Abstract:
An ink jet cartridge comprising a housing having a print head portion including a nozzle plate having opposed pairs of side edges, rows of nozzles and at least one row of slots between said rows of nozzles and which plate is initially attached to the head portion by beads of an adhesive material overlying the edges of one pair of the opposed pairs of side edges is prepared for renovation by applying a reinforcing bead of an adhesive material to overlie at least one of the other pair of the opposed pairs of side edges and the at least one row of slots. The beads may be a single bead or segmented and are applied by robotic glue applying apparatus.

Description:
BACKGROUND 
   This invention relates to the art of ink jet cartridges and, more particularly, to preparing a used ink jet cartridge for renovation to promote the extended life and reuse thereof. 
   It is known that the life of an ink jet cartridge can be extended beyond the time it takes to deplete the cartridge of its initial supply of ink. For example, refill kits are provided for replenishing a cartridge&#39;s ink supply, and continuous refill systems have been developed for providing a continuous flow of ink to a cartridge from a remotely located ink supply bag or the like. In connection with extending the life of a cartridge, the latter needs to be periodically cleaned or renovated to avoid the buildup of dried ink inside the cartridge and in areas such as the nozzle plate where the buildup can preclude or seriously impair quality printing. The renovating or cleaning process includes soaking the cartridge in a cleaning solution and then flushing the cartridge to force the cleaning fluid through the nozzles or jets in the nozzle plate. Further, a vacuum is pulled across the nozzle jets in the nozzle plate and the internal pressure and/or the vacuum create a force on the nozzle plate tending to lift it from the snout portion of the cartridge to which it is initially bonded during the manufacture of the cartridge. Still further, a centrifuge process is used to remove the cleaning fluid inside the cartridge by expulsion thereof through the nozzle jets, and this centrifugal force will also lift the nozzle plate from its attachment to the cartridge. If the cartridge is then refilled with ink and placed back into service, the loose nozzle plate can result in poor print quality, such as fuzzy print, and can result in cross-contamination of colors in a color printing cartridge. Furthermore, if a cartridge being renovated already has a loose nozzle plate, the renovating or remanufacturing process tends to further loosen or remove the plate. In any event, loose nozzle plates cause a considerable loss in the yield of reusable cartridges in connection with a renovating or remanufacturing process. 
   SUMMARY OF THE INVENTION 
   In accordance with the present invention, the attachment of a nozzle plate to an ink jet cartridge is reinforced prior to the renovating or remanufacturing process so as to reduce the occurrence of the plate being loose following the renovation process. More particularly in this respect, the nozzle plate of a cartridge which is adhesively bonded to the snout portion of a cartridge at the time of manufacture is provided with a supplemental bead or beads of an adhesive material to reinforce the attachment of the nozzle plate to the cartridge against loosening of the plate during renovation. The supplemental beads of adhesive material are applied in areas of the nozzle plate other than those in which the initial beads of adhesive are located. While the supplemental beads of adhesive can be applied by hand, it is preferred, in accordance with another aspect of the invention, to apply the adhesive through the use of programmable apparatus in that the latter provides optimal control of bead location and height as well as consistency with respect to these parameters which, in turn, promotes improved process efficiency and minimal material waste. Moreover, the supplemental beads of adhesive promote a higher yield of reusable cartridges at a reduced production cost. 
   It is accordingly an outstanding object of the present invention to provide an ink jet cartridge in which the attachment of the nozzle plate to the cartridge is reinforced prior to renovation or remanufacturing of the cartridge for continued use. 
   Another object is the provision of a method of reinforcing the original attachment of a nozzle plate to an ink jet cartridge by supplemental beads of an adhesive material. 
   Yet another object is the provision of apparatus for applying supplemental beads of an adhesive material to the nozzle plate of a used ink jet cartridge to provide consistency with respect to glue bead location and height. 
