Patent Publication Number: US-11046102-B2

Title: Ink tank cap and valve linkage

Description:
BACKGROUND 
     Printers are commonplace, whether in a home environment or an office environment. Such printers can include laser printer, inkjet printers or other types. Generally, printers require at least one consumable, such as paper or ink. Ink may be provided for the printers in cartridges that may be replaceable or refillable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of various examples, reference is now made to the following description taken in connection with the accompanying drawings in which: 
         FIG. 1  is a side view of an example ink tank; 
         FIG. 2  is a perspective illustration of an example ink tank with a closed cap; 
         FIG. 3  is a perspective illustration of an example ink tank with an open cap; 
         FIG. 4  is a sectional view of an example cap assembly in a closed position; 
         FIG. 5  is a sectional view of an example cap assembly in a partially opened position; 
         FIG. 6  is a sectional view of an example cap assembly in a fully opened position; 
         FIG. 7  is a side view of an example ink tank; 
         FIG. 8  is a perspective illustration of an example valve linkage; 
         FIG. 9  is a sectional view of an example ink tank with a closed cap; 
         FIG. 10  is a side view of an example ink tank with a partially open cap; 
         FIG. 11  is a sectional view of an example ink tank with a partially open cap; 
         FIG. 12  is a side view of an example ink tank with a fully opened cap; 
         FIG. 13  is a perspective illustration of an example printing system; 
         FIG. 14  is a magnified view of an example ink tank bay in the printing system illustrated in  FIG. 13 ; and 
         FIG. 15  is a flowchart illustrating an example method for sequencing internal and external seals. 
     
    
    
     DETAILED DESCRIPTION 
     Bubbler-style ink tanks for inkjet printers require a seal at the ink fill port during printing to create and maintain the negative back pressure required to prevent excessive ink flow due to gravity when the ink supply is located above the print head assembly. Breaking the seal to fill the ink tank may result in ink drool or flooding at the print head assembly. 
     To address the issues described above, various examples provide for linking the cap and valve actuations of external and internal seals of an ink tank. The linkage facilitates sealing of a valve in the ink tank before an external seal is broken and negative backpressure in the ink tank is lost. In one example, when an ink tank is opened for filling, the cap of the ink tank is automatically forced to a first, partially opened position by a pre-loaded hinge, while the cap remains sealed and the valve is actuated (i.e., closed). In some examples, the cap includes an effector that actuates the valve through the linkage. 
     Accordingly, the present disclosure describes example apparatus, methods and systems to facilitate the linked activation of cap and valve seals of an ink tank. 
     In one example, an apparatus includes an ink tank and a cap assembly attached to the ink tank with a preloaded hinge to rotate the cap assembly from a closed position to an open position. The rotation of the cap assembly may occur when the cap assembly is unlatched. The cap assembly of the example apparatus may include a bung to seal the ink tank during a partial rotation of the cap assembly when the cap assembly is unlatched. The example apparatus may further includes a spring-loaded linkage connected to a valve in the ink tank. An effector may extend from the cap assembly to engage and actuate the spring-loaded linkage when the cap assembly is latched and to disengage from the spring-loaded linkage after the cap assembly is unlatched. The spring-loaded linkage opens the valve when engaged with the effector, and closes the valve when disengaged from the effector. The bung maintains a tank seal until the internal valve is closed. An example apparatus is described below with reference to  FIG. 1 . 
     Referring now to the figures,  FIG. 1  illustrates a side view of an example ink tank  100 . Example ink tank  100  includes an ink tank body  101 , which may be a multi-chambered ink tank as described in greater detail below. The example ink tank  100  also includes a cap assembly  102  attached to the ink tank  100  with a hinge, such as hinge  103  illustrated in  FIG. 1 , which may be preloaded. In the example illustrated in  FIG. 1 , the cap assembly  102  is shown in a latched (closed) state. Cap assembly  102  may be attached to the example ink tank  100  by the hinge  103 . Hinge  103  may be any type of hinge that constrains the rotation of the cap assembly  102  to a single axis of rotation. In one example, hinge  103  may be an axle engaged with cylindrical bearings extending from the cap assembly  102 . In one example, hinge  103  may be preloaded with an elastic band  104  disposed around the hinge  103  to apply an opening force to the cap assembly  102 , such that when the cap assembly  102  is unlatched, the opening force applied by the elastic band  104  rotates the cap assembly  102  to a fully opened position and maintains the cap assembly  102  in the fully opened position until the force is overcome by force applied by a user to close the cap assembly  102 . 
