EP3437883A1 - Ink cartridge for a printer - Google Patents

Abstract

The invention relates to an ink cartridge for a printer, comprising a first chamber (4), an inlet structure (6) for supplying ambient air into the first chamber (4), a second chamber (8) for storing ink (10) and with a connection structure (12) for supplying ambient air supplied to the first chamber (4) into the second chamber (8), characterized in that the first chamber (4) is arranged to store a free-flowing bubbling liquid (14), and in that the inlet structure (6) has at least one channel (16) adapted to introduce ambient air into the free-flowing bubbling liquid (14) to be stored.

Description

The present invention relates to an ink cartridge for a printer, comprising a first chamber having an inlet structure for supplying ambient air into the first chamber, a second chamber for storing ink, and a connection structure for supplying ambient air supplied from the first chamber into the second one Chamber.

Inside an ink cartridge for a printer, there is usually a negative pressure, so that stored ink does not leak uncontrollably from the ink cartridge. In order to allow a uniform, independent of the level of ink withdrawal by a printer, the vacuum level should be kept as constant as possible within the cartridge. For this purpose, during an ink extraction via a differential pressure valve ambient air flows into the cartridge, such as in DE 20 2009 001 744 U1 described.

At the in DE 20 2009 001 744 U1 described solution flows ambient air via a capillary body soaked with a secondary liquid in an interior of the ink cartridge. In this case, bubble formation takes place in the region of the secondary fluid held within the capillary body.

However, the capillary body used requires a lot of effort in production and assembly. For example, blunt cutting tools can be used when assembling the capillary body to the end Deformation of capillaries lead. The resulting negative pressure level is influenced by the deformed capillaries. Furthermore, the capillary body has to be positioned accurately and positionally in a housing in order to function reliably. Slippage or even deformation of the capillary body during assembly can influence the self-adjusting vacuum level.

The invention is based on the technical problem to provide an ink cartridge for a printer, which does not have the disadvantages described above, or at least to a lesser extent and in particular allows a uniform extraction of ink at a substantially constant vacuum level.

The above-described technical problem is solved by an ink cartridge according to claim 1. Further embodiments of the invention will become apparent from the dependent claims and the description below.

According to a first aspect, the invention relates to an ink cartridge for a printer, having a first chamber, an inlet structure for supplying ambient air into the first chamber, a second chamber for storing ink, and a connection structure for supplying ambient air supplied to the first chamber in the second chamber. The first chamber is configured to store a free-flowing bubbling liquid and the inlet structure has at least one channel adapted to introduce ambient air into the free-flowing bubbling liquid to be stored.

Characterized in that the channel is arranged for introducing ambient air into the free-flowing bubbling liquid to be stored in the first chamber, in the printing operation Foaming and associated pressure fluctuations in the area of the ink can be avoided, as bubbling occurs in the first chamber. It can be a uniform removal of ink at a substantially constant level of negative pressure by a printer. Further, by supplying air through the bubbling liquid, drying ink can prevent an air inlet from clogging and possibly clogging. The assembly and manufacture is simplified compared to solutions with capillary elements.

As used herein, a "free flowing bubbling liquid" is a liquid that is not picked up by a capillary element such as a sponge or the like. Within the first chamber, in particular, no capillary element, such as a sponge or the like, is arranged, which is adapted to receive the bubble-forming liquid to be stored in the first chamber.

In principle, it can be provided that the channel has an orifice in the first chamber, which is formed flush with a substantially planar wall of the first chamber surrounding the mouth. In this case, however, when ambient air flows into the bubble-forming liquid, bubbles may adhere to the wall, so that comparatively large bubbles are formed, which may cause pressure fluctuations. In order to form smaller bubbles, it is provided according to a further embodiment of the invention that the channel has a projecting end portion which projects into the first chamber. Bubbles formed in the region of the projecting end section dissolve faster and there is a finer blistering with bubbles of smaller diameter.

The projecting web can be a narrow, thin-walled web whose transverse to a flow direction measured wall thickness is smaller than a clear width of a flow cross-section of the channel in the region of the projecting end portion.

