Sealing member for a fluid container

ES 2 224 559 T3

DESCRIPTION

Sealing member for a fluid container.

Background of the invention

The present invention relates to ink jet printing systems, and more particularly, to ink jet printing systems using ink containers that can be replaced separately from the printing head.

Inkjet printers frequently use a carriage-mounted inkjet printhead that moves back and forth through a print medium, such as paper. As the print head moves through the print medium, a control system activates the print head to deposit ink droplets on the print medium to form images and text.

Previously used printers have used an ink container that could be replaced separately from the print head. When the ink cartridge was depleted the ink cartridge was removed and replaced with a new ink container. The use of replaceable ink containers that detach from the print head allows users to replace the ink cartridge without replacing the print head. The print head is then replaced at the end or near the end of the life of the print head and not when the ink container runs out.

There is an ever-present need for printing systems that are capable of providing low operating costs such as printers using off-axis type ink supplies. In addition, these printing systems must be user-friendly, such as including some form of memory to store printing parameters so that the user is not required to adjust printing parameters when the ink container is replaced. These ink supplies must allow reliable insertion into the printing system to ensure proper fluid interconnection and electrical interconnection to the printer have been achieved. In addition, these interconnections must be reliable and must not degrade over time and use. For example, the fluid interconnect must not leak during use or over time and the electrical interconnect must be reliable during use and over time. In addition, these ink cartridges must not require special handling by the user and must be reliably and securely connected by the user to form a highly reliable positive electrical, mechanical, fluid interface with the printer.

These ink-containing systems must be able to provide ink with high flow rates to a printer so as to allow high performance printing. This ink supply system must be inexpensive to allow for a relatively low cost per printed page. In addition, the ink supply must be capable of delivering ink with high flow rates in a reliable manner to the print head.

JP-A-57131565 describes a sealing member for sealing an ink tank, the sealing member receiving a needle and further comprising a rubber plug for receiving the needle, so that the rubber plug forms a compressive seal on an outer surface of the needle. The sealing member further comprises a sealing plate to guide the needle through the rubber plug.

Document EP-0921005-A (published June 9, 1999; prior art according to Art. 54137, EPC) assigned to the present applicant, describes a replaceable ink container with a fluid outlet comprising a fluid diaphragm to seal the fluid outlet.

Summary of the invention

In accordance with one aspect of the invention, there is provided a sealing member for sealing an opening in a fluid container, the sealing member receiving a hollow tubular member for establishing communication between the hollow tubular member and the fluid container, comprising the sealing member: an elastic sealing portion, configured to receive the hollow tubular member, which with the hollow tubular member inserted through the elastic sealing portion forms a compression seal with an outer surface of the hollow tubular member to limit fluid passage between the elastic sealing portion and the hollow tubular member; an introduction portion in the elastic seal portion for guiding the hollow tubular member through the elastic seal portion to establish communication between the hollow tube member and the fluid container; and a sealing surface, spaced from the elastic sealing portion, and configured to engage a movable sealing member to prevent passage of fluid through the elastic sealing portion with the hollow tubular member at least partially disassembled from the portion of elastic seal. Brief description of the drawings

Figure 1 depicts a schematic of a printing system including an ink container of the present invention;

Figure 2 shows a perspective view of a representation of the printing system of Figure 1:

Figure 3 depicts the ink container of Figure 1, shown in section, with the fluid outlet and air inlet shown greatly enlarged;

Figure 4 depicts a cross section of a fluid outlet and an air inlet for the ink container of the present invention which are shown applied with a fluid inlet and an air outlet, respectively, associated with a printer portion;

Figure 5 represents an end view taken through lines 5-5 of the fluid outlet shown in Figure 3;

Figure 6 represents a sectional view of the fluid outlet shown in Figure 5, taken through lines 6-6; and Figure 7 depicts a sectional view of an alternative embodiment of the fluid outlet shown in Figure 6.

Detailed description of the preferred embodiment

Figure 1 depicts a schematic of a printing system 10 that includes the ink container 12 of the present invention. Also included in the print system 10 are a print head 14 and a source of pressurized gas such as a pump 16. The pump 16 is connected via a conduit

ES 2 224 559 T3 to provide a pressurized gas such as air to the ink container 12. A marking fluid 19, such as ink, is provided by the ink container 12 to the print head 14 via a conduit 20. This marking fluid is expelled from the print head 14 to effect printing.

