Abstract:
The invention relates to a molded cartridge body including a substantially one-piece molded polymeric structure defining two or more ink cartridge positions and being removably mountable on a printer carriage. The molded cartridge body has a front panel member opposite a back panel member, side panel members connected to the front and back panel members and a bottom panel member having an ink cartridge side and a printhead side which is connected to a lower edge of each of the front, back and side panel members, the front, back, side and bottom panel members defining an open-ended cavity. The open-ended cavity contains an ink chamber for each of the ink cartridges, each of the ink chambers being in flow communication with a printhead attached to a printhead location on the cartridge body. A needle panel member containing an ink needle for each of the ink chambers is provided, the panel member being attached to the ink chambers so as to define closed ink chambers. Filter elements are disposed in each of the ink chambers between the panel members and the cavities for filtering ink to the printheads. The components of the ink cartridge body promote easy assembly of critical parts and improved yield of useable parts.

Description:
FIELD OF THE INVENTION 
     The invention relates to ink jet printers and to components for the printers which improve the manufacturing and reliability of the assembled components. 
     BACKGROUND 
     Ink jet printers continue to evolve as versatile, reliable, low cost printers for a variety of individual and commercial applications. Instead of disposable printheads attached to disposable ink cartridges, permanent or semi-permanent printheads which have longer life than conventional printheads are becoming the printheads of choice. However, because the printheads are no longer disposable commodities which are replaced often, there is less manufacturing tolerance with respect to the printhead, associated components and assembly thereof. Furthermore, the printheads and components are required to maintain tolerances over their life which results in higher parts rejection during the assembly process. One method for maintaining the desired tolerances is to use exotic materials of construction which are more expensive than conventional materials and require more costly manufacturing techniques. As competition increases for low cost, high quality ink jet printers, a need has arisen for unique component configurations which provide reliable components which can be manufactured and assembled at substantially lower cost. 
     SUMMARY OF THE INVENTION 
     With regard to the above and other objects and advantages the invention provides a cartridge body for an ink jet printer. The cartridge body includes substantially one-piece molded body structure defining one or more ink cartridge positions. The body structure is mountable on a printer carriage and has a front panel member opposite a back panel member, side panel members connected to the front and back panel members and a bottom panel member having a ink cartridge side and a printhead side connected to a lower edge of each of the front, back and side panel members so as to define an open ended cartridge cavity with the ink cartridge side of the bottom panel member facing the cartridge cavity. One or more printhead locations are provided on the printhead side of the bottom panel member, each printhead location corresponding to an ink cartridge position in the cartridge cavity. One or more ink cavities are disposed in the bottom panel member opposite each of the printhead locations. An ink needle panel member containing an ink needle for each ink cavity is provided, the ink needle panel member being attached to the bottom panel member adjacent the one or more ink cavities providing closed ink cavities. A filter element is disposed in each of the ink cavities for filtering ink to a printhead attached to each printhead location, the filter element being attached to the ink needle panel member. 
     In another aspect the invention provides a method for constructing a cartridge body for an ink jet printer. The method includes molding a cartridge body from a polymeric material, the molded cartridge body defining one or more ink cartridge positions and being removably mountable on a printer carriage, the molded cartridge body having a front panel member opposite a back panel member, side panel members connected to the front and back panel members and a bottom panel member having a ink cartridge side and a printhead side connected to lower edges of each of the front, back and side panel members so as to define an open ended cartridge cavity with the ink cartridge side of the bottom panel member facing the cartridge cavity. One or more printhead locations are provided on the printhead side of the bottom panel member, each printhead location corresponding to an ink cartridge position in the cartridge cavity. An ink cavity is disposed in the bottom panel member opposite each of the printhead locations. An ink needle panel member containing an ink needle for each printhead location is also provided in the cavity. A filter element for filtering ink to each printhead is disposed in each cavity and is attached to the ink needle panel member. The ink needle panel member is fixedly attached to a peripheral edge of the ink cavity to provide an enclosed ink filter chamber for feeding ink to a corresponding printhead. 
     In yet another aspect the invention provides a stiffener assembly for stiffening an electrical connection wall of a cartridge body for an ink jet printer, the stiffener assembly including a bottom wall and one or more upstanding dividing walls attached to the bottom wall. The stiffener assembly is adapted for frictional engagement with a cartridge cavity of the cartridge body. 
