PISTON APPARATUS FOR USE IN WEB PRESSING COMPONENTS IN PAPERMAKING MACHINERY

摘要

A piston apparatus for use in a controlled deflection roll includes a rectilinear-shaped piston (10a) having at least one side seal (22a, 22a') extending longitudinally in a slot (12a, 12a') in each sidewall and an end seal (21) in each end of the piston extending between the side seals. The end seals have at least one pair of intersecting surfaces (62, 64) at each end thereof which cooperate with a corresponding pair of surfaces of each side seal to move longitudinally relative to the piston and side seals to maintain a continuous seal peripherally about the piston. The continuous seal engages the sidewalls (26, 26') of a channel (30) within the support shaft (32) of the controlled deflection roll (34) and a non-movable seal surface (37) in each of two, opposed dams (36, 36a) at either end of the channel in the support shaft (32). The side and end seals (22a, 21) move with the piston (10a) relative to the support shaft (32) and seal surfaces on the end dams.