HK1031851A - Ink bottle with puncturable diaphragm closure - Google Patents

Description

Ink bottle with pierceable membrane closure

The present invention relates to ink bottles (or other containers) for containing ink for inkjet printing systems. Inkjet printing apparatus using the ink bottle of the present invention is generally referred to as an industrial type inkjet printing system (unlike an office inkjet printer), and is generally used to print marks on product packages or secondary packages fed past an inkjet print head of the system while the product in the package is fed past the print head on a conveyor belt or the like. U.S. patent application No.08/728,774, assigned to Marsh Company of Belleville, Illinois, filed 10.11.1996, illustrates such an ink jet printing system. It should be appreciated that such industrial inkjet printing systems typically use much more ink in a given amount of time than an office inkjet printer because the area printed by such industrial printers is relatively large and the industrial printing system operates continuously. Thus, there is a need to provide a larger ink supply for such industrial ink jet printers as compared to office ink jet printers.

Ink is supplied to such commercially available inkjet printing systems by means of a disposable ink bottle that holds a desired amount of ink (e.g., one pint or one liter). U.S. patent 5,343,226 entitled "ink jet ink supply apparatus" shows an ink bottle having a spring biased poppet valve mounted in a screw thread on the cap such that when the bottle is inverted and screwed into a container in an ink jet printing apparatus, a finger will engage a normally closed spring biased valve in the cap and will force the valve open, thus allowing ink in the bottle to fill an ink reservoir of the ink jet printing apparatus. When an ink bottle is removed from the ink jet printing apparatus, under the bias of the spring, the valve will close and the valve will prevent ink from flowing out of the bottle when the ink bottle is removed. While such bottles work well for their purpose, it is expensive to have to include the spring biased valve in the cap of each bottle.

Reference is also made to us 4,531,656 and 4,678,101 which disclose bottles for pressure dispensing liquids employing a pierceable closure.

According to an aspect of the present invention, there is provided an inkjet printing apparatus including: an ink tank; a replaceable ink container for supplying ink to the gutter, the container having ink therein; a pierceable membrane closing said container; a piercing member supported by said ink tank, said piercing member being engageable with said membrane when said membrane faces said piercing member, said piercing member piercing said membrane when said container and said membrane are moved toward said piercing member and said membrane engaging a side of said piercing member to substantially prevent ink from leaking between said piercing member and said membrane, said piercing member establishing communication between ink in said container and said ink tank to allow ink to flow from said container into said ink tank; and an air passage in communication with the atmosphere and the reservoir, such that ink from within the container and ambient air may be exchanged within the container through the piercing member, such that ink may freely flow from the container into the reservoir and the pressure within the container is maintained at substantially atmospheric pressure.

According to another aspect of the present invention there is provided an ink bottle for an ink jet printing system, said ink jet printing system having an ink tank for holding ink for said ink jet printing system, said bottle having a closed container body with a mouth at one end thereof, a pierceable membrane sealingly secured to said mouth to close said bottle, said membrane being a sheet of resilient elastomeric material, a cap secured to said mouth and covering said membrane, said cap having a through opening exposing a portion of said membrane for piercing by a piercing member when the bottle is mounted on said ink jet printing system in an inverted mouth-down position, whereby ink and atmospheric air in said bottle are exchanged through said piercing member.

According to a third aspect of the present invention, there is provided an ink supply system for an inkjet printing apparatus, comprising: an ink reservoir for containing ink to be supplied to an ink jet printhead or the like, a replaceable ink bottle container for containing ink for use in said ink reservoir, an ink bottle membrane supported by said ink bottle, a piercing member supported by said ink reservoir, said piercing member being engageable with said membrane as said ink bottle is moved toward said piercing member so that said piercing member pierces said membrane, said piercing member being sealingly engageable with said membrane so as to substantially prevent leakage of ink between said piercing member and the area of engagement of said membrane with said piercing member, and an air passage between the external atmosphere and said tank so that air and ink in said ink bottle can be exchanged through said piercing member.

