| 摘要 |
<p>1,112,751. Feeding webs. P. NASH. 19 Jan., 1966 [22 Jan., 1965], No. 2482/66. Heading B6B. A device 1 for causing a moving web of material to be evenly tensioned across its width comprises a flexible shoe 31 over which the web passes and which extends beyond the web at both edges, the shoe being flexibly pressed towards the web. The even tensioning prevents flutter of the web which may cause faulty winding up of the web or erroneous operation of a web-inspection apparatus to which the web is being fed. As shown, a housing 15 is divided lengthwise into compartments 19 each of which contains an inflatable member 25. A flexible nylon sheet 30 passes around the bottom and sides of each member 25. The shoe 31 which is made of a material which flexes readily e.g. sheet phosphor bronze, beryllium &c., extends the full length of the housing 15 and has flanged parts 35 engaging side strips 22 on the housing. The flanges 35 are slotted (Fig. 5). The pressure in the members 25 is adjusted to give the required tensioning e.g. if the tension in the marginal portions of the web is less than that in the centre portions, the pressure in the outer members 25 is made greater than that in the centre members. The variation of the pressures may be effected under the control of flutter-detecting devices. A modified form of shoe (41, Figs. 6, 7) may be used in place of or in addition to the shoe 31. Further, mechanically-adjustable foam rubber or plastic pads may be used to apply resilient pressure to the shoe.</p> |
