WO2012153287A2

WO2012153287A2 - Ink cartridge

Info

Publication number: WO2012153287A2
Application number: PCT/IB2012/052321
Authority: WO
Inventors: Paul Geldenhuys
Original assignee: Nutec Digital Ink (Pty) Ltd; Lowndes, James
Priority date: 2011-05-11
Filing date: 2012-05-10
Publication date: 2012-11-15
Also published as: ZA201308657B; WO2012153287A3

Abstract

The ink cartridge disclosed comprises a casing (10), an ink pouch (56) within the casing and a flap (42) which is pivotally mounted on the casing (10). The flap (42) is secured the pouch (56) so that it follows the movement of the pouch (56) as pouch empties. There is a slot (40) in the casing and a tab (50) forming part of the flap. The tab emerges from the casing through the slot of the casing as the pouch empties.

Description

INK CARTRIDGE

FIELD OF THE INVENTION THIS INVENTION relates to ink cartridges for digital printers.

BACKGROUND TO THE INVENTION

Known ink cartridges for digital printers comprise a casing with an ink filled pouch inside the casing. A nozzle is welded to the pouch and this is accessible from outside the casing so that one of the printing ink dispensing needles of the digital printer can pass through the nozzle and into the pouch.

A tab is provided which moves with the pouch as it empties, the tab protruding further from the casing as the pouch progressively empties. The tab is used to generate a

"pouch empty" signal when it co-acts with an optical sensor or a microswitch.

The present invention provides improvements to ink cartridges of the type described above and also provides improvements to the method of assembly of a digital printing ink cartridge.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of the present invention there is provided an ink cartridge which comprises a casing, an ink pouch within the casing and a flap which is pivotally mounted on the casing and which is secured to the pouch so that it follows the movement of the pouch as the pouch empties, a slot in the casing and a tab forming part of the flap, said tab emerging from the casing through the slot in the casing as the pouch empties. The flap can include two trunnions at least one of which is inserted into a mounting hole of the casing thereby to provide a pivot about which the flap can rotate. Whilst both trunnions can be mounted in this way, it is preferred that one trunnion be mounted in a circular opening and the other be in a slot of the casing and be free to move along the slot as the pouch empties.

That edge of the tab which forms the leading edge as the tab emerges from the slot can be skew, the arrangement being such that the part of the edge which is closest to the trunnions emerges from the slot before the remainder of the edge during pivotal movement of the flap with the emptying pouch.

The pouch can have a transparent or translucent filling and discharge nozzle and the casing can have an opening in it through which the nozzle can be viewed. There can be opposed openings in the casing so that the nozzle, when viewed through one opening, is backlighted through the other.

The flap can include projections which contact the pouch and which have gaps between them, thereby preventing face-to-face contact between the pouch and the flap being of a nature such as to form a seal across the pouch that traps ink in the pouch.

According to a further aspect of the present invention there is provided a method of assembling a digital printing ink cartridge which comprises placing a filled digital ink pouch in an open casing, mounting a flap on the casing so that the flap can pivot, adhering the flap to the pouch and closing the casing, providing a tab on the flap, providing a slot in the casing, and positioning the flap with respect to the slot so that the tab emerges from the casing through the slot as the pouch empties.

The flap can be coated with an adhesive which is covered by a release layer, the layer being removed before the adhesive coating on the flap is pressed against the full pouch.

