Abstract:
A printhead cartridge for releasable mounting in a printer. The printhead cartridge includes a pagewidth printhead and an ink manifold defining multiple fluid flow paths in fluid communication with respective ink channels in the printhead. The ink manifold includes a plurality of openings for detachable connection with conduits in an interface of the printer; a plurality of shut off valves at each of the openings respectively, each shut off valve having a biasing member configured for biasing each shut off valve into an open position; an actuator biased towards a closed position by a resilient element such that the actuator holds all the shut off valves closed when in the closed position. The actuator is configured for engagement with the interface such that movement of the openings into connection with the interface simultaneously moves the actuator to an open position wherein the shut off valves are held open.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a Continuation of U.S. application Ser. No. 12/339,039 filed on Dec. 19, 2008, the entire contents of which are herein incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to fluidic couplings and in particular, ink couplings within inkjet printers. 
       CROSS REFERENCES 
       [0003]    The following patents or patent applications filed by the applicant or assignee of the present invention are hereby incorporated by cross-reference. 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                   
               
             
             
               
                 7,744,195 
                 7,654,640 
                 7,862,162 
                 7,758,149 
                 7,645,034 
               
               
                 7,637,602 
                 7,645,033 
                 7,661,803 
                 7,841,708 
                 7,771,029 
               
               
                 11/677,050 
                 7,658,482 
                 7,914,132 
                 11/872,718 
                 12/046,449 
               
               
                 61/033,357 
                 12/062,514 
                 7,931,360 
                 12/062,518 
                 7,819,515 
               
               
                 7,891,794 
                 12/062,522 
                 7,891,788 
                 12/062,524 
                 7,878,635 
               
               
                 12/062,526 
                 7,874,662 
                 7,984,981 
                 7,878,639 
                 7,891,795 
               
               
                 7,878,640 
                 8,007,068 
                 7,883,189 
                 12/192,118 
                 7,931,359 
               
               
                 7,887,148 
                 7,887,170 
               
               
                   
               
             
          
         
       
     