     The invention provides components of a cartridge body which can be easily assembled with high accuracy to provide a relatively low cost cartridge body without sacrificing the printer&#39;s ability to produce high quality, high speed images. Because of the unique design features incorporated in the components of the cartridge body design, the cartridge body can be molded on high speed molding equipment from relatively inexpensive polymeric materials. The components are amenable to assembly using relatively few assembly steps, yet the assembled components provide a robust design which provides a relatively rigid, inflexible structure for positive electrical contacting surfaces and for alignment purposes within a printer. The component design also provides guides for directing an ink cartridge outlet member in locking engagement with the cartridge body to provide a leak resistant ink flow from the ink cartridge to the printheads. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further advantages of the invention will become apparent by reference to the detailed description when considered in conjunction with the figures, which are not to scale, wherein like reference numbers indicate like elements through the several views, and wherein: 
     FIG. 1 is a partial cross-sectional side elevational view of a cartridge body and ink cartridge according to the invention; 
     FIG. 2 is a top perspective cut-away view of portions of a cartridge body according to the invention; 
     FIG. 3 is an exploded view in perspective of a stiffener structure and valve structure according to the invention; 
     FIG. 3A is a magnified cut portion of a valve guide according to the invention; 
     FIG. 3B is a magnified cut view of a seal assembly housing member according to the invention; 
     FIG. 4 is a partial cut-away exploded view of a cartridge body in and a stiffener in perspective; and 
     FIG. 5 is a top perspective view of an assembled cartridge body according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to FIG. 1, the invention provides a cartridge body  10  for receiving one or more replaceable ink cartridges  12  for supplying ink to corresponding permanent or semi-permanent ink jet printheads  14 . The printheads include a semiconductor substrate preferably containing heater resistors or piezoelectric pressure devices and a nozzle plate having a plurality of orifices for ejecting ink toward a print media. The printheads  14  are located on a printhead side  16  of a bottom panel member  18  of the cartridge body  10 , and the ink cartridges are removably positionable in the cartridge body  10  so as to supply ink to the printheads  14 . It is preferred that the bottom panel member  18  be shaped to provide an extension  20  which provides ink cavities  22  associated with each of the printheads for receiving ink from the ink cartridges  12 . 
     Ink is supplied from the ink cartridges  12  through a needle valve which includes a needle  24  and needle valve seal assembly  26  which is described in more detail below. The needle valve seal assembly  26  is preferably attached to a stiffener insert  28  which is preferably snap-fitted into the cartridge body  10  adjacent the bottom panel  18 . The needle  24  and needle valve seal assembly  26  are coupled to a boss fitting  30  extending from a lower portion  32  of the ink cartridge  12  when the ink cartridge  12  is inserted in the cartridge body  10 . 
     As shown in FIG. 1, an ink cartridge  12  is slidably engaged with the cartridge body  10  by substantially vertical movement of the ink cartridge  12  relative to the cartridge body  10 . As the ink cartridge  12  is lowered into the cartridge body  10 , boss  30  pending from the lower portion  32  of the ink cartridge  12  engages the needle  24  and needle valve seal assembly  26  for fluid flow communication between the ink cartridge  12  to the ink cavity  22 . 
     A cartridge body cavity  34  into which the ink cartridge  12  is placed also contains a cartridge urging member  36  which is attached to the stiffener insert  28  within cavity  34  to yieldably position the cartridge  12  in the body cavity  34 . In the case of a coil spring urging member  36 , the urging member  36  may be attached to a vertical column  38  pending from the stiffener insert  28 . Urging member  36  is positioned to contact the lower portion  32  of the ink cartridge  12  on an end  40  opposite boss  30  so that end  40  is urged away from stiffener  28 . Upon urging end  40  away from stiffener insert  28 , a latch member  42  attached to a front end  43  of the ink cartridge  12  is caused to positively engage a ledge  44  on the cartridge body  10 . Handle  46  is provided on an upper portion  48  of the ink cartridge for assisting in inserting and removing ink cartridge  12  from cavity  34  of the cartridge body  10 . 
     In order to assure proper placement of the ink cartridges  12  in the proper location in cavity  34  of the cartridge body  10 , in the case of multiple ink cartridges and multiple ink cartridge locations, a keying member  50  is preferably molded into a back or rear panel member  52  of the cartridge body  10 . The keying member  50  is particularly useful with cartridge bodies  10  containing two, three or four ink cartridge locations. 
     As seen in more detail in FIG. 2, the cartridge body  10  is preferably molded from a unitary piece of polymeric material, preferably high density polyethylene, polypropylene, polyvinyl chloride, polyphenylene oxide, modified polyphenylene oxide and the like. The cartridge body contains a bottom panel  18 , front panel  54  containing an upper section  56  and a lower section  58 , rear panel  52  and side panels  60 , one of which is shown. The side panels  60  are attached to the bottom panel  18 , rear panel  52  and front panel  54  thereby providing the open-ended cavity  34  for receiving one or more ink cartridges  12  (FIG.  1 ). 
