Abstract:
An example apparatus includes a container defining an internal volume including an aperture to provide access to the internal volume; and a vent associated with the aperture, the vent in a closed position prior to coupling the apparatus to a printer, the vent entering an open position in response to an interaction with a connector of the printer.

Description:
RELATED APPLICATIONS 
       [0001]    This patent arises from a continuation of U.S. patent application Ser. No. 14/394,145, filed Oct. 13, 2014, which is a U.S. national stage of PCT Application Serial No. PCT/US2012/047188, filed Jul. 18, 2012. Priority is claimed to U.S. patent application Ser. No. 14/394,145 and PCT Application Serial No. PCT/US2012/047188. U.S. patent application Ser. No. 14/394,145 and PCT Application Serial No. PCT/US2012/047188 are hereby incorporated herein by reference in their entireties. 
     
    
     BACKGROUND 
       [0002]    Large format ink tanks are ink tanks for large format printers. Large format printers are typically operated by professional users. Large format ink tanks typically contain relatively large volumes of ink, for example more than one liter. For example, these ink tanks are transported to the professional users by transport services. Existing examples of large format ink tanks are arranged to be emptied into permanent ink tanks in the large format printer. This creates a risk that ink is spilled. Other ink tanks have internal flexible bags that carry ink. The ink tank is placed in or on the printer during usage, and connected to an ink inlet. The ink is drawn from the ink tank by a pump or other ink suction device wherein the bag flexes to compensate for a changing backpressure in the bag. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]    For the purpose of illustration, certain examples constructed in accordance with the teachings of this disclosure will now be described with reference to the accompanying drawings, in which: 
           [0004]      FIG. 1  illustrates a diagram of an example of an ink tank; 
           [0005]      FIG. 2  illustrates a diagram of an example of an ink tank interconnect device before interconnection; 
           [0006]      FIG. 3  illustrates a diagram of an example of an ink tank interconnect device in an interconnected state; 
           [0007]      FIG. 4  illustrates a perspective view of an example of an ink inlet device; 
           [0008]      FIG. 5  illustrates a perspective view of an example of an ink tank lid; 
           [0009]      FIG. 6  illustrates a cross sectional side view of the example of the ink tank lid of  FIG. 5 ; 
           [0010]      FIG. 7  illustrates a top view of an example of the ink tank lid of  FIGS. 5 and 7 ; 
           [0011]      FIG. 8  illustrates a perspective view of the examples of the ink inlet device of  FIG. 4  and the ink tank lid of  FIGS. 5, 6 and 7  in an interconnected state; and 
           [0012]      FIG. 9  illustrates a flow chart of an example of a method of creating a vent hole through a solid ink tank wall. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    In the following detailed description, reference is made to the accompanying drawings. The examples in the description and drawings should be considered illustrative and are not to be considered as limiting to the specific example or element described. Multiple examples may be derived from the following description and/or drawings through modification, combination or variation of certain elements. Furthermore, it may be understood that examples or elements that are not literally described may be derived from the description and drawings by a person of ordinary skill in the art. 
         [0014]      FIG. 1  illustrates a diagrammatic example of an ink tank  1 . For example, the ink tank  1  includes a body portion  2  and a top portion  3 . For example the body portion  2  includes at least one rigid surrounding wall  18  enclosing an inner volume  4  for holding ink. For example, the top portion  3  defines a lid for closing off the body portion  2 . In an example, the lid is separately molded from the body portion  2 , and permanently connected to the body portion  2  after filling the tank&#39;s inner volume  4  with ink. In another example, the top portion  3  and body portion  2  for a single solid ink tank. For example, the top portion  3  includes an ink outlet  5 . 
         [0015]      FIG. 2  illustrates a diagrammatic example of a top portion  3  of an ink tank  1 , before being interconnected with an ink inlet ( FIG. 3 ). The top portion  3  includes an ink tank interconnect device  6 . The ink tank interconnect device  6  includes a set of features for fluidically connecting the ink tank  1  with an ink inlet. For example, the ink tank interconnect device  6  includes said ink outlet  5 . For example, the ink outlet  5  includes an outward protruding ink outlet tube  7  with an inner outlet channel  8 . For example the outlet tube  7  is arranged to connect to the ink inlet. The inner outlet channel  8  is connected to the inner volume  4  for transporting the ink out of the ink tank  1  to the ink inlet. 
