Abstract:
An ink cartridge for insertion into a cartridge holder has an ink supply tube coupled therewith for delivering ink to the cartridge from a remote source, and a clamping device on said cartridge is operable to open the supply tube when the cartridge is introduced into the holder and to close the tube when the cartridge is removed from the holder.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to the art of ink cartridges for ink jet printers and, more particularly, to improved clamping devices for opening and closing an ink supply line to an ink cartridge in a continuous ink supply system.  
         [0002]     Continuous ink refill systems for disposable ink jet cartridges are of course well known as shown, for example, in U.S. Pat. No. 5,469,201 to Erickson, et al. In such systems, basically, a cartridge is connected to an auxiliary ink supply reservoir by means of a flexible hose or tube, and during operation of the printing system the tube is open to allow ink to flow from the auxiliary reservoir to the ink cartridge. During shipment or handling of the ink supply reservoir system when it is outside the printing machine, the supply tube must be closed to prevent the transfer of ink from the reservoir to the cartridge. Moreover, after installation in the printer, cleaning of the printer and/or the ink delivery system requires removal of the cartridge from the printer. In connection therewith, changes in the cartridge position relative to the supply reservoir, and/or pressure on the latter, will cause the ink delivery system to lose its prime and fail. Clamping the supply tube to close the flow of ink therethrough from the reservoir to the cartridge during cleaning, or removal for any purpose, isolates the volume of ink in the reservoir so as to prevent such failure.  
         [0003]     Heretofore, closing of the delivery tube has been achieved such as by the use of a manually operated pinch clamp as shown, for example, in U.S. Pat. No. 5,745,137 to Scheffelin, et al., or a manually operated stopcock as shown for example in the aforementioned patent to Erickson, et al. The use of such devices for closing the flow of ink through the delivery tube not only requires the manual actuation of the device by the operator but also requires that the operator remember to open and close the device and, especially, to close the device before removal of the cartridge from the printer.  
       SUMMARY OF THE INVENTION  
       [0004]     In accordance with the present invention, a clamping device is associated with an ink cartridge so as to automatically open and close the ink supply tube to the cartridge in response, respectively, to introducing and removing the cartridge from a cartridge holder of a printer. Such automatic clamping and unclamping of the supply tube advantageously eliminates the concern for an operator having to remember to manually actuate a valve mechanism to open and close the supply tube upon insertion and removal of the cartridge from the printer. Further, such automatic opening and closing of the supply tube provides added stability to the ink supply system and security against leakage of ink to the cartridge during shipping, installation and cartridge cleaning operations.  
         [0005]     The clamping device may include component parts integral with a cartridge, or it may be an assembly of component parts mountable on a cartridge as a unit. As will become apparent hereinafter, clamping components of the clamping device are relatively displaced upon insertion of the cartridge into a cartridge holder to open the supply tube to the flow of ink therethrough from the reservoir to the cartridge. Likewise, the component parts are relatively displaced upon removable of the cartridge from the cartridge holder to close the supply tube to the flow of ink therethrough.  
         [0006]     It is accordingly an outstanding object of the present invention to provide improvements in connection with controlling the flow of ink from a reservoir to an ink cartridge in a continuous ink supply system.  
         [0007]     Another object is the provision of a clamping device operable to automatically open and close an ink supply tube to a cartridge respectively in response to introducing and removing the cartridge from a printer.  
