Abstract:
Disclosed is an apparatus and associated method for refilling a used ink cartridge of an ink jet printer with ink. Such cartridges have an aperture ( 30 ) through which ink can be inserted. Surrounding the aperture is a funnel ( 21 ) having a resiliently deformable washer ( 22 ) therein. The washer ( 22 ) has a tapered aperture ( 23 ) defining therebeneath a void space ( 25 ) which can have air entrapped therein. A refilling apparatus to be associated with an ink refill bottle includes a plug element ( 10 ) including a tip portion ( 13 ) to be received within the aperture ( 30 ). A widened portion ( 18 ) bears upon the washer ( 23 ) so as to expel any air entrapped therein to prevent such air passing into the ink cartridge when refilling with ink.

Description:
FIELD OF THE INVENTION 
     The following invention relates to a method and an apparatus for refilling a printer ink cartridge with ink. 
     Ink cartridges for use with ink jet printers are designed to be used once and discarded. As replacement ink cartridges are expensive, it has been known to refill used cartridges with new ink as an alternative. However, it is fundamental to the operation of known printers that little or no air is allowed to pass through the printer-head as otherwise poor print or even no print can result. 
     It has hitherto been difficult to refill used ink cartridges without entrainment of air in critical areas of the cartridge. 
     OBJECT OF THE INVENTION 
     It the object of the present invention to overcome or substantially ameliorate the above disadvantage and/or more generally to provide a method and apparatus for refilling used ink cartridges. 
     DISCLOSURE OF THE INVENTION 
     There is disclosed herein an apparatus for use in refilling a used ink cartridge with ink, wherein the ink cartridge has a funnel having situated therein a resiliently deformable washer having a void space therein which might receive air, said apparatus being in the form of a plug element having a longitudinal extent and a passageway throughout that extent and through which ink can press into said cartridge, the plug element further having a tip portion and a wide portion delimited from the tip portion by a ramp portion, the ramp portion and the wide portion being adapted, upon insertion thereof into the resilient washer, to deform same so as to expel entrained air from said void space. 
     Preferably, the tip portion is dimensioned so as to be sealingly received by an aperture in the ink cartridge. 
     Preferably, the plug element is essentially circular in transverse cross section. 
     Preferably, the ramp portion is frustoconical. 
     Preferably, the longitudinal passageway is adapted to receive the nozzle of an ink refiller bottle. 
     Preferably, the plug element is formed of a resiliently deformable material. 
     There is further disclosed herein a method of refilling a used ink cartridge with ink, the ink cartridge having an ink funnel, the method including the steps of forming an air hole in the ink cartridge if an air hole does not already exist therein, inserting a plug element into the funnel, which plug element has a passageway therethrough, inserting the nozzle of an ink refiller bottle partly into the passageway, injecting ink from the refiller bottle through the passageway into the ink cartridge, removing the nozzle from the passageway, and removing the plug element from the funnel. 
     Typically, associated with the ink funnel of the cartridge is a resiliently deformable washer element defining a void space therein and the step of inserting the plug element into the funnel includes inserting the plug element into the washer element so as to deform the same ad expel air from the void space. 
     Preferably, upon withdrawal of the plug element, some ink from the ink cartridge is drawn back from inside the cartridge to fill the void space of the washer, thus displacing air therefrom. 
