GB950490A - Improvements in or relating to printing machines - Google Patents

Abstract

950,490. Rotary printing machines. PROTECTIVE PACKAGING (DEVELOPMENTS) Ltd. Jan. 17, 1962 [Jan. 23, 1961], No. 2685/61. Class B6C. A rotary printing unit for printing by rotogravure on a web 14 of regenerated cellulose comprises printing and impression cylinders 27, 9, Figs. 1, 4, mounted in a housing 1 carried by a wheeled framework 55. The printing cylinder is swingably mounted on arms 20, 21, Fig. 2, about a shaft 22, Fig. 3, through hydraulic piston and cylinder arrangements 42 which connect between end plates 2 of the housing 1 and extensions 35 of the arms 20, 21. The end plates 2 are V- shaped the upper arms 4 mounting the impression cylinder 9 and web guide rollers 12, 13. A doctor blade 37 is carried between the extensions 35 in adjustable relation to the cylinder 27 whilst the housing also mounts an ink supply trough 45, an ink shield 49 and a rigid metering blade 52. Ink is pumped from a supply tank 48 to the trough 45 through a connection 46, excess ink being returned through an overflow 47. The shield 49 drains to the tank through a connection 50. The cylinder 27 is mounted in axially slidable bearings 25 the bearing carried by the arm 20 being associated with a hand wheel 30 by which the cylinder may be moved to effect axial impression adjustments. The adjusted cylinder is locked in position through a lock nut 31. The arm 21 is associated with the driving mechanism of the cylinder the shaft 26 of which is keyed to an internally splined hollow shaft 32 engageable with a male splined retractable driving shaft 33. The framework 55 has a gear-box 56 pivotable about an axis defined by hemispherical spigots 18, 19. The spigots engage flanged bushes 16, between which the shaft 22 is mounted, to align and position the printing unit relative to the framework 55. The shaft 33, which is movable through the box 56 to engage the shaft 32, is driven by gears in the box 56 from an input shaft 57. The framework also embodies a swingable arm (not shown) carrying the spigot 18 for engagement in its associated bush 16. The unit is particularly suitable for use in apparatus printing in several colours on a web such as 14. In such apparatus the web is led by guide rollers to the first of several units where it is printed in one colour. It is then pressed to drying chambers before traversing a further unit where printing is effected in another colour. After passage through further drying chambers a third colour is added by another unit and so on. The wheeled framework 55 enables the units to be readily interchanged and serviced.