         [0008]     A further object is the provision of a clamping device of the foregoing character which is structurally associated with an ink cartridge so as to be automatically operable in connection with inserting and removing the cartridge from a printer to respectively open and close the ink supply line to the cartridge. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     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:  
         [0010]      FIG. 1  is a perspective view of an ink cartridge having a clamping device in accordance with the present invention mounted thereon;  
         [0011]      FIG. 2  is a side elevation view of the ink cartridge in  FIG. 1  with the clamping device removed;  
         [0012]      FIG. 3  is an inverted perspective view of the clamping device shown in  FIG. 1 ;  
         [0013]      FIG. 4  is a sectional elevation view of a portion of the clamping device and somewhat schematically illustrates the clamping device in the open condition thereof;  
         [0014]      FIG. 5  is a sectional elevation view similar to  FIG. 4  and illustrating the clamping device in the closed condition thereof;  
         [0015]      FIG. 6  is a perspective view of the ink cartridge and clamping device mounted in a cartridge holder;  
         [0016]      FIG. 7  is a side elevation view of another embodiment of a clamping device in accordance with the present invention, mounted on a cartridge;  
         [0017]      FIG. 8  is an elevation view of the reversed side of the clamping device;  
         [0018]      FIG. 9  is an elevation view of the inside of the base component of the clamping device;  
         [0019]      FIG. 10  is an elevation view of the inside of the slide component of the clamping device;  
         [0020]      FIG. 11  is an enlarged cross-sectional view of the clamping device taken along line  11 - 11  in  FIG. 7 ;  
         [0021]      FIG. 12  is a side elevation view of yet another embodiment of the clamping device in accordance with the invention, mounted on an ink cartridge;  
         [0022]      FIG. 13  is an elevation view of the inside of the base component of the clamping device;  
         [0023]      FIG. 14  is an elevation view of the inside of the slide component of the clamping device; and,  
         [0024]      FIG. 15  is an enlarged cross-sectional view of the clamping device taken along line  15 - 15  in  FIG. 12 . 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0025]     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 cartridge  10  having a clamping device  12  in accordance with the present invention mounted thereon for controlling the flow of ink to the cartridge from a remote ink reservoir, not shown. More particularly in this respect, a flexible ink supply tube  14  has an end  14   a  for attachment to the cartridge, such as by a coupling  16 , and has an end  14   b  leading from the cartridge to the remotely located ink reservoir, such as a collapsible bag. As best seen in  FIG. 2 , cartridge  10  has front and rear walls  10   a  and  10   b,  respectively, a top wall  10   c  and a bottom wall  10   d.  Further, the cartridge has a handle  18  at the juncture between rear wall  10   b  and top wall  10   c  which, as is well known, facilitates introducing and removing the cartridge relative to a cartridge holder in a printer. A latching component  20  at the juncture between top wall  10   c  and front wall  10   a  provides for releasably interengaging the cartridge with the holder. Handle  18  has a laterally inwardly extending recess  22  which, as will become apparent hereinafter, is cooperable with a mounting protrusion on clamping device  12  for mounting the latter on the cartridge.  
         [0026]     Referring now to  FIGS. 1, 3 ,  4 , and  5  of the drawing, clamping device  12  in this embodiment is a unit independent of the cartridge and comprises a base component  24 , a slide component  26 , and a biasing spring  28  between the base and slide components. Base component  24 , includes an end  29  corresponding in contour with cartridge handle  18  and including a mounting protrusion  30  which is profiled to be received in recess  22  of cartridge handle  18  to securely attach the clamping device to the cartridge. The base component further includes a pair of openings  32  through which supply tube  14  extends, and the base component is provided with a half round boss  34  between the openings. Clamping device  12  has opposite ends  12   a  and  12   b,  and mounting protrusion  30  is on the base at end  12 a. Slide component  26  is interengaged with base component  24  for sliding displacement relative thereto in the direction between ends  12   a  and  12   b.  More particularly in this respect, the slide component has a pair of protrusions  36  received in elongated slots  38  in the base component and receiving screws  39  which slidably engage slot shoulders  38   a  to retain the base and slide in assembled relationship. The end of slide  26  at end  12   a  of the clamping device is also profiled to correspond in contour with cartridge handle  18 . Spring  28  is interposed between a mounting post  40  on the base component and a mounting post  42  on the slide component and biases the latter to the left in  FIGS. 4 and 5  relative to the base component. The slide component further includes a pair of half round bosses  44  which cooperate with boss  34  on the base component to provide a pinch point for closing supply tube  14 , as shown in  FIG. 5 . In this respect, and as will be explained more fully hereinafter, when clamping device  12  is mounted on a cartridge and the base and slide components are in the positions shown in  FIG. 4 , the cartridge is mounted in a printer and the bosses are separated for the tubing to be open to the flow of ink therethrough to the cartridge. When the base and slide components are in the positions shown in  FIG. 5 , the cartridge is outside the printer and the components are biased by spring  28  for bosses  34  and  44  to clampingly engage supply tube  14  therebetween to close the tube to the flow of ink from the reservoir to the cartridge. In this embodiment, the end of slide component  26  which provides end  12   b  of the clamping device includes a slide actuating wall member  46  which, as will become apparent hereinafter, interengages with a wall component on a cartridge holder of an ink printer to actuate the slide from the closed to the open condition of supply tube  14  in response to inserting the cartridge into the holder.  