It can be provided that the channel has a local constriction. The flow cross-section formed in the region of the local constriction influences the level of vacuum that is established. By sizing the local constriction, therefore, a negative pressure level within the ink cartridge can be adjusted.

The local restriction may be formed in the projecting end portion to prevent backflow of bubbling liquid from the first chamber into the channel.

A flow cross-section of the local constriction may be limited by a web projecting into the channel. Thus, a dimensioning of the flow cross-section in the region of the constriction can be carried out in a simple manner.

It can be provided that the local constriction has a profile formed on the housing and the web is formed on a cover closing the housing, wherein the profile and the web limit the flow cross-section of the local constriction. Thus, e.g. the ridge project into a profile cross section to form the local constriction. By assembling the housing and lid, a capillary can thus be easily formed.

For example, the profile may have a U-shaped cross section and the web may have a substantially rectangular cross-section, which is bordered on two sides by profile legs of the U-shaped profile cross section. By the height of the U-profile projecting web, the remaining flow cross section in the area of the local constriction can be defined.

The local constriction may have a slot, e.g. is limited by a U-profile. Thus, a dimensioning of the flow cross-section in the region of the constriction can be carried out in a simple manner.

A slot and / or land can be manufactured reliably and cost-effectively while maintaining close manufacturing tolerances.

According to a further embodiment, it is provided that the channel has a profile formed on the housing, which is covered by a molded element formed on the cover, wherein the profile and the shaping element define a channel cross-section. This can be formed in a cost effective manner a circumferentially closed channel cross-section.

The ink cartridge may have a housing that is capped with a lid.

The lid and the housing may be welded together.

The lid and the housing may be made of a thermoplastic, in particular by an injection molding method or the like.

The channel can run at least partially meandering. In this way, a large channel length can be achieved on a comparatively small base area, in order to avoid leakage of bubble-forming liquid to be stored in the first chamber and to set a flow velocity of incoming ambient air.

According to a further embodiment, a third chamber is provided between the first chamber and the second chamber, wherein the third chamber is a part of the connecting structure. Specifically, the third chamber is adapted to prevent mixing of bubbling liquid with ink in the first chamber and the second chamber.

It may be provided that in the first chamber, the bubbling liquid is received, that in the second chamber, ink is absorbed and that between the liquids, a gas-filled intermediate volume is formed, wherein the bubbling liquid delimits the intermediate volume relative to the inlet structure and wherein the intermediate volume is at a negative pressure relative to an environment.

In particular, a liquid stored in the first chamber in cooperation with the inlet structure forms a differential pressure valve to create a defined negative pressure within the ink cartridge.

The bubbling liquid stored in the first chamber may have a higher surface tension than the ink stored in the second chamber.

The blistering fluid received in the first chamber may be, for example, glycerin.

The inlet structure and / or the connection structure may comprise at least one semi-permeable membrane. The membrane may be adapted to allow an airflow to pass while being impermeable to a liquid to be stored in the first chamber and / or to be stored in the second chamber. This may be, for example, a membrane, as used in breathable, rainproof outdoor clothing.

Fig. 1

eine erfindungsgemäße Tintenkartusche in einer perspektivischen Ansicht von rechts;

Fig. 2

die Tintenkartusche aus Fig. 1 in einer perspektivischen Ansicht von links;

Fig. 3

Gehäuse und Deckel der Tintenkartusche aus Fig. 1;

Fig. 4

das Gehäuse der Tintenkartusche aus Fig. 1 ohne Deckel in einer Seitenansicht;

Fig. 5

eine Ausschnittvergrößerung der Fig. 4;

Fig. 6

eine Ausschnittvergrößerung der Fig. 3;

Fig. 7

die Tintenkartusche aus Fig. 1 in einer perspektivischen Ansicht von links, mit Folie;

Fig. 8

die Tintenkartusche aus Fig. 1 in einer perspektivischen Ansicht von links ohne Folie;

Fig. 9

eine schematische Darstellung der Verengung;

Fig. 10

eine schematische Darstellung der Tintenkartusche.