       BACKGROUND OF THE INVENTION 
       [0004]    The Applicant has developed a wide range of printers that employ pagewidth printheads instead of traditional scanning printheads. Pagewidth designs increase print speeds as the printhead does not traverse back and forth across the page to deposit a line of an image. The pagewidth printhead simply deposits the ink on the media as it moves past at high speeds. Such printheads have made it possible to perform full colour 1600 dpi printing at speeds in the vicinity of 60 pages per minute, speeds previously unattainable with conventional inkjet printers. 
         [0005]    The high print speeds require a large ink supply flow rate. Not only are the flow rates higher but distributing the ink along the entire length of a pagewidth printhead is more complex than feeding ink to a relatively small reciprocating printhead. 
         [0006]    Some of the Applicant&#39;s printers provide the printhead as a user removable cartridge. This recognizes that individual ink ejection nozzles may fail over time and eventually there are enough dead nozzles to cause artifacts in the printed image. Allowing the user to replace the printhead maintains the print quality without requiring the entire printer to be replaced. It also permits the user to substitute a different printhead for different print jobs. A draft quality printhead can be installed for some low resolution documents printed at high speed, and subsequently removed and replaced with the original high resolution printhead. 
         [0007]    A number of the Applicant&#39;s printhead cartridges do not have an inbuilt ink supply for the printhead. These printhead cartridges need to be fluidically coupled to the ink supply upon installation. The supply flowrate to the pagewidth printhead is too high for needle valves because of the narrow internal diameter. This requires the coupling conduits to be relatively large and therefore residual ink leaks freely out of the conduits once decoupled from the supply. This is typically not an issue for needle valve couplings because the surface tension at the open end of a small conduit will usually prevent leakage. 
         [0008]    In pagewidth printhead cartridges, the leakage problem is exacerbated by the length of the ink flow paths. If the cartridge is held vertically during removal (or even held with one end slightly raised), the residual ink in the cartridge generates hydrostatic pressure at the lower end. This pressure is a strong driver for leakage and as discussed above, the large conduits provide little resistance. 
         [0009]    Shut off valves that close upon disengagement of a fluid coupling are known and used in many devices. Unfortunately, these are unsuitable for the specific requirements of a consumable component such as an ink jet cartridge. Firstly, the ink should not contact any metal components. Reaction between the ink and metal can create artifacts in the print. Secondly, coupling the cartridge to the printer involves relatively high tolerances so that installation is fast and simple. The operation of an ink valve has much smaller tolerances to keep ink flow characteristics within specification. Coupling the printer and the cartridge in a way that also actuates the valve should not require the coupling tolerance to be reduced to that of the valve. Finally, the unit cost of consumables needs to be as low as possible. This requires design simplicity and low production costs. 
       SUMMARY OF THE INVENTION 
       [0010]    Accordingly, the present invention provides an ink manifold defining multiple fluid flow paths, the ink manifold comprising: 
         [0011]    a plurality of openings arranged for detachable connection with conduits in an interface; 
         [0012]    a plurality of shut off valves at each of the openings respectively, the shut off valves being biased open; 
         [0013]    an actuator biased to a closed position by a resilient element, such that the actuator holds all the shut off valves closed when in the closed position, the actuator being configured for engagement with the interface such that moving the interface into connection with the openings simultaneously moves the actuator to an open position where the shut off valves are able to open; wherein, 
         [0014]    the resilient element generates a bias greater than a combined bias exerted by the shut off valves on the actuator. 
         [0015]    Normally, shut off valves are biased closed such that they only open by engagement with a connecting conduit. In the present invention, the individual shut off valves are biased open and only close when subjected to the dominant bias of the common actuator. This allows the common actuator to ‘absorb’ the large tolerances associated with connecting the cartridge into the printer, while the individual shut off valves can operate at much smaller tolerances using their own biasing means. 
         [0016]    Preferably, the fluid flow paths are partially defined by a polymer channel molding having an arrangement of channels and a flexible polymer film sealed over the channels to seal the fluid flow paths from each other, the shut off valves being sealed within the polymer channel molding by the flexible polymer film and the actuator configured to act on an external surface of the flexible polymer film at areas adjacent the shut off valves. Heat sealing a polymer film to a plastic molding is an exceptionally cheap and effective means of providing the sealed flow paths within a fluid manifold. The flexible film allows the actuator to push on the individual shut off valves while remaining sealed from the ink. Accordingly, the actuator can be metal for strength, without the potential problems associated with direct ink contact discussed above. Preferably, the flexible sealing film is polypropylene film foil. 
