Abstract:
The present disclosure relates to a sealing member for sealing an opening in a fluid container. The sealing member receives a hollow tubular member to establish communication between the hollow tubular member and the fluid container. The sealing member includes a resilient sealing portion configured to receive the hollow tubular member. With the hollow tubular member inserted through the resilient scaling portion a compressive seal is formed with an outer surface of the hollow tubular member to limit passage of fluid between the resilient sealing portion and the hollow tubular member. Also included is a lead-in portion on the resilient sealing portion. The lead-in portion guides the hollow tubular member through the resilient sealing portion to establish communication between the hollow tubular member and the fluid container.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to ink-jet printing systems, and more particularly, ink-jet printing systems which make use of ink containers that are replaceable separate from a printhead.  
           [0002]    Ink-jet printers frequently make use of an ink-jet printhead mounted to a carriage that is moved back and fourth across a print media, such as paper. As the printhead is moved across the print media, a control system activates the printhead to deposit ink droplets onto the print media to form images and text.  
           [0003]    Previously used printers have made use of an ink container that is separably replaceable from the printhead. When the ink cartridge is exhausted the ink cartridge is removed and replaced with a new ink container. The uses of replaceable ink containers that are separate from the printhead allow users to replace the ink container without replacing the printhead. The printhead is then replaced at or near the end of printhead life and not when the ink container is exhausted.  
           [0004]    There is an ever-present need for printing systems that are capable of providing low operating costs such as printers that make use of off-axis type ink supplies. In addition, these printing systems should be easy to operate, such as, including some form of memory for storing printing parameters so that the user is not required to adjust printer parameters when the ink container is replaced. These ink supplies should be capable of reliable insertion into the printing system to ensure proper fluid interconnection and proper electrical interconnection with the printer is achieved. In addition, these interconnections should be reliable and should not degrade over time and use. For example, the fluid interconnect should not leak during use or over time and the electrical interconnect should be reliable during use and over time. In addition, these ink cartridges should not require special handling by the user and should be reliable and easily connected by the user to form a positive highly reliable mechanical, electrical, and fluid interconnect with the printer.  
           [0005]    These ink containment systems should be capable of providing ink at high flow rates to a printhead thereby allowing high throughput printing. This ink supply system should be cost effective to allow relatively low cost per page printing. In addition, the ink supply should be capable of providing ink at high flow rates in a reliable manner to the printhead.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention is a sealing member for sealing an opening in a fluid container. The sealing member receives a hollow tubular member to establish communication between the hollow tubular member and the fluid container. The sealing member includes a resilient sealing portion configured to receive the hollow tubular member. With the hollow tubular member inserted through the resilient sealing portion a compressive seal is formed with an outer surface of the hollow tubular member to limit passage of fluid between the resilient sealing portion and the hollow tubular member. Also included is a lead-in portion on the resilient sealing portion. The lead-in portion guides the hollow tubular member through the resilient sealing portion to establish communication between the hollow tubular member and the fluid container.  
           [0007]    Another aspect of the present invention is an ink container for providing ink to an ink jet printing system. The ink jet printing system has a fluid inlet having a hollow needle that has a blunt end and a lateral hole. The ink container includes a first sealing surface for tightly receiving the hollow needle to prevent fluid passage between the hollow needle and the first sealing member when the ink container is in fluid communication with the ink jet printer. Also included is a second sealing surface for receiving a movable sealing member. The movable sealing member is biased against the second sealing member when the hollow needle is at least partially removed from the first sealing member. The second sealing surface is spaced sufficiently from the first sealing surface so that debris resulting from movement of the hollow needle relative to the first sealing surface does not prevent the movable sealing member from seating with the second sealing member.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 depicts a schematic representation of a printing system that includes an ink container of the present invention.  
         [0009]    [0009]FIG. 2 depicts a perspective view of a representation of the printing system of FIG. 1.  