         [0016]    The ink tank interconnect device  6  includes a vent hole  9 , a vent hole barrier  10  and a top wall  11 . In the illustrated non-connected state, the vent hole  9  is open to the inner volume  4  for holding ink and sealed from the outside by the vent hole barrier  10 . In the illustrated non-connected state, the vent hole  9  is defined by a locally reduced wall portion or an indentation in the inner surface of the top wall  11 . In other not shown examples, the indentation can be provided on the outer surface of the top wall  11 . For example, the closes the vent hole barrier  10  in a substantially fluid tight fashion, for example to allow transport of the ink tank  1  in all orientations without ink leakage and with little or no gas exchange. 
         [0017]    For example, the ink tank  1  is provided with rigid walls  18 , including a rigid top wall  11 . For example, the ink tank  1  is bagless, that is, not provided with a flexible bag, contrary to conventional large volume ink tanks (not shown) that are sometimes provided with flexible bags for holding ink or air. These flexible bags can have different functions amongst which backpressure regulation, gas impermeability, transport requirement fulfillment or preventing chemical reaction with the rigid walls. The conventional flexible bags are typically arranged so as to move with respect to the outer box. 
         [0018]    In an example ink tank  1  of this disclosure, the ink is directly contained by the rigid walls  18 , not by a flexible bag. However, it is not excluded that an example ink tank  1  of this disclosure includes a foil or lining or the like that is placed against the inside of the walls for example to enhance fluid impermeability or prevent chemical reaction with the ink. For example, the material of the rigid walls  18  can be chosen to prevent chemical reaction with Ultra-Violet curable ink. For example, the inner volume  4  of the ink tank  4  holds ultraviolet curable ink. Ultraviolet curable inks well-known in the industry and are ink compounds that are design to be cured by ultraviolet radiation. For example, suitable polymer containing material such as plastic can be chosen. For example the ink tank walls include HDPE (High-Density Polyethylene). For example, the top portion  3  and/or ink tank lid includes PP (Polypropylene). For example, the ink tank  1  has an inner volume  4  large enough to contain at least approximately one, at least approximately three, at least approximately four, or at least approximately five liters of ink of a predefined color. In other examples, the inner volume  4  contains at least approximately ten liters, or at least approximately 15 liters of ink. 
         [0019]    For example, the top wall  11  includes the vent hole barrier  10 . For example, the vent hole barrier  10  is integrally molded together with the top wall  11 , the wall  11  and barrier  10  forming a solid single cast. For example, the vent hole barrier  10  is defined by a locally reduced wall portion wherein the locally reduced wall portion also defines the vent hole  9 . For example at least one notch  12 ,  13  is provided around the vent hole barrier  10 . For example the at least one notch is formed by one or more indentations or one or more cut lines. For example the at least one notch  12 ,  13  is defined by a wall portion that is more reduced than the wall portion that defines the vent hole barrier  10 . The notch  12 ,  13  is arranged to allow the vent hole barrier  10  to be cut loose with respect to the surrounding top wall  11 , thereby communicating the vent hole  9  with the environment ( FIG. 3 ). For example, the circumferential dimensions of the vent hole barrier  10  are defined by the at least one notch  12 ,  13 . For example, the at least one notch  12 ,  13  is arranged in the shape of a circle or ellipse. The at least one notch  12 ,  13  can be provided in an interrupted or continuous manner. 
         [0020]    For example, the vent hole barrier  10  is arranged to be pushed open by the ink inlet device  14  during interconnection. For example, the ink inlet device  14  is connected to a printer to transport the ink out of the ink tank  1  to the printer.  FIG. 3  illustrates an example ink inlet device  14  in interrupted lines, arranged to interconnect with the example outlet tube  7 . For example, the ink inlet device  14  is moved over the ink outlet  5  for interconnection. For example, during said interconnection the ink inlet device  14  pushes against the vent hole barrier  10 . When a sufficient pushing force is applied the vent hole  9  opens, allowing entry (or exit) of air into (or out of) the inner volume  4 , for example during dispensing of ink out of the inner volume  4 . For example, the vent hole barrier  10  is strong enough to resist unintended opening such as during transport. 