According to a fourth aspect of the present invention there is provided a method of supplying ink to an ink jet printing system having an enclosed ink tank, a piercing tube extending above the tank and providing communication to the interior of the tank, the piercing tube extending downwardly into the tank to a predetermined height, an air passage extending from the atmosphere outside the tank to the tank, and an ink bottle having a pierceable membrane, the method comprising the steps of: orienting the ink bottle so that the membrane faces the piercing tube; penetrating the piercing tube through the membrane to communicate the interior of the ink bottle with the gutter so that ink within the ink bottle can flow into the gutter; and allows the exchange of ink from the bottle into the tank and ambient air into the bottle as the ink flows through the piercing tube.

With regard to other features of the embodiments of the present invention, it should be noted that:

a container or bottle for holding ink for an inkjet printing apparatus is employed in which the mouth of the bottle is closed by a pierceable membrane sealed with respect to the mouth of the bottle such that, when the bottle is installed in the inkjet printing apparatus in an inverted condition, a hollow piercing member will pierce the membrane and communicate with the ink in the bottle, thereby allowing ink to flow by gravity through the piercing member into a slot in the inkjet printing apparatus and allowing atmospheric air to enter the bottle through the piercing member to displace the ink as it flows from the bottle into the inkjet printing apparatus.

A container or bottle is employed in which the membrane has a preformed yet sealed weakened area (line) which breaks open when the piercing member is inserted therethrough, with the edge of the weakened area at least partially sealingly engaging the side of the piercing member to substantially prevent ink leakage.

A container is employed in which the diaphragm is formed of an elastomeric sheet material having sufficient resiliency and memory such that when the piercing member is withdrawn from the diaphragm, the opening formed by the piercing member will close, effectively reclosing (and in some cases resealing) the opening and preventing ink leakage.

A container is employed in which the membrane is made of a material having a surface energy relative to the surface tension of the ink such that once the lines of weakness or slits in the membrane reclose, the ink will span the slits, thereby substantially preventing leakage of ink through the slits.

With such a container, which is simple and economical in structure, the ink can be filled conveniently, and the membrane can be sealed conveniently, is easy to use, does not require special requirements for use, and has a stable structure.

Briefly, embodiments of the present invention are intended for use in an ink jet printing apparatus having an ink tank for receiving ink from a replaceable ink container having a mouth and having ink therein, the ink tank having an ink reservoir containing ink. This embodiment includes a resilient pierceable membrane for closing the mouth of the bottle. A piercing member is supported by an ink tank of the ink jet printing apparatus. When the container is inverted so that the membrane faces downwardly and the container and membrane are moved downwardly over the piercing member, the piercing member can engage the membrane so that the piercing member penetrates the membrane. Once the piercing member penetrates the membrane, the latter will sealingly engage the sides of the piercing tube to substantially prevent ink from leaking therefrom. The piercing member communicates ink within the container with the ink reservoir, thereby allowing ink to flow from the bottle through the piercing member and into the ink reservoir. An air passage is provided in communication with the atmosphere and the ink reservoir such that ink and atmospheric air in the container can be exchanged through the piercing member such that ink can freely flow from the container into the ink reservoir such that the pressure in the container is maintained at substantially atmospheric pressure.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of an ink tank of a commercial inkjet printing apparatus to which two disposable ink bottles according to the present invention are mounted for supplying ink thereto;

FIG. 2 is a vertical cross-sectional view of one of the ink bottles of FIG. 1 containing ink and in an inverted installed position when installed in an ink tank, showing the ink in the container, and showing a piercing member that has pierced a flexible elastomeric membrane closing the mouth of the bottle, and also showing that atmospheric air can enter the container when the level of ink in the ink tank falls below a predetermined level so that air and ink can be exchanged within the bottle through the piercing member;

FIG. 3 is a perspective view of the elastomeric film or membrane closing the mouth of the bottle with a preformed partial slit (i.e., area of weakness) therein;

FIG. 4 is a cross-sectional view of a cap to be threadably mounted on a threaded neck of a bottle, the cap having external threads formed thereon for threaded engagement with internal threads in a receptacle on an ink reservoir;

FIG. 5 is an enlarged exploded view of a portion of an ink bottle and ink tank showing the ink bottle installed in a threaded receptacle of the ink tank and also showing a piercing member for piercing a pierceable membrane on the ink bottle cap to communicate ink in the bottle;

FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 2 showing a piercing tube or rod penetrating a slit in a diaphragm;

FIG. 7 is a plan view of the membrane showing ink drops thereon;

FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. 7, illustrating a preferred construction of the diaphragm wherein the membrane energy is less than the membrane tension of the ink so that ink droplets on the surface of the diaphragm and the re-closing slit openings do not leak through the slit; and

fig. 9 is a view similar to fig. 8, but with the surface energy of the membrane being slightly greater than the surface tension of the ink, so that at least some of the ink is drawn through the re-closed slits by capillary action (leakage).

