Abstract:
An ink jet printer comprises a container configured to hold ink, a first coupling component of a duplex coupler formed to the container, and a reservior configured to receive ink from the container. A complementary second coupling component of the duplex coupler is formed to the reservoir. The first coupling component is configured to mate with the second coupling component so as to mitigate leakage of ink.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention relates to systems for making inked imprints, and more particularly, to supplying ink for such systems.  
           [0002]    One system for making inked imprints provides droplets on demand in response to transducer energization of one or more print heads that are supplied with ink. In some cases, such as the on-line printing of corrugated containers, large volumes of ink are required and suitably large supply containers of ink are needed.  
           [0003]    In an impulse ink jet, positive pressure forces ink through chambers and orifices without the sucking back of ink. In one technique, a transport tube carrying ink between a supply chamber and a print head is squeezed to apply pressure that forces the ink to the printhead, followed by relief of the pressure to prevent back flow of ink from the print head.  
           [0004]    The supply of pressure by squeezing a transport tube facilitates not only the removal of partially filled ink source containers but also the refilling of partially filled containers.  
           [0005]    The desired squeezing of the ink transport tube is readily achieved by peristaltic pumping, having a roller moved into contact with the tube, then rolled along the tube to force ink to the printhead, followed by separation of the roller from the tube to allow the free flow of ink into the rolled area.  
           [0006]    One technique providing a large ink supply for impulse ink jet printing is disclosed in U.S. Pat. 5,343,226 issued Sep. 28, 1997 to John Niedermeyer et al. and assigned to Dataproduct Corporation of Woodland Hills, Calif.  
           [0007]    In Niedermeyer an impulse ink jet head is coupled to a ink reservoir that is supplied from a container with an opening for releasing ink by a valve in the opening. The valve is biased closed by a spring when the container when not mounted on the reservoir.  
           [0008]    In particular, the Niedermeyer container is a bottle with a neck enclosing the spring and a portion of the valve. Both the cap and bottle have mutually engageable threads, and the actuating surface of the valve is exposed through the opening of the container to receive a stationary actuator mounted within the reservoir. In addition, the cap has exterior threads so that it can be screwed into the reservoir.  
           [0009]    If there is misalignment between the stationary actuator of the reservoir and the actuating surface of the valve there can be interference with the ink supply. In addition, there can be ink leakage during the removal of a partially filled ink container because the valve does not close immediately during container removal by unscrewing the cap and bottle from the reservoir.  
           [0010]    Accordingly, it is an object of the invention to provide an improved impulse ink jet head coupled to a ink reservoir supplied from a container having an opening for releasing ink from the container.  
           [0011]    A related object is to improve the mechanism that controls the flow of ink from the container into the reservoir. Another related object is to improve the prevention of ink flow from the container when not mounted on the reservoir.  
           [0012]    Still another object is to avoid the need for having the container take the form of a bottle with a neck enclosing a spring and a portion of the valve mechanism, and to avoid a valve with an actuating surface exposed that is required to contact a stationary actuator within an ink reservoir.  
           [0013]    A further object of the invention is to avoid misalignment between a stationary actuator of a reservoir and a concave actuating surface of a valve, as well as avoid interference with the ink supply and ink leakage during the removal of a partially filled ink container because the valve does not close immediately during container removal.  
         SUMMARY OF THE INVENTION  
         [0014]    In accomplishing the foregoing and related objects, the invention provides an ink jet system with an ink reservoir connected to an ink jet head; a mechanism for causing ink flow from the reservoir to the ink jet head; and a mechanism for supplying ink to the reservoir independently of actuation by the reservoir.  
           [0015]    In accordance with one aspect of the invention, the ink jet system uses a flexible tube for causing ink flow by applying pressure to the tube through a pumping orbit from a static position out of squeezing contact with the tube to a position of squeezing contact with the tube.  
           [0016]    Ink is supplied to the reservoir independently of actuation by the reservoir by a duplex coupler having a first separable component insertable completely into a second component and locked in place.  
           [0017]    Alternatively, the first component can be inserted partially into the second component of the duplex coupler, or can be completely separated from the second component. The first component of the duplex coupler, when separated from the second component and attached to a replaceable bottle of ink provides a sealed unit that is easily unsealed for the dispensing of ink by simply inserting the first component, with its attached bottle of ink into the second component.  
           [0018]    When the second component is secured to the reservoir of an ink jet system, the complete insertion of the first component with its attached bottle of ink into the second component on the reservoir provides a flow path for ink into the reservoir. If the first component is only partially inserted into the second component, without actuating its flow through mechanism, but is nevertheless held securely in the second component, the first component remains sealed and there is no ink flow into the second component. Consequently, when ink is flowing into the reservoir through the duplex coupler and reaches a specified fill level, the filling procedure from the ink bottle is readily terminated by unlocking the connection between the first and second components which seals both of the components and thus provides an efficient spill-proof technique for controlling ink flow from the replaceable ink bottle into the reservoir.  