According to a further aspect of the present invention there is provided a nozzle structure for an ink pouch which pouch is fabricated from weldable sheet plastics material and which structure comprises a nozzle welded to the sheet material of the pouch, the nozzle having a through bore and the bore having a larger diameter end section in which there is a resilient closure plug, and a closure element which is secured to the nozzle and prevents said plug from being removed from the bore. Said nozzle can have a circular, external groove bounded by a flange with gaps in it, the closure element including bayonet catches which pass through the gaps and, upon turning of the closure element with respect to the nozzle, move along said groove to attach the closure element to the nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the

accompanying drawings in which:-

Figure 1 is a pictorial view of a digital printing ink cartridge;

Figure 2 is an exploded view of the cartridge;

Figure 3 is a pictorial view of the end portion of the cartridge in assembled but not closed form;

Figure 4 is a detail of one end of the inverted, closed cartridge;

Figure 5 is a pictorial view of an ink pouch;

Figure 6 is a plan view of the ink pouch and its nozzle structure; and

Figure 7 is a plan view showing the ink pouch in situ but with one casing part of the cartridge omitted it. DETAILED DESCRIPTION OF THE DRAWINGS

The ink cartridge 10 shown comprises first and second casing parts 12 and 14. The parts 12, 14 are secured together by means of sliding bayonet type connections and security against separation is provided by pins 16 pushed through registering holes 18 and 20 in the casing parts 12 and 14.

The casing part 12 has a depression 22 for receiving a programmable chip (not shown) from which the digital printer into which the cartridge is inserted reads information concerning the cartridge. The casing part 12 also has an opening 24 which forms a window for a purpose to be explained hereinafter. A nozzle locating tab 26 protrudes from the casing part 12 and has a semi-circular recess 28 in one of the edges thereof. The casing part 14 is in the form of a shallow box having a main panel 30 and a peripheral wall 32 which extends along the edges of the main panel 30. There is a cut out 34 in one of the transverse parts 32.1 of the wall 32, the cutout 34 including a semicircular recess 36 at the closed end thereof. An opening 38 is provided in the main panel 30, this opening registering with the opening 24 when the casing parts are assembled. There is a slot 40 (see Figure 1 ) where the main panel 30 and the peripheral wall join 32.

A flap 42 is mounted on the longitudinal parts of the wall 32 adjacent the transverse part 32.1. More specifically, the flap has a pair of co-axial oppositely directed trunnions 44.

One trunnion 44 is received in a circular opening 46 and the other trunnion is received in an elongate slot 48 in the opposed part of the wall 32.

A tab 50 is provided which is at right angles to the planar part 52 of the flap 42. The free edge 54 of the tab 50 is skew to the plane in which the planar part 52 of the flap 42 lies.

The ink pouch 56 comprises laminated sheet material, including plastics material layers and an aluminium foil layer to provide the barrier properties that are required.

A nozzle 58 (Figures 5 and 6) forming part of a nozzle structure is welded to the sheet material of the pouch 56. The nozzle 58 has a tubular centre section 60 and two wings 62 which protrude in opposite directions from the section 60. The wings 62 provide sufficient area to enable a secure leakproof weld to be obtained.

The nozzle 58 further includes an external circumferentially extending groove 64 which is bounded by two circular flanges 66 and 68. The flange 68 has two gaps 70 therein.

The nozzle 58 is moulded using transparent or translucent synthetic plastics material.

A disc-like sealing grommet 72 fits into the bore 74 of the section 60 at the end thereof remote from the wings 62. The part of the bore 74 which receives the grommet 72 is at the lower end of the nozzle (as viewed in Figure 6) and is of larger diameter than the remainder of the bore 74.

A closure 76 is provided for attachment to the nozzle 58. The closure 76 comprises a disc-like wall 78 which has a central recess 80 whereby the end wall has a thin walled section which can readily be penetrated by an ink dispensing needle of a digital printer. The closure 78 has a pair of bayonet type catches 82.

The pouch 56 is filled with ink through the bore of the nozzle 58 and thereafter the grommet 72 is pushed into the bore 74 of the nozzle 58 to seal the pouch. The closure 76 is then pressed onto the nozzle 58 so that the catches 82 pass through the gaps 70 and into the groove 64. The closure 76 is then rotated a few degrees so that the catches 82 move along the groove 64 and out of alignment with the gaps 70 thereby locking the closure 76 to the nozzle 58.

