Patent Publication Number: US-2004051764-A1

Title: Easy install ink tank for an ink jet off-carrier system

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention relates to an ink jet printer, and, more particularly, to a method and apparatus for installing an ink tank in an ink jet printer.  
       [0003] 2. Description of the Related Art  
       [0004] An ink jet printer includes a printhead having a plurality of nozzles arranged in the direction paper is fed. Connected to the ink jet nozzles is an ink delivery mechanism that supplies ink to the nozzles from an ink reservoir. Ink jet printers may have a single printhead containing an ink reservoir, which is replaced as an integral unit when the ink supply runs out. Some ink jet printheads have a combined set of colors contained in a single printhead. Another type of ink jet printer employs a printhead with a separate ink reservoir. The ink reservoir also known as an ink tank may be in constant fluid communication with the printhead or it may be in intermittent communication with the printhead.  
       [0005] Intermittent communication of the printhead with the ink tank allows a large supply of ink to be held in the ink tank with the printhead having a small reservoir of ink on board. When the printhead senses the need to replenish the ink in the on-board reservoir, it is positioned for refilling from the ink tank.  
       [0006] Constant fluid communication between the ink tank and the printhead is implemented either by a direct connection of the ink tank to the printhead or by way of flexible tubes.  
       [0007] Ink tanks in ink jet printers are replaced when an ink supply is diminished. Ink tanks are often compressed to interface with an ink conveyance mechanism for conveying the ink from the ink tank to the printhead.  
       [0008] A problem with inserting ink tanks is the amount of force necessary for the ink tank to come into fluid communication with fluid connectors.  
       [0009] What is needed in the art is a method and apparatus that reduces the effort needed to install an ink tank in an ink jet printer.  
       SUMMARY OF THE INVENTION  
       [0010] The present invention provides an apparatus and method for easily installing an ink tank in an ink jet off-carrier printer.  
       [0011] The invention, in one form thereof is directed to an ink tank latching system including a housing having an opening and at least one latching rod movably disposed across a portion of the opening.  
       [0012] The invention, in another form thereof, relates to an ink jet printer having an ink tank for containing a supply of ink including at least one printhead support, at least one printhead moveably connected to the printhead support and at least one ink tank receiver in fluid communication with the at least one printhead. The ink tank receiver includes a housing having an opening for receiving the ink tank and at least one latching rod movably disposed across a portion of the opening.  
       [0013] The invention, in still another form thereof, relates to a method of installing an ink tank in an inkjet printer including the steps of opening an ink tank receiver access door, inserting an ink tank in the ink tank receiver and engaging the ink tank with a latching rod across a surface of the ink tank, the latching rod interactively connected to the access door.  
       [0014] An advantage of the present invention is that an ink tank can be easily installed in an ink jet printer.  
       [0015] Another advantage is that the access door provides a mechanical advantage for pressing the ink tank against fluid connectors.  
       [0016] A further advantage is that the access door is retained in a closed position by way of an over-center mechanism. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0017] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:  
     [0018]FIG. 1 is an imaging system including an ink jet printer incorporating an embodiment of an ink tank receiver of the present invention;  
     [0019]FIG. 2 is a perspective view of the ink tank receiver used in the ink jet printer of FIG. 1;  
     [0020]FIG. 3 is a cross sectional side view of the ink tank receiver illustrated in FIGS. 1 and 2;  
     [0021]FIG. 4 is a cross sectional view showing the insertion of an ink tank in the ink tank receiver of FIGS.  1 - 3 ;  
     [0022]FIG. 5 is a cross sectional side view illustrating the ink tank being more fully inserted into the ink tank receiver of FIGS.  1 - 4 ; and  
     [0023]FIG. 6 is a cross sectional side view showing the ink tank fully inserted and the mechanism of the ink tank receiver of FIGS.  1 - 5 , in an over-center latched position. 
    
    
     [0024] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.  
     DETAILED DESCRIPTION OF THE INVENTION  
     [0025] Referring now to the drawings and particularly to FIG. 1, there is shown a perspective view of an imaging system  10  including computer system  12 , ink jet printer  14  and communication link  16 . Computer system  12  is interconnected with ink jet printer  14  by way of communication link  16 . Communication link  16  can be a point to point electrical cable connection between either serial or parallel ports of ink jet printer  14  and computer system  12  or the connection can be by way of a network connection such as an Ethernet network.  
