EP2226195B1 - Device for storing a cartridge for ink jet printers - Google Patents

Description

The present invention relates to a device for storing a cartridge for ink jet printers, the cartridge having a printhead with a nozzle plate with nozzles, and wherein the storage device comprises a carrier, which is designed for a selective stationary connection with the cartridge, and wherein the carrier Sealing element, which is designed to seal the nozzle from the environment when the cartridge is connected to the carrier.

Such storage devices are widely used for the transport and storage of brand new and especially recycled ink cartridges. The main purpose of such storage devices is to prevent the nozzles of the ink cartridge over longer storage periods and transport distances from drying out and to avoid mixing different inks, as may occur in multi-color printheads due to capillary forces, necessarily.

Although the present invention relates to an external inkjet printer cartridge storage and retrieval device, the principles of the present invention - particularly the sealing element used - can also be applied to ink jet printer-mounted elements for sealing ink cartridges currently not in need.

At one of the DE 43 44 746 A1 known storage device, an ink cartridge is locked in a detent formed as a plastic molding carrier. About cooperating with corresponding shapes of the ink cartridge insertion bevels the nozzle plate when inserted against a rubbery Pressed sealing element and held there in an end position by means of a pawl or latching element with application of a bias.

A problem with the known storage device is due to the properties of the rubber-like sealing element. With shocks and vibrations, which can occur in particular during the transport of the cartridges, it comes to minor relative movements between the nozzle plate of the cartridge and the sealing element due to unavoidable tolerances between the carrier and the ink cartridge, which ultimately leads to smearing of the ink and often to leaks.

According to the EP 1 647 405 A1 the cartridge is additionally fixed by spring elements in the carrier, so that despite the tolerances vibration-related undesirable relative movements of the nozzle plate relative to the sealing element can be prevented. However, such spring elements represent a design overhead.

The documents US 2006/012628 A1 and US 5648802 disclose the preamble of claim 1.

The concepts of known storage devices reach their limits when the nozzle plates of the ink cartridges with the nozzle structures are no longer substantially planar, but have fine, protruding or recessed structures, as is the case with many types of ink cartridges today. In these constellations, the contact pressure of conventional rubber-like sealing elements in certain areas would be too low for a reliable sealing effect and too large in certain areas, so that the sensitive nozzle structures could be destroyed by excessive pressure forces.

Furthermore, it is disadvantageous in the known storage devices that the sealing elements must be adapted to the configuration of the nozzle rows. For example, for cartridges having a plurality of rows of nozzles (or groups of closely spaced rows of nozzles) which are separated by a greater distance - typically are multi-color cartridges - the known rubber-elastic sealing elements web-shaped, each web one nozzle row or group of nozzle rows individually seals. For a cartridge with in comparison to the above-described cartridge of identical outer geometry, but having only one row of nozzles or group closely spaced rows of nozzles - typically a single color or black cartridge - contrast, a differently designed sealing element is used, so that the manufacturing and storage costs for the with storage devices provided with different sealing elements is high, and the risk of confusion (cartridge is inserted into matching support with mismatched sealing element) can not be excluded.

A disadvantage of known constructions is further that no visual control of the nozzle plate for damage or dirt is more possible once the cartridge is inserted into the carrier, which is why effective quality control is difficult.

The present invention has for its object to improve a storage device of the type mentioned in that od even without the compelling presence of centering spring elements. Like. An optimal sealing effect while sparing the nozzle structures even with complex nozzle plate geometries and at the same time universal for as many cartridge types can be used.

The solution of the aforementioned object is achieved by a device having the features of claim 1.

Advantageous embodiments of the invention are apparent from the dependent claims.

An essential feature of the invention is that the sealing element consists at least partially of a polyurethane gel. It has been found that such a gel-like material, with its physical properties lying between those of a solid and a fluid, is optimally suited for the reliable sealing of ink cartridges, since the gel-like material can flow into the nozzle structures when a specific contact pressure is predetermined, and this process is also reversible.

Since most known gel-like materials are not suitable for directly contacting residue-free and sealing with the nozzle plate of an ink cartridge, a separating material between the gel-like material and the nozzle plate is preferably provided; very particularly preferably it is a film material referred to below as a top film.

The upper film is preferably formed as a polyurethane film or as a flexible PVC film, in particular as so-called "blue tape" (blue-colored cover film), although of course other film types can be used.

