Patent Abstract:
Inkjet printing system with at least one ink cartridge and an associated ink cartridge receptacle in which a special ink cartridge exchange device can be omitted, wherein the ink cartridge is modified by a guide pin that is fastened on the convexity of the ink cartridge, or between convexity and top of said ink cartridge, and projects only to one side beyond the flat side wall for the purpose of guiding the ink cartridge, and slides along in a wall of the ink cartridge receptacle; wherein, given an inserted ink cartridge, a leaf spring is pre-tensioned in each cavity of the cartridge receptacle of the ink cartridge receptacle that is provided for an ink cartridge; and via elastic force the exchange of the ink cartridge is assisted when the locking nose and the locking element of the ink cartridge receptacle disengage via manual pressure; and the ink cartridge is pivoted on an axis running near and parallel to the guide pin in order to release the ink cartridge; wherein the separation of the lower rear edge of the ink cartridge to the contact panel of the cartridge carrier is precisely defined by the curve of the guide link.

Full Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention concerns an inkjet printing system with at least one ink cartridge and an associated ink cartridge receptacle. The ink cartridge can be easily exchanged without an ink cartridge exchange device and is suitable for all inkjet printing devices, both those that operate with a moving inkjet print head and those with an unmoving inkjet print head during the printing. 
     2. Description of the Prior Art 
     The known inkjet printing systems differ in the means for generation of a relative movement between the print item and the inkjet print head. In contrast to conventional printers, in franking machines often only the inkjet print head together with its receptacle is moved, and the print item remains unmoving during the printing, or the print item is moved and the inkjet print head is stationary, i.e. remains unmoving in a printing position during the printing. 
     As used herein, a print item encompasses flat articles to be printed such as mail pieces, letter envelopes, postcards, chip cards, admission cards [tickets], bands and other substrates for printed information. 
     A secure printing apparatus with a removable print head is known from the European patent application EP 875 861 A2, with which printing apparatus a franking imprint is only possible when a hatch is closed. The latter can be opened only if the print head was shifted into a region adjacent to the printing position, i.e. when the printing module has arrived in an exchange position. The print head is integrated into an ink cartridge and installed in a printing module. The access to the ink cartridges of the printing module in the exchange position ensues from the outside via a flap whose position is interrogated by a microswitch. If the printing module is located in the exchange position, no access to the data lines is possible. 
     A secure printing apparatus with a removal print head is known from the European patent application EP 881 086 B1. This printing apparatus is equipped with: electrical connection means which establish a connection to the electrical contacts of the ink cartridges, wherein the later are installed at the printing module that was moved into the printing station; and with localization means to localize the printing module in a park (exchange) station in which the electrical connection means no longer engage with the electrical contacts, and wherein the printing module in the park (exchange) station can be removed by a user; as well as with insulation means to insulate the park (exchange) station from the electrical connection means. 
     An arrangement to exchange inkjet printing modules was proposed in the European patent application EP 1 880 857 A2, wherein two ink cartridges are designated with the last term, which two ink cartridges—in contrast to the solutions cited above—do not still need to be completed with an exchangeable printing module, in that they are arranged in an additional housing. Rather, the two ink cartridges are inserted directly into a receptacle of the pivot device. The latter is pivoted together with the inserted ink cartridges, whereby in contrast to the aforementioned solutions their print heads do not shift from the printing position into an exchange position but rather are pivoted. The exchange arrangement is used in the franking machine of the Centormail® type from the manufacturer Francotyp Postalia GmbH and has additional differences relative to the aforementioned solutions: in the exchange position, the electrical contracts are connected to the ink cartridges, and in the exchange position there are no means that detach the electrical contacts of the print head beforehand for removal of the ink cartridges or insulate the printing device in the park position before the ink cartridges are exchanged. 