The pouch 58 is then placed in the casing part 14 with the closure 76 and the flange 68 in the recess 36. The part of the casing adjacent the recess 36 enters the groove 64. A layer of adhesive can be provided on the panel 30 to secure the pouch 56 to the casing part 14.

The flap 42 is next placed in the casing part 14 and its tunnions 44 are inserted into the opening 46 and the slot 48. The release sheet is peeled-off the flap to expose the adhesive, and the flap is then pressed down onto the pouch 56 so that the flap 42 adheres to the pouch 56.

The casing part 14 is then attached to the casing part 12 and the pins 16 inserted to hold the casing parts together. As the casing part 14 is fitted to the casing part 12 the bounding edge of the semi-circular recess 28 enters the groove 64 of the nozzle 58. The recesses 28 and 36 form a circular opening in which the nozzle 58 and closure 76 are located (see particularly Figure 4).

As the pouch empties the tab 26 moves towards the slot 40 and eventually protrudes from the casing 10 through the slot thereby to generate, by way of co-action with a microswitch or optical sensor externally of the casing 10, a "pouch empty" signal.

The nozzle can be viewed through one of the windows constituted by the openings 24 and 38 so that the ink colour can be checked.

Claims

CLAIMS:

1. An ink cartridge which comprises a casing, an ink pouch within the casing and a flap which is pivotally mounted on the casing and which is secured to the pouch so that it follows the movement of the pouch as the pouch empties, a slot in the casing and a tab forming part of the flap, said tab emerging from the casing through the slot in the casing as the pouch empties.

2. An ink cartridge as claimed in claim 1 , wherein the flap includes two trunnions at least one of which is inserted into a mounting hole of the casing thereby to provide a pivot about which the flap can rotate.

3. An ink cartridge as claimed in claim 2, wherein both trunnions are mounted in mounting holes.

4. A link cartridge as claimed in claim 2, wherein one trunnion is mounted in a

circular opening and the other is in a slot of the casing and is free to move along the slot as the pouch empties.

5. An ink cartridge as claimed in any one of claims 2 to 4, wherein that edge of the tab which forms the leading edge as the tab emerges from the slot is skew, the arrangement being such that the part of the edge which is closest to the trunnions emerges from the slot before the remainder of the edge during pivotal movement of the flap with the emptying pouch.

6. An ink cartridge as claimed in any preceding claim, wherein the pouch has a transparent or translucent filling and discharge nozzle and the casing has an opening in it through which the nozzle can be viewed.

7. An ink cartridge as claimed in claims 6, wherein there are opposed openings in the casing so that the nozzle, when viewed through one opening, is backlighted through the other.

8. An ink cartridge as claimed in any preceding claim, wherein said flap includes projections which contact the pouch and which have gaps between them, thereby preventing face-to-face contact between the pouch and the flap being of a nature such as to form a seal across the pouch that traps ink in the pouch.

9. A method of assembling a digital printing ink cartridge which comprises placing a filled digital ink pouch in an open casing, mounting a flap on the casing so that the flap can pivot, adhering the flap to the pouch and closing the casing, providing a tab on the flap, providing a slot in the casing, and positioning the flap with respect to the slot so that the tab emerges from the casing through the slot as the pouch empties.

10. A method as claimed in claim 9, wherein the flap is coated with an adhesive

which is covered by a release layer, the layer being removed before the adhesive coating on the flap is pressed against the full pouch.

1 1. A nozzle structure for an ink pouch which pouch is fabricated from weldable

sheet plastics material and which structure comprises a nozzle welded to the sheet material of the pouch, the nozzle having a through bore and the bore having a larger diameter end section in which there is a resilient closure plug, and a closure element which is secured to the nozzle and prevents said plug from being removed from the bore.

12. A nozzle structure as claimed in claim 11 , wherein said nozzle has a circular, external groove bounded by a flange with gaps in it, the closure element including bayonet catches which pass through the gaps and, upon turning of the closure element with respect to the nozzle, move along said groove to attach the closure element to the nozzle.