         [0021]    For example, in open condition the vent hole  9  maintains an ambient pressure in the inner volume  4 . The vent hole  9  can be opened by mere connection of the ink tank  1  with the ink inlet device of a printer, needing no additional tools or handling to create the vent hole  9 , and flexible ink holding bags can be prevented. For example, the rigid ink tank walls  18  are stiff and strong enough to withstand certain inner and outer pressures as required by international transport regulations, withstanding substantial changes of the inner volume size (although marginal deformation may occur). After interconnection with the ink inlet device  14  and during printing, the vent hole  9  allows for ambient air or basically any gas to enter the inner volume  4  preventing backpressure from building up in the inner volume  4  and preventing stresses on the walls  18 . In certain examples, it can prevent that an ink suctioning device such as a pump operates under too much load due to a high pressure differential between the inside of the ink tank  1  and the exit of the ink suctioning device. In a further example it prevents backpressure from limiting an amount of ink that can be removed from the inner volume  4 . 
         [0022]    For example, the ink inlet device  14  or the vent hole barrier  10  includes an opening structure  15  to allow the vent hole barrier  10  to be pushed open before the ink inlet device  14  abuts the top wall  11 . In the illustrated example, the opening structure is defined by a local extension  15  of the ink inlet device  14  that engages the vent hole barrier  10  and pushes the vent hole barrier  10  towards the inner volume  4  for opening the vent hole  9 . In another example that will be discussed below an opening structure  26  is attached to the vent hole barrier  10  and the ink inlet device  14  pushes against that opening structure  26  for opening the vent hole barrier  10 . 
         [0023]      FIG. 4  illustrates an example of an ink inlet device  14 . For example, the ink inlet device  14  includes an interconnect portion  16  for connecting the ink inlet device  14  to the ink tank interconnect device  6 . For example, the inlet interconnect portion  16  has a cylindrical shape for alignment with respect to a corresponding cylindrical interconnect feature  22  of the ink tank interconnect device  6  ( FIG. 5 ). For example the ink inlet device  14  includes an ink channel  17  that fluidically interconnects with the inner outlet channel  8  for receiving the ink from the ink tank  1  and delivering the ink to the printer. In an example, the ink inlet device  14  can be a separate interconnect piece for manual mounting to the printer and/or ink tank interconnect device  6  by an end user. In other examples the ink inlet device  14  is pre-assembled to the printer or pre-assembled to the ink tank interconnect device  6  by a printer or ink tank manufacturer or service provider. 
         [0024]      FIGS. 5, 6 and 7  illustrate an example of an ink tank lid  20 . In an example, the ink tank lid  20  is mounted to an ink tank body portion  2  in either a permanent or a replaceable manner ( FIG. 1 ). For example, the illustrated ink tank lid  20  is largely defined by a single cast. For example, certain parts such as seal rings, outlet seals or valves can be assembled afterwards. For example, the ink tank lid  20  includes a collar wall  21  and a top wall  11 . For example the ink tank interconnect device  6  is provided on the top wall  11 . For example, the ink tank interconnect device  6  includes an interconnect feature  22 . For example, the interconnect feature  22  is arranged to connect to the corresponding interconnect portion  16  of the ink inlet device  14 . For example, the interconnect feature  22  includes a substantially cylindrical side wall  23  and a second top wall  24 . The ink tank  1  and ink tank lid  20  are provided with mold release tolerances. 
         [0025]    For example, the outlet  5  includes an ink outlet tube  7  and an inner outlet channel  8 . For example, the ink outlet tube  7  protrudes from a second top wall  24  for connection to a corresponding inlet feature (not shown). For example, in the shown pre-connection state of the ink tank lid  20  the inner outlet channel  8  is sealed by a valve, sealing foil, thin wall or other suitable feature that needs to be pierced through or opened during interconnection of the ink outlet  5  and ink inlet device  14 , or manually removed before interconnection. For example, the vent hole  9  and vent hole barrier  10  are distanced from the ink outlet  5  and need to be opened at a distance from the ink outlet  5 . 
         [0026]    For example, the ink tank interconnect device  6  includes a color key  25 . For example, the color key  25  protrudes from the second top wall  24 . For example, for a set of ink tanks  1  of different colors, each ink tank  1  has a differently arranged color key  25 . For example, the color key  25  is arranged to prevent that the ink outlet  5  is connected to the wrong ink inlet device  14 , preventing color mix-up. Also, the color key  25  can provide for alignment of the ink inlet device  14  during interconnection. For example, the color key  25  includes one or more T-shaped beams having a length direction that is approximately parallel to the length direction of the protruding outlet tube  7 . For example, for each color the number of T-beams or the rotational orientation of the T-beams is predefined. 