     The arrangement has bars to lock the ink cartridges and, per ink cartridge, a draw hook mechanically connected with a return spring as well as a guide lever. This device for changing the ink cartridges that is attached to the ink cartridge receptacle is, on the one hand, materially intensive and can hardly satisfactorily solve a problem that is apparent using FIG. 9 of EP 1 880 857 A2: because the lower rear edge of the nozzle face rests on an elastic part which should prevent a contacting of the counterpart with the contact panel, the separation is small. Therefore, in the removal of the ink cartridge, the elastic parts and the contacts can nevertheless be contaminated by ink that has collected on the lower rear edge during the printing. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to provide an inkjet printing system with at least one ink cartridge and an associated ink cartridge receptacle which does not exhibit the aforementioned disadvantages of the ink cartridge exchange device, that reduces the probability of a contamination of the contacts by enlarging the separation of the ink cartridge from the contacts during exchange, and thereby enables a protection from product piracy in an uncomplicated manner. 
     The above object is achieved by an ink cartridge of the type described above that is provided in accordance with the invention with a guide pin is fastened on the convexity of the ink cartridge, or between convexity and top (non-positive and positive connection). The pin terminates with the one flat side wall of the ink cartridge and protrudes on the opposite side beyond the flat side wall for the purpose of guiding the ink cartridge. 
     The ink cartridge receptacle is bilocular (has two chambers), with shaft-shaped cavities arranged offset to one another in a carrier, and is designed with external walls with identical shape. The outer walls and the middle wall of the cartridge carrier of the ink cartridge receptacle possess on one side a guide link in which the guide pin of an ink cartridge slides along. 
     A leaf spring in each of the cavities of the cartridge carrier of the ink cartridge receptacle that are provided for an ink cartridge is pre-stressed given an inserted ink cartridge and assists in the exchange of the ink cartridge by elastic force. For this purpose, the latter is moved counter to the elastic force (via manual pressure on the grip element opposite the locking nose) and pivoted on an axis running near and parallel to the guide pin (advantageously through said guide pin) in order to unlock the ink cartridge. The locking nose and the locking element of the ink cartridge carrier disengage. Driven by the elastic force of the leaf spring, the guide pin travels along in the guide link, wherein the separation of the lower rear edge of the ink cartridge from the contact panel of the ink cartridge is precisely defined by the course of the guide link. A greater reliability of the device and the assurance that the contacts cannot be smeared or mechanically damaged advantageously results. 
     A material savings also results, in particular relative to the receptacle of the franking machine according to EP 1 880 857 A2 of the Centormail® type by the manufacturer Francotyp Postalia GmbH, since bars, return springs, draw hooks and guide levers as well as stripper elements of the cartridge exchange device can be omitted. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the known printing device with an ink cartridge with an ink cartridge receptacle in the franking machine of the Centormail® type. 
         FIG. 2   a  is a perspective view, from the front lower left, of a modified HP ink cartridge that has been rotated 90° to the right. 
         FIG. 2   b  is a perspective view, from the front lower left, of a modified HP ink cartridge that has been rotated 90° to the right and been tilted backwards. 
         FIG. 2   c  is a perspective view, from the front upper left, of a modified HP ink cartridge that has been rotated 90° to the left. 
         FIG. 3  is a perspective view, from the front upper right, of a modified carrier of the ink cartridge receptacle for the modified ½ inch HP ink cartridge. 
         FIG. 4  is a perspective view, from the front upper right, of a modified ink cartridge receptacle in an exploded presentation. 
