GB1563834A - Machine for multicolor printing of hollow cylindrical workpieces - Google Patents

Abstract

Using the machine, printing on tubes or sleeves (12) is to be possible at the highest possible speed. Following the feed station (19), this machine has a varnishing device (22) and subsequently a plurality of printing devices (24, 27, 29, 32, 34, 37), said printing devices having so-called flexographic printing units. An intermediate drying device (23, 26, 28, 31, 33, 36) is provided between the varnishing device (22) and the subsequent printing device (24) and between respectively successive printing devices (24, 27, 29, 32, 34, 37), and a final drying device (38) is provided before the delivery station (39) of the treated workpieces (12). At least two spindles (17) are assigned to each drying device. <IMAGE>

Description

(54) MACHINE FOR MULTICOLOUR PRINTING OF HOLLOW ! CYLINDRICAL WORKFTECES (71) 1, KLRT GCTTLOB HINTERKOPF, a citizen of the German Federal Republic. of Gutenbergstr, 5, Eislingen (Fils), German Federal Republic, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particu larly described in and by the following statement : The invention relates to a machine for : he multicolour printing of hollow cylindrical workpieces.

Known machines for the multicolour printing of hollow cylindrical workpieces include at least one varnishing device, at least one printing device and at least one drying device, between whtch devices the workpieces can be transported, preferably placed on spindles. In the known machines the printing device is arranged in the next space next to the varnishing device, to which the workpieces are directly supplied, the drying devices being arranged above the varnishing and printing devices. To this end the workpieces to be processed are guided by means of a band conveyor in the form of an open link chain through the varnishing device, upwardly to the drying device, then again downwardly to the printing device and then again upwardly to the drying device, from where they reach the removal station. In this construction it is disadvantageous that the path of travel, which the hollow workpieces must cover, is very long, which means that, on the one hand, the transport device is very expensive and, on the other hand, the time expended for the transport between the individual devices is very considerable. Therefore, a pick-up attachment must be provided in each of these devices, which attachment removes the workpieces from the spindles. takes them to the processing station and again puts them on to a spindle, the number of such workpiece-handling devices being multiplied, as in certain circumstances a plurality of printing devices must be provided each for a specifi colour. Nlore- over, it has been shown that during transport from and to the individual devices and on manipulation of the workpieces, there are relatively many rejets.

An object of the present invention is to provide a machine for the multicolour print ing of hollow cvlindrical workpieces, in which the lines of transport between the individual devices are considerable reduced and in which the workpieces to be processed can remain during processing thereof on the transport spindles.

According to the invention, I provide a machine for multicolour printing of hollow cylindrical workpieces, comprising a rotary table adapted to turn continuously or in steps and which has a plurality of peripherally-spaccd spindles for carrying workpieces, a plurality of stations arranged spaced around the periphery of the rotary table and including a supply station for workpieces succeeded in the table-turning direction firstly by a varnishing station and then by several printing stations having Qexographic printing mehanisms, drying stations each overlapping a plurality of consecutive spindles and located one intermediate the varnishing station and the printing station immediately subsequent to the latter, one intermediate each two adjacent printing stations, and one preceding a removal station for the treated workpieces.

The workpieces to be processed are thus directe past the processing stations arranged in direct succession to one another, so that not onlv are the transport paths between the individual stations reduced to a minimum, but also the losses of time expended in removal of the workpieces and replacement thereof on the spindles before or after processing are avoided. The arrangement of the drying stations is especially advantageous as the printing effected with one colour is already dried before the printing with another colour.

As several workpieces are exposed simultaneously and for a sufficient period of time to the drying effects of the drying stations on passage between the other stations, the efficiency of drying is increased and there is a saving in time. The heating stations may have hot-air discharge orifices, infra-red radiators, or IST-driers, whereby an extremely quick and intensive and effective drying is achieved.

The flexible printing mechanims, the use of which is indeed known per se in other fields, bring considerable unexpected advantages in the case of the machine according to the invention. In this case it is essential that the flexible printing mechamsm uses on transfer of the printing image printing inks which dry quickly through evaporation of solvents under the influence of the drying at said drying stations. This is consequently especially essential as the workpieces to be printed are generally of plastics material or metal, with which in contrast to paper the liquid is not even partly sucked off or evaporated.

Moreover, the flexible printing mechanism uses, in contrast to what is known, a single stereotype roller printing the workpiece, to which roller colour is supplied by an applicatory rcller which for its part rolls on a roller dipping into a colour container.

