GB1036880A - Improvements in or relating to web-fed printing machines - Google Patents

Abstract

1,036,880. Feeding webs. FORMMASTER Ltd. Nov. 25, 1963 [Nov. 23, 1962], No. 44301/62. Heading B6B. A web feeding device for a printing machine of the type described in Specification 950,053 comprises a pair of rotatable friction nip rollers, at least one of the pair being connected for driving and being readily interchangeable with a roller of different circumferential length. In the embodiment illustrated, Figs. 2 and 3, one of the pair of nip rollers 3 is mounted for rotation with a shaft 11 keyed to a driving shaft 16. The other of the pair of nip rollers is an idler roller spring biased against the driven roller 3. The shaft 11 is joumalled at 19 in a mounting block 20. With the aid of a knob 21, the mounting block 20 may be removed from its bayonettype connection, Fig. 3, comprising studs 22 and spring-loaded washers, Fig. 2. In this manner the shaft 11 and roller 3 may be removed for replacement by a shaft with a roller of different circumferential length. The nip rollers described above may be used as the feed-in and feed-out devices for the type of printing machine described in Specification 950,053, wherein they would be driven intermittently or continuously in synchronism with the printing rollers. In a modification (not illustrated), a set of two or more parallel rollers of different circumferential lengths are held in a turret which is rotatable to interchange the roller which cooperates with the spring biased idler roller forming the nip, the arrangement being that either the one co-operating with the idler roller or all of the rollers in the turret are driven. In a further embodiment (not illustrated) the driven roller may comprise a series of discs or wheels mounted for rotation with a shaft, the circumferential lengths of the discs or wheels increasing from the centre of the series, and the discs or wheels being relatively adjustable along the shaft. A selected pair of discs are adjusted to engage the web adjacent the edges. The idler roller may also be formed of a similar series of discs or wheels adjustable along the shaft thereof. Instead of different discs, a single member of tapering form adjustable along the shaft may be used to engage each margin of the web. An expandible roller or a roller to which pairs of semi-cylindrical shells may be added may be used instead of replacing the driven roller. The invention may be used in combination with that forming the subject matter of Specification 993,911.