Patent Publication Number: US-2023138198-A1

Title: Fluid recirculation

Description:
BACKGROUND 
     Printing systems may recirculate their printing fluids through fluid distribution systems. Some fluids, for instance inks, may comprise particles which should be in motion, either constantly or periodically, so as to preserve their properties. It is hereby disclosed recirculation devices and systems in which fluids can be recirculated within a printing system. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Features of the present disclosure are illustrated by way of example and are not limited in the following figure(s), in which like numerals indicate like elements, in which: 
         FIG.  1    shows a recirculation device having a fluid interconnect assembly, according to an example of the present disclosure; 
         FIG.  2    shows a recirculation device having a first module and a second module, according to an example of the present disclosure; 
         FIG.  3    shows a recirculation device having a first guiding element and a second guiding element, according to an example of the present disclosure; 
         FIG.  4    shows a printing system comprising an ink delivery system and a fluid bridge, according to an example of the present disclosure; 
         FIG.  5    shows a printing system comprising a fluid interface and a fluid bridge, according to an example of the present disclosure; 
         FIG.  6 A  shows a cross-sectional view of the fluid interface and the fluid bridge of  FIG.  5    in a closed state; 
         FIG.  6 B  shows a cross-sectional view of the fluid interface and the fluid bridge of  FIG.  5    in an open state. 
     
    
    
     DETAILED DESCRIPTION 
     For simplicity and illustrative purposes, the present disclosure is described by referring mainly to examples. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be readily apparent, however, that the present disclosure may be practiced without limitation to these specific details. In other instances, some methods and structures have not been described in detail so as not to unnecessarily obscure the present disclosure. 
     Throughout the present disclosure, the terms “a” and “an” are intended to denote at least one of a particular element. As used herein, the term “includes” means includes but not limited to, the term “including” means including but not limited to. The term “based on” means based at least in part on. 
     Printing systems may comprise a series of printheads to eject a fluid on a print media. Such fluid flows from fluid supplies to the series of printheads through a series of fluid lines. The series of fluid lines may comprise additional devices to control fluid parameters such as the fluid pressure, the density of the fluid, the flow rate, amongst other possibilities. 
     Some additional devices, such as pumps, may use those fluid parameters to control their operations. Also, the series of fluid lines may be interconnected to each other in order to reduce the dimensions of the system, and therefore, a fluid line may be used for different purposes based on which operation is executing the printing system. 
     Other additional devices, such as valves, may be used to guide the fluid in the desired direction, and therefore, a specific fluid path may be created within the fluid lines based on the state of the valves. However, in some cases, the redirection of fluid in a particular fluid path direction may not be achieved merely by opening and/or closing fluid lines comprised within the series of fluid lines. Examples of path directions which may not be obtained are the fluid paths that supply fluid to the printheads. In case that no printhead is inserted, the fluid comprised inside these lines may not be recirculated. 
     In an example, a fluid distribution system may comprise fluid lines and additional devices in order to supply fluid from fluid supplies to a series of printheads. However, the fluid distribution system may be used for other purposes, such as recirculate the fluid through the series of lines. For the recirculation of the fluid, additional devices may create an internal fluid path in which the fluid is not supplied to the printheads. 
     According to an example, a printing system may comprise a printhead that distribute different types of fluid. Since fluids may behave differently depending on their properties, a fluid distribution system of the printing system may perform different actions to the fluid based on a fluid type. In an example, the fluid distribution system may supply two different types of inks: a high-pigmented fluid and a low-pigmented fluid. Whereas the low-pigmented fluid may keep its properties substantially unchanged while not being used, the high-pigmented fluid may be recirculated periodically to maintain some of its properties, e.g., their absorbance or their viscosity. In case that the high-pigmented fluid is not enough recirculated, its properties may be affected. 
     As used herein, the absorbance of a fluid refers to an amount of light absorbed by a solution. For high-pigmented fluids, if the fluid is not well mixed, fluid measures will not be homogeneous in the fluid distribution system, and therefore, image quality defects may be obtained during printing operations, such as plot opacity variations. 
     As used herein, the viscosity of a fluid refers to a measure of the resistance of a fluid to deformation. In case that the fluid may not be recirculated, its pigments may settle, thereby increasing its viscosity. Additional devices, such as pumps, may not be able to work with high-viscosity fluids. 
