WO1998022290A1

WO1998022290A1 - An inkjet cartridge refill device

Info

Publication number: WO1998022290A1
Application number: PCT/GB1997/003150
Authority: WO
Inventors: John Michael Payne
Original assignee: Pbt International Ltd.
Priority date: 1996-11-18
Filing date: 1997-11-17
Publication date: 1998-05-28
Also published as: AU4959897A

Abstract

A refill jig for an ink cartridge having a print head formed of inkjet orifices, an ink chamber, a bubbler valve, spring loaded internally mounted air sacs and a passageway for ambient air to the air sacs is disclosed, the jig comprising a support frame (1) for mounting the cartridge in a refill position, a refill ink reservoir (14) mounted on the support frame, valve means (15) on the frame operable when the cartridge is in the refill position to release ink from the ink reservoir through the bubbler valve to refill the cartridge, and an intermittently operable air pump (9) on the frame for cyclically inflating and deflating the air sacs of the cartridge through the passageway for ambient air to the air sacs such that with the inkjet orifices closed, inflation of the air sacs causes air to be evacuated from the cartridge through the bubbler valve and into the refill ink reservoir and deflation of the air sacs causes ink to be drawn from the refill ink reservoir through the valve means into the cartridge ink chamber until the cartridge is filled with ink.

Description

AN INKJET CARTRIDGE REFILL DEVICE

The present invention relates to a cartridge refill device.

Inkjet printing devices known in the art use a small ink cartridge to deliver drops of liquid ink to form a visible image.

After ink depletion, the cartridge has to be replaced by a new one or the depleted cartridge may be refilled and used again. An inkjet cartridge known in the art manufactured and sold by Hewlett Packard, is comprised of a cartridge body for holding the ink and internally thereof, a pair of spring loaded air inflatable sacs in communication through a wall of the cartridge with ambient air.

A wall of the cartridge is provided with a print head formed of inkjet orifices which deliver ink during operation to the printing device and a bubbler valve which controls the outflow of ink in conjunction with the inflatable air sacs.

In this known cartridge, it is essential that when the cartridge has been filled, there is a negative pressure or vacuum in the cartridge chamber. The bubbler valve and air sacs work together during depletion so that if the air sacs become over-in lated through a higher than necessary vacuum created in the ink reservoir through depletion of the ink, then the bubbler valve will allow a small amount of air to enter the ink chamber thus creating exactly the amount of vacuum or negative pressure under which the cartridge is designed to operate.

The bubbler valve in the Hewlett Packard cartridge comprises a ball sealed in a spiral passageway. It is designed so that the viscosity of the ink which usually coats it will act as a vacuum limiter. If the vacuum exceeds a predetermined value, air will be pulled past the ball and into the cartridge chamber.

It is an object of the present invention to provide a refill jig for a refill cartridge of the type just described which is simple yet effective to use with a minimum amount of oper: tional parts.

According to the invention there is provided a refill jig for an ink cartridge having a print head formed of inkjet orifices, a bubbler valve, spring loaded internally mounted air sacs and a passageway for ambient air to the air sacs, the jig comprising a support frame for mounting the cartridge in a refill position, a refill ink reservoir mounted on the support frame, valve means on the frame operable when the cartridge is in the refill position to release ink from the ink reservoir through the bubbler valve to refill the cartridge, and an intermittently operable pressurised air supply on the frame for inflating the air sacs of the cartridge in the refill position through the passageway for ambient air to the air sacs cyclically to inflate the air sacs such that with the inkjet orifices closed, air is evacuated from the cartridge through the bubbler valve and valve means into the ink reservoir until the cartridge is filled.

According to the invention there is further provided a refill jig for an ink cartridge having a print head formed of inkjet orifices, a bubbler valve, spring loaded internally mounted air sacs and a passageway for ambient air to the air sacs, the jig comprising a support frame for mounting the cartridge in a refill position, and an intermittently operable pressurised air supply for inflating the air sacs of the cartridge in the refill position through the passageway for ambient air to the airs sacs cyclically to inflate the air sacs such that with the inkjet orifices closed, air is evacuated from the cartridge through the bubbler valve to allow the cartridge to be filled with ink. According to the invention there is further provided a valve means for a refill apparatus for an ink cartridge having a print head formed of inkjet orifices, a bubbler valve, spring loaded internally mounted air sacs and a passageway for ambient air to the air sacs, the valve means comprising a passageway which selectively allows ink to flow from a reservoir into the bubbler valve, the passage opening to an outlet in the form of an annular channel arranged to be adjacent, in use, to the bubbler valve.