The transport with the spindles may be effected in different ways, for example by providing the spindles around the entire periphery of the rotary table and putting the workpieces on the spindles and removing them therefrom at supply and removal stations. The advantage consists in that the turret-like rotary table can turn independently of supply and removal devices and is therefore to some extent independent of breakdowns of these devices, it being possible to interpose storage places or the iike. It is, however, also possible to have the spindies with the workpieces come to bear on the rotary table at the supply station and move away therefrom at the removal station.

The advantage in this case resides in that the spindles can be arranged on an endless chain and no handling devices are necessary to put workpieces which are to be treated from a transport device on to the spindles of the rotary table at the supply station, or to remove workpieces which have been treated at the removal station.

It order that the workpieces can be appropriately turned at the various stations. it is advantageous if the spindles, which can preferabfy be positively coupled with the workpiece. can be coupled with a central wheel arranged co-axially with the rotary table but ncverthciess turnable independently of the latter. For acaptation to different diameters of the workpieces, the turning of the central wheel and stereotype roller is determined as a function of the workpiece diameter, so that the peripheral speed of the stereotype roller and workpiece is a ! ways the same.

Further details and developments of the invention are tc be gathered from the following description in which the invention is described in more detail and explained with reference to the embodiment illustrated in the drawing. There are show : In Fig. I a diagrammatic representation of a machine according to the invention in plan view, and in Fig. 2 a detail on a larger scale of the embodiment according to Fig.

1.

The embodiment diagrammatically showii in the drawing of the machine 11 according to the invention for nlulticolour printing of hollow cylindrical workpieces 12, such for example as boxes, tubes and the like, which may be closed at one end or open at both ends, inclues a revolving or rotary table 13 which is rotated continuously or step by step about a central shaft 14 by means of a drive (not shown). The revolving or rotary table 13 has bearings or cut-outs 16 arranged evenly spaced at its periphery, workpiece carriers in the form of spindles 17 being pivoted in the bearings 16 in a suitable manner. One spindle 17 is provided in each bearing 16.

At a first position 18 of the periphery of the rotary table there is arranged a diagrammatically-shown supply station 19 for the workpieces 12 to be treated. At a second position of the rotary table periphery there is, moreover, arranged a varnishing station 22 indicated only by a turnable roller, there being a single cut-out 16 with a spindle 17 between the varnishing station 22 and the supply station 19 in the illustrated embodiment. Furthermore, there is arranged immediately subsequent to the varnishing device 22 a first intermediate drying station 23 which essentially overlaps three adjacent cut-outs 16. Immediately subsequent to the drying station 23 there is a first printing station 24, then again immediately subsequent to the latter a second intermediate drying station 26, a second printing station 27, then a third, fourth, fifth and sixth intermediate drying station 28,31,33 and 36, respectively, alternating with a third, fourth, fifth and sixth printing station 29, 32, 34 and 37, respectivelv.

Immediately subsequent to the last printing station 37 is a final drying station 38 which in this embodiment overlaps five adjacent cut-outs 16. A removal or deliverv station 39 is immediately subsequent to the final drying station 38.

The processing of the workpieces ! 2. that is the tubes, boxes and the like forming hollow cylindrical bodies, proceeds in the Following way: workpieces to be treated are supplie at the supply station 19 by a conveyor band 41 provided with spindles correspomding wlth the sphldles 17. and are placed each on one spindle 17 on the rotary table 13 by means of a pick-up attachment (not shown). On the rotary table 13 which is rotated step by step or continuously, the workpiece 12 concerncd is varnished during the rotation internally and'or externally at the varnishing station 22, while the workpiece rolls fo. example on a varnishing roll, is then dried at the first intermediatc drying station 23, is then printed at the first printing printing station 24 over its entire periphery or only over a part of its periphery by means of a specific colour, is then dried by the second intermediate drying station 26, is then again printed at the second printing station 27, for example with another colour and either at the same peripheral region or another peripheral region with the same motif or another motif of the same characterisation, then again dried etc., until it leaves the last printing station 37 and, after moving past the final drying staiton 38, is taken to the removal or delivery station 39 at which it is raised from the spindle 17 by means of a second pick-up device (not snown) and is set down on a conveyor band 42 likewise provided with spindles and which takes the workpiece 12, for example to a packing machine or a filling machine or the like. It will be manifest that further stations may be included between the final drying station 38 and the removal station 39, for example, a further varnishing station which coats or the likc the printed regions.