Due to the interaction of the gel-like material with a polyurethane film or a PVC soft film, there is the advantageous effect that the film with a corresponding bias very fine - even projecting or receding - structures of the nozzle plate form-fitting surround and seal, without it in the field "Steps" of these structures to a wrinkling and associated leaks would come, as for example this would be the case if a solid substrate, for example a sponge-like or a rubber-like material, would be adhesive-laminated by means of a corresponding foil.

In contrast, the polyurethane film or soft PVC film is not firmly connected to the gel substrate using a gel-like material and can - due to the inherent extensibility and malleability of the film and the lack of anchoring on a substrate - the structures of the nozzle plate without wrinkles form-fit surrounded and thus seal with long-term stability.

If there are vibration-related relative movements of the ink cartridge relative to the carrier, the upper film can "go along". That is, there is no relative movement between the top film and the nozzle plate, so that it does not come to smears or leaks. Rather, the relative movements collected by shearing movements within the gel-like material. For this reason, a fixing of the ink cartridge in the carrier by additional spring elements is no longer mandatory, since the corresponding relative movements can already be compensated by the sealing element.

On its rear side facing away from the nozzles, the sealing element can be applied (in particular glued) directly to the gel-like material on a base element of the carrier, so that the gel-like material is enclosed between the bottom and the upper film.

In an alternative embodiment, the sealing element could also be closed on the back side with an additional base film, so that a money-tight cushion is formed, e.g. could be connected to the carrier by means of a rubber adhesive.

The additional base film may further be equipped with self-adhesive, so that these can be removed from a carrier film and fixed without additional adhesives in the carrier for mounting the sealing elements in the carrier.

The sealing element preferably has a substantially planar base surface on the rear side. In this case, the upper film rests against the bottom of the carrier in marginal areas (and can be glued to it) and forms an inner area with a pad filled with gelatinous material of a predetermined thickness and essentially flat or light when the cartridge is not inserted crowned contact surface for conditioning the nozzle plate of the ink cartridge. Characterized in that a kind of cushion is formed by the upper film, migration of the gel-like material under the pressure influence of the cartridge is not possible, so that the counter-pressure is maintained by the sealing element.

The contact surface of the sealing element is in the unused state of the cartridge initially substantially flat or slightly convex. By a three-dimensional structure of the nozzle plate, the contact surface deformed when inserted Cartridge and is then usually no longer flat. However, the corresponding deformations are reversible, so that the holder can possibly be used several times even for different types of cartridges.

Preferably, the abutment surface is dimensioned such that different types of ink cartridges with similar outer dimensions but different nozzle arrangements can all be sealed by a uniformly dimensioned sealing element, that is, the surface is dimensioned so large that all existing nozzle positions can be sealed.

In addition, the contact surface is preferably dimensioned such that the nozzles are always sealed by the seal assembly despite tolerances that may occur in the selective connection of the ink cartridge with the carrier with respect to the relative position between the nozzle plate and sealing element. The ink cartridge can be easily accommodated in the carrier with a certain play, which leads to a different relative position between the sealing element and the nozzle plate, since the contact surface is large enough to compensate for these tolerances. For this reason, separate centering means may be attached to the support, such as e.g. separate spring elements - be waived.

The carrier is preferably designed such that in the selective connection of the ink cartridge with the carrier, the nozzle plate of the ink cartridge is pressed against the sealing element, wherein the sealing element is compressed by a predetermined amount. An expedient embodiment of the carrier with insertion bevels and locking elements is from the DE 43 44 746 A1 or the EP 1 647 405 A1 known.

The gel-like material may preferably be a polyurethane gel which is mixed from at least two components, via the ratio of which the Shore hardness of the gel can be adjusted. The Shore hardness of the gel, the thickness of the pad formed by the gel and the degree of compression of the sealing element through the ink cartridge are chosen so that a reliable seal of the nozzle structures is ensured in compliance with the maximum allowable pressure forces on the nozzle structures.

The compression may typically be on the order of 10% to 50%, preferably 20% to 40%, most preferably about 33%. Said degree of compression refers to the decrease in the height of the gel pad when inserting the cartridge, i. the difference between the original height without a cartridge (measured at the highest point in the case of a slightly spherical shape of the cushion) and the height after inserting the cartridge (at the "thinnest" point), this difference then relative to the original height of the cushion. For example, the height decrease in one embodiment of the invention is about 0.6 to 0.8 mm at an original height of the sealing element of about 2.3 mm. The compression levels mentioned are usually not achievable with conventional rubber seals without the risk of destroying the nozzles. In this way, provided on the nozzle plate structures with height changes in the 1/10 mm range can be easily compensated without specially adapted sealing elements would be required.