         [0017]    Preferably, the shut off valves are each resilient caps fitted to the respective peripheries of each of the openings by an integrally molded collapsible section such that the resilient cap is spaced from the opening until pressure from the actuator collapses the collapsible section and the cap seals against the opening periphery. Preferably, the shut off valves are formed from FKM synthetic rubber. 
         [0018]    Preferably, the flexible polymer film has plastically deformed areas adjacent each of the shut off valves, the plastically deformed areas extending out of the plane of the polymer sealing film and configured to invert to accommodate movement of the shut off valves. Forming deformations in the film lets the shut off valves fully open without being restrained by the tension in the film. 
         [0019]    Preferably, the channel molding defines a plurality of valve chambers for holding each of the shut off valves respectively, the valve chambers each connecting to one of the channels respectively, such that the channel connects to the valve chamber at a topmost section when the manifold is in use. By designing the channels to connect to their valve chambers at their most elevated points, air bubbles are not trapped in the valve chambers as the manifold primes with ink. 
         [0020]    Preferably, the manifold is part of a printhead cartridge and the interface is in fluid communication with an ink supply. In a further preferred form, the printhead cartridge has two of the ink manifolds, one being an inlet manifold and the other being an outlet manifold, the outlet being configured for detachable connection to a second interface in fluid communication with an ink sump. Preferably, the printhead cartridge has a pagewidth printhead. 
         [0021]    According to another aspect, the present invention provides a fluid coupling comprising: 
         [0022]    a first conduit; 
         [0023]    a second conduit having a seal seat and a compression member, the compression member being movable relative to the seal seat; 
         [0024]    an annular seal positioned in the seal seat; and, 
         [0025]    an engagement mechanism for moving the second conduit from a disengaged position where there is no sealed fluid connection between the first and second conduits, and an engaged position where the compression member moves toward the seal seat to compress the annular seal to form a sealed fluid connection. 
         [0026]    The invention uses an engagement mechanism to deform the annular seal instead of the force of one conduit being pushed into the other. The exertion needed to establish the sealed fluid coupling can be reduced or removed by incorporating mechanical advantage or power assistance into the engagement mechanism. Also there is no force acting on the first conduit so it is not subjected to structural stresses. 
         [0027]    Preferably, the engagement mechanism moves the second conduit such that it telescopically engages the first conduit and the second conduit prior to compressing the annular seal. Preferably, the engagement mechanism is manually actuated and compresses the seal with the assistance of a lever system. Preferably, the first conduit is part of a cartridge and the second conduit is part of a device that uses the cartridge during operation, the lever system latches to the cartridge when it has moved the second conduit to the engaged position. Optionally, the first conduit slides within the second conduit during telescopic engagement. Preferably, the annular seal is a ring of resilient material. In a particularly preferred form, the ring of resilient material has a radial cross sectional shape with at least one straight side when uncompressed, and said at least one straight side bulging to a curved shape when compressed. 
         [0028]    In some embodiments, the lever system completely disengages the second conduit from the first conduit when it moves the second conduit to the disengaged position. Preferably, the cartridge has a plurality of first conduits and the device has a corresponding plurality of second conduits, and the lever system actuates to simultaneously engage and disengage the plurality of first and second conduits. In a further preferred form, the coupling has a corresponding plurality of the annular seals for each of the second conduits respectively, wherein the compression member is arranged to compress all the annular seals respectively, the second conduits formed in an arrangement with a geometric centroid at which the lever system connects to the compression member. In a particularly preferred form, the second conduits are arranged in a circle and the lever system connects to the centre of the circle. 
         [0029]    In some embodiments, the device is a print engine for an inkjet printer and the cartridge has an inkjet printhead. In these embodiments, it is preferable if the inkjet printhead is a pagewidth inkjet printhead such that the cartridge has an elongate configuration and the lever system has a hingedly mounted latch for releasably engaging the cartridge to secure it in the print engine when in the engaged position and allow the cartridge to be lifted from the print engine when in the disengaged position. Preferably, half of the plurality of first conduits extend from an inlet manifold at one end of the elongate cartridge, and half of the plurality of first conduits extend from an outlet manifold at the other end of the elongate cartridge. 