The ink container 12 that is the subject of the present invention includes a fluid reservoir 22 containing ink 19, an outer shell 24, and a chassis 26. In the preferred embodiment the chassis 26 includes an air inlet 28 configured for connection with conduit 18 to increase the pressure of outer shell 24 with air. A fluid outlet 30 is also included in the chassis 26. Fluid outlet 30 is configured to be connected to conduit 20 to provide a fluid connection between fluid reservoir 22 and fluid conduit 20.

In the preferred embodiment the fluid reservoir 22 is formed from a flexible material such that the pressure of the outer shell produces a circulation of pressurized ink from the fluid reservoir 22 through the conduit 20 to the print head 14. . The use of a pressurized ink source in fluid reservoir 22 allows relatively high flow rates of fluid to be delivered from fluid reservoir 22 to printhead 14. Utilizing high flow rates or high rates of ink supply to the print head enables the print system 10 to have high printability.

The present invention is a method and apparatus for configuring a reliable fluid outlet 30 that constitutes a fluid interface between the ink container 12 and the printing system 10. More specifically, the fluid outlet 30 associated with the ink container 12 allows fluids to be transferred in a reliable manner between the ink container 12 and the print head 14. In addition, the fluid outlet 30 also tends to prevent fluid from leaking from the ink container 12 when it is not connected to the printing system 10, such as during storage and transportation. The fluid outlet 30 will be examined in more detail with respect to Figures 3-7. Before examining the fluid outlet in detail, the printing system will be examined with respect to Figure 2.

Figure 2 depicts an embodiment of the printing system 10 shown in perspective. The printing system 10 includes a printing chassis 38 that contains one or more ink containers 12 of the present invention. The embodiment shown in Figure 2 has four similar ink containers 12. In this embodiment, each ink container contains ink of a different color. Therefore, four-color printing is effected by providing blue-green, yellow, violet, and black inks from the four ink containers 12 to one or more print heads 14. Also included in the printer chassis 38 is a control panel 40 for controlling the operation of the printer 10 and a middle slot 42 from which a print medium such as paper is ejected.

As ink 19 in a container 12 runs out, it is replaced with a new container 12 containing a new supply of ink. In addition, the ink container 12 may be removed from the printer chassis 38 for reasons other than the ink depletion condition such as changing the inks for an application that requires different ink properties or for them to be used. on a different medium. It is important that the ink container 12 is not only accessible within the printing system 10 but is also easily replaceable. It is also important that the new ink container 12 forms reliable interconnections such as the fluid interconnect, the air interface, and the mechanical interconnect that allow the printing system 10 to behave reliably.

It is important that ink spillage and splashing are minimized to provide a reliable interconnection between ink container 12 and printer 10. Ink spillage is detrimental not only to the printer operator who has to handle the impregnated container 12 of ink but also from the point of view of the reliability of the printer. Inks used in inkjet printing often contain chemicals that are surfactants which on printer components can affect the reliability of these printer components. Therefore, spillage of ink within the printer can reduce the reliability of printer components thereby reducing the reliability of the printer.

Figure 3 shows a simplified representation of the ink container 12 of the present invention which is shown in section and disconnected from the printing system 10. Ink container 12 includes fluid outlet 30, shown greatly enlarged, which is in fluid communication with fluid reservoir 22 containing fluid supply 19. Ink container 12 further includes air inlet 28 that is in communication with an area within outer shell 24 and not within fluid reservoir 22. The application of a pressurized gas, such as air, to this region allows the pressure of the ink container 12 to be increased to provide a source of pressurized fluid from the fluid outlet 30.

The fluid outlet 30 and the air inlet 28 of the present invention include a sealing member 34 and 36 for sealing the fluid outlet 30 and the air outlet 28, respectively, when the ink container 12 is not installed in the printer chassis 38 shown in FIG. 2. More specifically, the sealing member 34 prevents or limits the loss of ink from the fluid outlet 30 when the ink container is not installed in the printer chassis 38. In addition, the member 34 and 36 provides a seal between the fluid outlet 30 and a fluid inlet (not shown) associated with the printer chassis 38 and a seal between the air inlet 28 and an outlet (not shown). associated with the printer chassis 38. The sealing member 34 and 36 tends to limit or prevent leakage of both air and ink when the ink container 12 is properly installed in the printer chassis 38. The sealing member will be examined in more detail with respect to Figures 4 to 7.

Figure 4 illustrates more details of the sealing member 36 and 38 associated with the fluid outlet 30 and the air inlet 28, respectively, of the ink container 12. As shown in Figure 4 fluid outlet 28 and air inlet 30 are shown connected to a corresponding fluid inlet 44 and air outlet 42 associated with an ink container receiving station 46 in printer chassis 38. .