         FIGS. 5   a, b, c  and  d  are sectioned side views of the ink cartridge receptacle in phases of the extraction of the ink cartridges. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A perspective view of the known printing device  1 * of the franking machine of the Centormail® type from the front lower right is shown in  FIG. 1 . An ink cartridge receptacle  12 * carries two inkjet print heads  110 *,  120 * and is shown pivoted on an axis  121 * into a cleaning position. A cleaning and sealing device (RDS)  13 * that bears wiper elements  1311 * has been moved into a starting position in the rear part of the franking machine. A stripper mount  1317 * is arranged between the RDS  13 * and the print head receptacle  12 *. The stripper mount carries strippers on its downward facing edges, at which strippers the stripped ink initially drips down. To clean the inkjet print heads  110 *,  120 *, the RDS  13 * and [sic] is driven up to the ink cartridge receptacle  12  and is then moved back into the starting position. An ink residue thus remains on the print head edge  1101 * and  1201 *. Each inkjet print head is a component of an ink cartridge. Given a removal of the ink cartridges, this ink residue could contaminate the electrical contacts (not shown) inside the ink cartridge receptacle  12 *. Therefore stripper elements  12611 * and  12621 * for the print head edge  1101 * and  1201 * are provided per opening at the edge on the floor of the ink cartridge receptacle  12 *, through which stripper elements  12611 * and  12621 * each of the two inkjet print heads  110 *,  120 * protrudes. Each opening is bounded on one side by a base plate  1266 * of the carrier  126 * to the front and laterally by two side walls  122 *,  123 * to the rear, where the aforementioned electrical contacts are situated in the docking wall. Each ink cartridge is plugged into a shaft-shaped cavity of the ink cartridge receptacle  12 * that are not each visibly equipped with a bar for the affixing of said ink cartridge receptacles  12 *. Each ink cartridge bears means for supplying ink to the inkjet print head, a locking nose and a chip on the one narrow side, as well as a contact panel (not visible). 
     The ink cartridge receptacle  12 * has means in the form of draw hooks  1228 *,  1238 * for drawing and, on the ink cartridge, means in the form of guide webs at the chip mount of the aforementioned chip as well as, in the print head receptacle  12 *, means (not visible) in the form of a spring pin and a spring part for disconnecting the ink cartridge. The spring pin and a spring part are mechanically coupled with one another so they are already disconnected before initiation of the of the pulling process. The draw hooks  1228 * and  1238 * are retracted into the starting position by tension springs  1227 *(not visible) and  1237 *. The tension springs  1227 *(not visible) and  1237 * are tensioned between pins  1222 *(not visible),  1232 * on the floor of the carrier  126 * and pins  12281 *(not visible),  12381 * that are attached in the middle of the draw hook and each protrude through an opening  1225 * (not visible) or  1235 * of the side walls  122 * or  123 *. 
     A stripper device  12611 *,  12621 * is arranged in the pivot region of the rear edge  1101 * of the inkjet print head  110 *. 
     The ink cartridge receptacle  12 * is pivotable into a printing position so that both inkjet print heads are arranged stationary in a printing window of a guide plate for flat mail pieces (printing media) during the printing. 
       FIG. 2   a  shows a perspective view of a modified ½ inch HP ink cartridge from the front lower left, wherein the oscillating circuit is shown rotated 90° to the right. The ink cartridge  11  fits in the shown (in  FIG. 1 ) print head receptacle of the known printing device of the franking machine of the Centormail® type, however is hidden there by the print head receptacle and is not visible. 
     The HP ink cartridge  11  has two large-area side walls, of which only the left side wall is visible, meaning that that side wall is shown which is situated to the left in the ink cartridge receptacle shown (in  FIG. 1 ) after the insertion of the HP ink cartridge. The other relative specifications (such as front and bottom) also orient on the shown ink cartridge receptacle. The ink cartridge has a convexity  1106  on one of the narrow sides and is inserted into the shown (in  FIG. 1 ) ink cartridge receptacle with the convex side forward and with the print head  110  downward. The ink cartridge  11  has an electronic semiconductor chip (not visible) in the print head  110  that sits on a neck  1103 . The head has a nozzle plate  1104  on its facing side (i.e. in the ink discharge direction), which nozzle plate  1104  transitions orthogonal to this into a narrow and short neck side  1103 . The head has a parallel interface with an electrical contacting unit  1105  orthogonal to the nozzle plate  1104  on the narrow back side, which interface serves to control the inkjet print head. An edge  1101  of the print head  110  lies between the nozzle plate  1104  and the narrow back side with the contacting unit  1105 . A chip mount  1108  with a chip  1107  is arranged on the narrow back side above the contacting unit  1105 . The narrow back side transitions above into a narrow top side. A locking nose  1109  is arranged at the transition. The narrow top side transitions above into a narrow front side. A grip element  1110  is arranged at the transition. The narrow front side and, in part, the two large-area side walls of the HP ink cartridge  11  can be bonded with an adhesive label  1111 . The ink cartridge  11  has a convex ink reservoir  1106  as an ink storage. The narrow front side transitions below into a narrow convexity underside. A convexity  1106  located at the transition is rounded. The narrow convexity underside transitions into the narrow neck side  1103 , and a compartment  11030  with a stop  11031  is molded at the transition, wherein the compartment is narrower than the narrow convex side. Moreover, a guide pin  1102  is shown before the installation on the convex underside of the ink cartridge  11 . After its installation the ink cartridge  11  no longer fits into the ink cartridge receptacle that was shown in  FIG. 1 . The chip mount  1108  on the narrow back side and the guide pin  1102  on the convex side of the HP ink cartridge  11  form a mechanical means for preventing an insertion of commercially available ink cartridges that are not authorized for this by the manufacturer of the printing device into an ink cartridge receptacle. 