         [0030]    In particular embodiments, the first conduits extend transversely to the longitudinal extent of the elongate cartridge such that the plurality of second conduits move transverse to the longitudinal extent of the elongate cartridge when moving between the engaged and disengaged positions. 
         [0031]    Preferably, the second conduit has a shut off valve that opens when the first and second conduits are in the engaged position and closes when they are in the disengaged position. 
         [0032]    In some preferred embodiments, the lever system has an input arm hinged to the compression member, the input arm having a compression lever fixed at an angle to the longitudinal extent of the input arm, the input arm arranged to push against the compression member as it rotates about the hinge connection to the compression member, the compression member in turn pushes against the second conduit to move it relative to the first conduit, until the input arm reaches a predetermined angle about the hinge where the compression lever engages the second conduit such that further rotation of the input arm moves the compression member relative to the second conduit to compress the annular seal. 
         [0033]    In further preferred forms, the device has a chassis and the lever system latches the cartridge with a latch arm hinged to the chassis, the latch arm being fixed for rotation with an actuation arm hinged to the input arm, such that user actuation of the latch arm advances and retracts the second conduit and the compression member. Conveniently, the latch arm provides the longest lever arm of the lever system and so requires the least force to rotate. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0034]    Preferred embodiments of the invention will now be described by way of example only, with reference to the accompanying drawings, in which: 
           [0035]      FIG. 1  is a schematic section view of a fluid coupling with the first and second conduits disengaged; 
           [0036]      FIG. 2  is a schematic section view of a fluid coupling with the first and second conduits engaged; 
           [0037]      FIGS. 3 and 4  are diagrammatic sketches of the fluid coupling being used to connect a printhead cartridge and an inkjet printer; 
           [0038]      FIG. 5  is a section view of the fluid coupling being used to connect a printhead cartridge and a print engine; 
           [0039]      FIG. 6  is a perspective view of the print engine with the printhead cartridge; 
           [0040]      FIG. 7  is a perspective of the printhead cartridge; 
           [0041]      FIG. 8  shows the printhead cartridge of  FIG. 7  with the protective cover removed; 
           [0042]      FIG. 9  is a partially exploded prospective view of the printhead cartridge of  FIG. 7 ; 
           [0043]      FIG. 10  is a section view of the print engine and printhead cartridge through the fluid coupling; 
           [0044]      FIG. 11  is an elevation of another embodiment of the ink manifold for the printhead cartridge with the shut off valve actuator removed for clarity; 
           [0045]      FIG. 12  is Section  12 - 12  shown in  FIG. 11 ; 
           [0046]      FIG. 13  is a rear elevation of the ink manifold shown in  FIG. 11 ; 
           [0047]      FIG. 14  is a cross section of one of the shut off valves used in the ink manifold of  FIG. 11 ; 
           [0048]      FIG. 15  is a perspective of the ink manifold of  FIG. 13 ; 
           [0049]      FIG. 16  is an exploded perspective of the ink manifold of  FIG. 13 ; 
           [0050]      FIG. 17  is an elevation of the ink manifold with the shut off valve actuator; 
           [0051]      FIG. 18  is Section  18 - 18  shown in  FIG. 17 ; and, 
           [0052]      FIG. 19  is an exploded perspective of the ink manifold together with shut off valve actuator. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0053]    The invention will be described with specific reference to a fluid coupling between an inkjet print engine and its corresponding printhead cartridge. However, the ordinary worker will appreciate that the invention is equally applicable to other arrangements requiring a detachable fluid connection. 
         [0054]    In  FIG. 1 , the fluid coupling  10  is shown with the first conduit  12  disengaged from the second conduit  14 . The first conduit  12  leads to the pagewidth printhead of the removable printhead cartridge (described below). The second conduit  14  is connected to the ink supply (not shown) and sized such that it can telescopically engage the first conduit  12  with a sliding fit. The ink is retained by the shut off valve  30  biased against valve seat  34  by the resilient struts  32 . The second conduit  14  defines a seal seat  35  for the annular seal  16 . The annular seal  16  is retained in the seal seat  35  by the compression member  18 . In the disengaged position shown in  FIG. 1 , the annular seal  16  is not compressed by the compression member  18  such that the inner surface  36  of the seal remains flat. When flat, the inner surface  36  does not to interfere with the sliding fit between the first and second conduits ( 12  and  14 ). 
         [0055]    An input arm  20  is hinged to compression member  18 . A compression lever  22  is fixed at an angle to the input arm  20 . The input arm  20  and the compression lever  22  are part of a lever system described in greater detail below with reference to  FIGS. 3 and 4 . The lever system is an engagement mechanism that the user actuates to advance the second conduit  14  and compression member  18  onto the first conduit  12 . As the input arm  20  rotates, it pushes on the hinge  24  which in turn moves the compression member  18  together with the second conduit  14 . 
