Egg Carton Printer

Abstract

The printing device for multicolor decorating the top of egg cartons or the like articles has a central blanket cylinder with four plate cylinders contacting it for transferring an inked image thereto, each one of the plate cylinders having its own inking device. An impression cylinder is arranged which has a saddle on a part of its circumference for supporting the cavernous top of the egg carton and pressing the top surface of it against the blanket cylinder for having the image which has been inked on the blanket cylinder, printed on it. Power-operated linkage mechanism for separating the plate cylinders from the blanket cylinder and for throwing off simultaneously the inking rollers of the inking devices is arranged.

Description

BACKGROUND OF THE INVENTION

The invention relates to multicolor printing devices and more specifically to printing devices for special purposes such as decorating the top of cavernous packaging boxes, for example of egg cartons.

Printing devices exist for printing indicia on objects which are not flat as a sheet of paper, cardboard or metal, and particularly on the outside of three-dimensional, hollow objects such as cardboard boxes or the like objects which have not sufficient resistance against crushing. Other "marking" devices are known for stamping or printing of indicia on box shaped packaging containers, on cylindrical parts such as bottles, cans, tubes and on similar articles of the packaging industry. The majority of these devices is manually operated and therefore not well suited for a large-scale mass production, particularly in view of the requirement for multicolor decorating of the outside of the packages. This is the problem involved in printing attractive and distinctive indicia on the lids of egg cartons which are not very strong and crushproof. The present invention of a new printing machine of this kind is directed to solving these problems.

SUMMARY

The invention consists of such novel features, construction arrangements, combination of parts and improvements as may be shown and described in connection with the apparatus herein disclosed by way of example only and as illustrative of a preferred embodiment. The general idea of the invention is to present a new structure and combination of structural elements by which multicolor decorations are applied to the outside surface of boxlike tops of egg cartons by rotary printing.

Objects and advantages of the invention will be set forth in part hereafter and in part will be obvious herefrom or may be learned by practicing the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

It is an object of the invention to provide a rotary printing device for printing indicia in colors in a continuous operation on the outside surface of the tops of egg cartons.

A further object of the invention is to provide rotatable support means for the egg cartons tops while the insignia are printed thereon.

Another object of the invention is to provide an intermittently operating conveyor system for feeding the egg cartons to the printing device where the carton is taken by the support means by which it it forwarded through the printing procedure during the dwell period of the conveyor.

Furthermore, it is an object of the invention to provide a mechanism for throwing off simultaneously all plate cylinders from the transfer cylinder and all ink motion form rollers from the plate cylinders without changing the relative setting of the form rollers with respect to the plate cylinder.

Yet another object of the invention is to provide a novel multicolor printing machine in a continuously operating production line for producing colorful decorations on the outside surface of the the top of egg cartons, which is relatively uncomplicated, easy to operate and to maintain.

Various further and more specific purposes, features and advantages will clearly appear from the detailed description given below taken in connection with the accompanying drawing which forms part of the specification and illustrates merely by way of example one embodiment of the device of the invention.

BRIEF DESCRIPTION OF THE DRAWING

In the following description and in the claims, parts will be identified by specific names for convenience, but such names are intended to be as generic in their application to similar parts as the art will permit. Like reference characters denote like parts in the several figures of the drawing, in which:

FIG. 1 shown diagrammatically the general arrangement of the printing device;

FIG. 2 shows the plate cylinder and form roller throwoff mechanism in the "on" position;

FIG. 3 shows the plate cylinder and form roller mechanism in the "off" position;

FIG. 4 is an axial section of the plate cylinder and of one pertaining form roller;

FIG. 5 is a radial section of the plate cylinder shown in FIG. 4, taken along the line 5-5;

FIG. 6 is a radial section of the plate cylinder shown in FIG. 4, taken along the line 6-6;

FIG. 7 is an axial section of the gear side part of the transfer cylinder; partly broken away;

FIG. 8 is a radial section of the transfer cylinder shown in FIG. 7, taken along the line 8-8;

FIG. 9 is an axial section of the impression cylinder;

FIG. 10 is a radial section of the impression cylinder shown in FIG. 9, taken along the line 10-10.

FIG. 11 is an axial section of the operating side of the transfer cylinder, partly broken away.

DESCRIPTION OF THE PREFERRED

EMBODIMENT

Referring now in more detail to the drawing illustrating a preferred embodiment by which the invention may be realized, there is a front frame 11 and a rear frame 12 which support rotatably the various cylinders and ink motions of the printing machine. Referring to FIG. 1 there is a centrally located transfer cylinder 20, four printing plate cylinders 30, 31, 32, 33 arranged around it in contact relationship with transfer cylinder 20 and an impression cylinder 40 located below transfer cylinder 20. Conventional ink motions 50, 51, 52, 53 each having two form rollers 54, 55, for inking the printing plates of plate cylinders 30, 31, 32, 33, are arranged for supplying the ink to the form rollers. Conveyor chains 60 carrying lugs 61 at regular intervals are arranged for transporting the egg cartons 62 to the printing machine and away from the same after the printing had been completed. Egg cartons 62 are sliding over a support table 63. Leaf springs 64 are arranged above the path of egg cartons 62 for holding the same down while they are printed.