         [0027]     Referring now to  FIG. 6 , an ink cartridge holder  48  of a printer includes pockets  50  for receiving ink cartridges, and the latter pockets include vertically inclined walls  52  adjacent the printing head end of the cartridge and horizontal walls  54  extending from the lower ends of walls  52  toward the opposite end of the cartridge. When the cartridge and clamping device  10  mounted thereon are outside the printer, the component parts thereof are in the positions shown in  FIGS. 1 and 5 , whereby the ink supply tube is closed. When the cartridge is introduced into the holder, wall  46  of the slide component engages against wall  52  of cartridge holder  48  whereby, as the cartridge is fully inserted into the holder, the component parts are displaced to the positions shown in  FIGS. 4 and 6  against the bias of spring  28  to open the ink supply tube  14  to the flow of ink from the reservoir to the cartridge. It will be appreciated from the foregoing description that when the cartridge is removed from the holder, wall  46  of slide component  26  disengages from wall  52  of the cartridge holder, whereupon spring  28  displaces the slide relative to the base component and to the positions thereof shown in  FIGS. 1 and 5  to again close the supply tube to the flow of ink therethrough.  
         [0028]      FIGS. 7-11  illustrate another embodiment of a clamping device in according with the present invention. In this embodiment, a clamping device, which is designated by the numeral  60 , comprises a base component  62 , a slide component  64  and a biasing spring  66  interposed therebetween for the purpose set forth hereinafter. Base  62  and slide  64  are slidably interengaged in part by a pair of bars  68  on the inner side of base component  62  and a plurality of bars  70  on the inner side of slide component  64  and which are spaced apart to define channels  72  therebetween for slidably receiving bars  68  on the base component. The base and slide components are further slidably interengaged by a pair of fingers  74  on the base which, during assembly of the base and slide, are insertable through the enlarged lower ends of L-shaped slots  76  in the slide and then moved into the upper ends of the slots for the fingers to overlie and slidably engage shoulders  76   a  of the slots. During such interengagement, bars  68  are slidably received in channels  72 , and the slide and base are then interconnected against separation by a pair of screws  78  extending through corresponding slots  80  in the base and into openings therefor, not designated numerically, in a mounting post  82  on the slide. The heads of these screws overlie shoulders  80   a  of the slots to maintain the base and slide against separation axially with respect to the screw axes, and it will be appreciated that the length of slots  80  accommodates the desired relative displacement capability between the base and slide in the direction of the slots.  
         [0029]     The bottom wall of base  62  is provided with a downwardly extending post  84  and bottom wall  85  of slide  64  is provided with an upwardly extending post  86 . The opposite ends of spring  66  receive the corresponding one of the posts  84  and  86  and is in compression so as to bias the base and slide components away from one another in the direction of slots  80 . Further, slide  64  includes a rounded boss  88  extending downwardly from mounting post  82 , and the bottom wall of base  62  includes a rounded boss  90  extending upwardly therefrom. As set forth hereinafter, bosses  88  and  90  are aligned for displacement between clamping and unclamping positions relative to supply tube  14  and in response to relative displacement between the base and slide components.  
         [0030]     Base  62  and slide  64  have extensions  92  and  94 , respectively, extending from one side thereof and in overlying relationship when the component parts are in the positions shown in  FIGS. 7 and 8 . Extensions  92  and  94  correspond in contour with the handle  18  of cartridge  10  on which the clamping device is mounted by means of a mounting protrusion  96  on extending  92  of base  62  and which is profiled to be received in recess  22  of the cartridge handle as in the previous embodiment. As will be appreciated from  FIG. 9 , the inside of base component  62  is defined in part by a planar wall  98  and a peripheral wall  100  extending inwardly therefrom and along the sides, bottom and extension  92 . Wall  100  is provided with openings  102 ,  103 ,  104 , and  106  for receiving supply tube  14  and which openings provide for selective routing of the tubing relative to the clamping device, cartridge and ink supply reservoir. In this respect, as shown in  FIG. 9 , openings  102 ,  103  and  104  provide for routing the tubing linearly through the clamping device at a location adjacent the lower end of the cartridge handle, and openings  102 ,  103  and  106  provide for routing the tubing horizontally into the clamping device and thence upwardly through extension  92 . In either event, it will be appreciated that the tubing has one end routed for connection to coupling  16  on a cartridge and the other end routed to the ink reservoir.  
         [0031]     It will be noted in this embodiment, as seen in  FIG. 7 , that the orientation of the base and slide components and protrusion  96  is such that when the clamping device is mounted on cartridge  10 , the slide component is displaceable vertically relative to the base component as opposed to horizontally as in the previous embodiment. When the component parts are assembled and in the positions thereof shown in  FIG. 8 , spring  66  biases slide component  64  downwardly relative to base  62 , whereby tube  14  is pinched between bosses  88  and  90  to close the tube against flow of ink therethrough. As in the previous embodiment, this is also the position of the clamping device components when the device is mounted on cartridge  10  and the latter is outside a printer. When cartridge  10  is introduced into a cartridge holder such as holder  48  shown in  FIG. 6 , bottom wall  85  of slide component  64  engages the upper edge of wall  54  of the cartridge holder whereby, as the cartridge is fully inserted into the holder, the slide component is displaced upwardly relative to the base component to displace boss  88  of the slide away from boss  90  of the base against the bias of spring  66  to open tubing  14  to the flow of ink therethrough. Similarly, when the cartridge is removed from the holder, slide wall  85  disengages holder wall  54  and spring  66  biases slide  64  downwardly relative to base  62  for bosses  88  and  90  to again pinch tube  14  therebetween to close the latter to the flow of ink therethrough.  