           [0019]    In the duplex coupler for the ink jet system of the invention, the first component and the second component both have a front end and a back end, a first portion and a second portion, with a front end of the first component received in the second portion of the second component.  
           [0020]    A poppet advantageously is reciprocally disposed in one component and acted upon by the other component to open a fluid passageway, and the other component can contain either a contactable poppet or a fixed post that is engaged by the poppet of the first component. When the second component contains a second poppet, which is reciprocally disposed in the second component, a tip end of the first poppet and a tip end of the second poppet can be engaged against each other, forcing each other to open a fluid passageway between the components.  
           [0021]    A first spring can be compressively received between a poppet and a back end of one component, and second spring can be compressedly received between a poppet and a back end of the other component, so that the springs bias the poppets forwardly when their tip ends are disengaged from each other, as when the first component is disconnected from the second component.  
           [0022]    In an ink jet system of the invention, a first coupling member can be-inserted into a second coupling member and locked in place, with at least one of the coupling members containing a poppet that closes when biased forwardly to seal the fluid passageway through the coupling member containing the poppet.  
           [0023]    In a method of the invention for operating an ink jet system, the steps include (a) inserting one component of a two-component coupler in an ink reservoir; and (b) inserting the other component of the two-component coupler into a replaceable ink bottle.  
           [0024]    In the method the first component can be partially inserted into the second component, or can be lockingly inserted into the second component.  
           [0025]    When the first component is inserted into the second component, a push button of one component can be pressed to release the other component and seal a fluid passageway through the component that contains the push button.  
           [0026]    The invention also provides a replaceable ink jet apparatus for an ink jet system formed by a container for ink-jet ink and having an outlet, and a cap for sealing the outlet of the container until ink in a reservoir of an ink-jet system is to be replenished.  
           [0027]    The cap has a base positionable upon the container and a hollow neck extending from from the base, having an exterior surface containing a circumferential grove for receiving a locking collar when ink in a reservoir of an ink-jet system is to be replenished and a taper beyond said circumferential groove for facilitating the entry of the locking collar into the groove.  
           [0028]    In accordance with one aspect of the replaceable ink jet apparatus, the container has ink-jet ink, the base is threaded upon the container and the cap seals the outlet until a reservoir of an ink-jet system is to be replenished.  
           [0029]    In accordance with another aspect of the replaceable ink apparatus, the neck contains a flow channel with a reciprocable poppet therein and is biased closed to prevent the flow of ink from the container until needed to replenish ink in a reservoir of an ink-jet system. The poppet has a circumferential grommet for forming a circumferential seal. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]    [0030]FIG. 1 is an outline view of an ink jet system with an ink supply container connected to a reservoir by a duplex coupler in accordance with the invention;  
         [0031]    [0031]FIG. 2A is a sectional view of the reservoir of FIG. 1 taken along the lines  2 A- 2 A;  
         [0032]    [0032]FIG. 2B is a sectional view of the reservoir connected component of the duplex coupler taken along the lines  2 B- 2 B of FIG. 1;  
         [0033]    [0033]FIG. 2C is a sectional view of the container connected component of the duplex coupler taken along the lines  2 C- 2 C of FIG. 1;  
         [0034]    [0034]FIG. 3 is a sectional view of the entire duplex coupler of FIG. 1 showing the flow path from the ink supply container to the reservoir;  
         [0035]    [0035]FIG. 4A is a sectional view of an alternative reservoir of FIG. 1 taken along the lines  2 A- 2 A;  
         [0036]    [0036]FIG. 4B is a sectional view of the reservoir connected component of the alternative duplex coupler taken along the lines  2 B- 2 B of FIG. 1;  
         [0037]    [0037]FIG. 4C is a sectional view of the container connected component of the alternative duplex coupler taken along the lines  2 C- 2 C of FIG. 1;  
         [0038]    [0038]FIG. 5 is a sectional view of the entire duplex coupler of FIGS. 4B and 4C showing the flow path from the ink supply container to the reservoir. 
     
    
     DETAILED DESCRIPTION  
       [0039]    With reference to the drawings, the inking system  10  of FIG. 1 includes a reservoir  11  for a replaceable ink container  17  that is connected to the reservoir  11  by a duplex coupler  20 . This allows replacement of the ink container  17  when the reservoir  11  is to be replenished, and the container is empty.  
         [0040]    The duplex coupler  20  is formed by a first component  21  that is shown inserted into a second component  22 . The first component  21 , which is attached to the ink supply container  17 , can be separated from the second component  22 , which is threaded into a collar  11 - c  of the reservoir  11 . When the separation of the components  21  and  22  takes place, as explained below, both components  21  and  22  are sealed, so that ink cannot leak from the container  17  or the reservoir  11 .  
