Patent Publication Number: US-6209996-B1

Title: Method and apparatus for securing an ink container

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This is a continuation of application Ser. No. 08/869,150 filed on Jun. 4, 1997 now U.S. Pat. No. 5,949,459. 
    
    
     This application is related to commonly assigned co-pending patent application, Ser. No. 08/869,038 filed herewith, entitled “Electrical Interconnect for Replaceable Ink Containers” incorporated herein by reference, and is related to commonly assigned co-pending patent application, Ser. No. 08,871,566, filed herewith, entitled “Replaceable Ink Container Adapted to Form Reliable Fluid, Air and Electrical Connection to a Printing System ” incorporated herein by reference, and is related to commonly assigned co-pending patent application, Ser. No. 08,869,240, filed herewith, entitled “Ink Container with an Inductive Ink Level Sense” incorporated herein by reference, and is related to commonly assigned co-pending patent application, Ser. No. 08/869,122, filed herewith, entitled “Ink Level Estimation Using Drop Count and Ink Level Sense” incorporated herein by reference, and is related to commonly assigned co-pending patent application, Ser. No. 08/868,773, filed herewith, entitled “Ink Container Providing Pressurized Ink with Ink Level Sensor” incorporated herein by reference and is related to commonly assigned co-pending patent application, Ser. No. 08/868,927, filed herewith, entitled “An Ink Container Having a Multiple Functioned Chassis” incorporated herein by reference and is related to commonly assigned co-pending patent application, Ser. No. 08/869,023, filed herewith, entitled “High Performance Ink Container with Efficient Construction” incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     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. 
     Inkjet printers frequently make use of an ink-jet printhead mounted to a carriage which 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 eject or jet ink droplets onto the print media to form images and text. 
     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 use 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. 
     One type of ink container spaced from the printhead is disclosed in U.S. Pat. No. 4,558,326 entitled “Purging System for Ink Jet Recording Apparatus” to Kimura et al. discloses the use of a replaceable ink cartridge having a hermetically sealed ink container bag disposed therein. Kimura makes use of the selective application of compressed air to the ink cartridge for pressurizing the ink container bag for forcing ink through a recording head thereby purging bubbles or solid matter from the ink flow path. Another type of ink cartridge is disclosed in U.S. Pat. No. 4,568,954 entitled “Ink Cartridge Manufacturing Method and Apparatus” to Rosback. The Rosback cartridge is a replaceable ink cartridge that is pressurizable. 
     There is an ever present need for ink containment systems that are 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. 
     These ink supplies should be easily replaceable as well as form reliable fluid connection with the printing device while minimizing or eliminating ink spillage which can reduce the reliability of the printing device. The ink supply should be capable of forming additional interconnects such as electrical as well as pressurized gas interconnects between the printing device and the ink container. 
     SUMMARY OF THE INVENTION 
     A replaceable ink container for providing ink to a printing device. The ink container has leading and trailing edges with respect to an insertion direction for the ink container into the printing device. The ink container includes a fluid outlet disposed on the leading edge and configured for connection to corresponding printing device fluid inlet. The ink container also includes an engagement feature disposed toward the trailing edge and extending outwardly from an ink container outer surface. The engagement feature is configured for insertion into a recessed engagement feature associated with the printing device. With the ink container properly positioned within the printing device and biased in a direction opposite the insertion direction, the engagement feature associated with the ink container engages the recessed engagement feature associated with the printing device. The engagement of the engagement features on each of the ink container and printer maintain the fluid outlet in engagement with corresponding printing device fluid inlet. 
     In one preferred embodiment the engagement feature associated with the ink container extends downwardly relative to a gravitational frame of reference. In this preferred embodiment the recessed engagement feature associated with the printing device defines a hook that is configured for engaging the engagement feature associated with the ink container. In this embodiment the ink container includes a pressurized gas inlet electrical contacts for connection with corresponding gas outlet and electrical contacts, respectively, associated with the printing device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 depicts a schematic representation of a printing system that includes an ink container of the present invention. 