         [0032]      FIGS. 12-15  illustrate a modification of the embodiment shown in  FIGS. 7-11  which advantageously eliminates the use of screws  78  for maintaining the base and slide components in assembled relationship. Accordingly, with the exception of the referenced modification, the component parts which correspond to those shown in  FIGS. 7-11  are designated by like numerals in  FIGS. 12-15 . In this embodiment, the base and slide components of the clamping device, which is designated  60 A, are modified to provide for an interengagement in the upper area thereof which enables relative sliding displacement vertically while precluding separation of the components transverse to the direction of sliding. More particularly in this respect, bars  68  and slots  80  of base  62  are replaced by L-shaped retaining members  108 , each of which includes an inner leg  110  extending upwardly from wall  98  and a leg  112  spaced above wall  98  and extending outwardly from leg  110 . Further, in this respect, bars  70  and mounting post  82  on the inner side of slide  64  are replaced by a pair of L-shaped retaining members  114 , each of which includes an outer leg  116  extending upwardly from the inner side of the slide and an upper leg  118  spaced above the inner side of the slide and extending inwardly from leg  116 . A rib  120  is provided between retaining members  114 , and the lower end of the rib is rounded to provide boss  88 . The base and slide components are assembled by introducing fingers  74  through the enlarged lower ends of slots  76 , displacing the base and slide into parallel relationship, sliding the components relative to one another to slidably interengage retaining members  108  and  114 , and mounting spring  66  between posts  84  and  86  to bias the slide downwardly relative to base  62 . It will be appreciated that the sliding interengagement between retaining members  108  and  114  provide for legs  112  of the retainers on base  62  to overlie legs  118  of the retainers on slide  64 . Legs  112  of retaining members  108 , and thus the relative positions between the base and slide components, are visible through windows  122  in the slide which underlie retaining members  114  on the slide. A further modification is provided by relocating opening  104  in base  62  from the lower portion of extension  92  to the outer end thereof.  
         [0033]     As will be appreciated from the embodiment described in connection with  FIGS. 7-11 , when clamping device  60   a  is mounted on a cartridge  10  as shown in  FIG. 12 , the cartridge is outside a printer and spring  86  biases a slide downwardly relative to base  62  for bosses  88  and  90  to pinch tube  14  therebetween to close the latter to the flow of ink therethrough. As will be further appreciated from the description with regard to  FIG. 7 , when cartridge  10  with clamping device  60   a  is inserted into a cartridge holder  48 , bottom wall  85  of the slide engages wall  54  of the holder and as the cartridge is fully seated in the holder, slide  64  is displaced upwardly relative to base  62  to displace bosses  88  and  90  away from one another to open tube  14  for the flow of ink therethrough. Upon removal of the cartridge from the holder, slide  64  is really displaced from wall  54  of the holder, whereupon spring  86  biases the slide downwardly relative to base  62  to again cause tube  14  to be pinched between bosses  88  and  90 .  
         [0034]     As will be appreciated from the foregoing description of the preferred embodiments, the spring force must be sufficient to crimp the tubing so as to assure against leakage of ink through the tubing when the cartridge is outside the printer. Since the cartridge is typically held in the cartridge holder by an over center or detent action type spring, the reaction force from the clamping spring may require that the holding force be increased which, in turn, would lead to higher insertion and removal forces for the operator. Accordingly, it is desirable to minimize the force required to crimp the tubing so as to minimize the affect on the detent holding force between the cartridge and cartridge holder. In accordance with another aspect of the present invention, this is achieved by using compliant, low durometer tubing which collapses easily when crimped. Preferably,  50  durometer silicone tubing is used to optimize the desired crimping action with minimum clamping spring force, although PVC or vinyl tubing having durometer values in the range of  65 - 70  can be used. An additional advantage of the silicone tubing is that it can be crimped for long periods of time with a minimum likelihood that the tubing would take a set from the crimping action.  
         [0035]     While considerable emphasis has been placed herein on the structures and structural interrelationships between the component parts of preferred embodiments of the invention, it will be appreciated that other embodiments can be devised and that many changes can be made in the preferred embodiments without departing from the principals of the invention. Therefore, 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.