GB309883A - Improvements in or relating to printing presses - Google Patents

Abstract

309,883. Goss Printing Press Co. of England, Ltd., and Smith, E. J. Jan. 13, 1928. Feeding webs.-A printing-press, and particularly a press equipped with web-renewing mechanism such as that described in Specifications 260,049, .265,667, and 280,272, is provided with two pairs of angularly movable arms so disposed as to receive between them a reserve roll which can be placed in either pair of arms while an active roll is supported in the other pair of arms, in conjunction with pressure rollers between which the active web passes to the press and also between which the leading end of the reserve web can be placed ready to be joined to the exhausting web when the rollers are pressed together. An active roll 1, Fig. 1, and a reserve roll 2, are mounted in pairs of arms 3 fixed to cross shafts 4 provided with worm-wheel segments 19 engaged by hand-operated worms 20. When a roll is to be inserted, the arms are lowered and a truck 35 bearing a new roll is run from the side of the press on to a second truck 33 mounted on rails 34 in a pit 32 and movable in a direction at right angles to the shafts 4 to bring the roll between the arms 3. The arms 3 carry short spindles 6, Fig. 4, having bung-like ends 7 to engage the ends of the roll core and one spindle is slidably keyed within a rotatable sleeve 10 and is movable axially, to facilitate the insertion of the roll, by a lever 13, actuated by a screw 16 and carrying pins 12 engaging a grooved collar 11 on the spindle 6. The web passes to the press between a pair of rollers 24 of the web-renewing mechanism such as described in Specification 280,272, and the web may be driven and controlled by belts 28 actuated in the manner also described in that Specification or, instead of the belts, a similarly driven and controlled roller 31 may be employed. A pit 36a in which the operator can stand is provided to facilitate the application of the paste to the web during the renewing operation. The sleeve 10 may be provided with a pair of screw-actuated brake shoes 36, or with a brake band 52, Fig. 7, actuated automatically by the varying tension of the web. For this purpose, the web passes round a spring-mounted roller 37 and round a roller 38 mounted in guides 40 and connected by a link 41 to a bell-crank lever 42 fixed to a shaft 42b and connected by a link 43 to an arm on a shaft 45 carrying a pulley 46 to which end of a cable 47 is attached, the other end of the cable being secured to an arm 51 on a shaft 51a carrying an arm 51b connected to the brake band 52. A torsion spring on the shaft 42b urges the roller 38 against the web., As the tension of the web varies the roller 38 is moved by or against the action of the torsion spring and increases or decreases the pull on the cable 47 to apply or release the brake and thus restore the normal web tension. To take up slack in the cable 47 when the arms 3 are actuated. the cable is passed round a jockey roller 48 on an arm 49 loose on the shaft 45 and having a slot connection with a link 53 connecting the arm 49 to a collar 54 or other member moving with the shaft 4. The torsion spring on the shaft 42b is secured at one end to a collar fast on the shaft and at the other end to a loose worm-wheel 55 rotatable by a worm 56 for adjusting the tension of the spring.