Other features and advantages of the present invention will become apparent from the following description of a preferred embodiment of the invention taken with reference to the accompanying drawings, wherein:

Figure 1 is a cross sectional view of the refill jig according to the invention, mounting a cartridge;

Figure 2 is a view of the refill jig similar to Figure 1 in the refill position; "igure 3 is a view of a refill sachet for use with the jig of Figures 1 and 2;

Figure 4 is a cross sectional view through a feed valve of the sachet of Figure 3 shown mounted to the refill jig in Figures 1 and 2; Figure 5 is a cross sectional view of the same nozzle of the sachet of Figure 3 with the feed valve in the refill position of the jig shown in Figure 2;

Figure 6 is a cross-sectional view through a feed valve according to a further embodiment of the invention in a pre-refill position;

Figure 7 is a cross-sectional view through the valve of Figure 6 in a refill position;

Figure 8 is a view showing how the valve of Figure 6 provides ink to a cartridge; Figure 9 is a cross-sectional view through a feed valve according to a yet further embodiment of the invention; and

Figure 10 is a cross-sectional view through the valve of Figure 9 in a refill position. The refill jig shown in Figures 1 and 2 comprises a housing 1 made of a thin resilient plastics material, for mounting a Hewlett Packard inkjet cartridge

2 of the type as described above and having two internally mounted air sacs 3 spring loaded to a non-inflated condition and in communication with ambient air through an inlet 4 in "he base of the cartridge 2.

The top of the cartridge is provided with a print head 5 having inkjet orifices (not seen) and an air vent 6 in the form of a bubbler valve, not shown in detail, but which may comprise an aperture opening into a spiral passageway sealed at the end opening into the cartridge chamber with a control ball.

The housing 1 is articulated at 7 to a support base frame 8 also made of a thin resilient plastics material, provided with an hermetically sealed depressible dome 9 which supplies air when depressed through an air supply tube 10, to the inlet 4 to the air sacs 3 when the jig is in the refill position shown in Figure 2.

A U-shaped recess 11 is formed in the top of the housing 1 for engagement with spaced rimmed flanges 12 on the nozzle 13 of a refill sachet 14 shown in Figure 3.

The nozzle 13 of the sachet 14 is provided with an actuable refill valve 15 as shown in greater detail in

Figures 4 and 5. The valve 15 is formed of a compressible material provided with an L-shaped internal passageway 16. The body 17 of the valve is bobbin shaped and the walls of the nozzle 13 are configured to occupy the space between the upper and lower flanges 18,19 of the bobbin shaped body 17. In the closed position, the passageway 16 is sealed against the wall of the configured portion of nozzle 13 as shown in Figure 4 to prevent loss of inkjet fluid. In the cartridge refill position shown in Figure

2 and Figure 4, the pressure between the valve body 17 and the top of the refill cartridge 2 compresses the lower flange 19 of the bobbin shaped valve body 17, raising the upper part of the valve body 17 and allowing the ink to flow through the passageway 16 from the refill sachet 14 into the chamber of the cartridge 2.

Also, in the refill position as shown in Figure 2, a closure member 20 mounted on the inside of the wall of the housing tightly engages the inkjet orifices of the print head 5 to close them.

As shown particularly clearly in Figure 2 , the jig is maintained in the refill position by means c a hook shaped resilient catch 21 engaging a slot 22 in the support base 8. The catch has a release button 23. The release button 23, in the jig refill position, is hidden behind the pressure supply dome 9 so that it is generally inaccessible to the user until the dome 9 is depressed.

The filing sequence using the refill jig as described above with the cartridge 2 held in the refill position shown in Figure 2 is as follows.

The user depresses the dome 9 which forces air into the air sacs 3, normally held flat under their spring loading, through the air supply tube 10. The cartridge 2 is thus pressurised, forcing air into the bubbler valve 6 and through the open valve 15 in the nozzle 13 of the sachet 14. Air then bubbles through the ink to the top of the sachet 14.

The capacity of the pressure supply dome is matched to that of the two air sacs 3 such that under thumb pressure the air sacs 3 inflate short of bursting. The cubic capacity is approximately 20 cc.