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring now to the drawings, there is shown an ink supply system for an ink jet printer in which an ink bottle or container 1 supplies ink to the head of an ink jet printing apparatus, such as that disclosed in U.S. patent application No.08/728,774. For the sake of brevity, only ink bottle 1 and the structures in an inkjet printing apparatus that need to be associated with bottle 1 and receive ink from bottle 1 will be described herein.

As shown in fig. 2, the ink bottle 1 is in an upside-down position when installed in the ink jet printing apparatus. The bottle 1 has a body 3 with a closed bottom 5, a neck 7 and a mouth 9. The neck 7 of the bottle 1 has a suitable external thread 11 (fig. 5) formed on its outer surface and a suitable cap 15 having an internal thread 16 (see fig. 5) is screwed onto the thread 11 on the neck 7 of the bottle 1. As shown in fig. 2, bottle 1 contains ink 17. Bottle 1 is preferably a semi-rigid bottle blow molded from a suitable synthetic resin, such as a High Density Polyethylene (HDPE) or the like, which is compatible with the ink 17 contained within the bottle. Of course, those skilled in the art will recognize that the bottle 1 should have sufficient barrier properties, etc., to ensure adequate ink shelf life.

According to the invention, an elastic, elastomeric membrane or film 19 covering the opening of the bottle 1 is sealingly fixed to the mouth 9 of the bottle in order to seal the ink inside the bottle. The membrane 19 is preferably an elastic sheet material, such as natural rubber or a sheet silicon material. However, other materials such as Low Density Polyethylene (LDPE) may also be used. The elastic material of which the membrane 19 is made preferably has sufficient memory properties after deformation that the membrane will quickly and elastically return to its flat position shown in fig. 2. As shown in fig. 2 and 5, the membrane 19 is interposed between the underside of the cap 15 and the rim of the neck finish 9 so that when the cap is screwed tightly into place on the neck of a bottle, the membrane will be clamped tightly between the neck finish and the cap, thereby sealing it between them. The membrane can also be fixed on the bottle mouth in a sealing way by ultrasonic welding and the like.

As shown in fig. 3, the elastic film sheet 19 may have an optional pre-formed slit 20. the slit 20 preferably does not extend completely through the thickness of the film sheet, but rather is a weakened line (area) that will open or tear once the bottle 1 is installed in an inkjet printing apparatus, as will be described in more detail below. In a broader aspect of the invention, however, the slit 20 is not required, as the piercing element can pierce the membrane without the need for a preformed area of weakness, as described below. Moreover, although the slits 20 are shown as a single slit, multiple star-shaped or pancake-shaped slits (or other areas of weakness) may be used.

As shown in FIG. 2, the ink tank of an ink jet printing apparatus, generally indicated at 21, has an ink reservoir 22a for holding ink 22 dispensed from bottle 1 for use by the ink jet printing apparatus. The ink from the gutter 21 is fed to a print head (not shown) of an ink jet printing apparatus to print the desired print on the object in a manner well known to those skilled in the art. The ink supply tubes from the gutter 21 to the printhead are not shown for the sake of simplicity and simplicity. The tank 21 has a tank cover 23 which encloses the ink in the tank.

The slot cover 23 has two recesses or sockets 25 on its upper surface for receiving the caps 15 of the bottles 1. Each recess 25 preferably has an internal thread 27 on its vertical side (see fig. 2 and 5), and the cover 15 has a matching external thread 29 on its outer side which can engage with the internal thread 27. A gasket 31 having a central opening 32 (see fig. 5) is interposed between the cap 15 and the bottom of the recess 25 so that when the cap 15 is screwed into the recess 25, the cap will sealingly engage the gasket 31 and seal the cap to the bowl cover 23. In addition to being screwed onto the neck 7 of the bottle, the cap 15 is preferably glued (or otherwise fixed) to the bottle so that it will not come loose. As shown in fig. 2, 4 and 5, the cover 15 has a central opening 33 that exposes a portion of the diaphragm 19 through the gasket 31.

