion arrangement.