     [0026] Computer system  12  includes a monitor  18 , a keyboard  20  and a computer  22 . Computer  22  includes application software operated by a user and provides image data representing an image to be printed and printing command data to ink jet printer  14  by way of communication link  16 .  
     [0027] Now, additionally referring to FIGS.  2 - 6 , there is shown ink jet printer  14  including printer housing  24 , paper tray  26 , printhead support  28 , printhead  30 , ink tank receiver  32 , connection mechanism  34  and ink tank  36 . Printer housing  24  includes the exterior shell of ink jet printer  14  that provides structural integrity and mounting points to the mechanisms contained within ink jet printer  14 . Paper tray  26  is connected to printer housing  24  allowing for the feeding of paper into ink jet printer  14 . Printhead support  28  is connected to printer housing  24  allowing for controllable movement of printhead  30  thereon. Printhead support  28  may consist of one or more cylindrical bars with an indexing feature either thereon or closely disposed thereby. Printhead  30 , although shown as a single printhead, may be multiple printheads each for at least one color of ink. Printhead  30  has nozzles within a nozzle array. The nozzles may alternate in size along a vertical axis of printhead  30  and have a fixed vertical pitch of {fraction ( 1 / 600 )} th  of an inch. Printhead  30  is in fluid communication with ink tank  36  that is contained in ink tank receiver  32 .  
     [0028] Ink tank receiver  32  is interconnected with printhead  30  by way of connection mechanism  34 . Ink tank  36  resides within ink tank receiver  32  having a supply of ink therein. Connection mechanism  34  includes parallel tubes, one tube for each color of ink contained in ink tank  36  that is supplied to printhead  30 .  
     [0029] Alternatively, connector mechanism  34  may be implemented as an intermittent or on-demand type interaction between printhead  30  and ink tank receiver  32 . Printhead  30  senses the need to increase the amount of ink in an on-board reservoir and then is positioned proximate to ink tank receiver  32  for a transfer of ink from ink tank  36  to printhead  30 .  
     [0030] Ink tank receiver  32  includes receiver housing  38 , ink tank guides  40 , ink tank fluid connectors  42  and latching mechanism  44 . Receiver housing  38  has an opening  39  on one end to accommodate the insertion of ink tank  36  therein. Receiver housing  38  provides structural integrity and mounting points for latching mechanism  44 , ink tank guides  40 , and ink tank fluid connectors  42 . Ink tank guide  40  is positioned within receiver housing  38  having guiding protrusions, which interact with recesses and/or protrusions on ink tank  36  to key and properly guide ink tank  36  to ink tank fluid connectors  42 . Ink tank fluid connectors  42  are positioned along a bottom portion of receiver housing  38  to accommodate septum positioned along the bottom of ink tank  36 . The septum on ink tank  36  come into contact with ink tank fluid connectors  42  thereby facilitating the flow of ink from ink tank  36  into connection mechanism  34  and on to printhead  30 .  
     [0031] Latching mechanism  44  includes access door  46 , sector gears  48 , idler gears  50 , over-center mechanisms  51 , latching rod  56 , side plates  58  and guide slots  60 .  
     [0032] Access door  46  is hingedly connected to housing  38  along one top side edge of housing  38 . Access door  46  opens sufficiently to allow the passage of ink tank  36  into and out of receiver housing  38 . Sector gears  48  may be integral with access door  46  or attached thereto. Sector gears  48  provides a transfer of mechanical movement of access door  46  to idler gears  50 . As sector gears  48  rotate the teeth thereof engage corresponding teeth on idler gears  50 , thereby transferring mechanical motion and reversing the direction of the motion to a corresponding over-center mechanism  51 .  
     [0033] Over-center mechanism  51  includes an over-center disk gear  52  and a rod linkage  54 . Over-center disk gear  52  is rotatably attached to housing  38  and pivotally attached to one end of rod linkage  54 . Teeth on a portion of over-center disk gear  52  are engaged by the teeth of a corresponding idler gear  50 . Rod linkage  54  has an other end connected to latching rod  56 . A sector gear  48 , an idler gear  50  and an over-center mechanism  51  are positioned on each side of housing  38  in a mirror image fashion. The positioning of gears  48 ,  50  and  52  and linkage  54  on each side of housing  38  allow for the insertion of ink tank  36  therebetween. The attachment of access door  46  to sector gears  48  and the interaction of idler gears  50  and over-center mechanisms  51  to latching rod  56  allow a uniform pressure to be applied to ink tank  36 .  