         [0010]    [0010]FIG. 3 depicts a representation of the ink container of FIG. 1 shown in section with the fluid outlet and air inlet shown greatly enlarged.  
         [0011]    [0011]FIG. 4 depicts a cross section of a fluid outlet and an air inlet for the ink container of the present invention shown in engagement with a fluid inlet and air outlet, respectively, associated with a printer portion.  
         [0012]    [0012]FIG. 5 depicts an end view taken across lines  5 - 5  of the fluid outlet shown in FIG. 3.  
         [0013]    [0013]FIG. 6 depicts a section view of the fluid outlet shown in FIG. 5 taken across lines  6 - 6 .  
         [0014]    [0014]FIG. 7 depicts a section view of an alternative embodiment of the fluid outlet shown in FIG. 6.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0015]    [0015]FIG. 1 depicts a schematic representation of a printing system  10  that includes the ink container  12  of the present invention. Also included in the printing device  10  are a printhead  14  and a source of pressurized gas such as a pump  16 . The pump  16  is connected by a conduit  18  for providing a pressurized gas such as air to the ink container  12 . A marking fluid  19  such as ink is provided by the ink container  12  to the printhead  14  by a conduit  20 . This marking fluid is ejected from the printhead  14  to accomplish printing.  
         [0016]    The ink container  12  which is the subject of the present invention includes a fluid reservoir  22  for containing ink  19 , an outer shell  24 , and a chassis  26 . In the preferred embodiment the chassis  26  includes an air inlet  28  configured for connection to conduit  18  for pressurizing the outer shell  24  with air. A fluid outlet  30  is also included in the chassis  26 . The fluid outlet  30  is configured for connection to the conduit  20  for providing a fluid connection between the fluid reservoir  22  and fluid conduit  20 .  
         [0017]    In the preferred embodiment the fluid reservoir  22  is formed from a flexible material such that pressurization of the outer shell produces a pressurized flow of ink from the fluid reservoir  22  through the conduit  20  to the printhead  14 . The use of a pressurized source of ink in the fluid reservoir  22  allows for a relatively high fluid flow rates from the fluid reservoir  22  to the printhead  14 . The use of high flow rates or high rates of ink delivery to the printhead make it possible for high throughput printing by the printing system  10 .  
         [0018]    The present invention is a method and apparatus for forming reliable fluid outlet  30  for forming a fluid interconnection between the ink container  12  and the printing system  10 . More specifically, the fluid outlet  30  associated with the ink container  12  allows for fluids to be transferred in a reliable manner between ink container  12  and the printhead  14 . In addition, the fluid outlet  30  also tends to prevent fluid from leaking from the from the ink container  12  when not connected to the printing system  10  such as during storage and transport. The fluid outlet  30  will be discussed in more detail with respect to FIGS.  3 - 7 . Before discussing the fluid outlet in detail the overall printing system will be discussed with respect to FIG. 2.  
         [0019]    [0019]FIG. 2 depicts one embodiment of the printing system  10  shown in perspective. The printing system  10  includes a printing chassis  38  containing one or more ink container  12  of the present invention. The embodiment shown in FIG. 2 is shown having four similar ink containers  12 . In this embodiment, each ink container contains a different ink color. Therefore, four color printing is accomplished by providing cyan, yellow, magenta and black ink from the four ink containers  12  to one or more printheads  14 . Also included in the printer chassis  38  is a control panel  40  for controlling operation of the printer  10  and a media slot  42  from which print media such as paper is ejected.  
         [0020]    As ink  19  in each ink container  12  is exhausted the ink container  12  is replaced with a new ink container  12  containing a new supply of ink. In addition, the ink container  12  may be removed from the printer chassis  38  for reasons other than an out of ink condition such as changing inks for an application requiring different ink properties or for use on different media. It is important that the ink container  12  be not only accessible within the printing system  10  but also easily replaceable. It is also important that the replacement ink container  12  form reliable interconnects such as fluid interconnect, air interconnect and mechanical interconnect so that the printing system  10  performs reliably.  