         [0027]    For example, the ink tank interconnect device  6  includes an opening structure  26  and the vent hole barrier  10 . As seen from the example top view of  FIG. 7 , the opening structure  26  and vent hole barrier  10  are arranged next to the ink outlet  5 , and next to the interconnect feature  22 . For example, the opening structure  26  is connected to the vent hole barrier  10  so that the vent hole barrier  10  can be ruptured by pushing the opening structure  26 , for example at notches (not illustrated in  FIGS. 5-7  but diagrammatically illustrated in  FIG. 2  with reference numbers  12 ,  13 ). For example, the opening structure  26  includes a protruding structure that protrudes from the vent hole barrier  10 . In the illustrated example, the opening structure is defined by a N- or U-shaped protruding structure, including a bridging structure or middle portion  30  that includes an engagement surface for being engaged by the ink inlet device  14 . 
         [0028]    For example, the opening structure  26 , the top wall  11  and the vent hole barrier  10  are molded by a single mold, that is, the top wall  11 , the barrier  10  and the opening structure  26  are defined by a solid single cast of a single material such as plastics. For example, the vent hole  9  is defined by an indentation the inner or outer surface of the top wall  11 . For example, a cross sectional wall thickness at the vent hole barrier  10  is thinner than the cross sectional wall thickness of the top wall  11  around the vent hole barrier  10 , while the cross sectional thickness at the notches around the vent hole barrier  10  is less than the cross sectional wall thickness of the vent hole barrier  10 . 
         [0029]    For example, the opening structure  26  is arranged close to the interconnect feature  22  so that the ink inlet device  14  can engage the opening structure  26  during engagement of the interconnect feature  22 . For example, the substantially cylindrical side wall  23  includes an indentation  31 . For example, the opening structure  26  or the vent hole barrier  10  resides close to the cylindrical wall  23 , at least partially in or near the indentation  31  of the cylindrical side wall. For example a part of the opening structure  26  and/or vent hole barrier  10  resides within a circular circumference that defines the cylindrical wall  23 . 
         [0030]    For example, the opening structure  26  includes a first leg  28  connected to the vent hole barrier  10 . For example, the opening structure  26  includes a second leg  29  connected to the top wall  11  next to the vent hole barrier  10 . For example, the opening structure  26  includes a middle portion  30  connecting the two legs  28 ,  29 . For example, the middle portion  30  includes the engagement surface for engaging the ink inlet device  14 . For example, the opening structure  26  is defined by a U-shaped beam. For example, the legs  28 ,  29  and middle portion  30  are defined by a solid single cast, and are cast together with the top wall  11  and vent hole barrier  10 . For example, the first leg  28  and/or the middle portion  30  facilitate engagement of the ink inlet device  14 , for pushing the vent hole barrier  10 . For example, the second leg  29  and/or the middle portion  30  are arranged to facilitate bending of the opening structure  26 , during opening of the vent hole barrier  10 , so that the opening structure  26  can push the vent hole barrier  10  downwards while remaining attached to the top wall  11 . 
         [0031]    For example, the second leg  29  and the middle portion facilitate a certain resistance towards being moved downwards for opening the vent hole  9 , so that when the ink inlet device  14  is disconnected again, the vent hole barrier  10  moves towards the original position again, substantially closing the vent hole  9  again. For example after rupturing the vent hole barrier&#39;s edge, the middle portion  30  functions as a cantilever beam wherein the internal material stresses tend to force the cantilever beam back towards the original position. For example, during disconnection the opening structure  26  and vent hole barrier  10  move from the open position, as illustrated in  FIG. 5 , towards the original position, as illustrated in  FIG. 8  but wherein the top wall  11  is ruptured around the vent hole barrier  10 . For example, a thickness and material of the opening structure  26  is such that the second leg  29  and middle portion  30  resist to bending. 
