GB860350A - Improvements in or relating to control systems for moving strips - Google Patents

Abstract

860,350. Feeding webs. BRITISH IRON & STEEL RESEARCH ASSOCIATION. July 2, 1958 [July 4, 1957], No. 21180/57. Class 100(1 ) [Also in Group XXXV] In an arrangement for feeding a strip in which the strip is fed from a driven supply device to a driven take-up device over a path which varies from a desired path if the supply rate and take-up rates differ, the drive of one of the devices is varied in response to a pneumatic or electromagnetic detector, detecting any variation-in the free space between the detector and the strip, so as to maintain the strip in the desired path. As shown, a loop 12, Fig. 1, in a strip passing from a driven storage drum 13, Figs. 1 and 2 through a processing container 15, Fig. 1, to a driven take-up drum 14 passes near a detector 16 when the loop has the desired position. The detector 16 develops a signal, which varies with the distance from the strip thereto, and which controls a servomotor 20 through an amplifier 19. The drums 13, 14 are driven from a common motor 17, Fig. 2, drum 14 being driven direct and drum 13 through a differential gear 18 controlled by the servomotor 20 in such a sense as to correct deviations of the strip from the desired path. When the strip is of ferrous metal the detector 16 is preferably a differential transformer, the strip providing the coupling between the windings. For non-ferrous materials eddy current or pneumatic detectors may be used.