The channel cover 23 has a piercing or piercing member or rod 35 which is fixed relative to the channel cover 23 and extends upwardly at the center of the recess 25. The piercing member 35 is a hollow tubular member that allows air and ink to be exchanged therein as described in detail below. The diameter of the piercing tube 35 is determined by the density and viscosity of the ink and by the elasticity of the membrane 19 so that the piercing tube will easily pierce the membrane and minimize leakage through the membrane.

As shown in fig. 5, the piercing tube 35 is supported by an open spider structure 39 having one or more passages 41 extending downwardly into the channel 21 from a region below the washer 33. In this way any ink that seeps or leaks between the slit opening 20 of the membrane 19 and the piercing tube 35 will drain into the tank without being wasted.

By way of example, a typical ink used in ink-jet printing has a surface tension of about 35 dynes/cm. and a viscosity of up to about 350 centipoise. The diaphragm 19 may be a sheet of silicone elastomer, commercially available from SEF Industries of Santa Fe Springs, California, having a thickness of 3/32 inches and a Shore hardness of about 70A. The diameter of the mouth 9 of the bottle 1 is about 1.48 inches and the length of the pre-formed slit 20 in the membrane 19 is about 0.8 inches. The piercing tube 35 is a length of stainless steel tubing having an outer diameter of about 0.375 inches.

The above examples illustrate one size bottle and film thickness. It will be appreciated by those skilled in the art that the material from which the diaphragm is made, the diameter of the piercing member, the diameter of the mouth of the bottle and other factors may vary widely in accordance with the present invention.

In addition to the above-described physical properties of the membrane 19, it is preferred that the membrane 19 have a surface energy that is less than the surface tension of the ink 17, so that the ink droplets D (shown in FIG. 8) will bead up on the surface of the membrane 19 (shown in FIG. 8) and will bridge a re-closing slit 20 so that ink does not leak through the slit by capillary action. Thus, once a portion of the filled bottle 3 is removed from the piercing tube 35, the elasticity of the diaphragm causes the slit to reclose and the energy of the lower surface of the diaphragm material prevents loss of ink. For example, for the above-described ink having a surface tension of about 35dyne/cm., the elastomeric material of diaphragm 19 should have a lower surface energy of about 20dyne/cm. to produce the ink bead shown in FIG. 8. The surface energy is greater than the surface tension of the ink and the drop D' shown in fig. 9 will not bridge the re-closed slit 20 and will leak through the slit.

By way of example, the filled ink bottle 1 is turned upside down so that its cap 15 faces downward. The cap 15 is inserted into the socket 25 and the external threads 29 on the outer surface of the cap 15 are threadably engaged with the internal threads 27 on the socket 25. When the cap 15 is screwed down into the recess 25, the upper end of the piercing member 35 engages the pre-formed weakened area (slit 20) and pierces the membrane 19 along the pre-formed slit (or weakened line) 20. When the piercing member 35 pierces the membrane 19, the membrane 19 resiliently clamps the outer surface of the piercing member 35 and seals the outer surface of the piercing member 35 relative to the membrane 19, thereby substantially preventing ink from leaking from the interface of the piercing member 35 and the membrane 19. Of course, once the inside of the bottle 1 and the ink tank 21 communicate, the ink will flow from the bottle 1 into the tank 21.

In addition, as shown in FIG. 2, the well cover 23 has an air passage 37 therethrough which allows ambient air to enter the well 21 and allows air to be exchanged with the ink in the bottle 1 through the piercing tube 35 as the ink flows from the bottle into the ink well 21. As shown in FIG. 2, the level of ink 22 in the tank 21 is at the level of the lower end of the piercing tube 35. Once the ink level in the tank 21 falls below the lower end of the piercing tube 35, air from the air channel 37 is free to enter the piercing tube 35 and bubbles up through the tube 35 into the interior of the ink bottle 1 and replace the ink 17 expelled from the bottle 1, allowing the ink in the bottle 1 to flow down through the piercing tube 35 into the ink tank 21. In this manner, ambient pressure is maintained within bottle 1 and ink 17 is free to flow from bottle 1 to maintain the desired amount of ink within tank 21.