ES 2 224 559 T3

In this preferred embodiment the fluid inlet 44 associated with the ink container receiving station 46 includes a housing 48 and an outwardly extending needle 50 having a blunt, closed top end, a blind bore (not shown) and a side port 52. The blind bore is fluidly connected to the side port 52. The end of the needle 50 opposite the side hole 52 is connected to the fluid conduit 20 to provide ink to the print head 14 as shown in the figure.

1. A slide collar 54 surrounds needle 50 and is upwardly biased by spring 56. Slide collar 54 has a compliant sealing portion with an exposed upper surface and an inner surface in direct contact with needle 50.

The air outlet 42 in the ink container that is received from the station 46 is similar to the fluid inlet 44 except that it does not include the slip collar 54 and spring 56. The air outlet 42 in the ink container Ink received from station 46 includes a housing 58 and an outwardly extending needle 60 having a blunt upper end, a blind bore (not shown), and a side hole 62. The blind bore is connected in fluid communication with the side port 62. The end of the needle 60 opposite the side port 62 is connected to the air conduit 18 to provide pressurized air to the ink container 12 shown in Figure 1.

In this preferred embodiment, the fluid outlet 30 associated with the ink container 12 includes a hollow cylindrical protrusion 64 that extends outwardly from an ink container chassis 66. The end of the boss 64 toward the chassis 66 opens into a conduit 68 which is connected in fluid communication with the ink reservoir 22 thereby providing fluid to the fluid outlet 30. A spring 70 and a sealing ball 72 are positioned within the boss 64 and are held in place by a sealing member such as the compliant diaphragm 34 and a clamping cover 74. Spring 70 biases shutter ball 72 against diaphragm 34 to form fluid seal that prevents leakage of fluid from ink container 12 when the ink container is removed from receiving station 46. In addition, the sealing member 34 forms a seal that prevents fluid within the ink container 12 from passing between the sealing member 34 and the outwardly extending needle 50 when the ink container 12 is properly inserted into the tube. chassis 38 of the printer. The sealing member 34 will be examined in more detail with respect to Figures 5 to 7.

In the preferred embodiment, the air inlet 28 associated with the ink container 12 is similar to the fluid outlet 30 except that the additional closure formed by the spring 70 and the plug ball 72 is eliminated. Air inlet 28 associated with ink container 12 includes a hollow cylindrical bulge 76 that extends outwardly from an ink container chassis 68. The end of the bulge 76 toward the chassis 68 opens into a conduit 78 that is in communication with a region comprised between the outer shell 24 and an outer portion of the fluid reservoir 22 to increase the pressure in the fluid reservoir 22. The sealing member 36 such as a compliant diaphragm and a clamping cover 80 form a seal to prevent pressurized air within the container 12 from passing between the sealing member 36 and the outwardly extending needle 60 when the container 12 ink is properly inserted into the printer chassis 38.

Figures 5 and 6 depict the sealing member 34 shown in Figure 4 in greater detail. The sealing member 36 is similar to the sealing member 34 and therefore will not be examined in detail. Figure 5 depicts an end view taken through lines 5-5 of the fluid outlet 30 shown in Figure 3. The crimp cap 74 is shown positioned on the sealing member 34. The sealing member 34 includes a groove 82 that is located centrally in the sealing member and extends axially through the sealing member 34. As shown in FIG. 6, slit 82 tapers from a leading edge 84 toward a trailing edge 86 of sealing member 34, relative to a direction of insertion into the printer chassis 38. Crimped cap 74 includes an aperture 88 to allow blunt end of needle 50 to engage slit 82 and penetrate through sealing member 34 to effect fluid communication between ink container 12 and ink chassis 38. the printer.

An insertion portion 90 is provided on the leading edge 84 of sealing member 34 to help guide the blunt end of needle 50 into slot 82 in the event of misalignment of needle 50 during insertion of ink container 12 into chassis 38 of the printer. In the preferred embodiment, insertion portion 90 is concave or cup-shaped to guide needle 50 into slot 82. The introduction portion 90 can be in a variety of other shapes, each of which tends to guide the needle 50 into the slot 82. In the preferred embodiment, a lubricant is disposed within the introduction portion 90. The lubricant is a suitable lubricant to reduce friction between the blunt end of the needle 50 and the insertion portion 90 of the sealing member 34 to minimize or eliminate damage such as ripping or tearing of the sealing material 34 during insertion of the needle. 50 through slit 82. In the preferred embodiment, the lubricant is poly (ethylene glycol) PEG 400.

