Patent Publication Number: US-2006012628-A1

Title: Transportation pad for ink cartridge

Description:
BACKGROUND OF THE INVENTION  
      The present invention relates to transportation pads useful for sealing and protecting an ink outlet such as the ink ejection outlet of an ink cartridge, an ink recording head, or an air communication hole, or for fixing, tentatively, an article against the ink outlet of an ink cartridge.  
      The ink outlet of an ink cartridge typically includes ink nozzles. Conventionally, in an ink jet apparatus, clogging or leaking of the ink nozzles during transportation, or trouble in ink ejection, is prevented by covering the ink ejection outlet face of the cartridge with a capping device or sealing member. Conventional capping devices, which may include flat contact pads, are liable to cause leakage of ink during transportation of an ink jet cartridge owing to rough movement and/or lateral forces on the pads which also can result in dislocation of the pads relative to the ink nozzles during transportation. The leakage leads to soiling of the cartridge as well as the interior of the recording apparatus and/or surrounding enclosure or housing into which the cartridge is inserted for use. Increasing the overall compression force between a pad and the ink nozzles is one method for overcoming the undesired dislocation of the capping device relative to the ink cartridge. This increased compression force, however, has a negative effect on a nozzle plate and/or flexible circuit surrounding the ink nozzles, such as loosening, bending, dislocating the plate, etc. In particular, the nozzle plate can become misaligned or damaged as a result of excessive compression force and increased lateral forces between the plate and the pad.  
      Another method for sealing an ink outlet is through the use of sealing tape. The sealing tape includes a sealing member with an adhering portion that bonds to a joint portion comprising the nozzle plate and surrounding areas. Another portion of the sealing member includes a bonding area having a pressure sensitive adhesive for holding the sealing member in place over the ink nozzles and adjacent areas. The elongation or bending properties of the sealing member in a thin film form (e.g. a tape) are desired for resistance to environmental variation and for durability. Sealing tape, however, typically degrades with changes to environmental conditions, i.e. temperature and time. Further, a conventional protective sealing tape which is constituted at least of a support and a pressure sensitive adhesive layer laminated thereon, is not satisfactory in sealing of an irregular face, resulting in gradual peeling during long term transport or storage and which peeling causes leakage of ink. If the adhesion force of the sealing tape is increased for more reliable prevention of ink leakage or evaporation and air inflow, the adhesive agent is intensified which results in an undesirable residue of adhesive remaining around the periphery of, and on, the ink ejecting nozzles when the sealing tape is removed. Additionally, sealing tapes cannot be reused effectively for subsequent sealing of the ink nozzles when an ink cartridge is removed from a printer and stored for future use.  
      In another approach, a cap member is installed over the sealing tape to press the tape by the elastic character of the cap member against the periphery of the ink nozzles. This alternative is a combination of the conventional capping device and the sealing tape and, thus, includes the inherent problems associated with each method and requires the use of two components.  
      Although many capping devices and sealing devices have been proposed to overcome the aforementioned problems, devices heretofore available have not been satisfactory for sealing an ink outlet so as to maintain sealing engagement over long periods of time and/or over extreme environmental variations. Moreover, sealing devices heretofore available have not been effective in maintaining the orientation of the nozzle plate of a cartridge during installation of the seal and, thereafter, storage, and multiple removals and replacements of the capping and/or sealing device relating to the ink cartridge.  
     SUMMARY OF THE INVENTION  
      The present invention provides an improvement for a transportation pad or sealing member of the type described which overcomes the referred to difficulties and others, and is easy to manipulate, while maintaining appropriate sealing forces on the ink ejecting nozzles. More particularly in this respect, a device is provided for protecting and sealing ink nozzles of an ink jet cartridge which includes a sealing member of resilient material having a compressible contact portion with a profiled contact surface for sealing against an ink nozzle. The nozzle includes a nozzle plate surrounding associated ink nozzles, and the contact surface of the pad is curvilinear and convex in the direction of contact with the nozzle. A transport clip is provided for selective attachment to the ink jet cartridge and supports the sealing member for progressive compressional engagement with the nozzle when the cartridge is assembled therewith and for progressive decompressional disengagement with the nozzle when the cartridge is separated from the clip.  
