Abstract:
An ink container shell for an ink jet cartridge has spaced apart side walls, a front wall, a rear wall, and a bottom wall, and is provided with a partition structure which divides the interior thereof into three ink chambers, at least one of which has a non-rectangular profile in cross-section transverse to said side, front and rear walls. The partition structures enable varying the volumes of the ink chambers with respect to a given shell exterior profile and enable isolating two the chambers from one another by interposing the third chamber therebetween.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates to the art of ink jet printers and, more particularly, to improvements in the configurations of ink chambers and partitions in the interior of the casing or shell of an ink container for an inkjet cartridge for color printing.  
         [0002]     As is known, an inkjet cartridge includes an ink container comprising a shell defined by spaced apart side walls, a front wall, a rear wall, and a bottom wall and, for color printing, the interior of the container is partitioned to define a plurality of chambers, each for a different color ink. Each of the chambers has an outlet port in the bottom wall for communication with a corresponding ink tapping component in a casing receiving the container, and the upper end of the container is closed by a cover which is heat sealed in place following the filling of the chambers with ink.  
         [0003]     Heretofore, the partition has been T-shaped in cross-section transverse to the side, front and rear walls whereby, for a given outer profile for the shell, the volume of each of the three chambers is substantially fixed. In this respect, the ability to change the dimensions of the leg or cross piece of the T so as to change the volumes in the three chambers is extremely limited. Moreover, with a T-shaped partition, each of the chambers is directly adjacent the other two, whereby a leakage problem across the leg or cross piece can result in the mixing of the ink in one chamber with the ink in both of the other two chambers.  
       SUMMARY OF THE INVENTION  
       [0004]     In accordance with the present invention, the interior of the shell of an ink container is provided with partition designs which, in accordance with one aspect of the invention, provide the ability to selectively design the chambers to have equal or different volumes. In accordance with another aspect of the invention, partition designs advantageously provide for each of the chambers to be immediately adjacent just one of the other two chambers. Accordingly, a leakage problem across a partition wall between adjacent chambers can only result in the mixing of the ink in the one chamber with that in the adjacent chamber.  
         [0005]     It is accordingly an outstanding object of the present invention to provide improved partition designs for the interior of an ink container shell of an ink container for an ink jet cartridge.  
         [0006]     Another object is the provision of an ink container shell of the foregoing character having improved versatility with respect to selectively designing the volumes of the ink chambers.  
         [0007]     Yet another object is the provision of a container shell of the foregoing character which advantageously optimizes isolation of the chambers from one another to minimize color mixing in the event of leakage between chambers. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The foregoing objects, and others, will in part be obvious and in part pointed out more fully hereinafter in conjunction with the written description of preferred embodiments of the invention illustrated in the accompanying drawings in which:  
         [0009]      FIG. 1  is a perspective view of an ink container shell for an inkjet cartridge;  
         [0010]      FIG. 2  is a top view of the shell showing a T-shaped partition therein;  
         [0011]      FIG. 3  is a perspective view of the container shell shown in  FIG. 1  and illustrates an L-shaped partition design inside the shell;  
         [0012]      FIG. 4  is a top view of the shell and partition shown in  FIG. 3 ;  
         [0013]      FIG. 5  is a top view of another embodiment of the partitioned interior of a container shell in accordance with the invention;  
         [0014]      FIG. 6  is a top view of yet another embodiment of the partitioned interior of a container shell according to the invention; and,  
         [0015]      FIG. 7  is a further embodiment of the partitioned interior of a container shell according to the invention. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0016]     Referring now in detail to the drawings, wherein the showings are for the purpose of illustrating preferred embodiments of the invention only, and not for the purpose of limiting the invention, an ink container shell  10  is shown in  FIGS. 1 and 2  of the drawing which is comprised of a pair of spaced apart side walls  12  and  14 , a front wall  16 , a rear wall  18  and a bottom wall  20 . As shown in  FIG. 2 , it is well known to provide the interior of the shell with a T-shaped partition  22  defined by a leg  24  and a cross piece  26  which divide the interior of the shell into three ink chambers  28 ,  30  and  32 . The T-shaped profile of partition  22  provides for each of the chambers  28 ,  30  and  32  to be rectangular in cross-section transverse to the side, front and rear walls of shell ten. Further, it will be appreciated from  FIG. 2  that chamber  28  is directly adjacent both chambers  30  and  32  and that each of the chambers  30  and  32  is directly adjacent one another as well as chamber  28 . Accordingly, leakage across cross piece  26 , for example, can result in the mixing of all three ink colors in one chamber. An outlet port  34  is provided in bottom wall  20  for each of the chambers and, as will be appreciated from  FIG. 2 , the T-shaped profile of the partition limits the ability to vary the cross-sectional areas of the chambers, and thus the volumes thereof, from that shown in  FIG. 2 .  
         [0017]     Embodiments of the present invention are shown in  FIGS. 3-7  of the drawing in conjunction with a container shell  10  which is basically of the structure shown in  FIG. 1 , whereby the component parts thereof are indicated by the same numerals in  FIGS. 3-7  as appear in  FIG. 1 . Moreover, while the chambers in the embodiments shown in  FIGS. 3-7  have different contours from the chambers shown in  FIG. 2 , the chambers are numbered the same as in the latter figure for purposes of comparison in size and shape.  
