GB1361565A - Method and apparatus relating to loading and separating rollers of a calender - Google Patents

Abstract

1361565 Calenders BRUDERHAUS MASCHINEN GmbH 3 March 1972 10094/72 Heading D2A In a super-calender having a vertical stack of rollers, the rollers are loaded by downward movement of pistons 16 of rams 14 acting on the top roller 2" while the bottom roller 2' is maintained in its operative position by pistons 11 of rams 9 moved upwardly against a stop 13 and acting on the bottom roller, and the rollers are separated, e.g. in the event of web breakage, by upward movement of the pistons 16 and downward movement of the pistons 11, the latter movement occurring when the force exerted by the pistons 16 corresponds substantially to that necessary to lift the top roller. The rollers consist of hard and resilient rollers alternating with each other and rotatably mounted in side plates 3 which are slidably mounted on a frame 4. Threaded spindles 6 carried by the top side plates 3" slidably engage in aligned lugs 5 on the other side plates, except the bottom side plates 3', and carry adjustable nuts 8 for engaging the lugs 5. The travel of the piston 11 is equal to the sum of all the gaps between the rollers when these are lifted. In a hydraulic circuit, Fig. 2 (not shown), magnetically operable valves control fluid flow from a first pump to the bottom sides of the pistons 11 and 16, and from a second pump to the top side of the pistons 16. The bottom roller 2' is lowered by draining fluid from below the pistons 11 through valves which are under the control of rams operating to mechanically unseat closing members of the valves in dependence upon the pressure of the fluid below the pistons 16 reaching that necessary to lift the top roller 2". When a limit switch 32 senses that the bottom roller 2' and the adjacent roller are separated it causes the upward movement of the pistons 16 to stop.