Referring to FIGS. 4, 5, and 6, there is shown as a typical example one of the plate cylinders 30, 31, 32, 33 and one of the two form rollers 54, 55. The body of the plate cylinder is a hollow sleeve 34 which is freely rotatable held on ball bearings 35 supported by a shaft 36. The ends 37, 37' of shaft 36 are eccentric with respect to bearings 35, and they are rotatably supported by bushings 38, 38' which are located in frames 11, 12. Printing plate supports 39, 39' are fitted on sleeve 34 and are secured thereon by the screws 131. On each side of supports 39, 39' blocks 132, 132' are fastened on sleeve 34 for rotatably supporting the mounting rods 133, 133' for the flexible printing plates 134. A row of pins 135 is arranged on each one of mounting rods 133, 133' for holding plates 134 which have correspondingly arranged holes. Near the end of each one of rods 133, 133' is a plug 136 inserted therein which extends radially thereof. A spring 137 abuts against plug 136 on one side and an adjustment screw 138 abuts against the other side of plug 136, for register setting and for tightening of printing plates 134 on plate supports 39, 39'. Rods 133, 133' are axially moveable against spring 139 by setscrews 231 for lateral register setting of printing plates 134. A gear 232 is fixed on the drive side of the machine at the end of sleeve 34, which is part of the driving mechanisms of the machine and which engages the corresponding gears of the other cylinders. Form rollers 54, 55 are supported by the bars 233, 234, which are swingably mounted on shaft 36. Bars 233, 234, support shaft ends 235' in which shaft ends 235 are located. A central shaft 236 extends between shaft ends 235 which have bores in which the ends of shaft 236 are located. Since shaft ends 235 are eccentric with respect to central shaft 236 and to bearings 238, it is possible to adjust the position of the form roller to the printing plate on the corresponding plate cylinder. Form rollers 54, 55, consist of tubes 237 which are freely rotatable mounted by ball bearings 238 on shaft 236. A conventional roller covering 239 consisting of a resilient synthetic rubber is arranged on tubes 237 extending over the area of printing plates 134.

Transfer cylinder 20 is shown in more detail in FIGS. 7 and 8. The cylinder body consists of a tubular member 21 into which the shaft ends 22, 22' are pressed. Roller bearings 23, 23' into which shaft ends 22, 22' are pressed are supported by frames 11, 12. A gear 24 is attached to tubular member 21 on the side of frame 12, meshing with gears 232 of printing plate cylinders 30, 31, 32, and 33. Transfer blanket bodies 25, 25' are mounted on tubular member 21, which receive the inked images from the printing plates 134. Each one of bodies 25, 25' consists of two disc-shaped sidewall plates 26, 26' which are firmly attached to tubular member 21. Mantle plates 27, 27' are welded on sidewall plates 26, 26'. Two blanket shafts 28, 28' are rotatably located diametrically opposed to one another in bearing plates 29, 29', which are attached to sidewall plates 26, 26'. Each one of blanket shafts 28, 28' has a plurality of blanket holding pins 121, and another plurality of stationary pins 122 is arranged in mantle plates 27, 27', for fastening the transfer blankets 123. Each one of blanket shafts 28, 28', has also a ratchet wheel 124 attached thereto which is engaged by a spring loaded releasable pawl 125. The other end of the blanket shaft opposite to ratchet wheel 124 is shaped as a square end 126 so that transfer blankets 123 may be firmly tightened on bodies 25, 25' by using a wrench and may be secured in the tightened condition by ratchet 124 and pawl 125.

Impression cylinder 40 which is located below blanket transfer cylinder 20, is shown in detail in FIGS. 9 and 10. The cylinder consists of a body 41 which is composed of several hollow tube parts, welded together, and of a solid stationary shaft 42. Body 41 is arranged to rotate freely on ball bearings 43, 43', which are located on shaft 42. A gear 44 is attached to body 41, meshing with the corresponding gear 24 on transfer cylinder tubular member 21. Printing saddles 45, 45' are attached to body 41 on locating studs 46, 46', by pins 47, 47'. Studs 46, 46' are secured on body 41 by setscrews 48, 48'. The shaft ends 49, 49' of shaft 42 are eccentric with respect to ball bearings 43, 43' and are rotatably located by needle bearings 141, 141', in frames 11 and 12 respectively. A lever 142 is keyed on shaft end 49, on which a screw block 143 is pivotally mounted. A rod 144 having one threaded end 145 is rotatably held in a bracket 146 which is attached to frame 11. Threaded end 145 is screwed into block 143, and a compression spring 147 is arranged on rod 144, which abuts against bracket 146 with one end and against the turnbuckle 148 with the other end, urging lever 142 in a counterclockwise direction of rotation as seen in FIGS. 1 and 2. By adjusting rod 144 by threading end 145 in or out of block 143, eccentric ends 49, 49' are rotated and the position of body 41 and printing saddles 45, 45' are adjusted away or against, respectively, transfer cylinder 20 for setting the necessary printing pressure according to the thickness of the carton to be printed.