         [0018]     With reference first to the embodiment shown in  FIGS. 3 and 4  of the drawing, the interior of shell  10  is provided with a partition  36  defined by a first wall  38  extending between side walls  12  and  14 , a second wall  40  spaced from wall  38  and extending from side wall  14  toward side wall  12 , and a third wall  42  between side walls  12  and  14  and extending from the inner end of wall  40  to rear wall  16 . Partition  36  further includes an arcuate bridging wall  44  connecting walls  38  and  40  at side wall  14  of the shell. In the embodiment shown in  FIGS. 3 and 4 , partition  36  is of one-piece construction, and side wall  14  of shell  10  is provided with a vertical slot  46  which receives bridging wall  44  and to which the latter is heat welded to seal the corresponding portions of chambers  28  and  32 . It will be appreciated, however, as will become apparent with the embodiments described hereinafter, that walls  38  and  40  of the partition could be separate from one another and sealingly interengaged with wall  14  through a tongue and groove arrangement. The one-piece construction shown in  FIGS. 3 and 4  is advantageous from the standpoint of minimizing the component parts necessary to produce an ink container.  
         [0019]     As will be further appreciated from  FIGS. 3 and 4  of the drawing, the profile of partition  36  provides for ink chamber  30  to have an L-shaped configuration in cross-section and for ink chambers  28  and  32  to be generally of rectangular configuration as are all three of the chambers in  FIG. 2 . The L-shaped configuration of chamber  30  advantageously enables the latter to have a larger volume than chamber  30  in  FIG. 2 , and the profile of partition  36  can be modified to enable varying the volumes of the three chambers. In particular in this respect, it will be appreciated that leg  42  of the partition can be shifted to the right in  FIG. 4  to vary the volumes of chambers  30  and  32 .  
         [0020]     As will be further appreciated from  FIG. 4 , chambers  28  and  32  are isolated from one another by chamber  30 . Therefore, leakage across any one of the partition walls  38 ,  40  and  42  can only result in the mixing of one color with one of the other two colors.  
         [0021]     In  FIG. 5 , the partition structure includes a first partition wall  46  which is S-shaped and a second partition wall  48  spaced therefrom. S-shaped wall  46  includes a first leg  50  extending inwardly from side wall  12  of the casing and transverse thereto, a second leg  52  extending from the inner end of leg  50  in the direction between front and rear walls  16  and  18  of the casing, and a third leg  54  extending from the second leg to side wall  14  of the casing and transverse thereto. Second partition wall  48  extends between side walls  12  and  14  and perpendicular thereto, whereby legs  50  and  54  of partition wall  46  lie in planes which are parallel to one another and to the plane of partition wall  48 . This partition profile provides for chambers  30  and  32  to be non-rectangular and for chambers  28  and  32  to be isolated from one another by chamber  30 . It will be appreciated that the positions of leg  54  and/or partition wall  48  can be selectively modified, as can the length of leg  52  of partition wall  46 , to achieve a desired volume for each of the chambers. Moreover, as will be appreciated from  FIGS. 3 and 4 , the ends of leg  54  and partition wall  48  could be connected by a U-shaped bridging portion connected to wall  14  as described in connection with  FIGS. 3 and 4 . Likewise, as will be appreciated from  FIG. 5 , legs  38  and  40  of the partition shown in  FIGS. 3 and 4  could interengage with wall  14  of the shell in the tongue and groove relationship shown in  FIG. 5 .  
         [0022]     In the embodiment shown in  FIG. 6  of the drawing, chambers  28 ,  30  and  32  are defined by a Y-shape partition  56  having a first leg  58  extending from front wall  16  toward rear wall  18  generally centrally between and parallel to side walls  12  and  14 , and second and third legs  60  and  62  which extend respectively from leg  58  to side wall  12  and side wall  14  at an angle to leg  58  and the corresponding side wall. It will be appreciated that the length of leg  58  as well as the angles of legs  60  and  62  relative thereto and to the side walls can be varied so as to obtain a desired volume for each of the chambers. In this embodiment, each of the three chambers is non-rectangular in cross-section transverse to the side, front and rear walls of the casing.  
         [0023]     In the embodiment shown in  FIG. 7 , the partition structure is defined by a Z-shaped wall  64  and a second wall  66  spaced therefrom. Z-shaped wall  64  includes a first leg  68  extending from side wall  12  toward side wall  14  and at an incline relative to wall  12 , a second leg  70  extending from the inner end of leg  68  toward rear wall  18 , and a third leg  72  extending from leg  70  to side wall  14  of the shell and at an incline thereto. Wall  66  extends between side walls  12  and  14  and is inclined relative thereto and, preferably, legs  68  and  72  and wall  66  lie in parallel planes. The partition structure in  FIG. 7  provides for each of the chambers  28 ,  30  and  32  to be non-rectangular in cross-section transverse to the side, front and rear walls of the shell and further provides for chambers  28  and  32  to be isolated from one another by chamber  30  therebetween. As will be appreciated from  FIG. 7 , the length of leg  70  and/or the angles of incline of legs  68  and  72  and wall  66  and/or the spacing between wall  66  and leg  72  can be altered to obtain a desired volume for each of the chambers.  
         [0024]     While considerable emphasis has been placed on preferred embodiments herein illustrated and described, it will be appreciated that other embodiments can be devised and that changes can be made in the embodiments disclosed herein without departing from the principals of the invention. In this respect, for example, many partition profiles can be devised which will provide for selectively varying the volumes of the three chambers and which will provide for two of the chambers to be isolated from one another by the third chamber. These and other embodiments and modifications will be obvious from the disclosure herein. Accordingly, it is to be distinctly understood that it is intended to include all such modifications as well as other embodiments insofar as they come within the scope of the appended claims or the equivalents thereof.