EP1926599A2

EP1926599A2 - A printer

Info

Publication number: EP1926599A2
Application number: EP06779511A
Authority: EP
Inventors: Brian Lee; Daniel White; David Lee; Martin Beardsley; Philip Lee; Robert Lee
Original assignee: Focus Label Machinery Ltd
Current assignee: Focus Label Machinery Ltd
Priority date: 2005-09-21
Filing date: 2006-09-21
Publication date: 2008-06-04
Anticipated expiration: 2026-09-21
Also published as: KR101410799B1; CN101090822A; ES2486257T3; WO2007034191A2; GB0519248D0; WO2007034191A3; KR20080077088A; GB2430405A; EP1926599B1; PT1926599E

Abstract

A cartridge (12) for a printer (2), the cartridge (12) comprising a chambered ink duct (14), a ink roller (8) attached to the ink (14) duct, and an attachment (18,22) for removably attaching the cartridge (12) to the printer (2).

Description

A Printer

This invention relates to a printer and particularly but not exclusively to a printer of the type used to print images onto textiles, such as a printer for printing labels for attachment to garments, and to an ink cartridge for such a printer. The term "textile printer" will be used herein to refer to a printer for printing images onto textiles.

Textile printers may be used to print images onto a range of textiles of various sizes, and in particular may be used to print images onto labels for garment. Such labels will generally provide information regarding the make of a garment, the type of textile from which the garment has been made, and washing instructions for the garment. It is therefore important that printed labels of this type are able to endure high temperatures during washing, for example, and that images printed onto the labels remain visible and legible generally for the life of the garment to which they are attached.

In order produce labels meeting these requirements, it is known to use high viscosity inks to print images onto textiles. Liquid inks are generally not suitable for use in textile printers, as the liquid ink would tend to run and fade on the textile onto which it had been applied.

Fabrics that may be employed in textile printing include polymers, such as various polyesters and polyamides. More specifically, such fabrics include polyester, polyester satin, nylon, cotton, self-adhesive satins, lace, twill, GroGrain and imitation leather materials.

A known textile printer comprises a central drum rotatable about an axis. A textile to be printed is fed onto the drum in such a manner that it extends around at least a portion of the circumference of the drum. As the central drum rotates the textile is fed over the drum enabling a continuous strip of textile to be printed. A print cylinder rotatable about an axis, is positioned so that, in use, a circumferentially outer surface of the print cylinder just touches a circumferentially outer surface of the central drum. In use, the axis of the print cylinder is spaced apart from, and substantially parallel to the axis of the central drum. The circumferentially outer surface of the print cylinder is shaped to apply a particular impression onto a textile extending around the central drum. In this respect, the surface of the print cylinder may be directly contoured to provide the required impression, or a relief image plate made from any suitable material, such a photopolymer material, may be applied to the print cylinder.

In order to translate an impression onto a textile extending around the central cylinder, ink must be applied to the print cylinder. It is known to apply ink to a print cylinder by means of an anilox roller. An anilox roller has a surface comprising a plurality of small cavities adapted to hold the ink. Ink is initially applied to the anilox roller through use of an ink duct and the surface of the anilox roller absorbs ink from the duct. The anilox roller is positioned so that, in use, its axis is substantially parallel to the axis of the print cylinder, it is spaced apart from the central drum, and its circumferential outer surface just touches the circumferential outer surface of the print cylinder. In use, the anilox roller is rotated as the print cylinder rotates, thus coating the print cylinder with ink.

In use, the print cylinder rotates as the central drum rotates. Since the print cylinder is positioned so that its outer surface just touches the outer surface of the central drum, rotation of the print cylinder and the central drum will result in an impression being translated onto the textile passing over the outer surface of the central drum. The circumference of the print cylinder will determine the repeat length of the impression translated onto the textile.

hi order to ensure an appropriate quality of print, it is necessary to ensure that the relative position of the print cylinder and the central drum is such that a predetermined pressure is applied to the textile during the printing process. This is achieved by adjusting the printing cylinder relative to the central drum. Such an adjustment may be time consuming, since it is not only necessary to adjust the position of the print cylinder in a direction that is perpendicular to the axis of the print cylinder, but it is also necessary to adjust the print cylinder in a direction parallel to the print cylinder axis, to ensure appropriate lateral positioning of the print cylinder relative to the central drum. In addition, the adjustment process must also take into account the variable size of different print cylinders.