A throwoff device for plate cylinders 30, 31, 32, 33 and for their corresponding form rollers 54, 55, respectively, is shown on FIGS. 2 in the "on" position and in FIG. 3 in the "OFF" position. The throwoff device serves the purpose of separating simultaneously the printing surfaces of plate cylinders 30, 31, 32, 33, from the corresponding surfaces of transfer cylinder 20 and of moving form rollers 54, 55 away from printing plates 134 on plate cylinders 30, 31, 32, 33. A lever 13 is rotatably located on a bracket 14 which is attached to the outside of frame 11 in such a manner that the center of rotation of lever 13 coincides with the center of transfer cylinder 20. (FIG. 11). However, lever 13 has no connection with shaft end 22' of transfer cylinder 20. Lever 13 has a circular center plate 15 on which four bars 16 are articulated. Each one of bars 16 is linked on a lever 17 which is clamped on eccentric end 37 of shaft 36. A lever 56 is clamped on each of the eccentric ends 235 of central shafts 236 of form rollers 237. Levers 56 are linked in pairs by connecting bars 19 to levers 17 in such manner that the levers 56 of the two form roller shafts 235 are linked to the lever 17 of the shaft 36 of the plate cylinder 30, 31, 32, 33, respectively, to which the corresponding form rollers belong. (See FIGS. 2 and 3)

Since form roller shafts 236 are thus linked with bracket 17 of the plate cylinders, the throwoff mechanism will always return them to the originally set position on the printing plate after they had been thrown off for operational reasons such as changing of plates, changing of ink of the like work. The piston rod 18 of fluid power cylinder 57 is articulated at the end of lever 13. Power cylinder 57 is swingingly foot-mounted on a bracket 58 which is fixed on frame 11. A bracket 59 is attached to frame 11 in such a position that a setscrew 68 of this bracket can be set in the path of lever 13 for limiting the stroke thereof.

THE OPERATION OF THE PRINTING

machine

With the plate cylinders and the form rollers in the "OFF" position, flexible printing plates 134 are clamped on the plate cylinders and, if necessary, printing blankets 123 are changed or renewed, whatever the case may be. After the various colors have been set in proper register, conveyor chains 60 are set in such manner that the egg cartons are pushed forward by lugs 61 to the point where the front edge of printing saddles 45 engages precisely the inner front corner of the egg carton cover. At this point the conveyor chains stop and printing saddles 45, 45' carry the egg cartons forward through the printing operation period. The dwell period of the conveyor movement is timed in such manner that the conveyors start again when the rear end of saddles 45, 45' have approached the inner rear corner of the egg carton cover, so that they can continue forwarding the printed cartons to the next following operation, for example to a stacket delivery.

While the invention has been described and illustrated with respect to a certain preferred example which gives satisfactory results, it will be understood by those skilled in the art after understanding the principle of the invention, that various other changes and modifications may be made without departing from the spirit and scope of the invention.

Claims

What I claim is:

1. A printing device for applying decorative indicia to the tops of egg cartons or like hollow articles in a plurality of colors, said device having a plurality of printing plate carrying cylinders, a corresponding plurality of ink motions each having a form roller for applying ink to a plate cylinder, a central transfer cylinder adapted to contact said plate cylinder, said transfer cylinder having at least one printing blanket fastened thereon for receiving said indicia from said plurality of plate cylinders, and a rotatable impression cylinder cooperating with said transfer cylinder; said impression cylinder comprising at least one circumferentially extending impression saddle having a front circumferential edge and a rear circumferential edge, said saddle adapted to support and engage the inside of said hollow articles to move said articles past said transfer cylinder as said impression cylinder is rotated, and an intermittently moving article carrying conveyor for intermittently forwarding said articles to said impression cylinder for engagement by said impression saddle.

2. A printing device for applying decorative indicia to the tops of egg cartons according to claim 1, said printing plate carrying cylinders having in addition flexible printing plate supports interchangeably fastened thereon and spring-loaded means for mounting said flexible printing plates thereon.

3. A printing device for applying decorative indicia to the tops of egg cartons according to claim 2 having in addition power-operated throwoff means for separating simultaneously all said printing plate cylinders from said transfer cylinder and all said form rollers from said printing plate cylinders.

4. A printing device for applying decorative indicia to the tops of egg cartons according to claim 3, said throwoff means comprising linkage bars connecting the throwoff means of each of said printing plate cylinders with the corresponding throwoff means of said form roller for separating said plate cylinders from their corresponding form rollers in such manner that the original adjustment setting of said form rollers relative to their corresponding printing plate cylinders is maintained.