GB1161208A - Rolling Mills. - Google Patents

Abstract

1,161,208. Rolling. DAVY & UNITED ENG. CO. Ltd. 21 Nov., 1966 [25 Nov., 1965], No. 50166/65. Heading B3M. [Also in Division G3] A four-high prestressed rolling mill includes spacers which are arranged between the working roll chocks, and which are automatically adjusted to maintain the thickness of a rolled product constant. For each housing 12 the spacers are in the form of screws 27 which are threaded into nuts 28, fixed in an upper working roll chock 21, and abut load cells 33 in a lower chock 18. Each screw is rotatable to vary the spacing of the chocks 18 and 21, by means of gearing 30-32, splined shafts 37 and 41, and a common driving motor 43. A prestressing cylinder 24 provides a force in excess of the rolling load. Signals are taken from the load cells 33, from position transducers 44 to give a measure of the roll spacing, and from a transducer 51 to give the prestressing load. These signals are processed and compared with a desired strip thickness set on a potentiometer 56. Any error signal is fed to the motor 43 to control the movement of the screws 27. It is preferred to maintain the prestressing force constant, in which case the signal from transducer 51 is compared with a reference set at 67, any difference signal being applied to a control valve 26 to maintain the pressure at the reference value. The value on the potentiometer may be automatically changed, however, in order to keep the difference between prestressing and rolling loads within a given low range.