     There is further disclosed herein an apparatus for use in refilling a used ink cartridge with ink, wherein the ink cartridge has a funnel having situated therein a resiliently deformable washer having a void space therein which might receive air, said apparatus being in the form of a plug element having a longitudinal extent and a passageway throughout that extent and through which ink can pass into said cartridge, the plug element further having a tip portion and a body portion, the tip portion widening toward the body portion, the tip portion being adapted, upon insertion thereof into the resilient washer, to deform same so as to expel entrained air from said void space. Preferably the plug element is formed of a resiliently deformable plastics material. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings wherein: 
     FIG. 1 is a schematic cross-sectional elevational view of a plug element, 
     FIG. 2 is a schematic cross-sectional elevational view of a portion of an ink cartridge having a funnel which houses a resiliently deformable washer therein, 
     FIG. 3 is a schematic cross-sectional elevational view of a plug element inserted into the deformable washer of FIG. 2 with the nozzle of an ink refill bottle inserted into its passageway so as to inject ink into the cartridge, 
     FIG. 4 is a schematic cross-sectional elevational view of the plug element of FIG. 3 being withdrawn from the washer, 
     FIGS. 5,  6 ,  7  and  8  are schematic illustrations depicting steps taken in refilling a used ink cartridge with ink, 
     FIG. 9 is a schematic cross-sectional elevational view of an alternative plug element, 
     FIG. 10 is a schematic elevational view of the plug element of FIG. 9, 
     FIG. 11 is a schematic cross-sectional elevational view of the plug element of FIGS. 9 and 10 having an end plug fitted thereto, and 
     FIGS. 12 and 13 are schematic cross-sectional elevational views of a sealing washer of an ink jet cartridge both before and after insertion of filling plug  100  therein. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In FIG. 1 of the accompanying drawings there is schematically depicted a plug element  10  typically fabricated from a resilient material such as PVC plastics. 
     Plug element  10  is generally circular in transverse cross-section and includes a longitudinal passageway  12  extending throughout its length. At one end of the plug element  10  there is provided a tip portion  13  having a tapered nose portion  14 . The diameter of the tip portion  13  is sized to sealingly engage with the aperture  30  of the ink cartridge. The remote end of the plug element  10  forms a tail  15  through which the passage  12  extends. The diameter of the passage is chosen so as to sealingly receive the nozzle  16  of an ink refill bottle  17 . 
     The plug element  10  also includes a wide portion  18  delimited from the tip portion  13  by a ramp portion  19 . Ramp portion  19  is typically frustoconical. The plug element  10  further includes a body portion  20 . The tail  15  is adapted to bend in use as to be described below. 
     The overall length of the plug element  10  is typically about 36 mm. However, this dimension could vary depending on the particular application. The tip portion  13  might slightly taper outwardly from the nose portion  14 . This taper might typically be of the order of 0.3 mm. The diameter of the wide portion  18  is typically constant at about 5 mm. The longitudinal extent of the nose portion might typically be about 1.5 mm. The longitudinal extent of the tip portion  13  might typically be about 3 mm. The longitudinal extent of the ramp portion  19  might typically be about 1.5 mm whereas the longitudinal extent of the wide portion  18  might typically be about 5 mm. 
     The funnel portion  21  of an Epson ink cartridge  11  is shown in FIGS. 2 to  4 . Within the funnel  21 , there is located a resiliently deformable washer  22  having a tapered aperture  23 . The funnel  21  and washer  22  are purpose-designed to cooperate with components of an Epson ink jet printer so as to enable ink from within the cartridge  11  to flow to the print head of the printer. More specifically, the printer includes a “spike” being an end projection of a tube or pipe which lead to the print head. The washer element  22  also includes a cylindrical wall  24  which rests against the inside surface of the funnel  21 . The space  25  situated between the tapered aperture  23  and wall  24  is annular and forms a void within which an air pocket can occur. It is important that air is removed from this void prior to reinsertion of the cartridge into the printer as air from this void could pass to the print head and either damage the print head or cause poor print quality. 
     As shown in FIG. 3, upon insertion of the tip portion  13  into the cartridge, the ramp portion  19  interacts with the tapered aperture  23  to open the same into the fully opened position wherein the tapered portion is held against the outside surface of the wide portion  18 . As a result of the action of tapered aperture  23  being pushed in by the ramp portion  19 , air from the void space  25  is expelled out through the longitudinal passage  12  of the plug element and/or into the body of the cartridge  11  in the directions generally indicated by arrows  26  in FIG.  2 . That is, most of the air from the void space  25  is expelled through the passage  12  or is forced into the body of the empty ink cartridge upon insertion of the plug element  10  as described. 