     In another example, a user may decide to replace one of the printheads of a printing system for a dummy printhead, wherein the dummy printhead can loop fluid back to the fluid distribution system of the printing system instead of ejecting it. Dummy printheads may enable the printing system to keep executing printing operations while using a lower number of printheads. Examples of dummy printheads comprise fluid bridges, recirculation devices, amongst other examples. 
     Disclosed herein are examples of devices and systems which may be used to recirculate a fluid within a printing system. Hence, different examples of devices and systems are described. 
     In some examples, a printing system comprises a fluid distribution system to supply ink to a series of printheads. The fluid distribution system may comprise a series of fluid interfaces (alternatively referred to as fluid interconnect holders) in which the series printheads are to be connected. A connection of one of the printheads to one of the fluid interfaces may extend the fluid distribution system by creating an internal fluid path. Upon the printhead is connected to the fluid interface, fluid can be supplied to the printhead. In other examples, printhead(s) may be replaced for recirculation devices which may recirculate the fluid supplied through the fluid interface(s). 
     According to an example, a recirculation device having a fluid interconnect assembly comprises an open state and a closed state. The fluid interconnect assembly may comprise an elastic element, a first hollow element, a second hollow element, and a seal movable along the fluid interconnect assembly. The first hollow element and the second hollow element comprise an opening, wherein the hollow elements are fluidly connected. In the open state of the device, the first hollow element opening and the second hollow element opening protrude from the seal so that the openings are unsealed. In the closed state of the device, the seal seals the first hollow element opening and the second hollow element opening, being the seal biased towards the closed state by the elastic element. 
     In an example, the recirculation device may further comprise a guiding element attached to the seal, wherein the guiding element is movable along a guide which is parallel to the first hollow element and the second hollow element. In some examples, the guide is an aperture of the fluid interconnect assembly. 
     In other examples, the openings of the first hollow element and the second hollow element are lateral apertures. 
     In some other examples, the recirculation device changes from the closed state to the open state if the device is connected to a printing device, for instance a fluid interface of a fluid distribution system. 
     According to other examples, a recirculation device, instead of a fluid interconnect assembly, comprises a first module and a second module, wherein each module having an open state and a close state. The first module may comprise a first elastic element, a first hollow element and a first seal movable along the first module and the second module may comprise a second elastic element, a second hollow element and a second seal movable along the second module. Each of the first and the second hollow elements comprises an opening, being the second hollow element fluidly connected to the first hollow element. In the open state, the openings of the first hollow element and the second hollow element protrude from the first seal and the second seal so that the openings are unsealed. In the closed state, the first seal and the second seal cover the openings, thereby blocking them. The first seal and the second seal are biased towards the closed state by the first elastic element and the second elastic element. 
     In an example, the recirculation device may be connected to a printing system. Upon connecting the recirculation device to the printing system, the device changes from the closed state to the open state, thus creating a fluid path between the first hollow element opening and the second hollow element opening. In some examples, the recirculation device may be connected to a fluid interface of the printing system. 
     In other examples, the recirculation device may further comprise a first guiding element attached to the first seal and a second guiding element attached to the second seal. The first guiding element may be movable along a first guide and the second guiding element may be movable along a second guide. The first guide may be parallel to the first hollow element and the second guide may be parallel to the second hollow element. In some other examples, the first guide is an aperture of the first module and the second guide is an aperture of the second module. 
     According to some examples, a printing system comprises an ink delivery system and a fluid bridge. The ink delivery system may supply fluid to a fluid interface, as previously described in the description. The fluid bridge may have a chamber assembly, wherein the chamber assembly comprises a first hollow element fluidly connected to a second hollow element, a sealing element movable along the chamber assembly, and an elastic element contacting the sealing element and the chamber assembly. The first and the second hollow element comprise an opening, wherein the sealing element is to seal the opening. The sealing element is biased towards sealing the openings by the elastic element, and upon connecting the fluid bridge to the fluid interface, the sealing element moves away so that the openings are unsealed. Once the openings are unsealed, fluid may flow between the first hollow element opening and the second hollow element opening. In some examples, the ink delivery system corresponds to the fluid distribution system previously described in the description. 
     In other examples, the fluid bridge of the printing system further comprises a guiding element attached to the sealing element, wherein the guiding element is movable within a guide parallel to the first hollow element and the second hollow element. The guiding element may prevent the tilting of the sealing element during a movement along the chamber assembly. 
     In some other examples, the ink delivery system may reduce a fluid pressure when an extraction of the fluid bridge is detected by the printing system. In an example, the extraction of the fluid bridge is determined by checking a printing system status. 
