Method and arrangement for positioning a shoe of a shoe press/shoe calendar in a paper machine

An arrangement for closing a shoe within a belt, against a backing roll to form a nip between the backing roll and the shoe of a shoe press/shoe calender in a paper machine, the nip extending in a cross machine direction, the arrangement comprising:

• a shoe roll, having a shoe, a belt within which the shoe is positioned, and hydraulic cylinders connected to the shoe for moving the shoe towards and away from the backing roll;
• at least two measuring devices for measuring the position of the shoe, the measuring devices being positioned to determine the position of the shoe with respect to a reference position at two positions on the shoe which are spaced in the cross machine direction;
• and
• means for controlling the position of the, shoe during the closing of the shoe against the backing roll to form the nip based on the results obtained by the measuring devices so the nip is of a desired shape.

An apparatus for closing a shoe against a backing roll to form a nip between the backing roll and the shoe in a paper machine, the apparatus comprising:

• a backing roll;
• a shoe;
• a belt within which the shoe is positioned, the shoe being loaded against the backing roll to define a nip by a plurality of hydraulic cylinders;
• a frame extending within the belt, the hydraulic cylinders supporting the shoe on the frame;
• at least two position measuring sensor arranged in connection with the shoe between the shoe and the frame, the sensors measuring the position of the shoe and producing position measurements, the position measuring sensors being spaced from one another in a cross machine direction;
• and
• a processing unit which receives the position measurements from the position measuring sensors, the processing unit generating signals which control the hydraulic cylinders to close the shoe towards the backing roll.