Patent GB-802595-A (GB)
Title: Machine for printing flexible plastic containers
IPC: B41F17/00
Filed: 1956-05-24
Abstract: 802,595. Printing on curved surfaces; inking-apparatus. HAYWARD, H. M. May 24, 1956 [May 24, 1955], No. 16087/56. Class 100 (2) In a machine for printing on flexible plastic containers, the latter are accommodated in pallets uniformly spaced on an endless conveyer which carries them below an etched metal printing - cylinder mounted in a printing head vertically adjustable and lockable in a selected position, and a doctor blade is mounted on an axially slidable shaft so as to be reciprocated with respect to the cylinder, against which it is held by a spring. Pallets 19, Fig. 1, are secured at their leading edges to a conveyer 12, Figs. 1 and 3, travelling over a table 10 on sprockets 16, 14 and guide rails 17, 18. Containers are placed in cradles attached to the pallets at position 22 and ejected therefrom at 23. Mounted on a shaft 61 journalled in the rails 18 is a printing head 24 in which rotates a shaft 34 carrying the printing-cylinder 33. The head 24 is provided with rack teeth 26, and its height is adjusted by a handwheel 28 on a shaft carrying a pinion 27 engaging the rack, a pointer 31 indicating the height against marks 32 on the table 10. A motor 53 by a belt drive 55, 59 rotates the shaft 61, a pinion on which rotates a gear 63 on a shaft 64. A sprocket 65 on the shaft 64 drives a chain 66 and thence the driving sprocket 16 of the conveyer 12. The gear 63 also drives a pinion 67, and thence a pinion 68 and a gear 69 on the cylinder: shaft. The cradles may be shaped to accommodate carious shapes of containers. The cradle 21A, Fig. 10, has a plurality of recesses 81 to accommodate elongated containers 82 longitudinally aligned by stops 83. The cradle may have one wide V-shaped recess with one end-stop. The containers are printed :on as they pass under the cylinder 33, and if it is desired to print on them prior to filling flexible pads of rubber are used to support them instead of cradles. For multi-colour printing several printing heads as above described are provided. Inking-apparatus. Ink is supplied to the top of the cylinder 33 through valve-controlled outlets 42 of a pipe 40 supported by a clamp 41 and communicating with the outlet of a pump 43 driven by the motor 53 through a belt 76. A doctor blade 35 is mounted on a bracket 36 secured to a shaft 37 carrying an arm 39 by which a spring 38 urges the blade against the cylinder. The pinion 67 is mounted on a shaft carrying a second pinion meshing with a gear 71 on one side of which is an off-centre scroll gear 70, which through a pinion 72, shaft 73, a further pinion and rack teeth on the shaft 37 reciprocates the latter and the blade 35 axially across the cylinder 13. Below the blade 35 is pivotally mounted on a shaft fixed to the frame 24 a reservoir tray 45 having a bottom part sloping up to and against the cylinder, and side limbs 47 projecting across the ends of the cylinder. A screw 49 bearing on the rail 18 locates the tray in correct position. From the tray a pipe 51 returns surplus ink to a reservoir or to the pump 43. The pipe 40 has a valve-controlled outlet 52 to the tray 45, for passing ink direct to the tray if it is desired to shut off the outlets 42. Specification 751,924 is referred to.