     According to other examples, the chamber assembly may comprise a first module and a second module, the sealing element may comprise a first sealing element and a second sealing element, and the elastic element may comprise a first portion and a second portion. The first module may comprise the first hollow element, the first sealing element, and the first portion of the elastic element. The second module may comprise the second hollow element, the second sealing element, and the second portion of the elastic element. 
     The first sealing element may seal the first hollow element opening and the first portion of the elastic element may contact the first module and the first sealing element. 
     The second sealing element may seal the second hollow element opening and the second portion of the elastic element may contact the second module and the second sealing element. Upon connecting the fluid bridge to the fluid interface, each of the first sealing element and the second sealing element moves away so that the openings are unsealed. 
     Examples of elastic elements may comprise, amongst others, springs, gas canisters, or any element capable of recovering size and shape after a deformation, for example, a deformation caused by the process transmitted forces. 
     Referring now to  FIG.  1   , a recirculation device  100  having a fluid interconnect assembly  110  is shown. The recirculation device  100  further comprises an elastic element  114 , a first hollow element  111 , a second hollow element  161 , and a seal  113 . The first hollow element  111  comprises a first opening  112  and the second hollow element  161  comprises a second opening  162 . In the example of  FIG.  1   , the openings are lateral apertures, however, alternative locations may be possible, such as openings on the hollow elements&#39; tips. In an example, the first and second hollow elements are integrally formed into a single element, e.g., a U-shaped element including the first hollow element and the second hollow element. 
     The first hollow element  111  is fluidly connected to the second hollow element, and thus, a fluid path may be created between both openings. The seal  113  is movable along a cavity  115  of the fluid interconnect assembly  110 , wherein the seal  113  is to seal the first hollow element opening  112  and the second hollow element opening  162  by covering the openings. 
     The recirculation device  110  may comprise an open state and a closed state, wherein the seal is biased towards the closed state by the elastic element  114 . In the closed state, the seal  113  covers the openings so that the first hollow element opening  112  and the second hollow element opening  162  are sealed. By sealing the openings, the fluid inside the first hollow element  111  and the second hollow element  161  remains inside, thereby preventing its spilling. In the open state, the first hollow element opening  112  and the second hollow element opening  162  protrude from the seal  113 , and thus, the openings are unsealed thereby allowing fluid to flow between the openings of each of the hollow elements. 
     As shown in  FIG.  1   , a transition between a closed state and an open state is caused when the seal  113  performs a movement  101 . The movement  101  of the seal  113  causes the openings to protrude from the seal  113 , thus creating a fluid path between the first hollow element opening  112  and the second hollow element opening  162 . In an example, the movement  101  may be caused by a connection of the recirculation device  100  to a printing device, e.g. a printing system. The printing system may comprise a fluid interface in which the recirculation device  100  can be connected so that the recirculation device  100  creates a new fluid path for the printing system. In an example, the new fluid path corresponds to an inner fluid path which enables to keep the fluid in motion. 
     In some examples, the first hollow element  111  and the second hollow element  161  are connected through a common chamber, wherein the common chamber is a shared volume between the first hollow element  111  and the second hollow element  161 . The volume of the common chamber may aid in reducing the pressure of the fluid comprised between the first hollow element  111  and the second hollow element  161  during the closed state of the recirculation device  100 . Common chambers having large inner volumes may be susceptible to perform more fluid spill compared with common chambers having small inner volumes, because of the pressure of the fluid comprised inside of the fluid path defined between the two openings. However, the dimensions of the common chamber should be enough so as to enable the pigments of the fluid to pass through the chamber without clogging the fluid path between the first hollow element  111  and the second hollow element  161 . 
     In some other examples, the first hollow element  111  and second hollow element  161  may be integrally formed into a single element, e.g., a U-shaped element including the first hollow element  111  and the second hollow element  161 . 
     Referring now to  FIG.  2   , a recirculation device  200  having a first module  210  and a second module  260  is shown. The first module  210  comprises a first hollow element  211  having a first hollow element opening  212 , a first seal  213 , and a first elastic element  214 . In the same way, the second module  260  comprises a second hollow element  261  having a second hollow element opening  262 , a second seal  263 , and a second elastic element  264 . 