   Still another object is the provision of a method and apparatus for preparing a used ink jet cartridge for remanufacturing which provides improved efficiency with respect to the preparation, minimal material waste, reduced production costs and increased yield of reusable cartridges. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     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: 
       FIG. 1  is a perspective view of an ink jet cartridge to be prepared for renovation in accordance with the present invention; 
       FIG. 2  is a plan view of the nozzle plate of the cartridge showing one embodiment of reinforcing adhesive beads in accordance with the invention; 
       FIG. 3  is a cross-sectional elevation view taken along line  3 - 3  in  FIG. 2 ; 
       FIG. 4  is a plan view of the nozzle plate showing another embodiment of reinforcing adhesive bead placement in accordance with the invention; 
       FIG. 5  is a cross-sectional elevation view taken along line  5 - 5  in  FIG. 4 ; 
       FIG. 6  is a plan view of the nozzle plate showing yet another embodiment of reinforcing adhesive bead application in accordance with the invention; 
       FIG. 7  is a cross-sectional elevation view taken along line  7 - 7  in  FIG. 6 ; 
       FIG. 8  is a plan view of the nozzle plate showing still another embodiment of reinforcing bead placement in accordance with the invention; 
       FIG. 9  is a cross-sectional elevation view taken along line  9 - 9  in  FIG. 8 ; 
       FIG. 10  is a perspective view of apparatus for applying beads of adhesive material to a cartridge in accordance with the invention; 
       FIG. 11  is an enlarged view of a portion of the adhesive dispensing needle for the apparatus; 
       FIG. 12  is a view of the outlet end of the needle taken along line  12 - 12  in  FIG. 11 ; 
       FIG. 13  is a perspective view of the apparatus showing a cartridge mounted thereon for receiving beads of glue; and, 
       FIG. 14  is a perspective view of apparatus supporting a plurality of cartridges to receive the glue in accordance with the invention. 
   

   DESCRIPTION OF PREFERRED EMBODIMENTS 
   Referring now in greater 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,  FIG. 1  illustrates an ink jet cartridge  10  having a front wall  12 , a rear wall  14 , a top wall  16 , a bottom wall  18 , and opposite side walls  20  and  22 , all of which cooperatively define a snout region  24  at the lower front end of the cartridge. Snout  24  is provided in a well-known manner with a print head portion of the cartridge including a nozzle plate  26 . 
   As best seen in  FIGS. 2 and 3 , nozzle plate  26  has opposed pairs of side edges  28  and  30  and is received in a recess  32  in snout portion  24  and, in connection with the initial manufacturing of the cartridge, is secured in the recess by beads  34  of adhesive material extending along and overlying edges  28  of the plate. In the embodiments illustrated herein, the nozzle plate is that of a Hewllet-Packard cartridge HP1823 which includes pairs of rows  36 ,  38  and  40  of nozzles N extending in the direction between side edges  28  of the nozzle plate and spaced apart from one another in the direction between side edges  30  of the plate. The nozzle plate further includes two pairs of rows  42  of slot S one of which is between and parallel to rows  36  and  38  of the nozzles and the other of which is between and parallel to rows  38  and  40  of the nozzles. In each of the rows  42 , slots S are offset relative to one another in the direction between side edges  28  of the nozzle plate, and the rows of slots overlie a substrate  44  of the print head. 
   While the invention is illustrated in connection with the cartridge HP 1823 it is applicable to other cartridges including, by way of example only, Hewllet-Packard cartridges HP 6626, HP 6578 and HP 1649A. 
   In accordance with one aspect of the present invention, prior to the renovating process the nozzle plate is wiped with a suitable cleaning solution to remove any dried ink therefrom, and reinforcing beads  46  of adhesive material are applied along side edges  32  of the nozzle plate. Beads  46  have a width w and a thickness t, and the beads are applied to have an overlap o inwardly of the corresponding side edge  30  of the nozzle plate. In the embodiment illustrated in  FIGS. 4 and 5  of the drawing, two reinforcing beads  46  of the adhesive material are applied along each of the side edges  30 . The adhesive material of beads  46  penetrates downwardly between side edges  30  of the nozzle plate and the corresponding edge of recess  32 . 
   In the embodiment illustrated in  FIGS. 6 and 7  of the drawing, a bead  48  of adhesive material is applied over and along each of the rows  42  of slots S and which beads, as set forth more fully hereinafter, penetrate slots S so as to adhere to silicon chip substrate  44  beneath the nozzle plate. As with beads  46  described hereinabove, each of the beads  48  has a width w and a thickness t. In the embodiment illustrated in  FIGS. 8 and 9 , two reinforcing beads  48  of adhesive material are applied over each of the rows of slots. 
   In the embodiments disclosed herein, a preferred adhesive material for the reinforcing beads is available from Henkel Technologies under the latter&#39;s product designation Loctite 3321. The latter adhesive is a UV cured acryoated urethane. With respect to beads  46 , the adhesive preferably has a viscosity of from 500 to 6,000 cP, and with respect to beads  48 , the adhesive preferably has a viscosity of from 1 to 150 cP. With respect to adhesive beads  46 , width w is 1.400 mm, thickness t is 0.250 mm, and overlap o is 0.250 mm. With regard to adhesive beads  48 , width w is 0.900 mm, and thickness t is 0.250 mm. 
   Preferably, with regard to the beads of adhesive applied along side edges  30  and over slots S of the nozzle plate, the glue is deposited at a pressure of between 12 and 15 psi. This pressure promotes dispensing of the glue into the area between the recess and plate edge and downwardly through the slots so as to adhere to the silicon chip therebelow. 