     Corresponding to these electronic and mechanical prevention means  1107  and  1108 , a control and contacting unit is arranged in the carrier of the ink cartridge receptacle for electronic signal conversion and mechanical connection with the ½ inch ink cartridge. A correspondingly modified carrier of the ink cartridge receptacle is explained in detail further below using  FIGS. 3 and 4 . 
       FIG. 2   b  shows, from the front lower left, a perspective view of a modified HP ink cartridge that is rotated 90° to the right and tilted back so that the convex underside of the ink cartridge is better visible. The print head has a nozzle plate  1104  with the print head edge  1101  on the one side. A short and narrow neck side  1103  begins on the other side. The guide pin  1102  of the ink cartridge  11  is attached at the transition from the narrow neck side  1103  into the narrow convex underside. The pin consists of, for example, plastic or metal and centrally has a fixing nose that positively engages in the compartment of the ink cartridge molded on the neck projection, which compartment has a central rectangular or U-shaped opening accessible from the outside that accepts the hook-shaped end of the fixing nose. 
       FIG. 2   c  shows a perspective view of a modified HP ink cartridge from the front upper left that is rotated 90° to the left. On the prominent transitions of the narrow sides, the modified HP ink cartridge has in a known manner: a convexity  1106 , a locking element  1109 ; and a grip element  110 ; as well as a guide pin  1102  in a novel and inventive manner. 
       FIG. 3  shows, from front upper right, a perspective view of a modified carrier of the ink cartridge receptacle for the modified ½ inch HP ink cartridges. The side walls  122  to the left and  123  to the right outwardly border two cavities in the carrier  126  of the ink cartridge receptacle  12  for the two modified ½ inch HP ink cartridges  11 . The side walls and the carrier can be manufactured entirely from plastic. In the first case, an injection molding method is applied to generate the plastic part. The left and right side walls are advantageously identically formed. Both can also be manufactured from metal. In the latter case, a guide link can be shaped in the metal via milling. The guide pin of the second ink cartridge slides in the left side wall. The middle wall of the cartridge carrier consists of plastic and contains a guide link (cast in injection molding) in which the guide pin of the first ink cartridge slides. 
     At least the carrier should be manufactured from plastic. The invention can be used in a printing device that possesses no pivotable ink cartridge receptacle. The carrier  126  then possesses three bearing points for guidance and moving of the ink cartridge receptacle into an exchange or, respectively, printing position and, if necessary, into other positions. Draw hooks, tension springs and other mechanical means to exchange the HP ink cartridges  11  are foregone relative to the known variants shown in  FIG. 1 . The ink cartridge receptacle is thereby designed significantly simpler and less error-prone and is cheaper to manufacture than the receptacle  12 * shown in  FIG. 1 . 
     Alternatively, the invention can naturally also be used in a printing device with a pivotable ink cartridge receptacle. 