In use, the print cylinder will be supplied with Mc of a particular colour by the anilox roller, which is itself supplied by ink from the ink duct. If, therefore, the textile is to be printed with more than one colour, more than one print cylinder must be used. Thus if a textile is to be printed with three colours, the textile printer will comprise three print cylinders spaced apart circumferentially around the central drum. Each print cylinder will have associated with it, an anilox roller and ink duct.

When a textile is printed with an image having more than one colour, the image will be printed in stages. At each stage a portion of the image in a particular colour will be translated onto the fabric by a particular print cylinder. The complete image will be produced once each printing cylinder has contacted the

^' portion of the textile being printed. Thus, if an image containing three colours is to be printed onto a textile, the complete image will be produced once the portion of the textile being printed has received an impression from all three printing cylinders.

hi order to ensure that the different colours are applied to the appropriate parts of the textile relative to the other colours, it is necessary to ensure that the individual print cylinders are in register with one another. In order to ensure that each print cylinder is in register with other print cylinders, each cylinder may have to be rotated a predetermined distance relative to the central drum. This process is time consuming and requires a high level of skill. In particular, it is necessary to move each print cylinder in turn out of contact with the central drum, rotate the print cylinder a small amount, reposition the print cylinder, and check whether the print cylinder is now in register. If the print cylinder is still not in register, the process must be repeated until it is.

A further problem with known textile printers is that each time a print cylinder is removed from the textile printer, for example, for cleaning, it is necessary to accurately reposition the print cylinder when the cylinder is replaced in the textile printer for further use.

Another problem with known textile printers is that it can be difficult to clean the anilox rollers after use. In addition it can be difficult to properly position an anilox roller relative to an associated ink chamber.

According to a first aspect of the present invention there is provided a cartridge for a printer, the cartridge comprising a chambered ink duct, a ink roller attached to the ink duct, and an attachment for removably attaching the cartridge to the printer.

By means of the present invention the ink duct and ink roller are formed into a single cartridge which cartridge is removably attachable to a printer. This means that the process of removing an ink roller for cleaning or repair is greatly simplified. In addition, because the ink roller and ink duct are contained within a single cartridge, it is not necessary to accurately position the ink roller relative to the ink duct, since the dimensions of the cartridge will ensure that the ink roller is appropriately positioned relative to the ink duct.

Preferably, the ink roller comprises an anilox roller.

Advantageously, the cartridge comprises, an attachment extending from a side of the cartridge. The attachment is receivable within the printer to which the cartridge is to be installed thus allowing easy attachment and removal of the cartridge from the printer.

Advantageously, the chambered ink duct comprises a first side, and an opposite second side, and the attachment comprises a first attachment portion extending outwardly from the first side, and a second attachment portion extending outwardly from the second side.

In such an embodiment of the invention, the cartridge will be held between two opposing portions of the printer thus allowing for alignment of the cartridge with other components in the printer.

Advantageously, each of the first and second attachment portions comprises an attachment roller. The attachment rollers allow for the cartridge to be rolled into position relative to other components in the printer.

Advantageously, each of the first and second attachment portions comprises a first attachment roller and a second attachment roller. Because the cartridge comprises two rollers on each side, movement of the cartridge within the printer is facilitated.

Advantageously, the cartridge further comprises an ink roller receiving portion for removably receiving the ink roller. This means that when the cartridge has been removed from the printer it is possible to remove the ink roller from the cartridge in order to clean or repair the ink roller, for example.

Preferably, the cartridge further comprises an ink roller adjustment for adjusting the position of the roller relative to the chambered ink duct.

