GB603910A - Improved means for the control of tension in strip or web material being drawn off from a roll - Google Patents

Abstract

603,910. Feeding webs. HENLEY'S TELEGRAPH WORKS CO., Ltd., W. T., and FRY, F. H. Nov. 5, 1945, No. 29364. [Class 100(i)] Apparatus for controlling the tension of a web or strip 5 during unwinding from a roll 1, e.g. paper strip lapping on to electric conductors to build up cable insulation, by the automatic and continuous adjustment of the braking-force applied by a brake-band 7 to a roll-carrier 6 rotatable about the roll-axis 2 under the pull exerted on the strip 5, the band 7 being anchored to a point 8, the band 7 is connected to a lever 19, 20 pivoted at 11 and acted on by a compression spring 18 pivoted to the lever and to a feeler arm 10 bearing against the roll 1, so that as the arm 10 turns with reduction of diameter of the roll, the force applied to the band is progressively reduced by expansion of the spring and simultaneous alteration of the direction of the force of the spring with reference to a line through the pivot 11 and the point of attachment of the spring 18 to the lever 19, 20: the other end of the spring is pivoted to an arm 21 extending from the arm 10, by a screw 22 adjustment of which varies the compression of the spring. Where the roll 1 ratates bodily about an axis, balance weights may be applied to the arm 10 to counteract centrifugal forces, and where it is found that the resistance to unwinding of the strip 5 from the roll 1 increases with the increase in the speed of the machine, a weighted lever may be provided to counterbalance some of the spring effect or to act directly on the brake to produce under centrifugal force a decrease in the braking effect. The arm 10 carries a feelerroller 12 which may be replaced by a shoe.