     Example ink tank  100  also includes a latch  105  to hold the cap assembly  102  in a closed position against the opening force applied by the elastic band  104  as illustrated in  FIG. 1 . Accordingly, the cap assembly  102  is constrained to two stable states: a closed state (closed position) as illustrated in  FIG. 1  when the latch  105  is engaged, and a fully opened state (fully opened position) when the latch is released, as described and illustrated below. 
     For greater clarity in describing the disposition and function of the elastic band  104 ,  FIG. 2  is a perspective illustration of the ink cap assembly  102  in the closed position, and  FIG. 3  is a perspective illustration of the example ink tank  100  with the cap assembly  102  in the fully opened position. It will be appreciated from these views that the elastic band  104  wraps around the ends of the axle of hinge  103  (as illustrated in  FIG. 3 ) and under the arms of the hinge  103  (as illustrated in  FIG. 3 ) to force to the cap assembly  102  to the fully open position as illustrated in  FIG. 3 . 
       FIG. 4  is a sectional view of an example cap assembly  102  illustrating internal details of cap assembly  102  in the closed position, and  FIG. 5  is a sectional view illustrating the cap assembly  102  of  FIG. 4  in a transient, partially open state after the cap assembly  102  has been unlatched by the operation of latch  105 . As illustrated in  FIG. 4 , the cap assembly includes a cap housing  106 , a bung  107  retained within the cap housing  106 , and a spring  108  disposed between the cap housing  106  and the bung  107 . In one example, and without limitation, cap housing  106  may be fabricated from an acetal homopolymer thermoplastic such as Delrin,® and the bung  107  may be fabricated from a natural or synthetic elastic polymer such as natural rubber or silicone rubber. Also shown in  FIG. 4  are the ink tank body  101  (partial), the elastic band  104 , and the latch  105 , previously described. 
     In the closed (latched) position illustrated in  FIG. 4 , the spring  108  is compressed between the cap housing  106  and the bung  107  and applies a sealing force between the bung  107  and the ink tank body  101 . In one example, the bung  107  may include an O-ring  109  to improve the seal between the bung  107  and the ink tank body  101 . As shown in  FIG. 4 , the bung  107  is retained within cap housing  106  by a number of complementary features comprising tabs or protuberances from the bung  107  and openings, cavities or channels in the cap housing  106 . These include tab  110  of the bung  107  in a channel  111  of the cap housing (hidden in  FIG. 4  but visible in  FIG. 5 ), tab  112  of the bung  107  in opening  113  of the cap housing  106 , and crown  114  of the bung  107  in cavity  115  of the cap housing  106 . It will be appreciated that these complementary features will allow for relative motion between the cap housing  106  and the bung  107  when the cap assembly  102  is unlatched, as described below. 
     As noted,  FIG. 5  is a sectional view illustrating the cap assembly  102  of  FIG. 4  in a transient, partially open state after the cap assembly  102  has been unlatched by the operation of latch  105 . This transient state is achieved by the combined forces of spring  108  and hinge  104 . When latch  105  is released, spring  108  applies a force to push the cap housing  102  away from the bung  107  while maintaining a sealing force between the bung  107  and the ink tank body  101 . It will be appreciated that this force decreases as spring  108  decompresses and that the relative motion of the cap housing  106  and the bung  107  is limited by the complementary features of the cap assembly  106  and the bung  107  described above. 
     In the transient state shown in  FIG. 5 , tab  112  is constrained by opening  113 , the crown  114  (with spring  108 ) has moved within cavity  115 , and tab  110  has reached the lower bound of channel  111 , which limits further relative motion between the cap housing  106  and the bung  107 . In one example, described in greater detail below, this transient position serves to actuate a valve in the ink tank (using other features of the cap housing  102 ) to effect a secondary seal in the ink tank body  101  before the seal between the bung  107  and the ink tank body  101  is broken. After the cap assembly  102  reaches the transient position illustrated in  FIG. 5 , further motion of the cap assembly  102  is controlled by the force applied to the cap assembly  102  by the elastic band  104 . As described previously, this force rotates the cap assembly to a fully open position. 