     As previously explained in reference to other examples, the recirculation device  200  comprises an open state in which the openings protrude from the first seal  213  and the second seal  263 , and a closed state in which the first seal  213  and the second seal  263  block the openings. The first seal  213  and the second seal  263  are biased towards the closed state by the first elastic element  214  and the second elastic element  264 . The first hollow element  211  is fluidly connected to the second hollow element  261 , and during an open state of the recirculation device  200 , a fluid path is enabled between the first hollow element opening  212  and the second hollow element opening  262 . 
     As shown in  FIG.  2   , each of the first seal  213  and the second seal  263  is movable along a cavity of the first module  210  and a cavity of the second module  260 , respectively. A first movement  201  illustrates how the first seal  213  moves from a closed position  213   a  to an open position  213   b . A second movement  251  illustrates how the second seal  263  moves from a closed position  263   a  to an open position  263   b.    
     If the seals  213 ,  263  are in their closed position  213   a ,  263   a , each of the first hollow element opening  212  and the second hollow element opening  262  are covered by the first seal  213  and the second seal  263  so that the openings are sealed. The sealing of the openings prevents the spill of the fluid that may be inside the first hollow element  211  and the second hollow element  261 . 
     The open position  213   b  of the first seal  213  and the open position  263   b  of the second seal  263  correspond to the open state of the recirculation device  200 . In the open state, each of the first hollow element opening  212  and the second hollow element opening  262  protrude from the first seal  213  and the second seal  263  so that the openings are unsealed. 
     In an example, the first hollow element  211  and the second hollow element  261  are needles, wherein the needles may be made of a material which can stand corrosion. The needles may have their openings at a lateral surface of their bodies, and thus, the seals can prevent the spill of the fluid which may be comprised along the fluid path enabled between the first hollow element opening  212  and the second hollow element opening  262 . 
     In other examples, the recirculation device  200  may further comprise guiding elements to ensure that each of the first seal and the second seal is aligned with their corresponding hollow element, thereby preventing the tilting of the seals. In an example, the recirculation device  200  further comprise a first guiding element attached to the first seal  213  and a second guiding element attached to the second seal  263 . The first guiding element is movable along a first guide and the second guiding element is movable along the second guide, wherein the first guide is parallel to the first hollow element  211  and the second guide is parallel to the second hollow element  261 . 
     In some other examples, the first module  210  and the second module  260  may have different relative position with each other. Although in  FIG.  2    the first hollow element  211  is parallel to the second hollow element  261 , other alternatives may be possible, such as the second module  260  being perpendicular to the first module  210  so that the recirculation device  200  is L-shaped. 
     In some other examples, the first hollow element  211  and the second hollow element  261  are connected through a common chamber, wherein the common chamber is a shared volume between the first hollow element  211  and the second hollow element  261 , as previously explained. In other examples, the first hollow element  211  and second hollow element  261  may be integrally formed into a single element, e.g., a U-shaped element including the first hollow element  211  and the second hollow element  261 . 
     Referring now to  FIG.  3   , a recirculation device  300  having a first guiding element  315  and a second guiding element  365  is shown. The recirculation device  300  further comprises a first module  310  and a second module  360 , wherein each of the first module  310  and the second module  360  may correspond to the first module and the second module previously explained in reference to  FIG.  2   . 
     The recirculation device  300  further comprises a common chamber  305 , wherein the common chamber  305  fluidly connects the hollow elements (not shown in  FIG.  3   ). In other examples, the common chamber may be replaced for other alternatives, such an additional hollow element connecting the first hollow element to the second hollow element. 
     The first module  310  comprises the first guiding element  315  and the second module  360  comprises the second guiding element  365 , wherein the guiding elements are movable within guides that are parallel to their respective hollow element. In the example of  FIG.  2   , a first guide  316  and a second guide  366  are lateral apertures of each of the first module  310  and the second module  360 . However, in other examples the guides may be disposed at other locations, for instance on inner surfaces of the modules (or module). 
     In some other examples, the first module  310  and the second module  360  may be replaced for a single chamber assembly. The chamber assembly may comprise a single elastic element, a single sealing element while defining a closed state and an open state for the recirculation device, as previously explained in reference to  FIG.  1   . 
     According to an example, a printing system may comprise an ink delivery system to supply fluid to a fluid bridge through a fluid interface, wherein the fluid bridge corresponds to the recirculation device previously explained in other examples. The fluid bridge comprises a chamber assembly, wherein the chamber assembly comprises a first hollow element fluidly connected to a second hollow element, a sealing element, and an elastic element. Each of the first hollow element and the second element comprise an opening, and the sealing element is biased by the elastic element towards a position in which the openings are sealed. Upon connecting the fluid bridge to the fluid interface, the sealing element moves away so that the openings of the hollow elements are unsealed. Once the openings are unsealed, a new fluid path may be enabled within the ink delivery system so that fluid can be flowed between the first hollow element opening and the second hollow element opening. 