     FIG. 2 depicts a perspective view of a representation of the printing system of FIG.  1 . 
     FIG. 3 depicts a perspective view of a leading edge portion of the ink container of the present invention. 
     FIG. 4 depicts a side plan view of the ink container of the present invention. 
     FIG. 5 depicts a perspective view of an ink container receiving station shown partially broken away with an ink container of the present invention installed. 
     FIG. 6 depicts a cross-section taken across line A-A′ of the ink container receiving station of FIG. 5 shown partially broken away. 
     FIG. 7 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 the ink container receiving station shown in FIG.  5 . 
     FIGS. 8A,  8 B,  8 C, and  8 D depict a sequence of side plan views, shown partially broken away, illustrating the insertion and latching of the ink container of the present invention into the receiving station shown in FIG.  5 . 
     FIGS. 9A,  9 B,  9 C and  9 D depict a sequence of side plan views, shown partially broken away, illustrating the removal of the ink container of the present invention from the receiving station. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 depicts a schematic representation of a printing system, printing device or printer  10  which includes the ink container  12  of the present invention. Also included in the printing device  10  is 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. 
     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 sealing portion or cap  26 . In the preferred embodiment the cap  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 cap  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 . 
     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 . 
     In the preferred embodiment, the ink container  12  also includes a plurality of electrical contacts, as will be discussed in more detail with respect to FIG.  3 . The electrical contacts provide electrical connection between the ink container  12  and printer control electronics  32 . The printer control electronics  32  controls various printing system  10  functions such as, but not limited to, printhead  14  activation to dispense ink and activation of pump  16  to pressurize the ink container  12 . In one preferred embodiment the ink container  12  includes an information storage device  34  and an ink level sensing device or ink volume sensing decice  36 . The information storage device  34  provides information to the printer control electronics for controlling printer  10  parameters such as ink container  12  volume as well as ink characteristics, to name a few. The ink level sensing device  36  provides information relating to current ink volume in the ink container  12  to the printer control electronics  32 . 
     FIG. 2 depicts one embodiment of the printing system  10  shown in perspective. The printing system  10  includes a printing chassis or printer chassis  38  containing one or more ink containers  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. 
     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 mechanical engagement with the printer chassis  38  as well as properly form necessary interconnects such as fluid interconnect, air interconnect and electrical interconnect so that the printing system  10  performs reliably. The present invention is directed to a method and apparatus for reliably engaging the ink container  12  into the printer chassis  38  to insure proper interconnections are formed. The present invention provides an engaging system that is positive and provides tactile feedback to the user indicating the ink container  12  is properly inserted and secured within the print chassis  38 . 
     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. 
     FIGS. 3 and 4 depict the ink container  12  of the present invention. The ink container  12  includes a housing or outer shell  24  which contains the fluid reservoir  22  shown in FIG. 1 for containing ink  19 . The outer shell  24  has a leading edge  50  and trailing edge  52  relative to a direction of insertion for the ink container  12  into the printer chassis  38 . The leading edge  50  includes the air inlet  28  and the fluid outlet  30  which are configured for connection to the air pump  16  and the printhead  14 , respectively, once the ink container  12  is properly inserted into the printer chassis  38 . The air inlet  28  and fluid outlet  30  will be discussed in more detail with respect to FIG. 8. A plurality of electrical contacts  54  are disposed on the leading edge  50  for providing electrical connection between the ink container  12  and printer control electronics  32 . In one preferred embodiment the plurality of electrical contacts  54  include a first plurality of electrical interconnects that are electrically interconnected to the information storage device  34  and a second plurality of electrical interconnects which are electrically interconnected to the ink volume sensing device  36  shown in FIG.  1 . In the preferred embodiment the information storage device  34  is a semiconductor memory and the ink volume sensing device  36  is an inductive sensing device. 
