摘要 |
Each of the movable rolls of the calendar is associated with an adjustable brake means by which the velocity of descent of each roll can be adjusted into a pattern to effect and maintain a gap between each pair of adjacent rolls immediately upon opening of the calendar. The individual brake means are constructed as threaded studs having a bore in which a piston is mounted and to which hydraulic medium can be pumped via a restricted duct. The restricted duct cooperates with a bypass valve in the hydraulic lines to allow the hydraulic medium to flow back to a reservoir from the bore upon descent of a roll. The restricted duct of each brake means is adjustable relative to the return flow of medium so that the lower rolls are allowed to descent more rapidly than the upper rolls. |