     In other examples, the chamber assembly comprises a first module and a second module, the sealing element comprises a first sealing element and a second sealing element, and the elastic element comprises a first portion and a second portion. The first module may comprise the first hollow element, the first sealing element and the first portion of the elastic element. The second module may comprise the second hollow element, the second sealing element and the second portion of the elastic element. 
     As previously noted, each of the first sealing element and the second sealing element is biased towards a closed state by each of the first portion of elastic element and second portion of elastic element. In the closed state, the openings of the first hollow element and the second hollow element are sealed. Upon connecting the fluid bridge to the fluid interface, each of the first sealing element and the second sealing element moves away so that the openings of the hollow elements are unsealed. Once the openings are unsealed, a new fluid path may be enabled within the ink delivery system so that fluid can be flowed between the first hollow element opening and the second hollow element opening. 
     Referring now to  FIG.  4   , a printing system  400  comprising an ink delivery system  410  and a fluid bridge  420  is shown. The ink delivery system  410  is to supply fluid to a fluid interface  411 , wherein the ink delivery system  410  may correspond to the fluid distribution systems previously described in the description. The fluid bridge  420  is connectable to the fluid interface  411  of the ink delivery system  410  so that fluid can be supplied to the fluid bridge  420 . 
     The fluid bridge  420  comprises a first hollow element  421  and a second hollow element  471 , wherein the first hollow element  421  comprises a first opening  422  and the second hollow element comprises a second opening  472 . The fluid bridge  420  may comprise a chamber assembly for the hollow elements, wherein the assembly may be a single chamber or multiple modules. When having a fluid bridge  420  with a single chamber, the fluid bridge  420  further comprises an elastic element and a sealing element in addition to the first hollow element  421  and the second hollow element  471 . When having a fluid bridge  420  with a first module and a second module, the fluid bridge  420  may further comprise a first sealing element and a second sealing element, and a first portion of elastic element and a second portion of elastic element, as previously explained in the description. 
     The fluid bridge  420  comprises an open state in which a new fluid path is enabled and a closed state in which the new fluid path is blocked. Upon connecting the fluid bridge  420  to the fluid interface  411 , the fluid bridge  420  changes its state from closed state to open state. The connection may cause the first opening  422  of the first hollow element  421  and the second opening  472  of the second hollow element  471  to protrude of the sealing element (or sealing elements when having two modules). Once the sealing element(s) move away from the openings, the new fluid path is enabled between the first opening  422  and the second opening  472 . The new fluid path may enable to flow fluid of the ink delivery system  410  back to the ink delivery system  410 . 
     However, a user may want to replace the fluid bridge  420  for a printhead in order to execute printing operations. Before extracting the fluid bridge  420  from the printing system  400 , the user may indicate to the printing system  400  that an extraction operation is to be executed. 
     In an example, the printing system further comprises a processor comprising instructions to perform a method comprising a series of actions to extract a fluid bridge  420  from the printing system  400 . In case the printing system  400  detects an extraction of the fluid bridge  420 , the printing system  400  may reduce a fluid pressure of the ink delivery system  410 . In some examples, the extraction of the fluid bridge  420  is determined by checking a printing system status, wherein the printing system status indicates the status of the actions that the printing system  400  is executing. Once the fluid bridge  420  is extracted from the fluid interconnect interface  411 , the fluid bridge changes from the open state to the closed state, and thus, the first opening  422  and the second opening  472  are sealed. Due to the sealing of the first opening  422  and the second opening  472 , the new fluid path which was enabled during the open state to flow fluid back to the ink delivery system  410  is blocked. 
     Referring now to  FIG.  5   , a printing system  500  is shown. The printing system  500  comprises a fluid interface  510  and a fluid bridge  520 . The fluid bridge  520  may correspond to the recirculation device  300  previously explained in  FIG.  3   . However, other examples of recirculation devices or fluid bridges may be possible, such as recirculation devices or fluid bridges having a chamber assembly, recirculation devices or fluid bridge without guiding elements, amongst others. 
     The fluid interface  510  is fluidly connected to the ink delivery system (not shown in  FIG.  5   ) of the printing system  500  by a first line  511  and a second line  561 . The ink delivery system may supply fluid to the fluid interface  510  through the first line  511  and/or the second line  561 . 