       FIG. 6  is a sectional view illustrating the cap assembly  102  of  FIGS. 4 and 5  in the fully open state. In this state, further rotation is limited by interference between a sidewall  116  of the ink tank body  101  and a flange  117  of the hinge  103  (not visible in  FIG. 6 ). 
     Turning now to a description of the secondary sealing mechanism referenced above with respect to the opening of the cap assembly  102 ,  FIG. 7  illustrates the side view of the example ink tank  100  previously illustrated in  FIG. 1 . In the example of  FIG. 7 , the cap assembly  102  is in the closed (latched) state. In this state, an effector  201  (an extension of cap assembly  102 ) extends downward from the cap assembly  102  to depress a slider  202 , which is retained in a channel in the body of the ink tank  100 . The slider may be retained by any means known in the art, such as by channels or tabs, for example. In this position, the slider  202  is engaged with a cam on lever arm  203  that is spring loaded by a spring  204 , and holds the lever arm  203  in a downward position against the force of the spring  204 . Lever arm  203  is fixed to a rotatable spline  205  that extends into the interior of the ink tank body  101 . In one example, spline  205  may be held in place by a snap-ring or c-clip, and sealed by an O-ring or the like as it passes through the wall of the ink tank body  101 . 
       FIG. 8  is a perspective illustration of the linkage described above, in isolation, showing additional details not visible in  FIG. 7 . In  FIG. 8 , the sealed pinion  205  is fixed to a second lever arm  206 , which in turn is connected to a valve body  207  by a pin  208  that is fixed with respect to lever arm  206  and free to rotate with respect to valve body  207 . Valve body  207  includes a valve seal  209  that is configured to provide a seal when seated in a valve seat  210  in the ink tank (see  FIG. 9 ). It will be appreciated that in the closed cap configurations illustrated in  FIG. 7  and  FIG. 8 , the lever arm  203  is held in a downward rotated position by the slider  202 , that lever arm  206  is held in an upward rotated position by its fixed connection to lever arm  203  via spline  205 , and that the valve assembly comprising valve seal  209  and valve seat  210  is held open. 
       FIG. 9  is a partial sectional (cutaway) view of the example ink tank  100 , showing internal details of the ink tank and the valve linkage described above in the closed cap configuration. In  FIG. 9 , lever arm  206  is in its upward rotated position, which translates through valve body  207  to an unseated valve seal  209 . Also illustrated in  FIG. 9  is an upper chamber  301  of ink tank body  101 , and a lower chamber  401  of ink tank body  101 , also referred to as a feeder tank. The valve assembly is positioned between the upper chamber  301  and the lower chamber  401  and permits fluid commination between the upper chamber  301  and the lower chamber  401 . 
     Turning now to  FIG. 10 , there is illustrated a side view of the example ink tank  100  with the cap in the transient, partially open state described above. In this transient state, the cap assembly  102  is partially open, such that the cap housing  106  is partially rotated and the bung ( 107 ) to ink tank ( 101 ) seal is maintained, but the holding force applied by effector  201  is removed from slider  202 , which allows the force of spring  204  to rotate lever arm  203  upward (clockwise in  FIG. 10 ). In one example, the angle of rotation of the cap assembly  102  relative to the closed position may be in the range of approximately 10 to 14 degrees. 
       FIG. 11  is a partial sectional (cutaway) view of the example ink tank  100 , showing internal details of the ink tank and the valve linkage described above in the transient, partially open cap state. In  FIG. 11 , lever arm  206  is rotated downward, which translates through valve body  207  to seat valve seal  209  into value seat  210 , thereby providing a seal between upper chamber  301  and lower chamber  401  and preventing fluid communication between the upper chamber  301  and the lower chamber  401 . 
       FIG. 12  illustrates the example ink tank  100  with the cap assembly rotated to its fully opened position under the force applied by the elastic band  104  described above. It will be appreciated that the internal seal between valve seal  209  and valve seat  210  will be maintained as the cap assembly  102  rotates from the transient position to the fully opened position because the effector  201  remains disengaged from the slider  202 , allowing the spring  204  to hold the lever arm  203  in its upward rotated position. As described above, this position of lever arm  203  corresponds to the seating of valve seal  209  in valve seat  210 . 