         [0021]    It is important that ink spillage and spattering be minimized to provide reliable interconnection between the ink container  12  and printer  10 . Ink spillage is objectionable not only for the operator of the printer who must handle the spattered ink container  12  but also from a printer reliability standpoint. Inks used in ink-jet printing frequently contain chemicals such as surfactants which if exposed to printer components can effect the reliability of these printer components. Therefore, ink spillage inside the printer can reduce the reliability of printer components thereby reducing the reliability of the printer.  
         [0022]    [0022]FIG. 3 depicts a simplified representation of the ink container  12  of the present invention show in section and disconnected from the printing system  10 . The ink container  12  includes the fluid outlet  28 , shown greatly enlarged, which is in fluid communication with the fluid reservoir  22  containing the supply of fluid  19 . The ink container  12  further includes the air inlet  30  that is in communication with an area within the outer shell  24  and not within the fluid reservoir  22 . The application of a pressurized gas, such as air, to this region allows pressurization of the ink container  12  for providing a source of pressurized fluid from the fluid outlet  28 .  
         [0023]    The fluid outlet  28  and air inlet  30  of the present invention includes a sealing member  34  and  36  for sealing each of the fluid outlet  28  and air inlet  30 , respectively, when the ink container  12  is not installed in the printer chassis  38  shown in FIG. 2. More specifically, the sealing member  34  prevents or limits ink leakage from the fluid outlet  28  when the ink container is not installed in the printer chassis  38 . In addition, the sealing member  34  and  36  provides a seal between the fluid outlet  28  and a fluid inlet (not shown) associated with the printer chassis  38  and a seal between the air inlet  30  and an air outlet (not shown) associated with the printer chassis  38 . The sealing member  34  and  36  tends to limit or prevent leakage of both air and ink when the ink container  12  is properly installed in the printer chassis  38 . The sealing member will be discussed in more detail with respect to FIGS.  4 - 7 .  
         [0024]    [0024]FIG. 4 illustrates further detail of the preferred sealing member  36  and  38  associated with the fluid outlet  30  and air inlet  28 , respectively, of the ink container  12 . As shown in FIG. 4 the fluid outlet  28  and air inlet  30  is shown connected to a corresponding fluid inlet  44  and air outlet  42  associated with an ink container receiving station  46  on the printer chassis  38 .  
         [0025]    In this preferred embodiment the fluid inlet  44  associated with the ink container receiving station  46  includes a housing  48  and outwardly extending needle  50  having a closed, blunt upper end, a blind bore (not shown) and a lateral hole  52 . The blind bore is fluidly connected to the lateral hole  52 . The end of the needle  50  opposite the lateral hole  52  is connected to the fluid conduit  20  for providing ink to the printhead  14  shown in FIG. 1. A sliding collar  54  surrounds the needle  50  and is biased upwardly by spring  56 . The sliding collar  54  has a compliant sealing portion with an exposed upper surface and an inner surface in direct contact with the needle  50 .  
         [0026]    The air outlet  42  on the ink container receiving station  46  is similar to the fluid inlet  44  except does not include the sliding collar  54  and the spring  56 . The air outlet  42  on the ink container receiving station  46  includes a housing  58  and an outwardly extending needle  60  having a closed, blunt upper end, a blind bore (not shown) and a lateral hole  62 . The blind bore is fluidly connected to the lateral hole  62 . The end of the needle  60  opposite the lateral hole  62  is connected to the air conduit  18  for providing pressurized air to the ink container  12  shown in FIG. 1.  