         [0056]    As best shown in  FIG. 2 , the compression member  18  and the second conduit  14  advances until the input arm  20  is parallel to the direction of travel. Continued rotation of the input arm  20  brings the compression lever  22  into contact with the rear  26  of the second conduit  14 . The compression lever  22  is carefully dimensioned to keep the second conduit  14  stationary relative to the first conduit  12  as the input arm  20  retracts the compression member  18  by pulling on the hinge  24 . The compression member  18  compresses the annular seal  16  to force the flat inner surface  36  to bulge and form a fluid tight seal against the outside of the first conduit  12 . 
         [0057]      FIG. 2  also shows the first conduit  12  engaging the shut off valve  30  to open fluid communication between the ink supply and the printhead. The resilient struts  32  buckle with little resistance upon engagement with the end of the first conduit  12 . Apertures  28  allow ink to flow around the valve member  30  and into the first conduit  12 . 
         [0058]    When the fluid coupling disengages, the input arm  20  is rotated in the opposite direction to simultaneously decompress the annular seal  16  and retract the second conduit  14  from the first conduit  12 . This coupling is configured establish a sealed fluid connection with the first conduit subjected to little or no insertion force. In light of this the structure that the supports the first conduit is not overly flexed or bowed. This protects any components that are not robust enough to withstand structural deformation. 
         [0059]    In  FIGS. 3 and 4 , the fluid coupling  10  is used to provide a detachable connection between the cartridge  38  and the printer  42 . Referring to  FIG. 3 , the cartridge  38  is seated in the printer  42  such that the first conduits  12  face the compression member  18  (which covers the second conduits). The latch  40  is lifted to allow the cartridge to be installed. An actuator arm  56  is fixed relative to the latch  40  and rotates therewith about the hinge  50 . The distal end of the actuator arm  56  is hinged to the input arm  20 . When the latch is raised for cartridge installation or removal, the input arm  20  is likewise raised, which retracts the compression member  18  away from the first conduit  12 . With the input arm in the raised and retracted position, the compression lever  22  is disengaged from the back of the second conduit (see  14  and  26  of  FIG. 2 ). As discussed above, the annular seal is not compressed in the disengaged position so as not to interfere with the sliding fit with the first conduit. 
         [0060]    Referring to  FIG. 4 , the fluid coupling  10  is engaged by simply lowering the latch  40  onto the cartridge  38  until the complementary snap-lock formations  46  and  48  engage. Actuator arm  56  rotates the input arm  20  and advances the compression member  18  towards the first conduit  12 . The first conduit  12  telescopically engages the second conduit with a loose sliding fit until the actuator arm  56  and the input arm  20  are parallel to the direction of travel. When the second conduit is at its maximum engagement with the first conduit, the shut off valve is opened and the cartridge  38  is in fluid communication with ink tank  44  via the flexible tubing  52 . 
         [0061]    When the compression member is at its point of maximum travel towards the cartridge, the compression lever  22  engages the second conduit (not shown). The compression lever  22  is dimensioned to hold the second conduit stationary relative to the first conduit as the input arm  20  continues to rotate and draw the compression member  18  back to compress the seal and establish the fluid seal (see  FIG. 2 ). 
         [0062]      FIG. 5  shows a printhead cartridge  38  installed in a print engine  3 . The print engine  3  is the mechanical heart of a printer which can have many different external casing shapes, ink tank locations and capacities, as well as different media feed and collection trays. The printhead cartridge  38  is inserted and removed by the user lifting and lowering the latch  40 . The print engine  3  forms an electrical connection with contacts on the printhead cartridge  38  and fluid couplings  10  are formed at the inlet and outlet manifolds,  148  and  150  respectively. 
         [0063]      FIG. 6  shows the print engine  3  with the printhead cartridge removed to reveal the apertures  120  in each of the compression members  18 . Each aperture  120  receives one of the spouts  12  on the inlet and outlet manifolds (see  FIG. 9 ). The spouts correspond to the first conduits  12  of the schematic representations of  FIGS. 1-4 . As discussed above, the ink tanks, media feed and collection trays have an arbitrary position and configuration depending on the design of the printer&#39;s outer casing. 
         [0064]      FIG. 7  is a perspective of the complete printhead cartridge  38 . The printhead cartridge  38  has a top molding  144  and a removable protective cover  142 . The top molding  144  has a central web for structural stiffness and to provide grip textured surfaces  158  for manipulating the cartridge during insertion and removal. The base portion of the protective cover  142  protects the printhead ICs (not shown) and line of contacts (not shown) prior to installation in the printer. Caps  156  are integrally formed with the base portion to cover the inlet and outlet spouts (see  12  of  FIG. 9 ). 