     In the case of multiple ink cartridges  12  it is preferred to include divider panels  62  preferably attached to the back panel member  52 . The divider panels  62  provide stiffening of the rear panel  52  and effectively guide the ink cartridges  12  into alignment with the ink needles  24  when inserting the ink cartridges  12  into cavity  34 . It is preferred that the divider panels  62  be made of the same material as the cartridge body  10  and preferably be formed during molding of the cartridge body  10  rather than being attached to the cartridge body  10  in a separate process step. 
     As described above, the bottom panel  18  of the cartridge body preferably contains the extension  20 . Ink cavities  22 , defined within extension  20  are in flow communication with ink needles  24 . The ink cavities  22  are preferably integrally molded with the cartridge body  10 . Each needle  24  is preferably an elongated hollow cylindrical rod  63  having a substantially rounded or blunt tip  65  and contain an aperture  67  in fluid flow communication with the inside of hollow rod  63 . 
     Each of the cavities  22  preferably contains a filter element such as filter elements  64  attached to the underside of panel member  66  defining a filter tower assembly  68  wherein the filter elements  64  are disposed in the cavities  22  between panel member  66  and ink cavity  22  so as to filter ink entering the cavities  22  from the ink needles  24 . The filter elements  64  preferably have a mesh size which is selected to prevent particles having an effective diameter ranging from about 0.1 μm to about 50 μm, preferably from about 5 μm to about 10 μm from passing through the filter element. The filter element  64  may be made from stainless steel, woven fiberglass, nylon mesh or any other suitable filtration media which is resistant to chemical attack of the ink. 
     It is preferred to ultrasonically weld or heat stake each filter element  64  to the panel member  66  around the perimeter of the element  64  so as to provide an unfiltered ink section  70  above the filter element  64  and a filtered ink section  71  below the filter element  64  (FIG.  1 ). It is particularly preferred to dispose filter elements  64  in the ink cavities  22  at an angle with respect to the cavities  22  in order to reduce the blockage of ink flow to the filtered ink section  71  caused by air trapped in the filtered and/or unfiltered ink sections  71  and  70 . The invention is not limited, however, to attaching the filter elements  64  to the panel member  66 . Ledges may be provided in ink cavities  22  for attaching the filter elements  66  directly to the ink cavities  22 . 
     The ink cavities  22  are separated from cartridge cavity  34  by filter tower assembly  68  which is attached to the peripheral edges  72  of the ink cavities  22 . It is preferred to include location pins  74  on one side edge of panel member  66  and corresponding pin receivers  76  adjacent the side panel members  60  and/or bottom panel member  18  of the cartridge body  10 . The panel member  66  preferably also contains a tab member  78  which is fittingly received in recess  80  of the bottom panel member  18 . The tab member  78  adds strength to the assembly while location pins  74  provide proper alignment of the filter tower assembly  68  with respect to the cartridge body  10  so that the panel member  66  may be sealingly attached to the peripheral edges  72  of the ink cavities  22  as by adhesive, ultrasonic welding and the like. 
     Referring now to FIG. 3, features of the stiffener insert  28  will be described. The stiffener insert  28  is preferably a one-piece molded body containing a bottom wall portion  82 , two or more upstanding dividing wall portions  84  attached to the bottom wall portion  82  and, optionally, one or more upstanding cross wall portions  86  attached to the bottom wall  82  and dividing wall portions  84  transverse to the dividing wall portions  84 . The open space between cross wall portions  86  and adjacent dividing wall portions  84  defines needle valve seal assembly areas  88  which contain an opening or aperture  90  in the bottom wall portion  82  for insertion therethrough of ink needles  24  (FIG.  1 ). 
     Upstanding seal assembly guides  92  are provided pending from bottom wall portion  82  each containing slots  94  for slidably guiding projections  96  on the seal assembly housing members  98 . The bottom  91  of the upper cross portions  95  of the seal assembly guides  92  are preferably angled downward toward the guiding projections on the housing members  98 , as shown in FIG. 3A, so as to urge the guides  92  toward the housing members  98  during assembly and movement of the housing members  98  with respect to the seal assembly guides  92 . The top  97  of guiding projections  96  are also preferably angled in the same direction as the bottom  91  of cross portions  95  to further urge the guides  92  toward each other as shown in FIGS. 3A and 3B. Angling the cross portions  95  and projections  96  as described above inhibits flexure apart of the guides  92 . 
     The seal assembly housing members  98  have apertures  100  therein for retaining molded resilient elastomeric valve sleeves  102  therein. The sleeves  102  are preferably made of natural rubber, synthetic rubber, polyurethane and the like and preferably contain flanges  104  and  106  to resist displacement of the sleeves  102  from engagement with apertures  100 . The sleeves  102  also contain apertures  108  for inserting ink needles  24  therethrough, the apertures  108  being sized to sealingly close needle aperture  67  (FIG.  2 ). The sleeves  102  may alternatively be insert-molded into the housing members  98  in a design similar to that shown in FIG.  3 B. 
