GB1425826A - Eccentricity correction means - Google Patents

Abstract

1425826 Rolling mills DAVY-LOEWY Ltd 14 May 1973 [21 Feb 1972] 7831/72 Heading B3M [Also in Division C3] During operation of a rolling mill measurements representative of eccentricity of the work rolls (or of the backing rolls if these are present) are made and are applied to a plurality of electrical stores, the outputs of the stores subsequently being fed, in synchronism with the work rolls (or the backing rolls), to apparatus for adjusting the roll gap, in a sense to compensate for the eccentricity. In a two-high mill, Fig. 1, or a four-high mill in which the backing rolls rotate in synchronism, the works rolls are rotated in contact and provide a pressure output signal at 5 representative of roll eccentricity. The signal is fed by a switch 6 successively to stores 7 (of which there may be sixteen). During subsequent rolling, the outputs of the stores are successively connected by a switch 8, which operates in synchronism with the rolls, to a roll gap adjuster 4. In a four-high mill in which the backing rolls do not rotate in synchronism, Fig. 2, a signal representing the eccentricity of all the rolls is provided by a workpiece thickness gauge 13 located downstream of the mill. The signal is fed through a time delay unit 14 to stores 16 and is subsequently fed to the roll gap adjuster 19. The period of delay corresponds to a whole number of revolutions of the backing rolls. The adjuster 19 is also fed with an error signal corresponding to any difference between a reference roll gap and the actual gap. The adjuster 19 in the arrangement of Fig. 1 can also be provided with an error signal relating to the roll gap. A combination arrangement, in which both pressure differences during initial rotation of the work rolls is measured and gauge variations in the roll workpiece are measured, may be employed.