Adjustment of the ink roller in this way can affect the quality of the printing in a printer incorporating a cartridge according to the present invention. Advantageously, the cartridge farther comprises an ink roller gear mechanism for allowing the ink roller to be driven in an appropriate manner.

Preferably, the chambered ink duct comprises a hopper having at least one open face. The open face of the hopper allows ink to be poured into the hopper either manually or through an automated process.

Conveniently, the cartridge further comprises a tray for collecting unused ink. The tray may be emptied when the cartridge is removed from the printer.

According to a second aspect of the present invention there is provided a printer comprising:

a central drum rotatable about a central axis and having a first side, and an opposite second side; a print cylinder rotatable about a second axis spaced apart from, and parallel to the central axis and having a first side and a second, opposite side; the printer further comprising an ink cartridge comprising a chambered ink duct, an ink roller attached to the ink duct and an attachment for removably attaching the cartridge to the printer.

Advantageously, the printer further comprises a print cylinder adjuster. The print cylinder adjuster serves to adjust the position of the print cylinder relative to the central drum. This can affect the quality of printing.

Advantageously, the print cylinder adjuster comprises a print cylinder retainer comprising a first retaining arm and second retaining arm, the first and second retaining arms being spaced apart from one another, and extending substantially parallel to one another, and substantially perpendicular to the central axis, the first retaining arm being operably engageable with the first side of the print cylinder, and the second retaining arm being operably engageable with the second side of the print cylinder.

Preferably, the print cylinder retainer comprises a first retaining portion forming part of the first retaining arm, and a second retaining portion forming part of the second arm.

Advantageously, the print cylinder is moveable within the print cylinder retainer in a direction substantially perpendicular to the central axis.

Preferably, the print cylinder adjuster further comprises a clamp for clamping the print cylinder in position within the print cylinder retainer.

Conveniently, the clamp comprises a first clamp portion moveable within the first retaining portion, and a second clamp portion moveable within the second retaining portion.

Conveniently, the print cylinder retainer further comprises a first and second clamp portion activator for causing movement of each clamp portion within a respective retaining portion.

Preferably, each clamp portion activators comprises a pneumatic cylinder forming part of a respective retaining arms.

Advantageously, the print cylinder adjuster further comprises a first adjustment arm, and a second adjustment arm, the first adjustment arm being attachable to the first retaining arm, and the second adjustment arm being attachable to the second retaining arm, the first and second adjustment arms allowing further adjustment of the print cylinder when the print cylinder is held in position in the print cylinder retainer by the clamp. By means of the first and second retaining amis, a print cylinder is held in position relative to the central drum. Accurate positioning of the print cylinder is possible since the retaining amis restrict an}' lateral movement of the print cylinder.

The first and second retaining arms are configured so that the position of the print cylinder may be adjusted by movement of the print cylinder either towards or away from the central drum by movement of the print cylinder along each of the retaining arms and within the print cylinder retaining portions.

Advantageously, the first side of the print cylinder is substantially coplanar with the first side of the central drum, and the second side of the print cylinder is substantially coplanar with the second side of the central drum.

Preferably, the central drum rotates about a shaft, and an end of the first retaining arm is, in use, in contact with a first end of the shaft, and an end of the second retaining arm is, in use, in contact with a second end of the shaft.

This means that each of the first and second retaining arms extend substantially radially from the axis of the central drum. This positioning of the first and second arm facilitates positioning of the print cylinder and ensures that the print cylinder is appropriately aligned with the central drum.

Advantageously, the cartridge is attachable to the print cylinder retainer. This ensures that the cartridge is appropriately aligned with the print cylinder.

In an embodiment of the cartridge having first and second attachment portions for attaching the cartridge to the printer, the first and second attachment portions are receivable in the first and second retaining portions respectively of the print cylinder retainer.

Preferably, the print cylinder comprises a gear mechanism contained within a gear housing, which gear housing is rotatably movably attached to the printer, the printer further comprising a gear housing adjuster engageable with the gear housing for causing rotational movement of the gear housing, thereby causing corresponding rotational movement of the print cylinder.