      The progressive compression and decompression provided by the curvilinear contact surface of the pad prevents the pad from loosening, bending, dislocating, etc., the nozzle plate and/or flexible circuit from the cartridge during installation and removal, respectively. It will be appreciated that the progressive decompression results in breaking the surface tension between the nozzle plate and pad around the perimeter of the nozzle plate first during cartridge removal from the transport clip. This advantageously progressively reduces the force against and laterally across the nozzle plate to maximize or eliminate the tendency to displace the plate relative to the cartridge.  
      In accordance with one aspect of the invention, the curvilinear surface can be a single surface profiled to seal against all of the nozzle openings through a nozzle plate, or can be a plurality of separate surfaces profiled to seal against a corresponding line of openings through a nozzle plate. The curvilinear surface may, for example, be dome shaped, in the form of a longitudinal part of a solid cylinder, or curved both longitudinally and laterally. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The invention may take physical form in certain parts and arrangements of parts, embodiments of which will be described in detail in the specification, and are illustrated in the accompanying drawings, which form a part hereof and wherein:  
       FIG. 1  is a perspective view of a transport clip and a sealing pad according to the present invention;  
       FIG. 2  is a perspective view of an ink cartridge showing the print head portion thereof;  
       FIG. 3  is an enlarged perspective view of the sealing pad shown in  FIG. 1 ;  
       FIG. 4  is an enlarged cross sectional elevation view of the sealing pad shown in  FIG. 3  in a pre-compressed condition;  
       FIG. 5  is an enlarged cross sectional elevation view of the pad in  FIG. 4  in a compressed condition;  
       FIG. 6  is an enlarged perspective view of a sealing pad according to a second embodiment of the present invention;  
       FIG. 7  is an enlarged cross-sectional elevation view of the sealing pad shown in  FIG. 6  in a pre-compressed condition;  
       FIG. 8  is an enlarged cross-sectional elevation view of the pad in  FIG. 7  in a compressed condition;  
       FIG. 9  is an enlarged perspective view of a sealing pad according to a third embodiment of the present invention;  
       FIG. 10  is an enlarged cross-sectional elevation view of the sealing pad shown in  FIG. 9  in a pre-compressed condition; and,  FIG. 11  is an enlarged cross-sectional elevation view of the pad in  FIG. 10  in a compressed condition. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION  
      Referring now in greater detail to the drawings, wherein the showings are for the purpose of illustrating preferred embodiments of the invention only, and not for the purpose of limiting the invention,  FIG. 1  shows a transport clip TC with a sealing member or pad  10  according to the present invention attached thereto and which clip TC and pad are adapted to be attached to an ink jet cartridge  12  shown in  FIG. 2  in the manner and for the purpose set forth more fully hereinafter. Ink jet cartridge  12  comprises an ink jet unit  13  including a print head or nozzle portion  14  on which a nozzle plate  15  having a multiplicity of ink nozzles or orifices  16  therethrough is adhesively mounted. The ink jet unit  13  further includes an ink tank or reservoir  18  for holding ink. The cartridge  12  has a tip portion  20  projecting from a bottom surface  22  of the ink tank  18 . The tip portion  20  includes a portion of a flexible circuit  21  located on a bottom surface. The flexible circuit  21  wraps around an edge  25  of the tip portion  20  and terminates along a front surface  23  of ink unit  13 . The ink jet cartridge illustrated is fixed and supported by a registration means, which when mounted, has electric contact points or pads  24 , is detachable from a carriage mounted on an ink jet recording apparatus, and is disposable.  
