| 摘要 |
1353586 Feeding webs DEBRIE-LAWLEY Ltd 19 April 1971 [13 March 1970] 12336/70 Heading B8R [Also in Division G2] A web 10, e.g. a cine-film, is guided in a serpentine path through a series of processing compartments 3, 4 by means of banks 14 of rollers 17, 19 arranged in upper and lower rows as shown. The upper rollers 17, except for the inlet roller to the first compartment 3, are mounted on shafts 21 each of which co-operates with a pivotally mounted driving roller 73 itself co-operating with a roller associated with a sprocket wheel 65 engaging an endless chain 55 driven by a motor 49, the inlet roller being positively driven from the chain 55 by means of a further chain and sprocket 69. The lower rollers 19 are mounted in saddles (29) Fig. 2 (not shown) which can move vertically under the pull of the web, this movement being communicated to the driving rollers 73 by way of a linkage including a connecting rod 35. The web is withdrawn from the processing apparatus by a take-up motor 35 at the same rate as it is fed into the apparatus by the positively driven roller 17, and each cradle 29 normally remains near the bottom of its compartment 3 or 4. However, should the length of web within a bank 14 decrease during operation of the apparatus, the relative cradle (29) will lift and urge its associated roller 73 upwardly, thus reducing or disengaging the drive from sprocket 65 to the co-operating upper roller 17, whereby the rate at which web is drawn from the bank 14 decreases and the cradle 29 moves down to its initial position. Should the length of web within a bank increase, the loops become loose and the positive drive into the bank is reduced to restore the position. Thus the arrangement tends to drive the web through a compartment at a constant speed with a constant length of web in the compartment throughout processing. |