By means of the gear mechanism, it is possible to rotate the print cylinder relative to the central drum. In a printer comprising more than one print cylinder, such movement of one of the print cylinders will cause relative movement of that print cylinder relative to the second print cylinder. Such movement may be used to bring the two print cylinders into register with one another.

Advantageously, the gear housing comprises a. worm wheel, and the gear housing adjuster comprises a worm threadably engageable with the worm wheel of the gear housing.

The worm may be operated by any desirable mechanisms such as a control knob. Operation of the control knob will cause rotation of the worm which in turn will cause rotation of the gear housing.

Advantageously, the print cylinder comprises an output shaft, and an input gear attached to the output shaft, which input gear is engageable with a plurality of planet gears which in turn are engageable with a ring gear enclosed within the gear housing.

The invention will now be further described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a schematic representation of a printer according to an embodiment of the invention;

Figure 2 is a schematic representation of a part of the printer of Figure 1 ; Figures 3 a, 3b and 3 c are schematic representations of an ink cartridge according to an aspect of the present invention, forming part of the printer of Figure 1 ;

Figure 4 is a sliced view of the ink cartridge of Figure 3;

Figure 5 is a schematic representation of a part of the printer of Figure 1 showing the ink cartridge of Figure 3 mounted in an adjustment mechanism;

Figure 6 is a rear view of the printer of Figure 1 showing two gear mechanisms according to an aspect of the invention; and

Figures 7 to 9 are schematic representations of one of the gear mechanisms shown in Figure 6.

Referring to the Figures, and initially to Figures 1 and 2, an embodiment of a printer according to the present invention is designated generally by the reference numeral 2. The printer 2 is particularly suitable for printing images in the form of text or other graphics onto a continuous strip of textile material. The continuous strip of material to be printed is fed onto the central drum, and once printed, will be cut to form individual labels for attachment to garments. The labels will typically indicate washing instructions and material composition of the garment to which they are attached.

The printer comprises a front plate 3 and a back plate 5.

The printer comprises a central drum 4 rotatable about a central shaft 6, and two print cylinders 8. Associated with each print cylinder 8 is an anilox roller 10. Each of the print cylinders will transfer an image in a particular colour onto the strip of material. In this example, printer 2 comprises two print cylinders 8 in order to print two colours onto the material. However, if more colours are to be printed onto the strip of material, the printer 2 would have more print cylinders. Similarly, if the material is to be printed with one colour only, the printer would have a single print cylinder.

The printer cylinder 8 is supported between the front plate 3 and back plate 5 by means of the central shaft 6 which is attached to each plate 3, 5.

The anilox roller 10 associated with each print cylinder forms part of an ink cartridge 12 shown in more detail in Figures 3a, 3b, 3c and 4. The cartridge 12, in addition to the anilox roller 8, comprises a chambered ink duct 14, comprising a hopper tray 15 into which ink may be poured either manually, or by an automated process. In order to print an image having a particular colour onto material passing around the circumference of the central drum 4, the print cylinder 8 is rotated as the central drum rotates, causing the material to be printed to pass between the central drum 4 and the print cylinder 8. The anilox roller 10 is also rotated, causing ink contained in the hopper tray 15 to be transferred onto the surface of the anilox roller. The surface of the anilox roller is formed with, small engraved cells which enable the anilox roller to retain a predetermined amount of ink in the indentations. The size of the cells may vary from roller to roller, but typically will have a diameter of between 5 and 50 microns.

The print cylinder 8 and anilox roller 10 are positioned so that, in use, the anilox roller 10 is in contact with the print cylinder 8, and the print cylinder 8 is also in contact with the central drum 4 or, in use, with a material to be printed. In addition, each of the central drum 4, print cylinder 8 and anilox roller 10 comprises a drive gear 60, 62, 64 respectively. In use the central drum drive gear 60 and the print cylinder drive gear 62 will engage with one another. The print cylinder drive gear 62 will also engage with the anilox roller drive gear 64. This ensures that rotation of the central drum 4, print cylinder 8 and anilox roller 10 is synchronised.