In order to enable a visual inspection of the nozzle plate and the nozzles of the inserted cartridge through the carrier, it can be provided that the gel-like material, the upper film and the part of the carrier carrying the sealing element are formed substantially transparent. In conventional storage devices, this would not be feasible, since the rubber-like sealing elements, in contrast to a gel can not be made transparent.

Fig. 1

eine perspektivische Ansicht einer erfindungsgemäßen Aufbewahrungsvorrichtung;

Fig. 2 a-d

verschiedene Ansichten eines erfindungsgemäßen Dichtungselements;

Fig .3

eine Vorderansicht der erfindungsgemäßen Aufbewahrungsvorrichtung gemäß Fig. 1;

Fig. 4

eine Ansicht eines Dichtungselemente-Pads vor der Vereinzelung;

Fig. 5

eine Schnittdarstellung von Fig. 3 entlang der Linie A-A;

Fig. 6

eine Schnittdarstellung von Fig. 3 entlang der Linie B-B;

Fig. 7

eine Draufsicht auf die erfindungsgemäße Aufbewahrungsvorrichtung.

The invention will be explained in more detail by way of example with reference to the figures.
Show it:

Fig. 1

a perspective view of a storage device according to the invention;

Fig. 2 ad

different views of a sealing element according to the invention;

Fig. 3

a front view of the storage device according to the invention according to Fig. 1 ;

Fig. 4

a view of a sealing element pad before singulation;

Fig. 5

a sectional view of Fig. 3 along the line AA;

Fig. 6

a sectional view of Fig. 3 along the line BB;

Fig. 7

a plan view of the storage device according to the invention.

According to FIG. 1 (See also the other views in the Fig. 3 and 5 to 7) has a generally designated 10 storage device for a - not shown in all figures - print cartridge of an ink jet printing unit on a generally designated 12 integral carrier made of a plastic material. The carrier 12 is formed to interact with the ink cartridge to be stored so as to be biased in the storage position with the nozzle plate to be sealed with a bias against a seal member 14 attached to a bottom 38 of the carrier 12.

For this purpose, in the present embodiment, the ink cartridge, not shown, laterally projecting guide pins which engage when inserting the cartridge in two provided in the carrier 12 lateral guide grooves 30. The guide grooves 30 go in a region just before the rear wall of the carrier 12 in recesses 32 over. When the guide pins of the cartridge have reached the recesses 32 (see the dashed arrow in FIG FIG. 1 ), which at this stage still sitting obliquely in the carrier cartridge can finally be pivoted about an imaginary pivot axis 34 in its end position, so that the upper side of the cartridge engages below a handle 28. It is by a means of the handle 28 exerted bias the cartridge with the nozzle plate pressed against the sealing member 14, wherein the cartridge is sitting in this end position straight in the carrier, ie nozzle plate and sealing element are parallel. By lifting the handle 28, the cartridge can be released and removed again if desired. The electrical contact surface of the print cartridge is held by spacers 40 relative to the rear wall of the carrier 12 at a distance.

The specific mechanism by which the cartridge is inserted and latched into the carrier 12 will, of course, depend on the type of ink cartridge and is to be understood in the present context only by way of example.

In the context of the present invention, the sealing element 14 is made of a gel-like material, namely polyurethane gel. Like from the Fig. 2a to 2d in more detail, the sealing element in the embodiment - without being limited thereto - a rectangular base 16 and has approximately the shape of a flat truncated pyramid. The sealing element 14 is glued with its base 16 on the bottom 38 of the carrier 12. On the rear side, the sealing element is limited only by the gel-like material. Above the gelatinous material is a polyurethane film 18 as a top film, which forms the contact surface for the nozzle plate of the ink cartridge in the use state. Alternatively, a PVC flexible film (so-called blue tape) can be used as the upper film 18.

The upper foil 18 has flanks with a 60 ° angle on the edge (cf. Fig. 2d ) and forms in the central region a substantially flat or slightly convex contact surface, which is smaller than the base surface 16 of the sealing element 14 due to the flank regions.

The upper film 18 is connected in its outermost edge regions 20 to the bottom, so that a cavity is formed which is completely filled with polyurethane gel 22. This substantially transparent gel is made of two components, whereby the Shore hardness of the gel can be adjusted. Total forms the sealing element a gel pad, which as described above can also reliably rebound and projecting structures of the nozzle plates and does not slip even with relative movements caused by vibration.