On releasing the pressure supply dome 9, the two air sacs 3 deflate which in turn produces a negative pressure in the chamber of the cartridge 2 causing ink to be sucked from the sachet 14 into the cartridge chamber through the bubbler valve 6. This intermittent depression of the pressure dome 9 is repeated until the cartridge is filled. It will be noted that the cartridge 2 cannot be overfilled as any excess ink will be forced backed into the sachet 14 if there is no air left to expel from the cartridge 2.

At the end of the refill process, it is essential that a negative pressure remains in the chamber of cartridge 2. If this has not been achieved, ink will leak from the bubbler valve 6 until that negative pressure is attained under the normal action of the bubbler valve. The refill jig of the present invention is designed to achieve refilling, but without subsequent ink leakage. Thus, as shown in Figure 1, the user is not able to operate the main catch 21,22,23 to open the jig, because access is blocked by the pressure supply dome 9. Access is only possible by pressing the dome 9 and simultaneously pressing the catch button 23, thus ensuring that the air sacs are partially inflated at the moment when the valve 15 in the sachet 14 is closed.

When the catch 21 is released, the air tube 10 and the sachet valve 15 are simultaneously disconnected from the cartridge 2.

Thereafter the air sacs 3 deflate under the action of their spring loading which provides the required negative pressure in the chamber of the cartridge 2, thereafter being regulated by means of the action of the bubbler valve 6 in the normal way. Figure 1 shows the position when the dome is depressed, after filling a cartridge, to release catch 10.

Although the preferred embodiment of the invention works by means of two articulated frame halves, it will be readily apparent to the skilled person that this type of action is not the only one which would bring about the advantages of the invention, and consequently the scope of the appended claims should not be construed as limiting the invention to the preferred embodiment. For example, other means built into the structure are possible to effect registration of the valve means with the bubbler valve, the closure member with the inkjet orifices and the air supply with the air sacs to allow refill to take place.

Also it is not essential that a closure member for the inkjet orifices need be incorporated in the refill jig. These orifices could be closed over before the cartridge is inserted into the jig for a refill operation. Figures 6 to 8 show a further embodiment of the invention and illustrates more clearly the manner in which the valve may function. A valve body 61 sits within a nozzle 62 as before. Valve body 61 includes an L-shaped passage 63 which is, in the closed position, sealed against the wall of the nozzle to present loss of inkjet fluid. Figure 7 shows how in the cartridge refill position, the lower part of valve 61 is compressed, raising the upper part of the valve and allowing ink to flow through passageway 63 from the refill sachet into the chamber of a cartridge. The valve of Figures 1 to 5 works in a similar way. In the embodiment shown in Figures 6 to 8 , however, the L-shaped passage 63 opens into an annular channel 64 in the base of the valve body 61.

The position of the fill hole (bubbler valve) in the surface of a cartridge can vary, either by variations unit by unit, or by design. In one example, the hole position of a cartridge was altered by Hewlett Packard by 3mm. The ball of the bubbler valve was also omitted. The annular fill channel of the embodiment of Figures 6 to 8 enables any fill hole, which at least partially lies within the region defined by the annular channel, to be filled. This is shown in Figure 8, which shows the top of a cartridge. Two alternative fill hole positions A and B are shown which both 'overlap' the extent of annular channel 64. Ink from passage 63 flows into channel 64, from where it can pass into hole A or hole B (only one of these will, of course, be provided on any cartridge), or indeed into a hole position anywhere else under annulus 64. The figure also shows the inkjets 65 of the cartridge.

By using an annular channel rather than an enlarged orifice, the amount of ink which touches the outside of the cartridge is minimised since the ink flow is restricted to the region defined by the annular channel .

Figures 9 and 10 show an alternative valve system which also comprises a compressible member 65. In addition, however, this embodiment further comprises a separate non-compressible sealing piece 66, incorporating a lengthwise groove 67. When the valve is at rest (Figure 9) , the compressible member 65 is relaxed (ie not compressed) and the head 68 of the sealing piece 66 firmly seals against the upper part of member 63, preventing ink flow through the valve. However, when the lower part of the compressible seal 65 is pressed against a fill hole (bubbler valve) of a cartridge (Figure 10), the sealing piece head is raised relative to the compressible member, allowing ink to flow from sachet 14, down the groove 67 in the sealing piece, through the open part of compressible seal 65 and into the fill hole.