     A stopper  28  as shown in FIG. 4 includes a projection  29  which can be sealingly fitted within the tail end of passage  12 . After filling the cartridge with ink as to be described below, the plug element  10  is withdrawn from the funnel  24  with stopper  28  in place. The close, sealing fit of the tapered aperture  23  about the plug element  10  and the fact that stopper  28  is in place, prevents any backflow of air through passage  12  and into the cartridge as the plug element  10  is withdrawn. Rather, the action of withdrawing the plug element  10  draws any air remaining in the void space  25  into the passage  12  in a direction generally indicated by arrow  30  in FIG.  4 . As an alternative to providing the plug element  28 , the tail portion  15  of the plug element  10  can be squeezed between the finger and thumb, so as to seal the passage  12 . 
     The method of refilling an ink cartridge is typically as follows. Firstly, and as shown in FIG. 5, if the ink cartridge does not already have a pin prick or other breathing aperture formed therein, a pin  27  can be used to make a vent hole in the cartridge. In certain cartridge models, it might be appropriate that the hole be made as close to the back edge of the cartridge top as possible. 
     The cartridge as shown in FIG. 6 should then be placed on its side with the ink funnel  21  located at the bottom. The plug element  10  is then inserted into the funnel via the resilient washer  22 . It may be necessary to twist the plug element  10  during this insertion process until it fits right in. It is during this step that most, if not all, air is removed from the void space as described above. 
     As shown in FIG. 7, and after having removed the cap from the nozzle of a refiller bottle, the bottle is held without squeezing whilst its nozzle  16  is inserted a short way into the passage  12 , typically to the point where the tail portion  15  joins the body portion  20 . 
     As shown in FIG. 8, the bottle should then be gently raised in the direction of the arrow such that the tail portion  15  is deformed. The body portion  20  might also deform slightly. The refiller bottle is then gently squeezed so as to inject ink through the longitudinal passage  12  into the cartridge  11 . It is important during this step not to squeeze any air into the cartridge. When ink passes out of the vent hole formed by pin  27 , the cartridge is full and the nozzle  16  can be withdrawn from the passage  12 . 
     The plug element  10  should then be withdrawn as described above, either using stopper  28  or whilst simultaneously squeezing the tail portion  15 . 
     The cartridge can then be placed right-way-up. The plug element  10  can then be removed from the funnel  21  with the stopper  28  still in place. After quickly cleaning any ink spillages, the cartridge can then be immediately reloaded into the printer. In certain printer models, the “load/eject” button of the printer can then be depressed. 
     In FIGS. 9,  10  and  11  of the accompanying drawings there is schematically depicted an alternative plug element  100 . Rather than providing a discrete narrow portion, a discrete ramp portion and a widened portion, the tip portion  300  of the plug element  100  is continuously tapered from the tip  800  to the body portion  200 . The plug element  100  includes a longitudinal passageway extending the whole way therethrough with a restricted portion  900  being adapted to seal tightly against the external surface of the nozzle  16  of a refill bottle  17 . A frustoconical internal tapered portion  400  is sized and shaped to receive an end plug element  700  as shown in FIG.  11 . The end plug  700  can have a projection  710  to fit tightly within the constriction  900 . The end plug  700  serves the same function as plug  28  described above with reference to FIG.  4 . 
     FIGS. 12 and 13 show the appearance of a sealing washer  220  both before and after insertion of the tapered tip portion  300  of filling plug  100 . As can be seen in FIGS. 12 and 13, there is a void space corresponding in form with that identified as  25  in FIG. 2 which is compressed and from which entrained air forced into the body of the ink cartridge when the tapered portion  300  is inserted so as to bear against the resilient washer. 
     It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention. For example, the plug elements  10  or  100  might be formed as an integral component to the lid of an ink refill bottle, rather than being provided as a separate unit. 
     Furthermore, whilst the above preferred embodiments relate to a single-color ink print cartridge, the invention is equally applicable to multi-color cartridges which include separate compartments, each containing a different colored ink. The method steps described above can be repeated for each of the ink compartments. 
     It should yet further be appreciated that the present invention is not necessarily restricted to application on Epson ink jet printers. The invention might be equally applicable to other brand printers and ink cartridges, though having similar features as are depicted in FIGS. 2 to  4 , or similar.