     In the example of  FIG.  5   , the fluid bridge 520  is not connected to the fluid interconnect interface  510 , and therefore, it is in a closed state. However, if the fluid bridge  520  is pressed downwards, the sealing elements of the fluid bridge  520  may move upwards relative to the modules. As a result of the movement, the fluid bridge  520  changes from the closed state to an open state in which a new fluid path is enabled between a first hollow element opening and a second hollow element opening. In case that the ink delivery system may flow fluid to the fluid interface  510  through the first line  511 , the fluid may flow through the fluid bridge  520  to the second line  561 . In the same way, if the ink delivery system flows fluid to the fluid interface  510  through the second line  561 , the fluid flows through the fluid bridge  520  to the first line  511 . 
     According to some examples, the ink delivery system of the printing system  500  may reduce a fluid pressure when an extraction of the fluid bridge  520  is detected by the printing system  500 . The fluid pressure may correspond to a pressure of the fluid which is to be flowed through the new fluid path enabled by the fluid bridge  520  during the open state. In some other examples, the extraction of the fluid bridge  520  is determined by checking a printing system status. 
     Referring now to  FIG.  6 A , a cross-sectional view of the fluid interface  510  and the fluid bridge  520  of  FIG.  5    is shown in a closed state  600   a . As previously explained in  FIG.  5   , the first line  511  and the second line  561  connect the ink delivery system of the printing system  500  to the fluid interface  510 . 
     During the closed state  600   a  of the fluid bridge  520 , the ink delivery system cannot flow fluid from a first fluid chamber  610  of the fluid interface  510  to a second fluid chamber  660  of the fluid interface  510 . A first sealing element  613   a  and a second sealing element  663   a  are biased by a first elastic element  614   a  and a second elastic element  664   a  towards to seal the openings of the hollow elements of the recirculation device  520 , and therefore, a fluid path between the first hollow element opening and the second hollow element opening is not enabled. During the closed state  600   a , the first elastic element  614   a  and the second elastic element  664   a  are in a relaxed state. When using springs as elastic elements, the relaxed state may be referred to as an expanded state of the spring. 
     Referring now to  FIG.  6 B , a cross-sectional view of the fluid interconnect interface  510  and the fluid bridge  520  of  FIG.  5    is shown in an open state  600   b.    
     During the open state  600   b  of the fluid bridge  520 , a first sealing element  613   b  and a second sealing element  663   b  are moved away from each of the first hollow element opening and the second hollow element opening, and therefore, the openings protrude from the sealing elements. As a result, a fluid path is enabled between the first hollow element opening and the second hollow element opening. In case the ink delivery system may flow fluid to either the first line  511  or the second line  561 , the fluid may flow from the first fluid chamber  610  (or the second fluid chamber  660 ) to the second fluid chamber  660  (or the first fluid chamber  610  when supplying fluid from the second supply chamber  660 ). During the open state  600   b , a first elastic element  614   b  and a second elastic element  664   b  are in a deformed state. When using springs as elastic elements, the deformed state may be referred to as a contracted state of the spring. 
     In other examples, the fluid interconnect interface  510  of the  FIGS.  6 A and  6 B  may use a different system to engage with the fluid bridge  520 . In some other examples, the fluid bridge  520  may comprise a single chamber assembly having a single sealing element, as previously explained in the description. In other examples, the first hollow element and the second hollow element may be fluidly connected through an additional hollow element, as previously explained. 
     In some examples, the fluid bridge  520  may prevent the spill of fluid comprised inside the first hollow element opening and the second hollow element opening. In case that the fluid bridge  520  is disengaged from the fluid interface  510 , the fluid bridge  520  changes from the open state  600   b  to the closed state  600   a . As a result, the elastic elements recover their original size, thereby moving the sealing elements back to a position in which the first hollow element opening and the second hollow element opening are sealed. Therefore, if fluid is supplied to either the first fluid chamber  610  by the first line  511  or the second fluid chamber  660  by the second line  561 , the fluid cannot be flowed back to the ink delivery system. 
     What has been described and illustrated herein are examples of the disclosure along with some variations. The terms, descriptions, and figures used herein are set forth by way of illustration only and are not meant as limitations. Many variations are possible within the scope of the disclosure, which is intended to be defined by the following claims (and their equivalents) in which all terms are meant in their broadest reasonable sense unless otherwise indicated.