The invention will be described in detail with reference to an exemplary embodiments illustrative drawing. Show it:

Fig. 1

an ink cartridge according to the invention in a perspective view from the right;

Fig. 2

the ink cartridge off Fig. 1 in a perspective view from the left;

Fig. 3

Housing and lid of the ink cartridge off Fig. 1 ;

Fig. 4

the housing of the ink cartridge Fig. 1 without lid in a side view;

Fig. 5

a section enlargement of the Fig. 4 ;

Fig. 6

a section enlargement of the Fig. 3 ;

Fig. 7

the ink cartridge off Fig. 1 in a perspective view from the left, with foil;

Fig. 8

the ink cartridge off Fig. 1 in a perspective view from the left without foil;

Fig. 9

a schematic representation of the constriction;

Fig. 10

a schematic representation of the ink cartridge.

The FIGS. 1 to 10 show an ink cartridge 2 for a printer, with a first chamber 4, with an inlet structure 6 for supplying ambient air from an environment U in the first chamber 4, with a second chamber 8 for storing ink 10 and with a connection structure 12 for supplying the first chamber 4 supplied ambient air into the second chamber eighth

The first chamber 4 is configured to store a free-flowing bubbling liquid 14, and the inlet structure 6 has at least one channel 16 adapted to introduce ambient air into the free-flowing bubbling liquid 14 to be stored.

In the present case, the bubble-forming liquid 14 is received in the first chamber 4. In the present case, the ink 10 is received in the second chamber 8.

The bubbling liquid 14 stored in the first chamber 4, in cooperation with the inlet structure 6, forms a differential pressure valve to maintain a defined negative pressure within the ink cartridge 2.

The bubble-forming liquid 14 stored in the first chamber 4 has a higher surface tension than the ink 10 stored in the second chamber 8.

The blistering fluid 14 received in the first chamber 4 is glycerine.

Within the first chamber 4, no capillary element, such as a sponge or the like, arranged to receive the bubbling liquid 14 to be stored in the first chamber 4 is presently arranged.

The channel 16 of the inlet structure 6 has a projecting end portion 18 which projects into the first chamber 4. In the projecting end portion 18 is a narrow, thin-walled web 18, whose measured transverse to a flow direction S wall thickness d is smaller than a clear width w of a Flow cross-section of the channel in the region of the projecting end portion 18th

The channel 16 has a local constriction 20. A flow cross-section 22 formed in the region of the local constriction 20 influences the self-adjusting negative pressure level.

The channel 16 runs meandering.

The local constriction 20 is formed in the projecting end portion 18. The local constriction 20 has a slot 24 into which a web 26 protrudes.

The ink cartridge 2 has a housing 28 which is closed with a lid 30. The lid 30 and the housing 28 are welded together. The lid 30 and the housing 28 have been made of a thermoplastic.

Fig. 3 shows the lid 30 and the housing 28 separately.

The local constriction 20 has a profile 32 formed on the housing 28. The web 26 is formed on the cover 28 closing the housing 28, the profile 32 and the web 26 delimiting the flow cross-section 22 of the local constriction 20. The web 26 protrudes into the profile 32 to form the local constriction 20.

The profile 32 has a U-shaped cross-section. The web 26 has a substantially rectangular cross-section. The web 26 is bordered on two sides by profile legs 34 of the U-shaped profile cross-section. By means of a height h of the web 26 projecting into the U-profile 32, the remaining flow cross-section 22 in the region of the local constriction 20 can be defined.

The profile 32 also forms the channel 16 in which the local constriction 20 is formed. The profile 32 is covered by a molded element 36 formed on the cover 30, the profile 32 and the shaping element 36 defining a channel cross-section which is larger than the remaining flow cross-section 22 of the constriction 20. The channel cross-section is defined by the profile 32 and the shaped element 36 peripherally completely bordered or closed, so that an inflowing air flow must completely flow through the channel 16 along its meandering shape to get into the chamber 4.

Between the first chamber 4 and the second chamber 8, a third chamber 40 is provided, wherein the third chamber 40 is a part of the connecting structure 12. The third chamber 40 is adapted to prevent mixing of bubbling liquid 14 with ink 10 in the first chamber 4 and the second chamber 8.