         [0032]    For example, the interconnect feature  22  has an alignment function for aligning the inlet interconnect portion  16  with respect to the ink outlet  5 . For example, the interconnect feature  22  includes an alignment feature  32  that provides for a rotational alignment of the ink inlet interconnect portion  16  with respect to the interconnect feature  22 . For example, the alignment feature  32  is defined by a protrusion extending away from the cylindrical side wall  23 . For example, the interconnect feature  22  includes a latch surface  33  for engaging a corresponding latch feature of the ink inlet device  14  to retain the ink inlet device  14  with respect to the ink tank interconnect device  6 . For example, the latch surface  33  is defined by a second indentation  34  in the cylindrical outer wall  23  of the interconnect feature  22  and the latch surface  33  extends inwards into the cylindrical side wall  23  of the interconnect feature  22 . 
         [0033]      FIG. 8  illustrates an example of the ink tank lid  20  and the ink inlet device  14  in an interconnected state. In the interconnected state the ink inlet device  14  pushes a part of the opening structure  26  into the top wall  11 , rupturing the vent hole barrier  10  along the notches. The example of  FIG. 6  shows a circular cut line  10 A along which the vent hole barrier  10  is torn open. For example, the vent hole barrier  10  is ruptured over 360 degrees opening, and remains connected to the top wall  11  only through the opening structure  26 . In another example, the vent hole barrier  10  is torn along only part of a circle so that a part of the vent hole barrier  10  is still connected to the top wall  11 . For example, the ink tank interconnect device  6  is arranged such that in the interconnected state the middle portion  30  of the opening structure  26  is inclined towards the vent hole  9 , the first leg  28  extends partially in the vent hole  9 , and the vent hole barrier  10  resides in the inner volume  4 . For example, the vent hole  9  communicates directly with the ink holding inner volume  4 . 
         [0034]      FIG. 9  shows an example of a flow chart of a method of creating a vent hole  9  through an ink tank wall  11 . For example, the ink tank  1  is first transported to a location near a compatible printer, and/or stored somewhere near the printer (block  100 ). Then, the ink tank  1  is brought to the printer, for example placed in or on a predefined location of the printer. For example, the method includes connecting one of the ink inlet devices  14  of the printer to the ink outlet  5  of the ink tank  1  (block  110 ). For example, during said connection the ink inlet device  14  pushes against the vent hole barrier  10 , arranged next to the ink outlet  5  (block  120 ). In a further example, during said connection the ink inlet device  14  pushes against the opening structure  26  connected to the vent hole barrier  10 . For example, the vent hole barrier  10  ruptures by said pushing action (block  130 ), allowing air to communicate between the ink holding inner volume  4  of the ink tank  1  and the environment (block  140 ). For example, the vent hole  9  does not communicate with a further tube or channel but directly with the open environment. In a further example, the ink tank  1  and the ink inlet device  14  are disconnected (block  150 ), for example when the ink tank  1  is substantially depleted or otherwise ceases to provide ink to the ink inlet device  14 . For example, the opening structure  26  and vent hole barrier  10  then move back towards the original position again. For example the middle portion  30  and/or second leg  29  bend back so that the vent hole barrier  10  substantially closes the vent hole  9  again. 
         [0035]    For example, in a first aspect, an ink tank interconnect device  6  is provided, including an ink outlet  5  arranged to interconnect with a corresponding ink inlet device  14 , walls  11 ,  18 ,  21 ,  23 ,  24 , and a vent hole  9  next to the outlet  5  formed in one of the walls  11 ,  18 ,  21 ,  23 ,  24 . In the illustrated example the vent hole  9  is formed in the top wall  11 . For example, the vent hole  9  can also be formed in an inclined wall or other wall. The wall  11 ,  18 ,  21 ,  23 ,  24  includes a vent hole barrier  10  closing the vent hole  9 , the vent hole  9  and vent hole barrier  10  being placed with respect to the ink outlet  5  so that the ink inlet device  14  pushes open the vent hole  9  during interconnection. For example, the wall  11  and the vent hole barrier  10  are defined by a single solid cast, that is, molded in the same mold and molding action, wherein molding may include injection molding, compression molding, rotation molding, blow molding, etc. For example, the top wall  11  includes at least one notch  12 ,  13  around the vent hole barrier  10  for tearing open the vent hole barrier  10  along the notch  12 ,  13  by said pushing action, therewith opening the vent hole  9  allowing air to pass through the vent hole  9 . For example, the ink tank interconnect device  6  includes an opening structure  26  