Field of the invention [0001] The present invention relates to printing devices, in particular to a means for holding a roll of printing media in the printer, as well as to a means for catching printing ink in the case of printing on meshed media.

State of the art [0002] Fig.l represents a general overview of the main parts of an inkjet printing device. The unwind roll 1 comprises the media to be printed. The media is printed by the print head 9, as it passes between the drive roll 16 and nip roller 6, and along the print area 10, which is preferably preceded by a pre-heated zone 7, a fixation zone 14 under the print head 9 and a post-heated zone 11. Before printing, the media is attached to the wind roll 15, onto which the printed media will eventually be wound. [0003] In the case of large and heavy media rolls, the inertia of rolls (1,15) in combination with the large (and also heavy) unwind and rewind shafts is likely to cause some slipping between the core of the roll and the shaft. The core is the central tube, often made of cardboard, around which the media (e.g. paper) is wound. Different systems exist for attaching the roll to the shaft, but many of these systems are mechanically complex and inefficient in reducing the abovementioned slip. Also, many systems can only be applied at the ends of a shaft, so that they are suitable only for holding a particular length of media roll . [0004] Document JP2004149229 relates to a core holder capable of easily fastening a paper roll . It comprises a shaft, a fixed side holder and a movable side holder. Both side holders comprise a paper roll holding part that can be fit onto the shaft . The movable side holder is further provided with a fastening member that can be fit onto the shaft and an elastic body installed between the holder body and the fastening member. [0005] JP 2000143043 relates to a paper roll holding device having two flanges in contact with the end parts of a paper roll and a support cylinder inserted into the paper roll. The support cylinder is provided on each side with a lock member and a spring and comprises holes on its peripheral wall wherein a locking claw can be arranged. [0006] JP 5294523 tackles the problem of securing the stable and smooth supply of rolled paper and providing the uniform and stable back-tension for the rolled paper. A cylinder is formed by a plurality of elastic piece parts, which are integrally formed on the inner side surface of a flange that is brought into contact with the end part of a cylindrical core part. [0007] Another problem in the art is that the printer of the type shown in figure 1 is normally not adapted to print on meshed media, i.e. media with small holes in, such as textiles. Some of the ink passes through these holes and cannot be effectively removed in standard printing devices. Printers exist which are espcecially designed to print on textiles, and which comprise a means to evacuate the ink. However, no existing printer is equipped with an adaptable means to make the printer capable of printing on meshed media. Aims of the invention [0008] The present invention aims to provide solutions to the above-presented problems occurring in prior art devices.

Summary of the invention [0009] The invention is related to devices such as described in the appended claims. The invention is firstly related to a holder for attaching the core of the media rolls that unwind the media to be printed and subsequently wind the printed media, respectively. The core holder according to the present invention is easy to use and most effective in avoiding any slip between the core and the shaft. It comprises rubber disks that compress and expand onto the tube and the shaft. The disclosed core holder allows quickly and easily clamping heavy rolls. Importantly, the core holder comprises a sequence of ring- shaped parts, so that the shaft to which the holder must be attached, can be slid through the whole of the core holder. This means that the holder can be placed around the shaft at any location along the shaft's length, so that it can support any length of media roll.

Short description of the drawings [0010] Fig. 1 represents a printing device together with its main parts. [0011] Fig. 2 represents a core holder according to the invention. [0012] Fig. 3 represents detailed views of the core holder in its open and closed position. [0013] Fig. 4 represents a shaft provided with a core holder according to the invention and further comprising a number of adapting pieces. [0014] Fig. 5 represents a detailed view of the adapting piece. [0015] Fig. 6 shows a printing device equipped with a shaft with two core holders according to the invention. [0016] Fig. 7 represents the gutter configuration according of a preferred embodiment of the present invention. [0017] Fig. 8 illustrates a possible way of attaching the removable gutter to the printing area.

Detailed description of the invention [0018] Figs. 2 and 3 show a core holder according to the invention. The holder comprises a first flange 20, onto which two handles 21 are rotatably mounted. An end flange 22 is fixed with respect to said first flange 20, through a number of long bolts 23. Between the first flange 20 and the end flange 22 are mounted a number of compressible, e.g. rubber discs 24, alternated by rigid, e.g. metal discs 25, and a movable flange 26. The discs and the movable flange are supported by the bolts 23 and thereby allowed to move only in the axial direction. As seen in the drawings, all these flanges and discs are ring- shaped with a circular opening, larger than the shaft diameter so that the shaft will be able to slide through all these components. By moving the handles from a position wherein they are essentially perpendicular to the symmetry axis of the holder (Fig. 3a) to a position wherein they are essentially parallel to said axis (Fig. 3b) , the rounded ends 30 of the handles are acting like cams which push the movable flange 26 , against the end flange 22, whereby the rubber discs are compressed and expand in a direction perpendicular to the symmetry axis (radial) . This way, the holder is clamped to the core 31 of a roll into which it is inserted, while equally being clamped to the shaft 32 passing through the holder (fig. 3b) . The holder can be used for all kinds of media on the core, without limitations to weight, length, core diameter, Other means for pushing the flange 26 towards the flange 22 could be applied, in stead of the handles 21. The number of compressible discs can differ within the scope of the invention (there must be at least one) . [0019] Figure 4 shows a view of the shaft 32, equipped with a core holder 40 of the invention on each end. This view illustrates the fact that the core holder of the invention can be placed anywhere along the length of the shaft, so that it can support any length of media roll. [0020] In the case of a large printing device, additional stiffness can be provided to the media roll by means of adapting pieces 41, as shown in Fig.4. In this way the bending of the core can be limited. The adapting pieces 41 are tube-shaped parts composed of a cylindrical centre part 42 and on each side a conically shaped end part 43 (see Fig.5) . The conical shape eases the mounting of the media roll on the shaft. The diameter of the cylindrical part corresponds to the diameter of the core, while the diameter of the end sections of the conical parts correspond to the diameter of the shaft, in such a way that the pieces can be slid onto the shaft with a minimum of radial play, while the core can be slid over the piece with equally minimum radial play, so that the pieces are instrumental in supporting the media roll . The adapting pieces are produced in such a way that they can be fixed to the shaft by a bolt (not shown) . [0021] For mesh printing, media material is used containing small holes all over to enable air through it. Therefore, when printing, means must be provided to collect the ink having passed through these holes. In a further aspect of the invention, a removable gutter 80 is provided under the printed material (see Fig. 6) to collect the superfluous ink. This solution offers several advantages, as no moving parts are required and no tight tolerances are needed for the gutter. The print head is slightly raised compared to the state of the art devices in order to create sufficient space for the gutter. The gutter device according to the preferred embodiment comprises a first ramp 81, the actual gutter section 82 and a second ramp 83, the ramps being used to guide the media towards and from the printing area. The gutter may however consist of only the gutter section 82, without the first and second ramp. [0022] This way, a standard printer can be used to print both normal non-meshed media, and meshed media such as textiles. The attachment of the gutter to the printer can be done by any suitable means, for example by providing one or more hooks 90 underneath one of the ramps, and a number of holes 91 underneath the other, so that the gutter can be hooked into the printer on one side and fixed on the other side by a bolt, which is screwed into the printer platform. Rectangular holes are preferably provided in the pre-heated zone of the printer, into which holes the hooks 90 can be fitted. The only adaptation to the printer would then be to provide these holes for fixing the gutter. Other means for attaching the gutter may be provided within the scope of the invention.