         [0041]    A connector, such as a flexible tube  12 , extends from the reservoir  11  to one or more ink jet heads, for example, by a manifold  14  that is fed from the reservoir  11  by a pump  13 . The pump  13  includes a roller  13 - r  that is acted upon by a flexible arch  13 - a  to squeeze the tube  12  and force ink to the manifold  14 .  
         [0042]    The manifold  14 , in turn, feeds a plurality of ink jet heads  16  through flexible tubes  15 . Each of the heads  16  is formed by a plurality of ink jet units in accordance with U.S. Pat. No. 4,459,601 in which a transducer acts through a coupling on an ink jet chamber having an orifice for the ejection of droplets under electronic control. An input opening is supplied by the tubes  15  from the manifold  14 . The heads  16  are positioned above the uppermost level of the ink supply reservoir  11  to avoid weeping from their input orifices.  
         [0043]    The reservoir  11  is filled from the container  17  through the duplex coupler  20  whose components are in cross-section in FIGS. 2B and 2C. After the second coupling component  22  of FIG. 2C has been threaded into the adapter  88  of the reservoir  11  in FIGS. 1 and 2A, the first coupling component  21  of FIG. 2B is insertable partially into the second component  22  for positioning, with both components sealed. Or the first component  21  is inserted fully into the second component  22 , and locked in place, with both components unsealed to permit ink flow from the container  17  to the reservoir  11  as shown in FIG. 3.  
         [0044]    The second coupling component  22  has a front end  150  and a back end  152 , as well as a first portion  156  and a second portion  158 . A front end  160  of the first coupling component  21  is receivable in the first portion  156  of the second coupling component  22  to form the connection shown in FIG. 3.  
         [0045]    Further, as shown in FIG. 2C, a poppet  162 , which is reciprocally disposed in the second housing portion  158  of the second coupling component  22 , is aligned in FIG. 3 with a poppet  164  that is reciprocally disposed in a housing portion  148  of the first coupling member  21 . After the component  21  has been moved into the component  22  in the direction of the arrow A, tip end  168  of the second poppet  162  and a tip end  170  of the first poppet  164  are engageable against each other, forcing each other to open a fluid passageway F as shown in FIG. 3 between the coupling components  21  and  22 .  
         [0046]    A spring  172  of FIG. 2C is compressively receivable between the poppet  162  and the back end  152  of the second coupling component  22 . Similarly, a second spring  174  is compressedly receivable between the second poppet  164  and a back end  175  of the first coupling component  21 . Therefore, spring members  172  and  174  bias the poppets  162  and  164  forwardly as indicated in FIGS. 2B and 2C when the tip ends  168  and  170  are disengaged from each other. This is the case when the first coupling component  21  is disconnected from the second coupling component  22 .  
         [0047]    Upon being biased forwardly, the poppets  162  and  164  seal and close the fluid passageway F through the coupling components  22  and  21 , respectively. The disengagement to forwardly bias the poppets is accomplished by pressing the push button  180  which releases the components  21  and  22  from each other and allows the poppets  162  and  164  to seal their respective seats  101  and  102  by elastomeric rings  100 .  
         [0048]    The button  180  is connected to a reciprocable collar  181  in component  22  that is moved laterally across the bore of the component  22  when the component  21  is inserted and acted upon by its circumferential cam  161  to move the collar of the second component until the second component has been sufficiently inserted to allow the collar to move back and enter the circumferential groove  162  on the inserted first component  21 .  
         [0049]    If the first component  21  is inserted to the point where the cam  161  has not contacted the collar  181 , an elastomeric ring  103  holds the first component  21  in the bore of the second component  22 , with both components sealed. Thereafter the components  21  and  22  are easily pushed together to permit fluid flow. Similarly, when fluid flow is to be terminated, depression of the button  180  against its spring  181  quickly releases the components  21  and  22  from each other by the expansion of the spring  172  in the second component  22 . This achieves a quick seal of the components when the flow of fluid to the reservoir  11  is to be terminated.  
         [0050]    It will be appreciated that the tips on the poppets can be eliminated, as indicated in FIGS. 4B and 4C, by having one of the component replace its poppet by an axial post that is fixed within the component and extends to the level of engagement with a poppet in the other component. The axial post is surrounded by a spring loaded sleeve with sealing rings so that when the components are engaged, the post acts against an opposing poppet, and an extension of the housing surrounding the poppet depresses the sleeve in the other component to provide an equivalent though passage for the flow of ink.  
         [0051]    As shown in the coupling component  22 ′ of FIG. 4C the poppet of FIG. 2C has been converted into a spring loaded sleeve  169 ′ surrounding a fixed post  168 ′, which may be flush with the sleeve  169 ′, or extend slightly beyond it as shown in FIG. 4C.  