     The seal between the upper chamber  301  and the lower chamber  401  isolates the upper chamber to prevent gravitationally induced pressure from causing ink drool at the print head assembly. 
     From the foregoing description, it will be appreciated that the sequence of events that occurs when the cap is opened is reversible when the cap assembly  102  is closed by a user. Between the fully opened state and the transient state, the internal valve is closed and the upper chamber  301  of ink tank body  101  is not sealed by the bung  107 . When the cap assembly reaches the transient position, the bung ( 107 ) seals the upper chamber  301  of ink tank ( 101 ) and the effector  201  engages the slider  202 . From the transient position to the closed position, the effector  201  depresses slider  202 , which rotates lever arm  203  downward and lever arm  206  upward to unseat valve seal  209  from valve seat  210 , reestablishing fluid communication between upper chamber  301  of ink tank body  101  and lower chamber  401  of ink tank body  101 . 
       FIG. 13  illustrates an example printer system  300  with an access door  301  in an open position to allow access to an ink tank bay  302  containing at least one ink tank, such as example ink tank  303 , for filling or refilling.  FIG. 14  is a magnified view of the ink tank bay  302  illustrating one of the example ink tanks  303  and a cap assembly  304  in a fully opened position. The example ink tank  303  and the cap assembly  304  may be similar to the example ink tank  100  and cap assembly  102  described above with reference to  FIGS. 1-12 . In this regard, the cap assembly  304  is attached to the ink tank with a preloaded hinge to rotate the cap assembly  304  from a closed position to an open position when the cap assembly  304  is unlatched. The cap assembly  304  of  FIG. 14  may include a bung to seal the ink tank during a partial rotation of the cap assembly  304  when the cap assembly  304  is unlatched. A spring-loaded linkage may be provided and may be connected to a valve in the ink tank. An effector may extend from the cap assembly  304  to engage and actuate the spring-loaded linkage when the cap assembly  304  is latched and to disengage from the spring-loaded linkage after the cap assembly  304  is unlatched. The spring-loaded linkage opens the valve when engaged with the effector, and closes the valve when disengaged from the effector. The bung maintains a tank seal until the internal valve is closed. 
     Referring now to  FIG. 15 , a flowchart illustrates an example method  500  for linking cap and valve actuation in an ink tank. The example method includes sealing an ink tank with a cap assembly comprising a bung and an effector, such as cap assembly  102  in  FIG. 4  illustrating bung  107 , and cap assembly  102  in  FIG. 7  illustrating effector  201  (block  501 ). Example method  500  further includes rotating the cap assembly from a closed position to a first position with a preloaded hinge to close a valve in the ink tank (block  502 ). For example,  FIG. 10  illustrates cap assembly  102  rotated by hinge  104  to a first, partially rotated position to disengage effector  201  from the external linkage comprising slider  202 , external lever arm  203 , hinge  204 , and sealed spline  205 .  FIG. 11  illustrates the internal linkage comprising lever arm  206 , valve body  207 , and valve seal  209  seated in valve seat  210  to seal (close) the valve. Finally, example method  500  includes rotating the cap assembly to a second position with the preloaded hinge, where the ink tank is unsealed and the valve in the ink tank remains closed (block  503 ). For example,  FIG. 12  illustrates cap  102  rotated to a second, fully opened position where the effector  102  is disengaged from the linkage described above, and the linkage is in the same position as in  FIG. 10 , corresponding to a closed valve 
     Thus, in accordance with various examples described herein, linking the actuation of the external cap and internal valve of an ink tank during ink filling operations insures that a valve internal to the ink tank is sealed before an external seal is broken and negative backpressure in the cartridge&#39;s ink tank is lost. 
     The foregoing description of various examples has been presented for purposes of illustration and description. The foregoing description is not intended to be exhaustive or limiting to the examples disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of various examples. The examples discussed herein were chosen and described to explain the principles and the nature of various examples of the present disclosure and its practical application to enable one skilled in the art to use the present disclosure in various examples and with various modifications as are suited to the particular use contemplated. The features of the examples described herein may be combined in all possible combinations of methods, apparatus and systems. 
     It is also noted herein that while the above describes examples, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope as defined in the appended claims.