connected to the vent hole barrier  10 , for engagement by the ink inlet device  14 , the opening structure  26  and vent hole barrier  10  being defined by a single solid cast. For example, the opening structure  26  includes a first leg  26  connected to the vent hole barrier  10 , a second leg  29  connected to the wall  11  next to the vent hole barrier  10 , and a middle portion  30  connecting the two legs  28 ,  29 . For example, the middle portion  30  is arranged to bend during opening of the vent hole barrier  10  and to move back towards the original position when the ink inlet device  14  is disconnected. For example, the opening structure  26  moves back from the position of  FIG. 8  to the position of  FIG. 5  but wherein the notches  12 ,  13  remain ruptured. For example, an interconnect feature  22  protrudes from the wall  11 , wherein the interconnect feature has a substantially cylindrical side wall  23  that has a substantially circular circumference, wherein at least a part of the vent hole barrier  10  extends within the circular circumference, in an indentation  31  of the cylindrical side wall  23 . For example, the ink tank interconnect device  6  includes an outwards protruding color-specific color key  25 . In a further example, the ink tank interconnect device  6  includes an interconnect feature  22  protruding from a top wall  11 , the interconnect feature including a cylindrical side wall  23  and a second top wall  24 , the ink tank interconnect device  6  further including an opening structure  26  connected to the vent hole barrier  10 , the opening structure  26  arranged next to the interconnect feature  22 , for engagement by the ink inlet device  14 . For example, the ink tank interconnect device  22  further includes a color key  25  extending away from the second top wall  24  of the interconnect feature  22 , and an ink outlet  5  extending away from the second top wall  24  of the interconnect feature  22 , a length direction of the ink outlet  5  and the color key  25  being parallel to facilitate the fluidic interconnection of the ink inlet device  14  and the ink outlet  5 . For example, an ink tank lid  20  is provided for connection to the ink tank body portion  2  including the ink tank interconnect device  6 . For example, an ink tank  1  is provided that includes the ink tank interconnecting device  6 . For example, the ink tank  1  is a bagless ink tank  1 , includes rigid plastic walls  11 ,  18 ,  21 ,  23 ,  24 , the rigid plastic walls  11 ,  18 ,  21 ,  23 ,  24  enclosing an inner volume  4  of at least approximately one liter. For example, the ink tank  1  is at least partially filled with ultra-violet curable ink. 
         [0036]    For example, in a second aspect, an ink tank  1  is provided, including an inner volume  4  for holding ink, defined by rigid ink tank walls  11 ,  18 ,  21 ,  23 ,  24 . For example the ink tank  1  includes an ink outlet  5  connected to a second top wall  24  of the ink tank  1 , arranged to be interconnected with an ink inlet device  14 . For example the ink tank  1  includes a vent hole  9  near the ink outlet  5  that is open to the inner volume  4  and sealed from the outside by a vent hole barrier  10 , the barrier  10  being arranged to be pushed open when the ink inlet device  14  is connected to the ink outlet  5 , to allow entry of ambient air into the inner volume  4 , for example so that free ambient air enters directly into the vent hole  10  without passing through a tube or channel. For example, the ink tank  1  further includes an interconnect feature  22  for aligning the ink inlet device  14  with the ink outlet  5 , and an opening structure  26  connected to the vent hole barrier  10  that is placed next to the interconnected feature  22 , so as to be engaged by the ink inlet device  14  during interconnection so that the ink inlet device  14  pushes against the opening structure  26  therewith opening the vent hole barrier  10 , for example by rupturing. 
         [0037]    For example, in a third aspect a method of creating a vent hole  9  through an ink tank wall  11  is provided. For example, the method includes (i) connecting an ink inlet device  14  of a printer to an ink outlet  5  of the ink tank  1 , (ii) pushing the ink inlet device  14  against a vent hole barrier  10  next to the ink outlet  5  during the connection, and (iii) by said pushing action rupturing the vent hole barrier  10 , allowing air to communicate between an ink holding inner volume  4  of the ink tank  1  and the environment. For example, the connecting of the ink inlet device  14  to the ink outlet  5  includes pushing the ink inlet device  14  against an opening structure  26  connected to the vent hole barrier  10 . For example, after using at least some of the ink in the ink tank  1  the ink inlet device  14  is disconnected from the ink outlet  5 , and the opening structure  26  and vent hole barrier  10  move back towards the original position. For example, the middle portion  30  bends back so that vent hole barrier  10  closes the vent hole  9 , at least in such a manner that it is more difficult for air or ink to pass through the vent hole  9 . 