As the central drum 4, print cylinder 8 and anilox roller 10 rotate, ink from the hopper tray 15 transfers to the anilox roller 10, and then to the print cylinder 8. The surface of the print cylinder 8 is contoured so that when the material passes between the central dram and the print cylinder 8, an impression is transferred onto the material.

The positions of the print cylinder 8 and the anilox roller can be adjusted relative to one another and to the central drum 4 as will be described in more detail below, in order that a predetermined level of pressure is applied by the central drum 4 and the print cylinder 8 onto material passing over the central drum 4, and between the anilox roller 10 and the print cylinder 8.

The ink cartridge 12 further comprises an attachment for allowing removable attachment of the cartridge 12 to the textile printer 2. In this example, the attachment comprises a first attachment portion 18 extending from a first side 20 of the cartridge 12, and a second attachment portion 22 extending from a second side 24 of the cartridge 12. Each of the attachment portions 18, 22 comprises two attachment rollers 26 which are receivable within a roller receiving portion of printer 2 as will be described in more detail hereinbelow.

The cartridge 12 also comprises an anilox roller adjustment in the form of screws 28 for adjusting the position of the ink roller relative to the chambered duct.

The cartridge 12 further comprises a tray 30 for collecting any ink not adhering to the surface of the anilox roller 10.

The printer 2 further comprises a print cylinder adjuster 32 in the form of a pair of spaced apart retaining arms 34, 36 and adjustment arms 65, 66.

The print cylinder adjuster 32 further comprises receiving portions 38 for receiving the print cylinder 8, and also for receiving the attachment rollers of the ink cartridge 12. The arms 34, 36 are each shaped to receive the print cylinder 8. When the cartridge 12 and the print cylinder 8 are each held in position by the arms 34, 36, the axes of each of the central drum 4, print cylinder 8, and anilox roller 10 will all be substantially parallel to one another.

The adjustment arms 65, 66 are pivotably attached to the front plate 3 and the back plate 5 respectively, at pivot points 67, 68. The print cylinder adjuster 32 further comprises clamp 69 operated by a pneumatic cylinder 40 forming part of a respective arm 34, 36. In use, when print cylinder 8 is to be positioned relative to the central drum 4, the print cylinder will be positioned between adjustment arm 34, 35 in receiving portions 38. Print cartridge 12 will also be positioned between the arms 34, 36 in the receiving portion 38.

Once the print cylinder 8 and the print cartridge 12 are in position between the arms 34, 36, the clamp 69 will be caused to move towards the print cartridge 12 engaging with the attachment rollers 26, causing the ink cartridge 12 to bear down on bearings 70 of the print cylinder 8.

Ih order to adjust the position of the print cylinder relative to the central drum 4, and thus to control the pressure exerted on the central drum by the print cylinder 8, the position of the print cylinder may be adjusted by means of impression adjuster screws 42. The screws 42 are connected to rods 71 which are each, operably connected to a respective arm 65,66 causing the arms to pivot about pivot points 67, 68.

Each adjustment arm 65, 66 is moveably attached to a respective arm 34, 35, by means of a pin 72 retained in a slot 73. Movement of the arms 65, 66 causes movement of the receiving portion 38.

Each of the arms 34, 36 has a first end 42 and a second end 44. The second ends 44 of each of the arms 34, 36 abut with the central shaft 6 of the central drum 4.

This means that each of the arms 34, 36 extends substantially radially from the shaft 6. The length of the print cylinder 8 is approximately the same as the length of the central drum 4 and the portions 40 are positioned so that when a cylinder 8 is held in position between the portions 40, sides 46 of the print cylinder 8 are coplanar with sides 48 of the central drum 4.