The sealing member 34 seals the ink container 12 when the needle 50 is withdrawn from the sealing member 34. Therefore, it is important that the sealing member 34 is under compression so that the sealing member 34 slides while keeping the slit 82 in the sealing member 34 closed. This compression is effected by a compression fitting between the sealing member 34 and the crimp cap 74. In addition, it is important that the sealing member material has sufficient elasticity to spring back rapidly to close the slit 82 so that ink leakage is minimized or eliminated when the ink container 12 is removed from the chassis 38 of the chamber. printer.

The groove 82 in the preferred embodiment is tapered to form a well-defined sealing area between the sealing member 34 and the needle 50. The groove can be in a variety of other ways such as hourglass or some other contour providing a small sealing area providing a point of contact

ES 2 224 559 T3 well controlled between the sealing member 34 and the needle. In addition, it is important that the contour of the slot 82 is deformed in a controlled manner as the needle 50 is inserted to provide a well-controlled force around the point of contact between the sealing member 34 and the needle 50 to minimize strain. ink leakage between needle 50 and sealing member 34. Although the embodiment shown in FIG. 5 uses a contoured groove to achieve a well controlled sealing surface, alternatively the sealing member 34 adjacent the needle 50 may be contoured to form a well controlled sealing surface. For example, a sealing surface adjacent needle 50 may have an hourglass-shaped cross section whose thickness increases radically from the central axis.

In the preferred embodiment, a secondary seal is provided to eliminate or reduce fluid leakage when needle 50 is withdrawn from seal member 34. This secondary seal is provided by a seal member 72 such as a seal ball that is loaded against a seal surface 92 in a complementary manner at the trailing edge 86 of seal member 34. The sealing surface 92 is contoured to provide a well defined sealing surface with the sealing member 72. In the preferred embodiment the sealing member 72 is biased towards the sealing surface 92 when the needle 50 is withdrawn from the sealing member 34. Upon insertion of the needle 50 into the sealing member 34 the blunt end of the needle 50 engages with the sealing member 72 and displaces the latter from the sealing surface 92 allowing fluid to pass between the ink container 12 and the printer chassis 38.

An important aspect of the sealing member 34 of the present invention is that the sealing member 72 must be spaced from the slit 82. The spacing between the sealing member 72 and the slit 82 having sealing surfaces is represented by a distance d in figure 6. To the Applicant's surprise, if the spacing represented by the distance d is not sufficient, correct engagement of the sealing member 72 with the sealing surface 92 is prevented by debris dislodged from the groove 82 which prevent the sealing ball 72 from moving. apply correctly with sealing surface 92. Applicant discovered that repeated insertions and withdrawals of needle 50 through slit 82 tend to erode or tear portions of sealing member 34 that tend to accumulate in region 94 between sealing member 72 and the slit. It was found that when the spacing represented by the distance d between the plug ball 72 and the slot 82 was insufficient these debris tended to prevent the plug ball 72 from being properly engaged in the plug 92 allowing a fluid leak to pass into the seal. secondary obturation when needle was withdrawn 50. Therefore, it is important that a debris accumulation region 94 is large enough to accumulate debris without interfering with the seating of the sealing member 72 on the sealing surface 92. The size of the debris accumulation region 94 or distance d that is required will generally depend on the erosion characteristics of the sealing member 34 and the value of the frictional forces between the needle 50 and the sealing member 34 during insertion. and withdrawn through slit 82.

Figure 7 depicts an alternative embodiment of the sealing member 34 shown in Figure 6. Similar numbers are used to represent similar structures. The sealing member 34 'shown in Figure 7 is similar to the sealing member 34 shown in Figure 6 except that the insertion surface 90' ​​is contoured differently than the insertion surface 90 shown in Figure 6. The insert 90 'is shallower than the insert 90 shown in Figure 6. In addition, the sealing surface 92' in the secondary seal has a different contour than the more contoured sealing surface 92 shown in Figure 6. In addition, this sealing surface 92 'is disposed relative to the groove 82' so that with the sealing member 72 positioned to engage the sealing surface 92 'at a distance d' is provided between the groove 82 'and seal member 72 to accommodate dislodged debris or particles from seal member 34'.

It is critical that the loss of ink from ink container 12 is reduced or eliminated when ink container 12 is inserted into printer chassis 38 and when ink container 12 is removed from printer chassis 38. Ink leakage from the ink container 12 when installed in the printer chassis 38 can damage the printer. In addition, leakage of ink during storage and transportation of the ink container 12 is unacceptable to the user of the printer.