As an alternative to the dome as shown in the embodiments described, other air pressure supply means, such as bellows for example, may be used.

Claims

1. A refill jig for an ink cartridge having a print head formed of inkjet orifices, an ink chamber, a bubbler valve, spring loaded internally mounted air sacs and a passageway for ambient air to the air sacs, the jig comprising a support frame for mounting the cartridge in a refill position, a refill ink reservoir mounted on the support frame, valve means on the frame operable when the cartridge is in the refill position to release ink from the ink reservoir through the bubbler valve to refill the cartridge, and an intermittently operable air pump on the frame for cyclically inflating and deflating the air sacs of the cartridge through the passageway for ambient air to the air sacs such that with the inkjet orifices closed, inflation of the air sacs causes air to be evacuated from the cartridge through the bubbler valve and into the refill ink reservoir and deflation of the air sacs causes ink to be drawn from the refill ink reservoir through the valve means into the cartridge ink chamber until the cartridge is filled with ink.

2. A refill jig as claimed in Claim 1, wherein the support frame is provided with closure means for closing the inkjet orifices in the refill position.

3. A refill jig as claimed in Claim 2, wherein the support frame is composed of two frame parts, one articulated to the other for movement between an open cartridge load position whereat the valve means, closure member and air supply inlet are out of register respectively with the bubbler valve, inkjet orifices and ambient air passageway of the cartridge, and a closed cartridge refill position where the valve means is opened against the bubbler valve to release ink from the reservoir through the bubbler valve, the closure member closes the inkjet orifices and the air pump inlet is in communication with the air sacs of the cartridge.

4. A refill jig as claimed in Claim 3, wherein the valve means is part of a flexible sachet for refill ink, the sachet being releasably mounted to said one frame part.

5. A refill jig as claimed in Claim 4, wherein the valve means is part of a refill nozzle of the sachet, the nozzle having a pair of spaced outwardly extending flanges for engaging the walls of a receiving slot in said one frame part.

6. A refill jig as claimed in any one of Claims 2 to 5, wherein said valve means is in the form of a main valve body having a passageway for refill ink, said body being of a compressible material which in a relaxed state acts to seal the passageway to prevent ink flow, and in a compressed state, when the jig is in the closed cartridge refill position, acts to open the passageway and allow flow from the reservoir to the chamber of the ink cartridge.

7. A refill jig as claimed in Claim 6, wherein the inlet to the passageway for refill ink from the refill sachet is sealed against the nozzle of the sachet in which the main valve body is mounted, in the relaxed state, subsequently to communicate with the interior of the sachet in the compressed state.

8. A refill jig as claimed in Claim 6 or Claim 7, wherein the passageway opens to an outlet in the form of an annular channel.

9. A refill jig as claimed in Claim 8, wherein a cartridge to be filled is arranged relative to the jig so that its bubbler valve at least partially lies within the region defined by the annular channel.

10. A refill jig as claimed in any preceding claim, wherein the intermittently operable air pump is in the form of a hermetically sealed flexible dome or bellows.

11. A refill jig as claimed in Claim 10, wherein cooperating catch means are provided to retain the two frame parts in the closed cartridge refill position, the catch means being shielded by said flexible dome so that release of the catch means occurs either simultaneously with or after depression of the dome.

12. A refill jig for an ink cartridge having a print head formed of inkjet orifices, a bubbler valve, spring loaded internally mounted air sacs and a passageway for ambient air to the air sacs, the jig comprising a support frame for mounting the cartridge in a refill position, and an intermittently operable pressurised air supply for inflating the air sacs of the cartridge in the refill position through the passageway for ambient air to the airs sacs cyclically to inflate the air sacs such that with the inkjet orifices closed, air is evacuated from the cartridge through the bubbler valve to allow the cartridge to be filled with ink.

13. A valve means for a refill apparatus for an ink cartridge having a print head formed of inkjet orifices, a bubbler valve, spring loaded internally mounted air sacs and a passageway for ambient air to the air sacs, the valve means comprising a passageway which selectively allows ink to flow from a reservoir into the bubbler valve, the passage opening to an outlet in the form of an annular channel arranged to be adjacent, in use, to the bubbler valve.

14. A refill jig for an ink cartridge, substantially as hereinbefore described, with reference to, and as illustrated in, the accompanying drawings.

15. A refill sachet comprising the valve means of any of Claims 1 to 13.