GB806370A - Automatic thickness regulation in rolling machines - Google Patents

Abstract

806,370. Rolling plastic materials. BRUCKER, H. April 15, 1957 [April 23, 1956], No. 12260/57. Class 87(2). [Also in Groups XXII and XXXV] In apparatus for regulating the thickness of rolled thermoplastic materials, &c. by automatically varying the tension before or after the roll gap according to measured thickness variations, the roll pass is also adjusted automatically when the tension varies outside preset limits. Strip 1, Fig. 1, supplied under tension from a reel 2 braked by a motor 4 is rolled between adjustable rolls 7, 8 and wound under tension onto a reel 12 driven by a motor 14. The strip passes over tension rollers 16, 17, 18 on each side of the roll pass, the control movable roller 18 being supported through a piston rod 19 by a spring 25 and a piston 20 in a cylinder 21 in which the pressure is set to give a predetermined tension of the strip. The tension is normally maintained constant by the engagement of a contact arm 22 on the piston rod 19 with contacts 23, 24 controlling the torque of the motors 4, 14 through servo-motor systems. A thickness measuring device 29 with sensing rollers 30, 31 is placed behind the rolls 7, 8 and varies the tension in the strip by opening inlet or outlet valves 26 or 27 which raise or lower the pressure in the cylinder 21 so that the roller 18 and piston 20 is moved causing the contacts 23 or 24 to be engaged with a resultant change in the torque of the motor 14 and strip tension. The pressure in the cylinder 21 is indicated by a monometer 32 having electrical contacts 33, 34 set at the limiting values of pressure as determined by the required limits of strip tension. As soon as these limits are exceeded the contacts cause the valves 26 or 27 to close preventing further changes in tension and operate a servo-motor which reduces or increases the roll pass by raising or lowering the roll 7.