     The ink container  12  includes one or more keying and guiding features  58  and  60  disposed toward the leading edge  50  of the ink container  12 . The keying and guiding features  58  and  60  work in conjunction with corresponding keying and guiding features on the printer chassis  38  to assist in aligning and guiding the ink container  12  during insertion of the ink container  12  into the printer chassis  38 . The keying and aligning features  58  and  60  in addition to providing a guiding function also provide a keying function to insure only ink containers  12  having proper ink parameters such as proper color and ink type are inserted into a given slot of the printer chassis  38 . Keying and guiding features are discussed in more detail in co-pending patent application Ser. No. 08/566,521 filed Dec. 4, 1995 entitled “Keying System for Ink Supply Containers” assigned to the assignee of the present invention and incorporated herein by reference. 
     Latch features  62  are provided toward the trailing edge  52  of the ink container  12 . The latch features  62  which are the subject of the present invention work in conjunction with corresponding latching features on the printer portion to secure the ink container  12  within the printer chassis  38  such that proper interconnects such as pressurized air, fluidic and electrical are accomplished in a reliable manner. Each latch feature  62  is a molded tang which extends downwardly relative to a gravitational frame of reference. The ink container  12  shown in FIG. 4 is positioned for insertion into a printer chassis  38  along the Z-axis of coordinate system  64 . In this orientation gravitational forces act on the ink container  12  along the Y-axis. 
     At the trailing edge  52  of the ink container  12  is a flanged outer portion  66  which provides several functions. Firstly, the flanged portion  66  is larger than the insertion slot within the printer chassis  38  thereby preventing the ink container  12  from backward insertion. In addition, the flanged portion  66  provides a gripping portion for insertion of the ink container  12  into the printer chassis  38 . 
     FIG. 5 depicts an ink container  12  of the present invention shown secured within an ink container receiving station  72  within the printer chassis  38 . Because ink container  12  is similar except for keying and guiding features  58  and  60  and corresponding ink properties contained within the respective fluid reservoir, the same reference numbering will be used for each ink container  12 . An ink container indicia  70  may be positioned proximate each slot in the ink container receiving station  72 . The ink container indicia  70  may be a color swatch or text indicating ink color to assist the user in color matching for inserting the ink container  12  in the proper slot within the ink container receiving station  72 . As discussed previously the keying and guiding features  58  and  60  shown in FIGS. 3 and 4 prevent ink containers from being installed in the wrong slot. Installation of an ink container in the wrong slot can result in improper color mixing or the mixing of inks of different ink types each of which can result in poor print quality. 
     Each receiving slot within the ink container receiving station includes a corresponding keying and guiding slot  74  and recessed latching portions or latching features  76 . The guiding slot  74  cooperates with the keying and guiding features  58  and  60  to guide the ink container  12  into the ink container receiving station  72 . The keying and guiding slot  74  associated with the corresponding keying and guiding feature  60  is shown in FIG.  5  and the keying and guiding slot associated with the corresponding keying and guiding feature  58  on the ink container  12  is not shown. The latching features  76  are configured for engaging the corresponding latch features  62  on the ink container  12  as will be discussed in more detail with respect to FIGS. 6,  8  and  9 . 
     FIG. 6 shows a cross-section of a single ink container receiving slot within the ink container receiving station  72 . The ink container receiving slot includes interconnect portions for interconnecting with the ink container  12 . In the preferred embodiment these interconnect portions include a fluid inlet  80 , and air outlet  82  and an electrical interconnect  84 . Each of the interconnects  80 ,  82 ,  84  are positioned on a floating interconnect portion  86  which is biased along the Z-axis toward the installed ink container  12 . 
     The fluid inlet  80  and the air outlet  82  associated with the ink container receiving station  72  are configured for connection with the corresponding fluid outlet  30  and air inlet  28 , respectively on the ink container  12 . The electrical interconnect  84  is configured for engaging the plurality of electrical contacts  54  on the ink container  12 . 