       FIG. 4  shows a perspective view of a modified ink cartridge receptacle from the front upper right in an exploded representation. The carrier  126  of the ink cartridge receptacle  12  possesses a middle wall  1263  to separate the cavity into two cavities that are matched to the shape of the ink cartridges. The two cavities are spaced apart from one another and arranged offset. The docking wall  1262  of the left half of the carrier  126  is arranged offset to the rear relative to the docking wall  1261  of the right half of the carrier  126 . A locking nose is arranged and the transition from the narrow top side to the narrow back side of each ink cartridge, and the carrier  126  possesses a respective corresponding, hook-shaped locking element  1281 ,  1282  in the upper part that accepts the nose and thus locks the ink cartridge. A hook respectively projects upwards and forwards, and the hook end  12811 , (and another hook end (not shown) in the other cavity) points downward in the direction of the nose of the ink cartridge. The locking element  1281 ,  1282  has an incline  12812 ,  12822  falling from the left side to the right side. Opposite the hook, a first stop  12601  is attached on a first step that rises beyond the docking wall  1261  in the direction of the ink cartridge. The step leads toward the center over a ramp  12681  to a first window in a trough. The locking element  1281  is shown enlarged as Detail A. 
     In the assembled state of the ink cartridge receptacle  12 , a leaf spring  1241 ,  1242  that rests on the floor  12611 ,  12621  of the carrier  126  pushes the ink cartridge (not shown) upward with its elastic end so far that the locking nose of the ink cartridge engages with the locking element  1281 ,  1282 . 
     A contact panel and a chip with six electrical contacts on its surface are arranged on the narrow back side of each ink cartridge. The carrier  126  possesses respective connectors  1251 ,  1252  and  1271 ,  1272  for contacting that are fashioned as a corresponding counterpart for the contact panel. Each connector  1251 ,  1252  for the contacts to control the inkjet print head is arranged in a second window  12651  ( 12652  is hidden) on a second step, wherein the second step has likewise been molded on a respective docking wall  1261 ,  1262 , however near the floor of the ink cartridge receptacle  12 . Connectors with elastic contact elements (what are known as pogo connectors) are used. The pogo connector of the connector  1251  ( 1252  is hidden) is presented magnified as Detail B and, for example, possesses  52  elastic contact elements. From the second step, the aforementioned trough in which a respective first window  12671  ( 12672  is hidden) is arranged is reached via a respective ramp  12661 ,  12662  towards the center. A connector  1271  (and a hidden connector in the other cavity) contacts the chip contacts and is arranged in the respective first window, and the peg connector of the connector  1271  (and the hidden connector) possesses 6 elastic contact elements. 
     The middle wall  1263  has the shape of the Latin letter ‘d’ and, in the bulged portion, has a window  12631  with an elastic tongue  126311 , wherein the elastic force towards the left side is exerted to laterally press on an ink cartridge inserted into the left cavity. A threaded bore  12634  on the right ( 12644  to the left is hidden) and  12635  to the right ( 12645  to the left is hidden) as well as  12636  to the right ( 12646  to the left is hidden) are respectively arranged at the lower end of the floor  12611 ,  12621  of the carrier  126  and at the front side (as well as in the upper part) of the carrier  126 . The floor  12611 ,  12621  of the carrier  126  respectively transitions into the front side, which possesses a respective second stop  12641 ,  12642  for the ink cartridge in the lower half of the carrier  126 . 
     A straight guide  12632  running from top to bottom is introduced into the bulging part of the center wall  1263  on its right side, which guide ends in a bow-shaped part  12633  near the floor. 
     The right and left side walls  123 ,  122  likewise have the shape of the Latin letter ‘d’ and have a window  1231 ,  1221  with an elastic tongue  12311 ,  12211  in the bulged part. The elastic force of the right side wall  123  is directed towards the left side and is fashioned to laterally press on an ink cartridge inserted into the right cavity. A hole  1234  to the right,  1224  to the left and  1235  to the right,  1225  to the left as well as  1236  to the right,  1226  to the left are respectively arranged on the lower end of the right and left side walls  123 ,  122  and on their front sides, as well as in the upper parts. A straight guide  1232 ,  1222  running from top to bottom is introduced into the bulged part of the side wall  123 ,  122  on their right sides, which guide  1232 ,  1222  ends in a bow-shaped part  1233 ,  1223  near the floor. 