      The transport clip TC, as shown in  FIG. 1 , is generally L-shaped and comprises a base member  30  having front and rear ends  30   a  and  30   b , respectively, and a rear wall  32  extending upwardly from the base at the rear end thereof. Sealing pad  10  is mounted on the base member  30  adjacent rear end  30   b , and the transport clip further includes side walls  34  extending upwardly from the base member and a cartridge support member  36  extending upwardly from base  30  adjacent front end  30   a  thereof. The upper ends of rear wall  32  and side walls  34  terminate in an inwardly and forwardly projecting flexible retaining clip  38  adapted to releasably interengage with cartridge  12  when the latter is mounted in the transport clip TC to releasably hold the cartridge therein. When the cartridge is assembled with the transportation clip TC, the bottom end of print head  14  facially engages and compresses sealing pad  10 , as described hereinafter, bottom surface  22  of the ink tank engages against the upper end of support member  36 , and clip  38  releasably inter-engages with the upper end  56  of the cartridge  12 .  
      The transport pad  10 , as shown in  FIG. 3 , includes a body  40  which is substantially square, opposed pairs of sidewalls  41  and  43 , only one of each pair being visible in  FIG. 3 , a lower end  42  and an upper end  44 . As shown in  FIGS. 4 and 5 , the body  40  is hollow for mounting on a post  45  on the base member  30  of the transport clip TC. The pad  10  further includes contact portion  46  extending upwardly from upper end  44  and having a profiled contact face or surface  48 . The attributes desirable of the transport pad  10  include a pad material, for example silicone, that does not degrade or contaminate the constituent material of the nozzle portion  14 , and which pad material is not degraded or contaminated by the nozzle portion  14  and/or the ink. Typically, the ink nozzle orifices  16  are very fine, whereby the contact surface  48  needs to be smooth.  
      The manner in which the above ink jet cartridge  12  is attached to the transport clip TC is briefly explained. First, the base member  30  of the transport clip TC, including the cartridge support member  36  extending therefrom, is positioned at an angle relative to the nozzle portion  14 . As the nozzle portion  14  is moved inwardly across base member  30 , cartridge support member  36 , and sealing pad  10  are moved toward contact with cartridge surface  22  and nozzle portion  14 , respectively. As the cartridge and the transport clip TC are relatively rotated in the direction of assembly, the base member  30  and nozzle portion  14  are moved into parallel alignment. Simultaneous with the transport clip and cartridge reaching the aligned positions, inside surface  39  of the retaining clip  38  engages mounting member  54  on the upper end  56  of the cartridge  12  to releasably interconnect the transport clip and cartridge. When so interconnected, rear wall  32  of the transport clip TC is aligned along the front surface  23  of the ink tank  18  thereby protecting the electric contact points  24  from exposure and inadvertent contact. In the mounted orientation, it is to be appreciated that the transport pad  10  engages the nozzle portion  14  and the nozzle plate  15  on the tip portion  20  of the ink unit  13 , while upper end  37  of support member  36  engages the bottom surface  22  of the ink unit  13 . When the transport clip TC is mounted, the transport pad  10  is retained between the base member  30  and the nozzle portion  14  and is elastically deformed. As a result, the contact portion  46  and the contact surface  48  of the transport pad  10  is compressed against the nozzle plate  15  and the orifices  16 . As described in more detail below, the contact portion  46  of the transport pad  10  supports contact surface  48  for compression against the nozzle plate and orifices  16 , thus sealing all of the orifices  16 .  
      It is to be appreciated according to the first embodiment, and as shown in  FIGS. 4 and 5 , that the transport pad  10  includes a dome shaped contact portion  46  such that an apex  50  of the contact face  48  is generally centered with respect to nozzle plate  15  and thus is centered over the nozzle portion  14  when the transport clip TC and pad  10  are attached to the ink cartridge  12 . The contact surface  48  is curvilinear or dome-shaped relative to a first axis  53  and a second axis  55  in the pre-compressed orientation shown in  FIG. 4 . First axis  53  is orthogonal to the second axis, and contact portion  46  includes a convex cross section in a plane through first axis  53  and perpendicular to body  40  and a convex cross section in a plane through second axis  55  and perpendicular to body  40 . In the compressed orientation shown in  FIG. 6 , the contact portion  46  compresses to a generally rectilinear cross section  46 ′ including a more linear contact surface  48 ′ along axis  53 .  