     It is the interaction between the keying and guiding features  58  and  60  associated with the ink container  12  and the corresponding keying and guiding feature  74  associated with the ink container receiving station  72  which guide the ink container  12  during the insertion such that proper interconnections are accomplished between the ink container  12  and the printer chassis  38 . In addition, sidewalls associated with each slot in the ink container receiving station  72  engage corresponding sidewalls of the outer shell  24  of ink container  12  to assist in guiding and aligning the ink container  12  during insertion into the ink container receiving station  72 . 
     FIG. 7 illustrates further detail of the fluid outlet  30  and air inlet  28  associated with the ink container  12  and the corresponding fluid inlet  80  and air outlet  82  associated with the ink container receiving station  72 . 
     In this preferred embodiment the fluid inlet  80  associated with the ink container receiving station  72  includes a housing  90  and outwardly extending needle  92  having a closed, blunt upper end, a blind bore (not shown) and a lateral hole  94 . The blind bore is fluidly connected to the lateral hole  94 . The end of the needle  92  opposite the lateral hole  94  is connected to the fluid conduit  20  for providing ink to the printhead  14  shown in FIG. 1. A sliding collar  96  surrounds the needle  92  and is biased upwardly by spring  98 . The sliding collar  96  has a compliant sealing portion with an exposed upper surface and an inner surface in direct contact with the needle  92 . 
     The air outlet  82  on the ink container receiving station  72  is similar to the fluid inlet  80 . The air outlet  82  on the ink container receiving station  72  includes a housing  100  and outwardly extending needle  102  having a closed, blunt upper end, a blind bore (not shown) and a lateral hole  104 . The blind bore is fluidly connected to the lateral hole  104 . The end of the needle  102  opposite the lateral hole  104  is connected to the air conduit  18  for providing pressurized air to the ink container  12  shown in FIG. 1. A sliding collar  106  surrounds the needle  102  and is biased upwardly by spring  108 . The sliding collar  106  has a compliant sealing portion with an exposed upper surface and an inner surface in direct contact with the needle  102 . Alternatively, the sliding collar  106  and spring  108  can be eliminated because a fluid seal is not required at the air interface. 
     In this preferred embodiment, the fluid outlet  30  associated with the ink container  12  includes a hollow cylindrical boss  110  that extends outward from an ink container chassis  112 . The end of the boss  110  toward the chassis  112  opens into a conduit  114  which is fluidly connected to the ink reservoir  22  thereby providing fluid to the fluid outlet  30 . A spring  116  and sealing ball  118  are positioned within the boss  110  and held in place by a compliant septum  120  and a crimp cover  122 . The spring  116  biases the sealing ball  118  against the septum  120  to form a fluid seal. 
     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  116  and sealing ball  118  are eliminated. The air inlet  28  associated with the ink container  12  includes a hollow cylindrical boss  124  that extends outward from an ink container chassis  112 . The end of the boss  124  toward the chassis  112  opens into a conduit  126  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 . A compliant septum  128  and a crimp cover  130  form a seal. 
     The insertion of the ink container  12  into the ink container receiving station  72  will now be discussed with respect to FIGS. 8A,  8 B,  8 C, and  8 D. As shown in FIG. 8A the ink container  12  is inserted along an insertion direction corresponding to the Z-axis in coordinate system  64 . During insertion the guiding and keying features  58  and  60  associated with the ink container  12  in conjunction with guiding and keying features  74  associated with the ink container receiving station  72  guide and align the proper ink container  12  into the ink container receiving station. 
     As shown in FIG. 8B the keying and guiding features  58  and  60  associated with the ink container  12  together with the keying and guiding features  74  associated with the ink container receiving station  72  align and guide the ink container  12  so that the fluid outlet  30  and air inlet  28  engage the corresponding fluid inlet  80  and air outlet  82 , respectively, associated with the ink container receiving station  72 . 
