Method of adjusting the contact pressure of a rolling mill and apparatus for the performance thereof

A method of adjusting the contact pressure of a rolling mill for rolling a web of material, comprising the steps of:

• providing at least one pair of rolls comprising at least one controlled deflection roll equipped with a plurality of pressure elements operable by a pressure medium and a counter-roll cooperating with said controlled deflection roll;
• passing a web of material through the nip between the controlled deflection roll and the counter-roll;
• measuring at a number of measuring locations across the web of material, downstream of the nip of the pair of rolls with respect to the direction of travel of the web of material, the action of the pair of rolls upon the throughpassing web of material to thereby obtain measured values;
• and
• regulating the pressure of the pressure medium supplied to the pressure elements associated with the measuring locations as a function of the measured values so as to establish a required set value at each of the measuring locations.

An apparatus for adjusting the contact pressure of a rolling mill for rolling a web of material, comprising:

• at least one controlled deflection roll;
• said controlled deflection roll including a plurality of hydrostatic pressure elements;
• means for supplying a hydraulic pressure medium to said hydrostatic pressure elements;
• a counter-roll;
• means for mounting said controlled deflection roll and said counter-roll in cooperating relationship to define therebetween a nip through which passes the web of material undergoing rolling;
• at least one measuring device for measuring a web characteristic which can be influenced by the pressure of the cooperating pair of rolls at measuring locations distributed along at least part of the width of the web;
• and
• means for adjusting the pressure of the pressure medium supplied to the pressure elements as a function of measured values derived by the measuring device at the associated measuring locations.

An apparatus for adjusting the contact pressure of a rolling mill for rolling a web of material, comprising:

• at least one controlled deflection roll;
• said controlled deflection roll including a plurality of pressure elements;
• means for supplying a pressure medium to said pressure elements;
• a counter-roll;
• means for mounting said controlled deflection roll and counter-roll in cooperating relationship to define therebetween a nip through which passes the web of material;
• measuring means for measuring a web characteristic which can be influenced by the pressure of the cooperating pair of rolls at one or more measuring locations distributed along at least part of the width of the web;
• and
• means for adjusting the pressure of the pressure medium supplied to the pressure elements as a function of measured values determined by the measuring means at the measuring locations.