         [0052]    To engage the sleeve  169 ′, the first coupling component  21 ′ has an engagement ring  165 ′ mounted on either the flush end of the poppet  164 ′ or the end of the housing.  
         [0053]    A further modification in the system of FIGS. 4A through 4C is the elimination in the reservoir  11 ′ of the actuator  62  from the reservoir  11  of FIG. 2A. The result of bringing the components  21 ′ and  22 ′ into a coupling connection between the container  17 ′ and the reservoir  11 ′, and the movement of the sealing rings  100 ′ and  104 , are shown in FIG. 5.  
         [0054]    To accomplish pumping from either the reservoir  11  or  11 ′, once filled though the duplex coupler  20  or  20 ′, the flexible tube  12  is contacted with the roller  13 - r . When the pumping is actuated, the squeezing surface on the roller  13 - r  moves through an orbit to force ink through the flexible tube  12  during a pumping stroke. When the pressure of the roller  13 - r  is removed, the sucking of ink back through the tube  12  and the ink jet print head  14  is prevented. Initially, the roller  13 - r  is in a static position spaced from the tube  12 . Thereafter, the roller is moved against the tube  12  and pressure is applied to commence a pumping stroke. At the conclusion of the pumping stroke, pressure is released and the roller is automatically lifted from the tube  12  to permit return to the decompressed position, and the roller  31  automatically moves back to its static position.  
         [0055]    The ink reservoir  11  or  11 ′ permits a relatively large supply of ink to be used while facilitating efficient, ecologically sound and easy priming. The reservoir  11  or  11 ′ includes an ink supply base  52  with a cover  53  having a container support portion  54  and a level detect portion  56 . The container support portion  54  includes an opening  58  in the cover  53  which extends upwardly and is adapted to receive the component  22  or  22 ′ of the duplex coupler  20  or  20 ′. After the component  22  or  22 ′ is inserted into the reservoir  11  or  11 ′, the first component  21  or  21 ′ is inserted into the second component  22  or  22 ′.  
         [0056]    It will be appreciated that the container  17  may come with the first component  21  or  21 ′ in place, or the container may have a temporary shipping cap which is removed and replaced with the component  21  or  21 ′.  
         [0057]    A neck  63  of the container  11  or  11 ′ extends upwardly from the cover  53  and includes threads  64  for receiving the ink supply adapter  88 .  
         [0058]    The level detector  56  in the cover  53  includes a level detect mechanism  66  with a float  68  that is free to move along a shaft  70  to the position shown in phantom, and a magnet located in an internal opening of the float  68  actuates a proximity switch to signal through wires  76  the level  73  of the ink within the reservoir  11 . A washer  78  holds the float  68  on the shaft  79 .  
         [0059]    A port  80  in the base  52  allows connection to the tube  12  as shown in FIG. 1. A vent opening  92  is also provided in the top of the cover  53 , and a filter  93  is in the base  52  adjacent the fitting  80 .  
         [0060]    The replaceable ink supply , when mounted on the cover  53  includes the duplex coupler  20  or  20 ′ by which easy interruption can be made of gravity feed of ink into the base  52  by simply depressing the button  80  or  80 ′ of the component  22  or  22 ′. As shown in FIGS. 2A and 4A, the duplex coupler  20  or  20 ′is engaged by the threaded cap  88 . When the flow of ink to the reservoir is to be terminated, as signaled over the wires  76 , the button  80  or  80  on the second coupling component  22  or  22 ′is depressed. This immediately seals both the first and second components.  
         [0061]    It is to be noted that the base  52  also includes a member  62  that is used for ink supplies which require actuation of a valve enclosure inserted into the neck of the container  17  with an enclosed plunger.  
         [0062]    The invention avoids the need for employment of the member  62  and provides an instant non-leaking seal of the components  21  and  22  when the flow of ink into the reservoir  11  is to be terminated.  
         [0063]    In this manner, flow of ink from the container  17  is precisely controlled after mounting of the first coupling component  21  on the second component  22  without locking engagement. Once the first component is pushed into the second component to be locked in place ink is permitted to flow to the base  52  of the reservoir  11  without without any leakage from the container  17 . It also will be appreciated that the container  17  may be readily refilled after removal from the base  52  by simply unscrewing the first coupling component  21 , thereby providing an ecologically suitable supply replenishment.  
         [0064]    The manifold  14  is optional and a single head  16  may be used with the peristaltic pumping apparatus  12 .  
         [0065]    It will also be appreciated that the manifold  14  may be used with a plurality of peristaltic pumping apparatus  14 , one for each tube  20 .  
         [0066]    Although a particular embodiment of the invention has been shown and described, it will be appreciated that other modifications and embodiments will occur to those of ordinary skill in the art which will fall within the true spirit and scope of the appended claims.