When it is desired to replace the print cylinder 8 in order to, for example, clean the cylinder, or replace the cylinder with a different cylinder having a different diameter, for example, it is necessary to first to remove the ink cartridge 12 by sliding the ink cartridge along the arms 34, 36 in a direction away from the central drum 4 and then to remove the print cylinder 8. When the cylinder 8 is replaced, or a new cylinder is positioned between the arms 34, 36, it is necessary only to adjust the position of the print cylinder 8 by adjusting the adjustment arms 65, 66 via the impression adjuster screws 42. No other adjustment is necessary. By means of the retaining arms 34, 36, in conjunction with the pneumatic cylinders 40, and clamp 69, print cylinders of different diameters may easily be positioned correctly relative to the central drum 4 since once a print cylinder 8 is positioned within the arms 34, 36 the sides of the print cylinder 46 will be positioned appropriately relative to the sides 48 of the central dram. In other words, once a print cylinder 8 is retained between arms 34, 36, only movement that is possible is in a direction substantially perpendicular to the axis of the central shaft is possible. As such movement is effected by adjusting the adjustment arms 65, 66 via the impression adjuster screw 42. This in turn results in movement of the print cylinder and print cartridge 12 in a direction either towards or away from the central drum 6 in a direction that is substantially perpendicular to the axis of the central shaft 6.

In the illustrated example, the printer 2 comprises two print cylinders 8 each with an associated anilox roller 10. The printer 2 is therefore set up to print two different colours on to a continuous strip of material extending round the central drum 4. It is therefore necessary to ensure that the two print cylinders 8 are in register with one another. If the two cylinders are not in register with one another, the two colours will not be appropriately positioned relative to one another in the image to be printed onto the continuous strip.

Each print cylinder comprises a print registration adjusting gearbox 50 that extends through a back plate 5 of the printer 2.

The print registration adjusting gear box 50 comprises an outer casing 54 enclosing an input gear 56 attached to an output shaft 57 of the print cylinder 8, and planet gears 58 orbiting the input gear. In addition the gear box comprises a ring gear 59, and the planet gears 58 are in engagement with the ring gear. An outer surface of the casing 54 is gearcut to form a worm wheel. The gear box 50 further comprises a worm 60 threadably engageable with the threaded outer surface of the gear casing 50.

In order to ensure that the two print cylinders 8 are in register with one another, it may be necessary to rotate one or both of the print cylinders 8 relative to the central drum 4 and also to the other print cylinder 8. In order to rotate a print cylinder in this way, the outer casing 50 associated with the particular printer cylinder 8 is rotated by turning knob 62 which causes the worm 60 to rotate. Due to the threaded engagement of the worm 60 and the casing 50, rotation of the worm causes corresponding rotation of the outer casing.

When the outer casing is rotated, the planet gears 58 will move with the outer casing and will cause rotation of the output shaft of the print cylinder 8 through their engagement with the input gear 56 and the ring gear 59. The adjustment may thus be carried out without having to move the print cylinder away from the central drum. By means of the gear mechanism of the print cylinder, it is possible to rotate the print cylinder 8 by a small measured amount in order to ensure registration between the print cylinders 8.

Claims

1. A cartridge for a printer, the cartridge comprising a chambered ink duct, a ink roller attached to the ink duct, and an attachment for removably attaching the cartridge to the printer.

2. A cartridge according to Claim 1 wherein the attachment extends from a side of the cartridge.

3. A cartridge according to Claim 1 or Claim 2 comprising a first side, and an opposite second side, and the attachment comprises a first attachment portion extending outwardly from the first side, and a second attachment portion extending outwardly from the second side.

4. A cartridge according to Claim 3 wherein each of the first and second attachment portions comprises an attachment roller.

5. A cartridge according to Claim 3 wherein each of the first and second attachment portions comprises a first attachment roller and a second attachment roller.

6. A cartridge according to any one of the preceding claims further comprising an ink roller receiving portion.

7. A cartridge according to any one of the preceding claims further comprising an ink roller adjustment for adjusting the position of the ink roller relative to the chambered ink duct.

8. A cartridge according to any one of the preceding claims further comprising an ink roller drive gear mechanism.

9. A cartridge according to any one of the preceding claims wherein the chambered ink duct comprises a hopper having at least one open face.