If it is desired to remove the bottle 1 from the ink jet printing apparatus, the bottle can simply be unscrewed from the internal threads 27 in the well cap 23. Upon unscrewing the bottle, the membrane 19 will remain in sealing engagement with the outer surface of the piercing tube 35. When the membrane 19 is disengaged from the piercing tube 35, the elastic membrane 19 will return to close effectively closing the slit 20 (or other opening of the piercing membrane) and thus retaining the ink remaining in the bottle 1. In principle, the elastic properties of the membrane 19 are such that the slit 20 acts as a normally closed valve which will automatically and rapidly close upon removal of the piercing tube. In this manner, a partially filled bottle can be removed from piercing tube 35 without substantial spillage or leakage of ink, even if the bottle is in an inverted dispensing position. Moreover, since the slits 20 in the diaphragm 19 are resiliently closed, any remaining ink in the bottle is retained in the closed channel, which prevents evaporation of the solvent and prevents contaminants in the air from entering the ink bottle. Due to the spider-like support structure 39 piercing the openings of the tube 35 and the channel 41, in the event of ink leakage from the slit 20 when the bottle is removed, the ink will flow into the tank and not be wasted.

Claims (18)

1. An inkjet printing apparatus comprising: an ink tank (21); a replaceable ink container (1) for supplying ink to said tank (21), said container (1) having ink therein; a pierceable membrane (19) closing said container (1); a piercing member (35) supported by said ink tank (21), said piercing member (35) being engageable with said membrane (19) when said membrane (19) faces said piercing member (35), said piercing member (35) piercing said membrane (19) and said membrane (19) engaging a side of said piercing member (35) when said container (1) and said membrane (19) are moved toward said piercing member (35) to substantially prevent ink from leaking between said piercing member (35) and said membrane (19), said piercing member (35) providing communication between ink in said container (1) and said ink tank (21) to allow ink to flow from said container (1) into said ink tank (21); and an air passage (37) communicating with the atmosphere and the tank (21) such that ink from within the container (1) and ambient air can be exchanged within the container (1) through the piercing member (35) such that ink can flow freely from the container (1) into the tank (21) and the pressure within the container (1) is maintained substantially at atmospheric pressure.

2. Inkjet printing system according to claim 1, wherein the pierceable membrane (19) has a weakened area (20) engageable with the piercing member (35) to facilitate piercing of the membrane (19).

3. Inkjet printing system according to claim 2, wherein the weakened area (20) is a slit (20) preformed in the film web (19) which does not extend completely through the thickness of the film web (19).

4. Inkjet printing system according to claim 1, 2 or 3, wherein the piercing member (35) projects downwardly into the gutter (21), and wherein atmospheric air and ink passing through the air passage (37) are exchanged within the container (1) via the piercing member (35) once the level of ink within the gutter (21) falls below the level of the lower end of the piercing member (35).

5. Inkjet printing system according to any one of the preceding claims wherein the container (1) has a lid (15) secured to its mouth (9) covering the pierceable membrane (19), the lid (15) having an opening (33) for receiving the piercing member (35) when the container (1) is brought into piercing relationship with the piercing member (35) which pierces the membrane (19).

6. Inkjet printing system according to any one of the preceding claims, wherein the membrane (19) has a surface energy which is less than the surface tension of the ink, such that when the container (1) is removed from the piercing member (35) ink droplets are substantially prevented from leaking through the area of the membrane (19) pierced by the piercing member (35).

7. The inkjet printing system of claim 6, wherein the surface energy of the membrane (19) is about 20 dynes/cm and the surface tension of the ink is about 35 dynes/cm.

8. An ink bottle for an ink jet printing system having an ink reservoir (21) for holding ink for said ink jet printing system, said bottle having a closed container body (1) with a mouth (9) at one end thereof, a pierceable membrane (19) sealingly secured to said mouth (9) to close said bottle, said membrane (19) being a sheet of resilient elastomeric material, a cap (15) secured to said mouth (9) and covering said membrane (19), said cap having a through opening (33) exposing a portion of said membrane (19) for piercing by a piercing member (35) when the bottle is mounted on said ink jet printing system in an inverted position with the mouth (9) facing downwardly, whereby ink and atmospheric air in said bottle are exchanged through said piercing member (35).