         [0027]    In this preferred embodiment, the fluid outlet  30  associated with the ink container  12  includes a hollow cylindrical boss  64  that extends outward from an ink container chassis  66 . The end of the boss  64  toward the chassis  66  opens into a conduit  68  which is fluidly connected to the ink reservoir  22  thereby providing fluid to the fluid outlet  30 . A spring  70  and sealing ball  72  are positioned within the boss  64  and held in place by a sealing member such as compliant septum  34  and a crimp cover  74 . The spring  70  biases the sealing ball  72  against the septum  34  to form a fluid seal preventing fluid leakage from the ink container  12  when the ink container is removed from the receiving station  46 . In addition, the sealing member  34  forms a seal to prevent fluid within the ink container  12  from passing between the sealing member  34  and the outwardly extending needle  50  when the ink container  12  is properly inserted into the printer chassis  38 . The sealing member  34  will be discussed in more detail with respect to FIGS.  5 - 7 .  
         [0028]    In the preferred embodiment, the air inlet  28  associated with the ink container  12  is similar to the fluid outlet  30  except that the additional seal formed by the spring  70  and sealing ball  72  are eliminated. The air inlet  28  associated with the ink container  12  includes a hollow cylindrical boss  76  that extends outward from an ink container chassis  68 . The end of the boss  76  toward the chassis  68  opens into a conduit  78  which is in communication with a region between the outer shell  24  and an outer portion of the fluid reservoir  22  for pressurizing the fluid reservoir  22 . The sealing member  36  such as compliant septum and a crimp cover  80  form a seal to prevent pressurized air within the ink container  12  from passing between the sealing member  36  and the outwardly extending needle  60  when the ink container  12  is properly inserted into the printer chassis  38 .  
         [0029]    [0029]FIGS. 5 and 6 depicts greater detail of the sealing member  34  shown in FIG. 4. Sealing member  36  is similar to sealing member  34  and therefore will not be discussed in detail. FIG. 5 depicts an end view taken across lines  5 - 5  of the fluid outlet  28  shown in FIG. 3. The crimp cap  74  is shown positioned on the sealing member  34 . The sealing member  34  includes a slit  82  that is centrally located in the sealing member and extends axially through the sealing member  34 . As shown in FIG. 6, the slit  82  is tapered from a leading edge  84  to a trailing edge  86  of the sealing member  34 , relative to a direction of insertion into the printer chassis  38 . The crimp cap  74  includes an opening  88  for allowing the blunt end of needle  50  to engage slit  82  and penetrate through the sealing member  34  to accomplish fluid communication between the ink container  12  and the printer chassis  38 .  
         [0030]    A lead-in portion  90  is provided at the leading edge  84  of the sealing member  34  to aid in guiding the blunt end of the needle  50  into the slit  82  in the event of needle  50  misalignment during the insertion of the ink container  12  into the printer chassis  38 . In the preferred embodiment, the lead-in portion  90  is concave or bowl-shaped to guide the needle  50  to the slit  82 . The lead-in portion  90  may be a variety of other shapes each of which tend to guide the needle  50  to the slit  82 . In the preferred embodiment a lubricant is disposed within this lead-in portion  90 . The lubricant is a suitable lubricant for reducing friction between the blunt end of the needle  50  and the lead-in portion  90  of the sealing member  34  to minimize or eliminate damage such as ripping or tearing of the sealing member  34  during insertion of the needle  50  through the slit  82 . In the preferred embodiment, the lubricant is poly(ethylene glycol) PEG 400.  
         [0031]    The sealing member  34  seals the ink container  12  when the needle  50  is removed from the sealing member  34 . Therefore, it is important that the sealing member  34  be under compression so that the sealing member  34  creep shut to seal the slit  82  in the sealing member  34 . This compression is accomplished by a compressive fit between the sealing member  34  and the crimp cap  74 . In addition, it is important that the sealing member material have sufficient resiliency to spring back quickly to seal the slit  82  such that ink leakage is minimized or eliminated when the ink container  12  is removed from the printer chassis  38 .  
