GB947591A - Improvements in or relating to rolling mills - Google Patents

Abstract

947,591. Rolling. UNITED ENGINEERING & FOUNDRY CO. April 28, 1960 [April 30, 1959], No. 14912/60. Heading B3M. A mill for reducing strip of uniform thickness comprising a pair of small diameter work rolls 14, and large diameter back-up rolls 15, 16 for supporting the work rolls includes means for applying to said backup rolls a force of a controlled magnitude to eliminate camber and maintain the strip thickness constant. The back-up roll 15 is supported at the ends and adjusted to define the pass by screwdowns 21 operated by wormwheels 22 and is further supported by a roll 25 journalled in a vertically slidable frame 27. Variable pressure is applied to the frame 27 by fluid cylinders 31, the particular pressure used being related to the dimensions and properties of the strip in the pass and is sufficient to eliminate the camber of the working rolls. A roll 32 applies a similar pressure to the backing roll 32. Fluid is supplied to cylinders 31, 36 by a variable pressure pump 38 driven by a variable speed motor 39. The rolls may be uncrowned or crowned, in the instance the rolls 25, 32 compensate for the latter thickness error due to using a given crown under varying conditions of rolling, e.g. varying properties and dimensions of strip. The frame 27 is supported by a cylinder 28 and the chocks of both the backing and the working rolls are biased apart by cylinders 41, 42 respectively. In a modification, the screwdowns 21 are replaced by fluid cylinders acting on the chocks of the back-up rolls, the cylinders being supplied by a pressure pump driven by a variable speed motor.