         [0065]      FIG. 8  shows the cartridge  38  with its protective cover  142  removed to expose the printhead ICs (see  FIG. 10 ) on the bottom surface and the line of contacts  133  on the side surface. The protective cover is discarded to the recycling waste or fitted to the printhead cartridge being replaced to contain leakage from residual ink.  FIG. 9  is a partially exploded perspective of the cartridge  38  without the protective cover. The top cover  144  has been removed reveal the inlet manifold  148  and the outlet manifold  150 . The inlet and outlet shrouds  146  and  147  have been removed to expose the five inlet and outlet spouts  12 . The inlet and outlet manifolds  148  and  150  feed ink to their respective connectors  60  which lead to the molded liquid crystal polymer (LCP) channels  4  that supply the printhead ICs  31  (see  FIG. 10 ). A detailed description of the fluid flows through the cartridge  38 , and the printhead assembly within it, is provided by co-pending U.S. Ser. No. 12/014,768 (Our Docket RRE013US) filed Jan. 16, 2008, the disclosure of which is incorporated herein by cross reference. 
         [0066]      FIG. 10  is a section view through a fluid coupling  10  of the print engine  3  with the cartridge  38  installed. The components corresponding to the elements of the schematic representations of  FIGS. 1-4  have been identified using the same reference numerals. For context, the paper path  5  is shown extending through the print engine  3  and past the printhead ICs  31 . 
         [0067]    The coupling is shown forming a sealed fluid connection between one of the spouts  12  and the one of the second conduits  14 . It will be appreciated that the coupling at the inlet and outlet manifolds are identical with the exception that the ink flows from the second conduit  14  to the spout  12  at the inlet manifold and in the opposing direction at the outlet manifold. For the purposes of this description, the coupling will be described at the inlet manifold. Accordingly, flexible tubing  52  feeds ink from an ink tank (not shown) to the second conduit  14 . The shut off valve  30  in the second conduit  14  is being held open by the end of the spout  12 . The ink flows into the spout  12  and down to the LCP channel molding  4  where it is distributed to the printhead ICs  31 . 
         [0068]    The coupling  10  is actuated by the actuator arm  56  hinged to the print engine chassis  42  at shaft  50 . As discussed above the latch  40  (not shown in  FIG. 10 ) also extends from the shaft  50  for fixed rotation with the actuator arm  56 . The actuator arm  56  rotates the input arm  20  to push the compression member  18 , and in turn the second conduit  14  into telescopic engagement with the spout  12 . Upon further rotation, the compression lever  22  engages the rear  26  of the second conduit  14 . The input arm  20  draws back on the hinge connection  24  which in turn pulls on the central rod  58  extending to the middle of the compression member  18 . The resilient seal  16  is compressed and bulges to form a fluid tight seal against the outer surface of the spout  12 . It will be appreciated that the compression member  18  compresses all the annular seals  16  for each of the input spouts  12  simultaneously. Using a central rod  58  attached to the middle of the compression member  18  ensures that the compressive force on each annular seal is uniform. Furthermore, as the latch  40  is the longest lever of the lever system, the force that the user needs to apply is conveniently weak. 
         [0069]    When the printhead cartridge  38  is to be replaced, the latch (not shown) is lifted off the cartridge to automatically rotate the actuator arm  56  upwards, thereby lifting and retracting the input arm  20 . The annular seal  16  is released when the compression lever  22  swings out of engagement with the surface  26 . The second conduits and the corresponding spouts  12  now have a loose sliding fit and slide easily away from each other. With the compression member  18  and the spouts  12  completely disengaged, the user simply lifts the cartridge  38  out of the print engine  3 . 
         [0000]    Ink Manifolds with Shut Off Valves 
         [0070]      FIGS. 11 to 19  show another embodiment of the ink manifolds  148  and  150  on the printhead cartridge. As discussed above, the inlet and outlet manifolds are mirror images of each other and so only the inlet manifold  148  be described. However, the description is equally applicable to the outlet manifold  150  with the exception that the ink flow direction is opposite and the outlet manifold  150  couples to the sump instead of the ink supply. 
         [0071]    As discussed in the Background of the Invention, the internal diameter of the spouts  12  is relatively wide (approximately 2 mm) to provide the flow rate necessary for the high ink consumption of a pagewidth printhead. However, this causes high levels of ink leakage when the printhead cartridge is removed from the printer, particularly when one end is raised and hydrostatic pressure drives the ink flow from the lower end. To avoid this, the ink manifold shown in  FIGS. 11 to 19  has shut off valves for each of the spouts  12 . 
         [0072]    Referring to  FIGS. 11 and 12 , the spouts  12  extend from the front of the polymer channel molding  152 . The spouts  12  and the connectors  60  are positioned in the same locations as the inlet and outlet manifolds  148  and  150  described in the previous embodiment. However, the spouts  12  each lead to an opening  162  and a shut off valve  160 . The shut off valve  160  is a dish-shaped rubber molding best shown in the partial enlarged section view of  FIG. 14 . A central sealing cap  164  is shaped to seal the periphery of the opening  162 . An integrally molded collapsible section  166  mounts to the channel molding  152  and supports the sealing cap  164  over the opening  162 . The shut off valve is an FKM synthetic rubber molding with a set of compression characteristics that ensure it will consistently return to its original shape after compression. 