9. The ink bottle of claim 8, wherein said cap (15) has external threads (29) for threaded engagement with internal threads (27) provided on said ink jet printing system such that said bottle is mountable on said ink jet printing system with said piercing member (35) penetrating said membrane (19) to maintain said bottle in substantially sealed relation to said ink jet printing system.

10. An ink bottle as claimed in claim 8 or 9, wherein said membrane (19) has a surface energy less than the surface tension of said ink, such that when said container (1) is removed from said piercing member (35) ink droplets are substantially prevented from leaking through the area of said membrane (19) pierced by said piercing member (35).

11. An ink supply system for an inkjet printing apparatus, comprising: an ink tank (21) for containing ink to be supplied to an ink jet printhead or the like, a replaceable ink bottle container (1) for containing ink for said ink tank (21), an ink bottle membrane (19) supported by said ink bottle (1), a piercing member (35) supported by said ink tank (21), said piercing member (35) being engageable with said membrane (19) when said ink bottle (1) is moved toward said piercing member (35), such that the piercing member (35) pierces the membrane (19), the piercing member (35) sealingly engaging the membrane (19), so as to substantially prevent ink from leaking between the piercing member (35) and the region where the membrane (19) engages the piercing member (35), and an air passage (37) between the external atmosphere and the tank (21), so that air and ink in the ink bottle (1) can be exchanged through the piercing member (35).

12. An ink supply system as claimed in claim 11, wherein the piercing member (35) extends downwardly into the tank (21) to a predetermined height such that when the level of ink in the tank (21) falls below the level of the piercing member (35), air in the tank (21) can enter the piercing member (35) to exchange with ink in the bottle (1) to allow ink to flow into the tank (21) through the piercing member (35).

13. An ink supply system as claimed in claim 11 or 12, wherein the membrane (19) has a surface energy less than the surface tension of the ink, such that when the container (1) is removed from the piercing member (35) ink droplets are substantially prevented from leaking through the region of the membrane (19) pierced by the piercing member (35).

14. An ink supply system as claimed in claim 11, 12 or 13, wherein the diaphragm (19) has a weakened region (20) engageable with the piercing member (35) when the bottle (1) is moved into its operative position to facilitate piercing of the diaphragm (19).

15. An ink supply system as claimed in any one of claims 11 to 14, wherein the tank (21) has a passage (41) adjacent the piercing member (35) so that ink which may leak around the piercing member (35) or through the diaphragm (19) will flow into the tank (21).

16. An ink supply system as claimed in any one of claims 11 to 15, wherein the diaphragm (19) is formed from a sheet of elastomeric material such that on removal of the bottle (1) from the piercing member (35) the opening pierced by the piercing member (35) will substantially re-close, thereby substantially re-sealing the bottle (1) to at least partially prevent contamination of any ink remaining in the bottle (1) so that the bottle (1) can be re-mounted on the piercing member (35).

17. A method of supplying ink to an ink jet printing system having an enclosed ink tank (21), a piercing tube (35), the piercing tube (35) extending above the tank (21) and providing communication to the interior of the tank (21), the piercing tube (35) extending downwardly into the tank (21) to a predetermined height, an air passage (37) extending from the atmosphere outside the tank (21) to the tank (21), and an ink bottle (1) having a pierceable membrane (19), the method comprising the steps of: orienting the ink bottle (1) so that the membrane (19) faces the piercing tube (35); penetrating the piercing tube (35) through the membrane (19) to communicate the inside of the ink bottle (1) and the tank (21) so that the ink in the ink bottle (1) can flow into the tank (21); and allows the exchange of ink from the bottle (1) into the tank (21) with the ambient air entering the bottle (1) as the ink flows through the piercing tube (35).

18. The method of claim 17, further comprising the step of allowing ink and air to exchange through the piercing tube (35) when the level of ink in the tank (21) falls below the level of the lower end of the piercing tube (35) in the tank (21).