GB735932A - Rotary printing machine - Google Patents

Abstract

735,932. Printing-machines. LINDELL, A. T. July 28, 1951, No. 17941/51. Class 100(2). In a web-printing machine wherein one or more printing cylinders 19 coact with a single impression cylinder 18, each cylinder 19 has bearings which are slidable radially relatively to the cylinder 18 and is rotated from a central main drive through a radial telescopic shaft to permit of changing the printing cylinders for others of different diameter without affecting the drive. The shaft 20 of the impression cylinder 18 is journalled in bearings 22 in side frames 16, 17, Figs. 3 and 5, and each printing cylinder 19 is held between chucks 23, 24 rotatably mounted in bearing members 26 slidable in the frames radially of the shaft 20. The drive is arranged on the frame 16 and comprises a main shaft 31 coaxial with the cylinder 18 and carrying a bevel gear 30 meshing with bevel gears 32, one for each cylinder 19 and each on a shaft 35 entering and keyed to a socket 36 so as to form a telescopic shaft. The socket 36 is journalled in and axially fixed with regard to a housing 37 attached to the slidable bearing 26 and, as shown in Fig. 3, drives a shaft 25 carrying the chuck 23 through gears 34, 28. The impression cylinder is driven by contact with the printing cylinders. Radial bolts 40 with wrench-receiving outer ends coact with the bearing members 26 to adjust the pressure of the cylinders 19 against the cylinder 18. In order that the pressure may be a yielding one, each bolt 40 is fixed to a piston 40a movable axially only in a cylinder 42 which is externally threaded for axial adjustment in the member 26 by turning the bolt 40. Air under pressure which is adjustable is supplied to the cylinder 42. To permit of adjusting a printing cylinder about its axis relatively to the cylinder 18 for obtaining correct registration of the impressions of all the cylinders, the drive between the shafts 31, 25 may contain gears 49, 50, Fig. 4 (not shown), whose axes can be adjusted angularly. In Fig. 5 is shown an arrangement for obtaining the same result and wherein the bevel gear 34<SP>1</SP> on the telescopic shaft 33 engages a gear 28<SP>1</SP> fixed to a coaxial externally-toothed gear 54 which meshes with a planet gear 55 running on a stationary internally-toothed ring 56. The gear 55 is free on a spindle 57 carried by a rotatable sleeve 58 having an internally-toothed extension 59 engaging teeth 60 formed on the end of a hollow shaft 25<SP>1</SP> carrying the chuck 23. The shaft 25<SP>1</SP> is thus driven from the shaft 33 through the gears 28<SP>1</SP>, 55, 56, 59, 60 and the cylinder 19 can be adjusted circumferentially for registration of the impressions by rotating the stationary ring 56 by means of a worm 61 engaging external teeth on the ring. As shown in Fig. 5, each cylinder 19 consists of an engraved shell 63 with cover-plates 64 secured to its ends by screws 66. A projection 68 on each chuck fits closely into a recess 67 in the corresponding cover-plate, and the cover-plate is secured to the chuck by a head 71 on a bush 69 having threaded engagement with a bolt 73 turnable by means of a spanner at its outer end. The shaft of the chuck 24 on the non-driven side is mounted in bearings 83 in an eccentric bushing 77 having a nut-like end 84 whereby it can be turned to adjust the axes of the printing cylinder relatively to that of the impression cylinder. The bushing 77 and chuck 24 can be withdrawn axially to permit of the insertion of a printing cylinder in the machine. In a construction for mounting a printing cylinder having an etched copper shell backed by a thicker cylinder, each bushing 69 extends through a collar fixed within each end of the cylinder. For mounting a thin walled shell 63, Fig. 8, between the chucks, a rod 86 is mounted within the shell between the cover-plates 64b and carries three radial shell-supporting members 87 spaced at 120 degrees apart. A stem 88 within the rod 86 has a tapered end engaging the inner ends of the members 87 whereby endwise movement of the stem causes the members 87 to be moved outwardly to support the central part of the shell. The stem 88 is threaded at its other end to engage a screwed bore in the rod 86 and has a socket 89 which can be engaged by a similarly-shaped end on a member 90 inserted through an axial bore in the bush 69a and associated parts so that the stem can be moved axially.