GB1180961A - Web Transport System. - Google Patents

Abstract

1,180,961. Feeding webs. EASTMAN KODAK CO. 5 June, 1967 [6 June, 1966 (2)], No. 25836/67. Heading B8R. [Also in Divisions F2 and G2] A support roller such as is used in transporting film strip through a processing system comprises a flanged spool 20 having a rigid rim 24 bounded by the flanges 23, and a rigid hub 32. Rim and hub are maintained in concentric relation by flexible connecting means, which may be two spiral members 31 as shown in Fig. 3, or an annular member of foam rubber (36, Fig. 4, not shown). If any variation in tension occurs as the film passes over such rollers (e.g. because of stretching or shrinking), the rim can be displaced relative to the hub. Fig. 1 is an arrangement in which the film is passed through a processing tank over a set of upper and lower rollers 20, 22. The upper rollers rotate so that they are just out of contact with a drive roller 26 mounted on a drive shaft 18. If tension in the film increases, the rims of rollers 20 are displaced downwards so that they are brought into contact with drive roller 26. This is rotating at a slightly faster speed than rollers 20, so that the speed of the film is increased, so relieving the tension beyond that point. In the modification of Fig. 5, a drive roller 52 is secured to a drive shaft 50 by a set screw 54. A film support spool 55 having a rigid flanged rim 56 is mounted freely on shaft 50 by means of a loosely fitting rigid hub 66. Normally the spool 55 rotates concentrically round drive roller 52 but is just out of contact with it. Hub and rim are connected by spiral flexible members 68 of involute shape (see also Fig. 6, not shown). Thus when film tension is increased, as by shrinkage, the rim is displaced against the spring members 68 until the inner surface of spool 55 comes into contact with drive roller 52, and is hence driven at a slightly faster speed, until the increased tension is reduced, and the reverse " de-clutching " action takes place.