         [0038]    For example, the indentation that forms the vent hole  9  is provided on the inner surface of the top wall  11  to allow the opening structure  26  to facilitate molding of the opening structure  26 . In this example, the vent hole barrier  10  can be relatively flush with the outer surface ( FIGS. 3, 5 ). In other examples, the opening structure  26  can have other shapes, for example non-U-shaped. For example, depending on the shape of the opening structure  26  the indentation can be provided on the outer surface of the top wall  11 , and for example the vent hole barrier  10  can be flush with the inner surface. In a further example, a U-shaped opening structure  26  with said two legs  28 ,  29  and middle portion  30  can have the advantage of providing a relatively large and robust engagement feature for the inlet device  14 , in addition to the resilience that facilitates moving the barrier  10  towards closing position after disconnection of the inlet device  14 . 
         [0039]    An example ink tank interconnect device including an ink outlet to interconnect with a corresponding ink inlet device, walls, and a vent hole next to the ink outlet formed in one of the walls, the wall including a vent hole barrier closing the vent hole, the vent hole and vent hole barrier being placed with respect to the ink outlet so that the ink inlet device pushes open the vent hole during interconnection. 
         [0040]    In some examples, the wall and the vent hole barrier are defined by a single solid cast. In some examples, the wall comprising at least one notch around the vent hole barrier for tearing the vent hole barrier open over the notch by said pushing, wherein the vent hole barrier has a thinner cross section than the surrounding wall and the wall at the notch has a thinner cross section than the vent hole barrier. In some examples, an opening structure connected to the vent hole barrier, for engagement by the ink inlet device, the opening structure and vent hole barrier being defined by a single solid cast. In some examples, the opening structure comprising a first leg connected to the vent hole barrier, a second leg connected to the wall next to the vent hole barrier, and a middle portion connecting the two legs. In some examples, the middle portion is arranged to bend during opening of the vent hole barrier, against a resilient force of the middle portion or second leg, and to move back towards the original position when the ink inlet device is disconnected by the resilient force of the middle portion or second leg. 
         [0041]    In some examples, an interconnect feature protruding from the wall, wherein the interconnect feature has a substantially cylindrical side wall that has a substantially circular circumference, wherein at least a part of the vent hole barrier resides within the circular circumference, in an indentation of the cylindrical side wall. In some examples, an interconnect feature protruding from a top wall and comprising a cylindrical side wall and a second top wall, an opening structure connected to the vent hole barrier, arranged next to the interconnect feature, for engagement by the ink inlet device, a color key extending away from the second top wall, and an ink outlet extending away from the second top wall, the length directions of the color key and ink outlet being parallel to facilitate said interconnection. 
         [0042]    In some examples, an ink tank lid for connection to an ink tank body portion including ink tank interconnect device as disclosed herein. 
         [0043]    In some examples, an ink tank includes the ink tank interconnect device of as disclosed herein being a bagless ink tank, including rigid plastic walls, the rigid plastic walls enclosing an inner volume of at least approximately one liters. In some examples, the example ink tank is at least partially filled with ultra-violet curable ink. 
         [0044]    An example ink tank includes an inner volume for holding ink defined by rigid ink tank walls, an ink outlet connected to a top wall of the ink tank, to be interconnected with an ink inlet device, a vent hole near the ink outlet, the vent hole open to the inner volume, and a vent hole barrier that seals the vent hole from the outside, to be pushed open when the ink inlet device is connected to the ink outlet, to allow entry of ambient air into the inner volume. In some examples, the ink tank as disclosed herein includes an interconnect feature for aligning the ink inlet device with the ink outlet, and an opening structure connected to the vent hole barrier that is placed next to the interconnected feature, so as to be engaged by the ink inlet device during interconnection so that the ink inlet device pushes against the opening structure therewith opening the vent hole barrier. 
         [0045]    An example ink outlet is arranged to interconnect with a corresponding ink inlet device. A vent hole is formed next to the ink outlet. A vent hole barrier is arranged to be pushed open by the ink inlet device during interconnection. 
         [0046]    An example method of creating a vent hole through a solid ink tank wall includes connecting an ink inlet device of a printer to an ink outlet of the ink tank, pushing the ink inlet device against a vent hole barrier next to the ink outlet during the connection, and by said pushing action rupturing the vent hole barrier, allowing air to communicate between an ink holding inner volume of the ink tank and the environment. In some examples, the method includes pushing the ink inlet device against an opening structure connected to the vent hole barrier, disconnecting the ink inlet device from the ink outlet, and the opening structure and vent hole barrier moving back towards the original position. 