     Valve urging members  110  are disposed between each pair of valve guides  92  and between the housing members  98  and the bottom wall portion  82  of stiffener insert  28 . The valve urging members  110  are preferably resilient coil springs which urge seal assembly housing members  98  upward in a direction generally away from the bottom wall portion  82  of stiffener insert  28 . In the upward position, sleeves  102  providing sealing closure to apertures  67  in needles  24  (FIG. 2) in the absence of an ink cartridge  12  attached to the cartridge body  10 . Upon attachment of an ink cartridge  12  to the cartridge body, boss  30  urges seal assembly housing members  98  toward the bottom wall portion  82  thereby promoting ink fluid flow communication between the ink in the ink cartridge  12  and aperture  67  in needles  24  so that ink flows through hollow needles  24  into unfiltered ink cavity  70  (FIG.  1 ). In order to reduce misalignment between boss  30  and needle  24 , each seal assembly housing member  98  preferably includes two or more guiding projections  112 , preferably four guiding projections  112  for capturing and guiding boss  30  into proper alignment with needle  24 . 
     The stiffener insert  28  is designed to be snappingly attached to the cartridge body  10  in cavity  34  as shown in FIG. 4 so that the apertures  108  in valve seal assemblies  26  slidably engage ink needles  24 . Accordingly, the bottom wall portion  82  of the stiffener insert  28  preferably contains an elbow section  114  which is dimensioned to frictionally engage shoulder section  116  of bottom panel member  18  of the cartridge body  10 . Upon engagement between elbow section  114  and shoulder section  116 , front edges  118  of dividing wall portions  84  preferably engage the inside of the lower section  58  of the front panel  54 . One or more apertures  120  may be provided in the lower section  58  for engaging tabs  122  on the front edges  118  of dividing wall portions  84 . It is also preferred that cross wall portions  86  contact side panels  60  to reduce flexure of the side panels  60  and to provide further frictional engagement between the stiffener insert  28  and the cartridge body  10 . 
     An important advantage of the stiffener insert  28  apart from the features described above is that it enables a reduction in the overall cost of the cartridge body  10 . The stiffener insert  28  is molded to contain seal assembly guides  92  for the valve seal assembly  26 . Accordingly, there is no need to provide a separate needle valve seal assembly structure which must be assembled to the needles  24  in a separate production step. Furthermore, since the seal assembly guides  92  are molded as part of the stiffener insert  28  rather than molded with the cartridge body  10  itself, only the stiffener insert  28  need be replaced if one or more of the guides  92  break or are otherwise deformed during manufacture or assembly rather than replacing the entire cartridge body  10 . The stiffener insert  28  may also be produced in a non-clean room atmosphere and assembled to the cartridge body  10  at an appropriate step in the production process. 
     With further reference to FIG. 4, the lower section  58  of front panel  54  is adapted to receive a printed circuit board (PCB)  124  which contains printer electrical contact pads, memory devices and the like for control of ink ejection from the ink jet printheads  14 . The PCB  124  is preferably adhesively attached to lower section  58  using alignment holes  126  or other suitable alignment means. It is particularly preferred that the PCB  124  be supported on its entire surface  128  by lower section  58  so as to reduce flexure of the PCB  124  during connecting contact between its electrical contact pads on opposing surface  130  of the PCB  124  and a carriage in a printer device on which the cartridge body  10  is mounted. As described above, stiffener insert  28  provides support for lower section  58  and thus PCB  124  to reduce flexure thereof during electrical connection of the cartridge body  10  to an ink jet printer carriage. 
     A fully assembled cartridge body  10  containing ink cartridge slots  134 ,  136 ,  138  and  140  is illustrated in perspective view in FIG.  5 . The cartridge slots  134 ,  136 ,  138  and  140  are defined by dividing wall portions  84  and side panels  60  and may have the same width between dividing wall portions  84  or different widths for accepting different color ink cartridges  12  therein. It is particularly preferred to include a wider slot  134  for a black ink cartridge and to provide substantially the same width slots  136 ,  138  and  140  for cyan, magenta and yellow ink cartridges  12 . In order to assure proper placement of the cyan, magenta and yellow ink cartridges  12  with respect to the cartridge body  10 , the cartridges  12  may contain keys for engagement with keying members  50 . The keying members  50  may have different widths, different lengths, be disposed in different locations relative to their corresponding cartridge slots  136 ,  138  and  140  or a combination of any two or more of the foregoing to provide proper insertion of the ink cartridges  12  on the cartridge body  10 . 
     Having described herein various aspects and embodiments of the invention and several advantages thereof, it will be recognized by those of ordinary skills that the invention is susceptible to various modifications, substitutions and revisions within the spirit and scope of the appended claims.