Accordingly, a gas-filled intermediate volume is formed between the liquids 14, 10, wherein the bubble-forming liquid 14 delimits the intermediate volume with respect to the inlet structure 6 and wherein there is a negative pressure in the intermediate volume relative to an environment U. The intermediate volume therefore comprises the gas volumes of the chambers 4, 8 and 40.

Hereinafter, the influx of ambient air from the environment U will be described.

In the printing operation, the ink cartridge 2 ink 10 is removed from the chamber 8 via an ink outlet 42. The arrows with the label T _of describing the leakage of ink 10. The ink removal causes an inflow of ambient air into the ink cartridge 2. The arrows with the label _{L, a} describe the inflow of ambient air into the ink cartridge 2 due to the ink removal.

The air is conducted via an inlet port 44 of the inlet structure 6 to the channel 16, wherein the air passes through a first air-permeable, liquid-impermeable membrane 45. The air continues to flow along the meandering channel 16 to the projecting end portion 18 and thereby passes through the local constriction 20, in the region of which the channel cross section is reduced to the flow cross section 22 in the manner of a throttle.

The air flows into the bubbling liquid 14 and forms small air bubbles 46 rising toward the surface 49 of the bubbling liquid 14.

Starting from the chamber 4, the air flows via a connection opening 48 into the chamber 40. From the chamber 40, the air flows through passages 50 and a second diaphragm 52 into the chamber 8. In this case, the air through the passage openings 50 along an outer side of the cartridge 2 wherein the outer region of the passage openings 50 and an inflow channel 54 is covered by a foil 56 ( Fig. 7 ). In Fig. 6 the foil 56 is blanked to illustrate the flow of air along the outside from the ports to the inflow channel 54.

In this way, the incoming ambient air enters the chamber 8. The initially increased by the ink extraction negative pressure in the chamber 8 is adjusted by the inflow of ambient air to the intended negative pressure level.

Claims (10)

Ink cartridge for a printer, with a first chamber (4), with an inlet structure (6) for supplying ambient air into the first chamber (4), - With a second chamber (8) for storing ink (10) and - With a connecting structure (12) for supplying the first chamber (4) supplied ambient air into the second chamber (8), characterized, - That the first chamber (4) for storing a free-flowing bubbling liquid (14) is arranged, and - That the inlet structure (6) has at least one channel (16) which is adapted for introducing ambient air into the to be stored, free-flowing bubbling liquid (14). Ink cartridge according to claim 1,
characterized in that the channel (16) has a projecting end portion (18) which projects into the first chamber (4). An ink cartridge according to claim 1 or claim 2,
characterized in that the channel (16) has a local constriction (20). Ink cartridge according to claim 2 and claim 3,
characterized in that the local constriction (20) is formed in the projecting end portion (18). An ink cartridge according to claim 3 or claim 4,
characterized in that a flow cross-section (22) of the local constriction (20) by a in the channel (16) projecting web (26) is limited. Ink cartridge according to claim 5,
characterized in that the local constriction (20) has a profile (32) formed on a housing (28) and the web (26) is formed on a cover (30) closing off the housing (28), wherein the profile (32) and the web (22) delimiting the flow area (22) of the local constriction (20). Ink cartridge according to one of claims 3 to 6,
characterized in that the local constriction (20) has a slot (24). Ink cartridge according to one of the preceding claims, characterized in that the channel (16) a profile (32) formed on a housing (28) which is covered by a molded element (36) formed on a cover (30), the profile (32) and the shaped element (36) delimiting a channel cross-section,
and or - At least partially meandering runs. Ink cartridge according to one of the preceding claims,
characterized in that between the first chamber (4) and the second chamber (8) a third chamber (40) is provided, wherein the third chamber (40) is a part of the connecting structure (12). Ink cartridge according to one of the preceding claims,
characterized in that the bubble-forming liquid (14) is accommodated in the first chamber (4), that ink (10) is received in the second chamber (8) and that a gas-filled intermediate volume is formed between the fluids, the bubble-forming fluid (14) delimiting the intermediate volume from the inlet structure (6), and wherein there is a negative pressure in the intermediate volume relative to an environment (U).

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