10. A cartridge according to any one of the preceding claims further comprising a tray for collecting unused ink.

11. A printer comprising:

a central drum rotatable about a central axis and having a first side, and an opposite second side; a print cylinder rotatable about a second axis spaced apart from, and parallel to the central axis and having a first side and a second, opposite side; the printer further comprising an ink cartridge according to any one of Claims 1 to 10.

12. A printer according to Claim 11 further comprising a print cylinder adjuster for adjusting the distance between the second axis and the central axis.

13. A printer according to Claim 12 wherein the print cylinder adjuster comprises a print cylinder retainer comprising a first retaining arm and a second retaining arm, the first and second retaining arms being spaced apart from one another, and extending substantially parallel to one another, and substantially perpendicular to the central axis, the first retaining arm being operably engageable with the first side of the print cylinder, and the second retaining arm being operably engageable with the second side of the print cylinder.

14. A printer according to Claim 13 wherein the print cylinder retainer comprises a first print cylinder retainer portion forming part of the first retaining arm, and a second print cylinder retaining portion forming part of the second arm.

15. A printer according to Claim 13 or Claim 14 wherein the print cylinder is moveable within the print cylinder retainer in a direction substantially perpendicular to the central axis.

16. A printer according to any one of the Claims 13 to 15 wherein the print cylinder adjuster further comprises a clamp for clamping the print cylinder in position within the print cylinder retainer.

17. A printer according to Claim 16 wherein the clamp comprises a first clamp portion moveable within the first retaining portion, and a second clamp portion moveable within the second retaining portion.

18. A printer according to Claim 17 wherein the print cylinder retainer further comprises first and second clamp portion activators for causing movement of the first and second clamp portion respectively.

19. A printer according to Claim 18 wherein each clamp portion activator comprises a pneumatic cylinder forming part one of the first and second retaining arms.

20. A printer according to any one of Claims 13 to 19 wherein the print cylinder adjuster further comprises a first adjustment arm and a second adjustment arm, the first adjustment arm being attachable to the first retaining arm, and the second adjustment arm being attachable to the second retaining arm, the first and second adjustment arms allowing further adjustment of the print cylinder when the print cylinder is held in position in the print cylinder retainer via the clamping portion.

21. A printer according to any one of Claims 11 to 20, wherein the first side of the print cylinder is substantially coplanar with the first side of the central drum, and the second side of the print cylinder is substantially coplanar with the second side of the central drum.

22. A printer according to any one of Claims 11 to 21 wherein the central drum rotates about a shaft, and the second end of the first arm is, in use, in contact with a first end of the shaft, and the second end of the first arm is, in use, in contact with a second end of the shaft.

23. A printer according to any one of Claims 14 to 22, wherein the cartridge is attachable to the print cylinder retainer.

24. A printer according to Claim 23, when comprising a cartridge having first and second attachment portions for attaching the cartridge to the printer, wherein the first and second attachment portions are receivable in the first and second retaining portions respectively of the print cylinder retainer.

25. A printer according to Claim 11 and any claim dependent thereon, wherein the print cylinder comprises a gear mechanism contained within a gear housing, which gear housing is rotatably moveably attached to the printer, the printer further comprising a gear housing adjuster engageable with the gear housing for causing rotational movement of the gear housing, thereby causing a corresponding rotational movement of the print cylinder relative to the central drum.

26. A printer according to Claim 25 wherein the gear housing comprises a worm wheel, and the gear housing adjuster comprises a worm threadably enagageable with the worm wheel.

27. A printer according to Claim 25 or Claim 26 wherein the gear mechanism further comprises a toothed inner surface forming a ring gear, an input gear attached to an output shaft of a print cylinder, and a plurality of planet gears engageable with the input gear and the ring gear.

28. A cartridge substantially as hereinbefore described with reference to the accompanying drawings.

29. A printer substantially as hereinbefore described with reference to the accompanying drawings.