      The contact portion  46  of the pad  10 , being a compressible elastic or elastomeric layer, creates a friction boundary condition over the nozzle plate  15  and orifices  16 . It is to be appreciated that, in contrast to the present invention, a planar contact surface results in a compression force field which is dominant at the periphery of the contact zone. In the embodiments shown, the contact portion  46  and curved contact surface  48  results in compression or sealing forces applied progressively across the nozzle portion  14 . Specifically, the compression forces progressively move from the apex  50  of the contact surface  48  toward the peripheral edge  17  of the nozzle plate  15  over the entire nozzle portion  14  during mounting. The domed configuration concentrates the compressive forces between the pad  10  and the orifices  16  to seal the orifices  16  and prevent leakage of ink therefrom. In this manner, a variable surface tension is created around the nozzle plate  15  and the nozzle portion  14 . In particular, the surface tension is generally lower at the periphery  17  of the nozzle plate  15  relative to the center of nozzle portion  14 . It is to be appreciated that the lower surface tension allows the transport clip TC to be installed or removed from the ink cartridge  12  without dislocating or disturbing the nozzle plate  15  and/or the flexible circuit  21 . As the transport clip TC is pivoted away from the ink cartridge  12 , during dismounting, the dome shaped contact surface  48  provides an inwardly advancing disengagement and inwardly advancing decreasing stress, both of which gradually decline inwardly from the periphery  17  of the nozzle plate  15 . It is to be appreciated that the benefits of the aforementioned compression and decompression characteristics of the pad is further realized with repeated mounting and dismounting of the clip TC and pad  10  with the ink jet cartridge  12  as the cartridge  12  is swapped in and out of an ink jet recording apparatus.  
      Referring now to  FIGS. 6-8 , a second embodiment of a sealing member or transport pad  110  is shown. The pad  110 , as shown, includes a body  140  having multiple and separate elongate contact portions  141 ,  142 ,  143 , respectively, including contact faces or surfaces  151 ,  152 ,  153  spaced from one another. The body  140  has a lower end  144  and an upper end  146  and, preferably, is hollow for mounting on post  45  of the transportation clip. The contact portions  141 ,  142 ,  143  extend upward from the upper end  146 . An associated nozzle plate  115  includes rows  114  each including multiple orifices  116 . Contact portions  141 ,  142 ,  143  are aligned with rows  114  for the associated contact surfaces  151 ,  152 ,  153  to span orifices  116 . As described above, it is to be appreciated that each of the contact surfaces  151 ,  152 ,  153  of the transport pad  110  is curved or convex relative to the body  140  and to a first axis  155  and the respective one of second axes  156 ,  157 ,  158  in the pre-compressed condition. The first axis  155  is orthogonal to second axes  156 ,  157  and  158 . Prior to compression, the apexes  171 ,  172 ,  173  of the contact surfaces are generally centered laterally and longitudinally of the corresponding row  114  for the surfaces to span the central orifice in each row in the nozzle plate when transport clip TC and pad  110  are initially positioned for attachment to the ink cartridge. As the cartridge is moved into the transport clip toward the attached position, the contact portions  141 ,  142 ,  143  are progressively compressed to a generally rectangular cross-section  141 ′,  142 ′,  143 ′ as shown in  FIG. 8  and in which contact surfaces  151 ′,  152 ′,  153 ′ are distended into the orifices  116 .  
      Contact portions  141 ,  142 ,  143  of the pad  110  are compressible elastic layers which create a friction boundary condition over the nozzle plate  115  and the rows of orifices  116 . Similar to the above described contact portion  46 , the curved contact portions  141 ,  142 ,  143  and contact surfaces  151 ,  152 ,  153  result in compression or sealing forces being applied progressively along and laterally of the corresponding portion of nozzle plate  115  and orifices  116 . Specifically, the compression force progressively moves from the apexes  171 ,  172 ,  173  of the contact surfaces  151 ,  152 ,  153  both longitudinally and laterally relative to the corresponding row of orifices in the nozzle plate during mounting. This configuration concentrates the compressive forces between the pad  110  and the orifices to seal the orifices and prevent leakage of ink therefrom. A variable surface tension is created around the nozzle plate and each of the nozzle portions. In particular, the surface tension is generally lower at the periphery of each of the nozzle plate orifices relative to the center of each nozzle portion. It is to be appreciated that the lower surface tension allows the transport clip TC to be installed or removed from the ink cartridge  12  without dislocating or disturbing the nozzle plate and/or flexible circuit  21 . As the transport clip TC is pivoted away from the ink cartridge  12 , during dismounting, the dome shaped contact surfaces  151 ,  152 ,  153  provide a longitudinally and laterally inward advancing disengagement and decreasing stress, both of which gradually decline around the peripheries of the plate openings. It is to be appreciated that the benefits of the aforementioned compression and decompression characteristics of the pad are further realized with repeated mounting and dismounting of the clip and pad  110  with the ink jet cartridge.  