         [0047]    An ink tank interconnect device including an ink outlet to interconnect with a corresponding ink inlet device, walls, a vent hole next to the ink outlet formed in one of the walls, the wall including a vent hole barrier closing the vent hole, the vent hole and vent hole barrier being placed with respect to the ink outlet so that the ink inlet device pushes open the vent hole during interconnection, an interconnect feature protruding from a top wall and comprising a cylindrical side wall and a second top wall, and an opening structure connected to the vent hole barrier, arranged next to the interconnect feature, for engagement by the ink inlet device. 
         [0048]    In some examples, the wall and the vent hole barrier are defined by a single solid cast. In some examples, the wall includes at least one notch around the vent hole barrier for tearing the vent hole barrier open over the notch by said pushing, wherein the vent hole barrier has a thinner cross section than the surrounding wall and the wall at the notch has a thinner cross section than the vent hole barrier. In some examples, the ink tank interconnect device includes an opening structure connected to the vent hole barrier, for engagement by the ink inlet device, the opening structure and vent hole barrier being defined by a single solid cast. In some examples, the opening structure includes a first leg connected to the vent hole barrier, a second leg connected to the wall next to the vent hole barrier, and a middle portion connecting the two legs. 
         [0049]    In some examples, the middle portion is arranged to bend during opening of the vent hole barrier, against a resilient force of the middle portion or second leg, and to move back towards the original position when the ink inlet device is disconnected by the resilient force of the middle portion or second leg. In some examples, the ink tank interconnect device includes an interconnect feature protruding from the wall, wherein the interconnect feature has a substantially cylindrical side wall that has a substantially circular circumference, wherein at least a part of the vent hole barrier resides within the circular circumference, in an indentation of the cylindrical side wall. 
         [0050]    In some examples, the ink tank interconnect device includes a color key extending away from the second top wall, and an ink outlet extending away from the second top wall, the length directions of the color key and ink outlet being parallel to facilitate said interconnection. In some examples, an ink tank lid for connection to an ink tank body portion includes the ink tank interconnect device as disclosed herein. An example ink tank includes the ink tank interconnect device as disclosed herein being a bagless ink tank, including rigid plastic walls, the rigid plastic walls enclosing an inner volume of at least approximately one liters. In some examples, the ink tank as disclosed herein is at least partially filled with ultra-violet curable ink. An example ink tank comprising an inner volume for holding ink defined by rigid ink tank walls, an ink outlet connected to a top wall of the ink tank, to be interconnected with an ink inlet device, a vent hole near the ink outlet, the vent hole open to the inner volume, a vent hole barrier that seals the vent hole from the outside, to be pushed open when the ink inlet device is connected to the ink outlet, to allow entry of ambient air into the inner volume, an interconnect feature for aligning the ink inlet device with the ink outlet, and an opening structure connected to the vent hole barrier that is placed next to the interconnected feature, so as to be engaged by the ink inlet device during interconnection so that the ink inlet device pushes against the opening structure therewith opening the vent hole barrier. 
         [0051]    An example method of creating a vent hole through a solid ink tank wall, includes connecting an ink inlet device of a printer to an ink outlet of the ink tank, pushing the ink inlet device against a vent hole barrier next to the ink outlet during the connection, by said pushing action rupturing the vent hole barrier, allowing air to communicate between an ink holding inner volume of the ink tank and the environment, pushing the ink inlet device against an opening structure connected to the vent hole barrier, disconnecting the ink inlet device from the ink outlet, and the opening structure and vent hole barrier moving back towards the original position. 
         [0052]    The above description is not intended to be exhaustive or to limit this disclosure to the examples disclosed. Other variations to the disclosed examples can be understood and effected by those of ordinary skill in the art from a study of the drawings, the disclosure, and the claims. The indefinite article “a” or “an” does not exclude a plurality, while a reference to a certain number of elements does not exclude the possibility of having more or less elements. A single unit may fulfil the functions of several items recited in the disclosure, and vice versa several items may fulfil the function of one unit. Multiple alternatives, equivalents, variations and combinations may be made without departing from the scope of this disclosure.