     [0034] Latching rod  56  is connected near each end by a corresponding rod linkage  54  and latching rod  56  extends somewhat beyond the connection with each rod linkage  54  into a corresponding guide slot  60  on each side of housing  38 . Rod linkage  54  traverses guide slot  60  along the path of slot  60  as latching mechanism  44  is moved from a latched position to an unlatched position. The coordinated movement of each rod linkage  54  causes latching rod  56  to move in a uniform manner along guide slot  60 .  
     [0035] Guide slot  60  is formed as a part of side plate  58 , which is attached to housing  38 . Alternatively guide slot  60  may be integral with housing  38 . Guide slot  60  is shaped to position latching rod  56  toward a side of housing  38  when access door  46  is an open position, thereby allowing ink tank  36  to be inserted without interference from latching rod  56 . As latching mechanism  44  is moved to a latched position, latching rod  56  travels along guide slot  60  in a motion which allows engagement of latching rod  56  with ink tank  36  and to thereby apply pressure upon the top of ink tank  36  as latching mechanism  44  is moved to a latched position.  
     [0036] Referring to FIGS.  4 - 6 , there is shown the insertion of ink tank  36  into ink tank receiver  32 . Ink tank  36  includes an ink tank top surface  62 , an ink tank guide interface  64  and ink tank septum  66 . As shown in FIG. 4 access door  46  is in a fully open position with gears  48 ,  50  and  52  so positioned as to extend rod linkages  54 , thereby causing latching rod  56  to be disposed toward an edge of ink tank receiver  32 . The positioning of latching rod  56  along an edge of ink tank receiver  32  clears opening  39  for the insertion of ink tank  36 . Ink tank  36  is initially inserted by an operator and ink tank guide interfaces  64  interact with ink tank guides  40  to properly orient and position ink tank  36  for engagement with ink tank fluid connectors  42 .  
     [0037] Once ink tank  36  is positioned within ink tank receiver  32  and ink tank guide interfaces  64  have interacted with ink tank guides  40 , access door  46  is moved in a closing motion, in the direction of arrow S. The action of closing access door  46  causes gears  48 ,  50  and  52  to rotate pulling rod linkage  54 , thereby moving latching rod  56  toward a point of engagement with ink tank top surface  62 . As shown in FIG. 6 access door  46  is in a closed or nearly closed position having caused ink tank septum  66  of ink tank  36  to engage ink tank fluid connectors  42  along the bottom of ink tank receiver housing  38 . Latching rod  56  presses against top surface  62  of ink tank  36  pushing ink tank septum  66  into fluid communication with ink tank fluid connectors  42 . When access door  46  is in a closed latched position, rod linkages  54  become over-centered relative to the pivoting point of over-center disk gear  52  as shown in FIG. 6. Rod linkages  54  (see FIG. 6) are above the pivot point for over-center disk gear  52 . Over-centering mechanism  51  allows for a latched position to be maintained utilizing the pressure against the top surface  62  of ink tank  36  by latching rod  56  to hold rod linkage  54  in the over-center position. While over-center mechanism  51  is in an over-center position force is transmitted by way of gears  48 ,  50  and  52  to access door  46 , thereby retaining access door  46  in a closed position.  
     [0038] To remove ink tank  36  from ink tank receiver  32  access door  46  is lifted thereby relieving pressure from ink tank top surface  62  that has been applied by latching rod  56 . As access door  46  is moved to an unlatched position, gears  48 ,  50  and  52  cause latching rod  56  to move to the side of housing  38 . As pressure to ink tank  36  is removed the resilient nature of ink tank fluid connectors  42  cause ink tank  36  to move away from the bottom of ink tank receiver  32  allowing ink tank  36  to be grasped by an operator and thereby removed from ink tank receiver  32 .  
     [0039] Although one ink tank receiver  32  has been illustrated in the drawings and is described herein, multiple ink tank receivers  32  may be employed in ink jet printer  14 .  
     [0040] Latching mechanism  44  provides a mechanical advantage relative to the insertion force required to install ink tank  36  into ink tank receiver  32 . The mechanical advantage allows an easy insertion of ink tank  36  and a positive connection of ink tank septum  66  with ink tank fluid connectors  42 .  
     [0041] While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.