The manufacture and shaping of the sealing elements 14 takes place as described with reference to FIG FIG. 3 can be seen by the top sheet 18 is brought into the desired shape of rectangular flat truncated pyramids by this is nestled by vacuum to a corresponding hard shape. Subsequently, the gel material 22 is applied continuously, whereby it collects in particular in the depressions of the hard mold. Temporarily then a base film made of polyurethane (not shown) is placed over it as the back cover. It then results in the FIG. 3 shown pad 36. The individual sealing elements 14 are then still isolated and glued or otherwise fixed in the carrier 12.

The base film is peeled off again before being mounted in the carrier 12, and the sealing element 14 is fixed in the carrier 12, if necessary by means of an adhesive.

Alternatively, the fixation can also be carried out simply by inserting the sealing element without base film with the gel material down into the carrier 12 at the appropriate position and then inserting the ink cartridge, whereby the sealing element is pressed firmly against the carrier. The gel material acts in this case sufficiently adhesive to keep the sealing element in later removed again cartridge in its position without any additional bonding would be required.

However, the base film could in principle also remain on the back of the sealing element 14, wherein the base film can be self-adhesive and provided with a siliconized cover, so that the sealing elements can be glued after removing the cover in the carrier.

The surface of the sealing elements 14 is dimensioned so that a sealing element for different nozzle constellations, possibly also for different types of printhead can be used.

LIST OF REFERENCE NUMBERS

10

Storage device

12

carrier

14

sealing element

16

Floor space

18

Upper folie

20

border area

22

gel-like material

28

handle

30

guide

32

recesses

34

swivel axis

36

Sealing elements before separation

38

ground

40

spacer

Claims (10)

1. A device (10) for storing a cartridge having a print head with a nozzle plate having nozzles, for ink jet printers, wherein the device has a carrier (12) adapted for selective stationary connection to the cartridge and wherein the carrier (12) has a sealing element (14) adapted for sealing off the nozzles with respect to the environment when the cartridge is connected to the carrier (12),
   characterised in that
   the sealing element (14) at least partially comprises a polyurethane gel (22).
2. A device according to claim 1 characterised in that the sealing element (14) comprises a polyurethane gel (22) which has an upper film (18) at its side towards the nozzles.
3. A device according to claim 2 characterised in that the upper film (18) is in the form of a polyurethane film or a soft PVC film, preferably in the form of 'blue tape'.
4. A device according to claim 2 or claim 3 characterised in that at its rear side remote from the nozzles the sealing element (14) bears against a bottom (38) of the carrier (12), wherein the polyurethane gel (22) is enclosed between the upper film (18) and the bottom (38).
5. A device according to claim 4 characterised in that on its rear side the sealing element has a flat base surface and that the upper film (18) bears in edge regions against the bottom (38) of the carrier (12) and in an inner region forms a cushion which is filled with polyurethane gel and which is of a predetermined thickness and has a flat contact surface for contact with the nozzle plate of the ink cartridge, wherein the contact surface is smaller than the base surface.
6. A device according to claim 5 characterised in that
   the contact surface is of such large dimensions that all nozzle positions of different types of ink cartridge of similar external dimensions but with different nozzle arrangements
   and/or
   the nozzles of the ink cartridge irrespective of the tolerances which can occur upon selective connection of the ink cartridge to the carrier (12) in respect of the relative position between the nozzle plate and the sealing element (14) can be sealed off by a sealing element (14) of unitary dimensions.
7. A device according to one of claims 1 to 6 characterised in that the carrier (12) has at least one inclined introduction surface and at least one latching element whereby upon selective connection of the ink cartridge to the carrier (12) the nozzle plate of the ink cartridge is pressed against the sealing element (14), the sealing element (14) being compressed by a predetermined amount.
8. A device according to claim 7 characterised in that the predetermined amount of compression is about 10% to 50%, preferably about 20% to 40%, particularly preferably about 33% reduction in height of the sealing element (14).
9. A device according to claim 7 or claim 8 characterised in that the polyurethane gel (22) is mixed from at least two components, by way of the ratio of which the Shore hardness of the polyurethane gel is adjustable, and that the Shore hardness, the thickness of the sealing element (14) and the degree of compression of the sealing element (14) occurring upon insertion of the ink cartridge are so selected that reliable sealing of the nozzle structures is ensured while maintaining the maximum permissible forces in relation to surface pressure on the nozzle structures.
10. A device according to one of claims 2 to 9 characterised in that the polyurethane gel (22), the upper film (18) and the part (38) of the carrier (12), that carries the sealing element (14), are transparent.

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