     As the ink container  12  is inserted into the ink container receiving station  72  the crimp caps  122  and  130  are guided into the internal bores of housings  90  and  100 , respectively, by the keying and guiding features  58 ,  60  and  74 . As the ink container  12  is further inserted, the alignment of the ink container  12  within the ink container receiving station  72  is then defined by the leading edge or crimp caps  122  and  130  and the internal bores of the housings  90  and  100 , respectively. As the ink container  12  is pushed inward or sideways, along the z axis of coordinate system  64 , into the receiving station  72  the crimp caps  122  and  130  engage the sealing members  96  and  106 , respectively, compressing springs  98  and  108 . 
     During insertion of the ink container  12  into the ink container receiving station  72 , the outwardly extending needles  92  and  102  pierce the septums  120  and  128 , respectively of the fluid outlet  30  and air inlet  28 , receptively, of ink container  12 . As needle  92  pierces the septum  120  of fluid outlet  30  and displaces the sealing ball  118  a fluid flow path is established from the ink reservoir  22  into the lateral hole  94  of the needle  92  through the blind bore and into the fluid conduit  20  to the printhead  14 . Similarly, as needle  102  pierces the septum  128  of air inlet  28  an air flow path is established between the air pump  16  to a region between the ink container outer shell  24  and ink reservoir  22 . 
     Once the ink container  12  is inserted into the ink container receiving station  72  such that the latch features  62  on the ink container  12  moves past the latching features  76  associated with the ink container receiving station  72  as shown in FIG. 8C, the ink container  12  drops downward along the y axis. As the ink container  12  drops down the springs  98  and  108  bias the ink container  12  in a direction opposite the insertion direction into a latched position such that the latch features (i.e. engagement features)  62  on the ink container  12  engage the latching features (i.e. recessed engagement features)  76  associated with the receiving station  72  as shown in FIG.  8 D. In addition, the floating interconnect portion  86  is spring biased along the Z-axis opposite the insertion direction. Therefore, this spring force together with springs  98  and  108  tends to bias the ink container  12  such that the engagement features  62  and  76  engage. 
     The latch feature  62  is shown partially broken away to more clearly show the engagement of engagement features  62  and  76 . Once in the latched position the ink container  12  is firmly secured in the ink container receiving station  72 . In this latched position fluid communication between the fluid outlet  30  and fluid inlet  80  is established and communication between the air outlet  82  and air inlet  28  is established. In addition, in the latched position electrical connection is established between the plurality of electrical contacts  54  associated with the ink container  12  and the electrical interconnact  84  associated with the ink container receiving station  72 . 
     FIGS. 9A,  9 B,  9 C and  9 D illustrates the removal of ink container  12  from the printer chassis  38 . FIG. 9A shows the ink container in a latched position within the ink container receiving station  72 . The application of a force at an upper portion  136  of the trailing edge  52  of the ink container  12  identified by a circular depression is used to release the ink container  12 . This force, when applied in a direction along the direction of insertion, urges the ink container  12  inwardly, compressing springs  98  and  108 , and moving the engagement feature  62  inwardly and away from the engagement feature  76 . Because the force applied at the upper portion  136  creates an unbalanced force a torque results tending to lift the trailing edge  52  of the ink container  12  in an upward direction as shown in FIG.  9 B. As the force applied at the upper portion  136  of the trailing edge is removed the force applied by the springs  98  and  108  tends to urge the ink container  12  outward in a direction opposite the direction of insertion as shown in FIG.  9 C. As the ink container  12  is urged outward from the ink container receiving station  72  the engagement portion  62  moves up and over the engagement portion  76  allowing removal of the ink container  12  from the ink container receiving station  72  as shown in FIG.  9 D. 
     The method and apparatus for securing the ink container  12  of the present invention provides a reliable technique for securing the ink container  12  within the ink container receiving station  72 . This technique secures the ink container so that reliable interconnections such as fluid, air and electrical interconnects are formed between the ink container  12  and the printer portion. This technique of the present invention provides for an insertion and removal of the ink container which is quick and easily accomplished by the user.