| 摘要 |
945,953. Feeding webs. COMPAGNIE FRANCAISE THOMSON-HOUSTON. April 11, 1960 [April 9, 1959], No. 12926/60. Heading B6B. [Also in Division D1] A device for regulating the tension in an elongate non-rigid moving element (e.g. strip) comprises a first rotatable member over which the element passes and which is driven relative to the element and a second member freely rotatable by the element passing over it, the axis of the second member being movable relative to the driven member to vary the length of element contacting the driven member. As shown, a wire 1 passes over a capstan 3 driven about an axis O, over a freely rotatable pulley Q, and about a pulley P freely rotatable about the axis O before passing to a support 2 to be wound. The pulley Q is mounted on an arm 4 which is rotatable about the axis O and is fast with a pulley M about which a wire 5 is wrapped and weighted by a weight P to give a constant anti-clockwise couple acting on arm 4. Because of the difference in radii of capstan 3 and pulley P the tension in the wire 1 causes a clockwise couple to act on the arm 4 which therefore takes up a position such that the opposing couples are equal. The tension F 1 in the elongate element downstream of the capstan is therefore maintained constant irrespective of the tension F 2 upstream of the capstan. In the form shown capstan 3 is driven clockwise to make tension F 1 less than tension F 2 . If F 1 is to be greater than F 2 then capstan 3 should be driven in an anticlockwise direction, the couple produced by the weight P should be reversed and the radius of the capstan should be made greater than the radius of the pulley P. |