         [0032]    The slit  82  in the preferred embodiment is tapered to form a well-defined seal area between the sealing member  34  and the needle  50 . The slit may be a variety of other shapes such as an hourglass shape or some other contour which provides a small sealing area that provides a well controlled contact point between the sealing member  34  and the needle. In addition, it is important that the contour of the slit  82  deflect in a controlled manner as the needle  50  is inserted to provide a well controlled force about the contact point between the sealing member  34  and needle  50  to minimize ink leakage between the needle  50  and the sealing member  34 . Although the embodiment shown in FIG. 5 makes use of a contoured slit to achieve a well controlled sealing surface alternatively the sealing member  34  adjacent the needle  50  can be contoured to form a well controlled sealing surface. For example, a sealing surface adjacent the needle  50  can have an hourglass shaped cross-section that thickens radically from the central axis.  
         [0033]    In the preferred embodiment, a secondary seal is provided to eliminate or reduce fluid leakage when the needle  50  is removed from the sealing member  34 . This secondary seal is provided by a sealing member  72  such as a sealing ball that is biased against a complementary shaped sealing surface  92  at the trailing edge  86  of the sealing member  34 . The sealing surface  92  is contoured to provide a well-defined sealing surface with the sealing member  72 . In the preferred embodiment the sealing member  72  is biased towards the sealing surface  92  when the needle  50  is removed from the sealing member  34 . Upon insertion of the needle  50  into the sealing member  34  the blunt end of the needle  50  engages the sealing member  72  and displaces it from the sealing surface  92  allowing fluid to pass between the ink container  12  and the printer chassis  38 .  
         [0034]    An important aspect of the sealing member  34  of the present invention is that the sealing member  72  should be spaced from the slit  82 . The spacing between the sealing member  72  and the slit  82  having sealing surfaces is represented by a distance d in FIG. 6. To Applicant&#39;s surprise, if the spacing represented by distance d is not sufficient the sealing member  72  is prevented from properly engaging the sealing surface  92  because of debris dislodged from the slit  82  which prevent the sealing ball  72  from properly engaging the sealing surface  92 . Applicant discovered that repeated insertions and removals of the needle  50  through the slit  82  tends to erode or tear portions of the sealing member  34  which tend to accumulate in the region  94  between the sealing member  72  and the slit  82 . It was discovered that when the spacing represented by distance d between the sealing ball  72  and the slit  82  is insufficient this debris tends to prevent the sealing ball  72  from properly engaging the seal  92  allowing fluid leakage past the secondary seal when the needle  50  is removed. Therefore, it is important that a debris accumulation region  94  be provided that is sufficiently large provided to allow debris accumulation without interfering with the seating of the sealing member  72  with the sealing surface  92 . The size of the debris accumulation region  94  or distance d that is required will in general depend on the erosion characteristics of the sealing member  34  and the degree of frictional forces between the needle  50  and the sealing member  34  during insertion and removal through slit  82 .  
         [0035]    [0035]FIG. 7 represents an alternative embodiment of the sealing member  34  shown in FIG. 6. Similar numbering is used to represent similar structures. The sealing member  34 ′ shown in FIG. 7 is similar to the sealing member  34  shown in FIG. 6 except for a lead-in  90 ′ is contoured differently from the lead-in  90  shown in FIG. 6. The lead-in  90 ′ is more shallow than the lead-in  90  shown in FIG. 6. In addition, the sealing surface  92 ′ at the secondary seal is contoured differently than the more contoured sealing surface  92  shown in FIG. 6. In addition, this sealing surface  92 ′ is disposed relative to the slit  82 ′ such that with the sealing member  72  positioned to engage the sealing surface  92 ′ a space d′ is provided between the slit  82 ′ and the sealing member  72  to accommodate debris or particles dislodged from the sealing member  34 ′.  
         [0036]    It is critical that ink leakage from the ink container  12  be reduced or eliminated both when the ink container  12  is inserted into the printer chassis  38  as well as when the ink container  12  is removed from the printer chassis  38 . Ink leakage from the ink container  12  when installed in the printer chassis  38  can damage the printer. In addition, ink leakage during storage and transportation of the ink container  12  is unacceptable for the printer user.