      Referring now to  FIGS. 9-11 , a third embodiment of a sealing member or transport pad  210  is shown. The pad  210 , as shown, includes a body  240  having multiple, separate elongate contact portions  241 ,  242 ,  243 , respectively, including contact faces or surfaces  251 ,  252 ,  253 . The body  240  has a lower end  244  and an upper end  246 . Preferably, body  240  is hollow to facilitate mounting the pad on post  45  of the transport clip. The contact portions  241 ,  242 ,  243  extend upward from the upper end  246 . As with the embodiment of  FIGS. 7-9 , an associated nozzle plate includes corresponding rows of orifices with which the contact surfaces  251 ,  252 ,  253  are aligned, as will become more apparent hereinafter. In this embodiment, each of the contact surfaces  251 ,  252 ,  253  of the transport pad  210  is linear with respect to the corresponding longitudinal axis  256 ,  257 ,  258  and is arcuate transverse to the corresponding axis and convex relative to body  240 . In the uncompressed condition shown in  FIG. 10 , contact portions  241 ,  242 , and  243  each overlie a corresponding row  214  of nozzle orifices  216  in a nozzle plate  215 , and in the compressed condition shown in  FIG. 11 , each of the contact portions is compressed to a generally rectangular cross-section  241 ′,  242 ′,  243 ′ in which contact surfaces  251 ′,  252 ′,  253 ′ are distended into orifices  216  along axis  255 .  
      Similar to the dome shaped pad  110 , contact portions  241 ,  242 ,  243  of the pad  210  proximal to the contact surfaces  251 ,  252 ,  253  are compressible elastic layers which create a friction boundary condition over the nozzle plate  215  and orifices  216 . The curved contact portions  241 ,  242 ,  243  and contact surfaces  251 ,  252 ,  253  result in compression or sealing forces being progressively applied laterally of the nozzle plate  215  and the rows of nozzle orifices. This configuration concentrates the compressive forces between the pad  210  and the orifices. A variable surface tension is created around the nozzle plate and each of the nozzle portions. In particular, the surface tension is generally lower along the edges of each of the nozzle plate orifices parallel to the axes  256 ,  257 ,  258  of each ink ejecting portion. It is to be appreciated that the lower surface tension allows the transport clip TC to be installed or removed from the ink cartridge without dislocating or disturbing the nozzle plate and/or flexible circuit  21 . As the transport clip TC is pivoted away from the ink cartridge during dismounting, the curvilinear shaped contact surfaces  251 ,  252 ,  253  provide a laterally inward advancing disengagement and decreasing stress, both of which gradually decline. It will be appreciated that the benefits of the aforementioned compression and decompression characteristics are further realized with repeated mounting and dismounting of the clip TC and pad  210  with the ink jet cartridge.  
      While considerable emphasis has been placed herein on the structures and configuration of the disclosed embodiments of the invention, it will be appreciated that other embodiments, as well as modifications of the embodiments disclosed herein, can be made without departing from the principles of the invention. In this respect, it will be appreciated that the transport pad can be configured to accommodate various designs and structures of ink cartridges. This, as well as modifications of the embodiments shown, will be obvious and suggested to those skilled in the art from the disclosure herein. It is to be distinctly understood therefore that the foregoing descriptive matter is to be interpreted merely as illustrative of the present invention and not as a limitation thereof. It is intended that the invention be construed as including all such modifications and alterations as fall within the scope of the appended claims or the equivalents thereof.