       FIG. 5   a  shows a sectioned side view of the ink cartridge receptacle according to the invention before the extraction of the ink cartridge, in a zero phase. This is thereby the same phase as was shown in  FIG. 1 . In  FIG. 5   a - 5   d  the housing of the ink cartridge receptacle is presented orthogonal to the nozzle plate of a cartridge and orthogonal to the contact surface of the two connectors  1251 ,  1271 . The connectors  1251 ,  1271  are mechanically fastened and electrically contacted to a circuit board  12501  inside the ink cartridge receptacle and aligned on the cavity for the insertion of the ink cartridge  11 . The circuit board and connectors were not shown in section. The connectors contain elastic contact elements (not visible) on which the contacts of the ink cartridge are pressed (due to the link guide) when the bow-shaped part  12633  at the lower end of the link guide is traversed by the guide pin  1102 . A contacting unit  1105  and a chip mount  1108  with a chip (not visible in the side view are arranged on the narrow back side of the ink cartridge, the contacts of which chip are correctly contacted when the locking nose  1109  engages with the hook-shaped locking element  1281  arranged in the upper part of the carrier  126 . If both ink cartridges are properly inserted into the carrier, the locking nose  1109  of the narrow back side of each ink cartridge then rests on a respective first stop  12601  of the carrier  126 . 
       FIG. 5   b  shows a sectioned side view of the ink cartridge receptacle according to the invention in a first phase of the extraction of the ink cartridge. For this a force is manually exerted (not shown) on the grip element  1110  in the ink discharge direction (see white arrow) and counter to the elastic force of the leaf springs  1241 , wherein the locking nose  1109  disengages with the hook-shaped locking element  1281  arranged in the upper part of the carrier  126 . Via a forward tilting motion (see patterned arrow), the stop  12601  is abandoned and the contacts (initially of the connector  1271  for the chip contacts) are thereby broken [disconnected]. The connector is arranged in a trough that leads upward via a first ramp  12681  to the first step and that leads downward via a second ramp  126681  to the second step, which steps are molded on the docking wall. The forward tilting motion is on the one hand bounded by the second step  12641  and on the other hand by a third ramp  12691  that is arranged in the lower part of the carrier  126  and forms a third stop. 
       FIG. 5   c  shows a sectioned side view of the ink cartridge receptacle according to the invention in a second phase of the removal of the ink cartridge. In said second phase the ink cartridge  11 , due to upward motion driven by elastic force, is directed—via the link guide in the bow-shaped part  12633 —sufficiently far away from the third ramp  12691  (i.e. the docking wall) and thus also from the contacts of the connectors. A second stop  12641  ( 12642  not shown) for the narrow front side if the ink cartridge is respectively molded on the front side of the carrier  126 . The second stop and the guide  12623  prevent the ink cartridge  11  from rotating too far downward when the ink cartridge is drawn upward in the exchange (see white arrow). 
       FIG. 5   d  shows a sectioned side view of the ink cartridge receptacle according to the invention in a third phase of the extraction of the ink cartridge. In the third phase, the ink cartridge  11  leaves the movement region in the ink cartridge receptacle that is guided by the carrier  126 . 
     The ink cartridge receptacle is advantageously identically constructed in the region of both cavities for both ink cartridges. 
     The invention can be used in a different, alternative ink cartridge receptacle than was described in the preceding. For example, a franking machine with printing carriage by means of which a print head can be moved from the printing position into an exchange position was described in the European Patent EP 1 300 807 B1. The printing carriage would merely have to be adapted to the modified ink cartridges. 
     The invention can also be used in a printing device that possesses a pivotable ink cartridge receptacle or in which the ink cartridge receptacle is moved during the printing. 
     The invention is not limited to the present embodiments. Ink cartridges of a different manufacturer can clearly also be modified and used. The attachment of the guide pin on the ink cartridge can alternatively ensue by means of a ultrasound welding connection, bolt, rivet or staple connection. 
     Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventor to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of his contribution to the art.

Technology Classification (CPC): 1