         [0073]    In  FIG. 12 , the shut off valve is shown in its uncompressed state whereby the sealing cap is spaced from the opening  162  and the valve is open. Hence the shut off valve  160  is biased to the open position.  FIG. 14  shows the shut off valve  160  in its compressed state. The valve actuator that applies the compressive force to the shut off valve  160  has been omitted in the interests of clarity. Pressure from the actuator on the sealing cap  164  elastically deforms the thin collapsible section  166  that forms an annular skirt around the cap. The sealing cap  164  form a fluid seal at the opening  162  to close the valve. The sealing cap  164  is held in the closed position by the actuator, against the bias of collapsible section  166 . 
         [0074]    The rear of the channel molding  152  is sealed by a polypropylene film foil  168 . This is a highly cost effective and simple method of providing a reliable fluid seal around the channels  176  and the valve chambers  178  formed by the channel molding  152 . To accommodate the movement of the shut off valves  160 , dome-shaped plastic deformations  172  are pressed into the sealing film  168 . The deformations  172  extend inwardly, out of the plane of the sealing film  168  when the actuator  190  (see  FIG. 17 ) is compressing the shut off valves  160 . When the actuator  190  releases the shut off valves  160 , the deformations  172  can invert outwardly such that the sealing film  168  does not impede the opening of the valve. Furthermore, the plastic deformations  172  ensure that the actuator or the shut off valves do not create excessive tension in the film  168  that can compromise the fluid seal. 
         [0075]      FIG. 16  is an exploded view of the perspective shown in  FIG. 15 . With the sealing film  168  and the shut off valves  160  removed, the features of the valve chambers  178 . The openings  162  extend into the chambers  178  for contact with the sealing cap  164 . The sealing cap  164  and the collapsible section  166  are held in position by a series of ribs  180 . The ribs  180  also create gaps between the shut off valve  160  and the side walls of the chamber  178  to provide a flow path for the ink. 
         [0076]    Each of the valve chambers  178  feeds one of the channels  176  respectively. The channels  176  lead to the connector  60  which in turn feeds the LCP channels  4  (see  FIG. 10 ). The channel  176  connects to the corresponding valve chamber  178  at its most elevated point. This avoids the top of the chamber becoming a bubble trap as the manifold primes with ink. 
         [0077]      FIGS. 17 ,  18  and  19  illustrate the structure and function of the valve actuator  190 . A polymer flange body  174  extends through a central aperture  170  in the channel molding  152  and the sealing film  168 . An abutment face  188  extends proud of the front face of the channel molding  152 . Flange  182  sits on the exterior of the sealing film  186  on the rear face of the channel molding  152 . A metal plate  196  reinforces the back of the flange  182 . The sealing film  168  is protected from any sharp burrs on the plate  196  by the flange  182 . 
         [0000]    A metal spring cage  186  fits over the abutment face  188  and seats against the front face of the channel molding  152 . The metal spring cage  186  has a pair of arms  194  that extend through the central aperture  170 , the holes  192  in the flange  182  and the metal plate  196 . The arms  194  hook over one end of a steel compression spring  184 . The other end of the spring  184  sits on the plate  196 . The spring is held in compression such that plate  196  and the flange  12  press all the shut off valves  160  to the closed position. It will be appreciated that the compressive force of the spring  184  needs to exceed the bias of the shut off valves  160 . 
         [0078]    As discussed above, the compression members are the interface between the printer and the printhead cartridge. Referring back to  FIGS. 3 and 4 , the compression member  18  advances onto the spouts  12  to form a connection with the second conduits  14  and the ink supply. As the compression member  18  advances towards the ink manifold  148 , it pushes on the abutment surface  188  to further compress the spring  184  and draw the flange  182  away from the shut off valves  160 . The tolerances for the engagement of the compression member  18  and the ink manifold  148  are much higher than the tolerances on the operation of the shut off valves  160 . However, the flange  182  completely disengages from the shut off valve  160  so any variation in the travel of the compression member  18  is isolated from the shut off valves  160 . Shut off valves are normally biased closed to provide a fluid seal as soon as the fluid coupling is disconnected. However, the ink manifold according to this invention achieves the same shut off action with valves that are biased open such that they can operate independent of the closing actuator. 
         [0079]    The above embodiments are purely illustrative and not restrictive or limiting on the scope of the invention. The skilled worker will readily recognize many variations and modifications which do not depart from the spirit and scope of the broad inventive concept.