It will also be manifest that more or fewer printing stations may be provided and be in operation on rotation of the rotary table 13, all according to the number of different colours with which the hollow body 12 is to be printed. Storage devices may also be provided between the rotary table and the supply and/or removal stations or station.

It is also possible to combine the conveyor bands 41 and 42 and place them at the periphery of the rotary table, so that there is no need for transfer to and from the rotary table.

The printing stations 24, 27,29,32,34 and 37 are equipped with flexible printing mechanisms which have a stereotype roller 43 on which the stereotype 44 extends over part only of the roller periphery. This part of the periphery depends on the diametrical relationships of the stereotype roller 43 and the workpieces 12 to be processed. The stereotype roller 43 rolls on an applicatory roller 46 which takes care of transfer of colour on to the stereotype 44. The appli catory roller 46 rolls on a roller 47 of greater diameter and which dips over at least part of its periphery into a colour container 48 fi (led with colour. The appropriatc required colour is in he individual colour containers 48.

In order that the application of colour from the stereotype roller 43 on to the workpiece is always uniform independent of the diameter in use of the workpiece, the drive (not shown) of the stereotype roller 43 is coupled by way of an adjustable gearing with a central pinion 51 which is disposed below the rotary table 13 and is freely rotatable relative to the latter and its shaft 14. The adjustable gearing (not shown) may be adjusted depending on the diameter of he workpieces 12.

The spintlles 17, ahich have camping devices 52 for positive rotationally-fast connection with the pertaining workpiece 12, can be connected rotationally-fast with a pinion 54 by way of diagrammaticallv shown change-shift gearing 53, which pinion 54 meshes with the central pinion 51.

The gearing 53 is shifted at least on printing at the individual printing stations, so that by way of the central pinion 51 not only the stereotype roller 43 but also the Fertaining spindle 17 is driven. With the ajustable gearing (not shown) for the stereotype roller 43 is it possible to makc the peripheral speeds of the stereotype roller 43 and the workpiece 12 the same, which must be the case on printing.

The intermediate drying stations 23, 26, 28,31.33 and 36 and the final drying station 38 are equipped with quick drying devices with which it is possible to have the solvent used in the printing inks with the flexible printing mechanisms to vaporise quickly, so that the print dries quickly and a further processing can be undertaken.

Drying devices may be operated, for example by means of hot air. It is, however, also possible to use infra-red enerov bearing ight, and IST-drying or other elec tromagnetic radiation. Such a quick drying device is therefore necessary as the workpieces 12 in general are of plastics material or metal which do not in any way absorb the liquid contained in the ink.

It will be understood that more or a lesser number of spindles and processing stations may be provided at the rotary table than are shown in the present case.

Claims (6)

1. WHAT I CLAIM IS :- 1. A machine for multicolour printing of hollow cylindrical workpieces, comprising a rotary table adapted to turn continuously or in steps and which has a plurality of peripherally-spaced spindles for carrying workpieces, a plurality of stations arranged spaced around the periphery of the rotary table and including a supply station for workpieces succeeded in the table-turning direction firstly by a varnishing station anl then by several printing stations having tlexographic printing mechanisms, drying stations each overlapping a plurality of consecutive spindles and located one intermediate the varnishing station and the printing station immediately subsequent to the latter, one intermediate each two adjacent printing stations, and one preced- ing a removal station for the treated workpieces.
2. 2. A machine according to claim 1 or 2, in which the drying at the drying stations is effected by hot-air, infra-red energy-bearing light IST-driers or other electromagnetic radiation.
3. 3. A machine according to claim 1 or 2, in which the flexible printing mechanisms each include for printing the hollow workpieces a stereotype roller which is of greater diameter than the workpieces and bears over part only of the roller periphery the stereotype to which colour is transferred in operation of the machine from an applicatory roller which for its part rol ! s on a roller dipping into a colour container.
4. 4. A machine according to claim 1, in which the spindles are individual asso ciated each through a clutch coupling witii pinions which mesh with a toothed wheel comn-on thereto and movable about a rotary table shaft independently of the rotary table.
5. 5. A machme according to any one of the nreceding. : aaims in which the spindles are adapted to be coupled positively with the workpieces.
6. 6. A machine for multicolour printing of hollow cylindrical workpieces, substantially as hereinbefore described with reference to the accompanying drawings.