   While it is possible to manually apply the adhesive in the patterns described hereinabove, it is preferred to apply the glue through the use of robotic apparatus which is programmable to deposit the various patterns at the desired pressure and with the preferred dimensions. In particular in this respect, the use of such apparatus provides accuracy with respect to bead location and height and consistency of deposit from one cartridge to the next. Accordingly, process efficiency is realized with minimal material waste and product costs are advantageously reduced. 
   Robotic glue dispensing apparatus for the foregoing purpose is illustrated in  FIGS. 10 ,  13  and  14  of the drawing and is available from Henkel Technologies under the latter&#39;s product designation 98279. Loctite  203 . Bench Top Robot. Briefly, the apparatus includes a base  50  and a track post  52  extending upwardly therefrom and supporting a horizontally extending track member  54 . Track member  54  supports a carriage  56  for a glue dispensing nozzle assembly  58  which includes a glue dispensing nozzle or needle  60 . Carriage  56  is displaceable horizontally along track  54  and in opposite directions as indicated by arrow  62 , and nozzle assembly  58  is displaceable vertically relative to carriage  56  and in opposite directions as indicated by arrow  64 . Base  50  is provided with a workpiece support table  66  which is displaceable horizontally in opposite directions as indicated by arrow  68  and which direction is perpendicular to that represented by arrow  62 . Base  50  is provided with an on/off switch  70  by which programmed operation of the apparatus is initiated, and a kill switch  72  enables stopping the operation should it become necessary or desirable to do so. 
   In accordance with another aspect of the present invention, table  66  is provided with a cartridge clamping assembly  74  which, as shown in  FIG. 13 , is operable to mount a cartridge  10  on the table for displacement therewith and with nozzle plate  26  facing upwardly. In this respect, clamping assembly  74  includes a plate  76  against which side  22  of the cartridges engage, and a plate  78  at right angles to plate  76  for engaging front wall  12  of the cartridge. Plates  76  and  78  provide a corner into which the cartridge is pressed by an angularly-oriented spring-loaded clamping member  80  having a V-shaped nose portion, not designated numerically, for engaging the corner between rear wall  14  and side wall  20  of the cartridge so as to bias the cartridge into the corner between plates  76  and  78 . Preferably, the clamping assembly further includes a spring-loaded, toggle-type clamping member  82  having a resilient nose portion  84  for engaging side wall  20  of the cartridge. This clamping member is perpendicular to plate  76  and biases the cartridge thereagainst. As will be appreciated from the foregoing description, a cartridge  10  is firmly clamped in place on table plate  66  and on/off switch  70  is actuated to initiate displacements of table  66 , carriage  56  and nozzle assembly  58  for the application of beads of adhesive to the nozzle plate of the cartridge in accordance with the programmed glue pattern. When the program is completed, the apparatus turns off and the cartridge is removed therefrom. 
   In accordance with yet another aspect of the invention, as shown in  FIGS. 11 and 12  of the drawing, the glue dispensing nozzle or needle  60  includes a circular stem portion  86  having a vertical axis  88  when mounted in the glue dispensing assembly and a terminal end  90  at an angle x to horizontal. The terminal end is provided with an outlet opening  92  which is in a horizontal plane and, accordingly, has an oval contour. Preferably, angle x is 45°. During the depositing of glue, the needle moves relative to a nozzle plate in the direction of arrow  94 , and the oval or ellipsoidal contour of the needle allows the continuous flow of glue so as to maintain a straight line edge of a glue bead onto the nozzle plate. The oval contour also enables the bead of adhesive to be drawn along the surface to which it is applied rather than being plowed along the surface as would be the case if the outlet opening was at an angle to the nozzle plate as opposed to being parallel thereto. Still further, the needle tip contour promotes accuracy with respect to the glue bead overlap of the side edge of the nozzle plate as well as accuracy with respect to maintaining the desired width and thickness of the adhesive feed. 
     FIG. 14  illustrates a modification of the workpiece support plate  66  of the apparatus for the latter to accommodate a plurality of cartridge clamping assemblies  74  as described hereinabove in connection with  FIGS. 10 and 13 . It will be appreciated of course that the apparatus in this instance is programmed to apply a preselected adhesive bead pattern to each of the plurality of cartridges during a cycle of operation of the apparatus. 
   While considerable emphasis has been placed herein on preferred embodiments of the invention, it will be appreciated that other embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the invention. Accordingly, it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation and that it is intended to include other embodiments and all modifications of the preferred embodiments insofar as they come within the scope of the appended claims or the equivalents thereof.