Abstract:
A printing apparatus has a transport module with a moving transport belt that transports strip-like print media past a printhead for printing thereon. The transport module has an entrance region upstream of the printhead, a magazine for the strip-like media located upstream of the entrance region of the transport module, the transport belt also serves as a take-off device to remove the strip-like media from the magazine, the magazine is mounted laterally offset with respect to the transport belt, thereby causing the strip-like media to be captured by the transport belt only in an edge region of the transport belt. The transport belt is wider by the edge region than is precisely needed to transport the strip-like media, in order to print on a remaining region of the strip-like media, which is smaller by the edge region than a total width of said strip-like media.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention concerns an arrangement to print strip-like print media in a franking and/or addressing machine. 
     2. Description of the Prior Art 
     An arrangement of the aforementioned general type is known (see DE 197 12 077 C1) in which the print media are transported on edge, resting on a guide plate with a printing window, by means of contact pressure elements attached to a revolving transport belt, and the media are printed by an ink printhead located behind the printing window. In the entrance region of the otherwise typical print media, a strip magazine is arranged transversely to the guide plate and at a distance from the guide plate that is greater than the largest permitted thickness of the otherwise typical print media. The strip-like print media—simply strips in the following—are supplied as an output from a magazine transversely to the transport direction and above the transport plane of the transport belt toward the guide plate. For this purpose, the strip magazine is provided with a separate drive formed by a motor, reduction gear and drive roller. A recess is provided in the guide plate in the impact region of the strips, into which recess is inserted a specifically shaped guide part. The middle of the exit opening for the strips from the magazine, the middle of the guide part and the middle of the printing window are all situated at approximately the same level. 
     As is apparent from the above description, this solution is limited to only a specific, complicated transport system, and the technical design cost is also significant. The output relationships do not allow any reloading during operation. 
     A modular strip dispenser is known (see DE 202 18 855 U1) that is designed so as to be connectable with a mail processing machine. The strip dispenser has a shaft beam and a removable strip receiver shaft that is adapted in terms of its length to different strip lengths. Integrated into the shaft beam are a take-off unit and sensors that can be electrically connected with a control unit of the mail processing machine. The take-off unit has a stepper motor that can be controlled by software o as to produce a desired take-off speed, corresponding to the different machine variants. A sensor installed in the shaft beam checks whether a strip has been taken off or whether a strip is located in the strip guide. The strip receiver shaft has a mechanical sluice with which the maximum fill level is established. In the output region of the strip receiver shaft, two levers that can be moved against an elastic force are supported between the upper outer wall and the inner wall. The spring-loaded levers extend to the exit opening and press the strips against a take-off roller. 
     If only one or a few strips is/are isolated, the strips may be pushed too far through, and recurve at a blocking part, and therefore an error mode is triggered (given one strip) or an isolation is impossible (given multiple strips). 
     In addition to the technical cost for the separate drive for the strip dispenser, the matching between ejection velocity and the transport velocity of the mail processing machine is problematical. Given a difference between these velocities, print offsets can occur in the print image. The maximum offset occurs when the drive in the strip dispenser is deactivated immediately after the isolation. Depending on the geometric dimensions in the region between strip ejection and printing region, for a particular strip length it may occur that a portion of the strip still sticks into the strip dispenser while the front part of that strip is already being printed. It is clear that a reloading during operation is not possible here. 
     Furthermore, a strip dispenser for mail processing machines is known (see U.S. Pat. No. 6,773,524 B2) that has a strip magazine in which the strips are stacked one after another, resting with their leading edges on a base plate. The mail processing machine has a transport system that has multiple parallel (upper and lower), revolving transport belts actively driven by rollers. The strip magazine has a matching slit located centrally relative to one of the upper transport belts in the outermost region of the forward driven roller. The strip take-off position is centrally established by an electromagnet that pulls the slit of the magazine into the engagement region of this transport belt. If the electromagnet is not fed with current, the magazine remains pivoted away and no strip is taken. The removed strip is initially non-positively taken along by the upper transport belt through the slit between floor plate and transport belt, then strikes with its leading edge on the lower transport belt and is deflected by the lower transport belt and is directed further. In the subsequent printing position, the strip segment located there lies only on the lower transport belt opposite the printheads. A correspondingly designed counter-pressure element might not be necessary. 
     The strips must be situated at a defined angle relative to the base plate so that they are not excessively curved and safely arrive at the slit to the transport belt. If they are wavy or do not have a smooth cut edge, this can lead to malfunctions. Different flexural strengths of the webs can likewise have a disadvantageous effect. In this solution there is also the risk that, upon insertion of one or a few strips, the strip or strips may already have slid into the output slit, which results in the errors described above. The transport system is complicated and requires a precise matching between the upper and lower transport belts. 
     In addition, a transport module is cited (see DE 10 2007 060 789 A1) that is arranged above a feed table and (in a known manner) has a transport belt for flat print media. The print media, arriving from the feed table, are pressed against the transport belt by means of elastically arranged, spring-loaded pressure elements (advantageously brush elements) below the transport belt. Due to a number of such contact pressure elements, a correspondingly large contact area is achieved, so start-stop errors in the print image are largely avoided (see  FIGS. 2 and 3 ). 
     Finally, a transport device for flat goods to be printed is known (see DE 10 2008 032 804 A1) that has a driven, revolving transport belt supported on rollers. A number of spacers that are axially parallel to one another are arranged between one end of a bearing plate of a roller support and a first shaped plate, and a number of spacers axially parallel to one another are likewise arranged between the other end of the bearing plate and a second shaped plate. The spacers are all identical and designed as bearing shafts. Respective tensioning means are mounted at the ends of the bearing plate of the roller support and are designed for force transmission from a connecting rod. For a defined flexing of the roller support with corresponding loading of the bearing plate, a mechanical draw tension is transmitted via the tensioning means to the two ends of the bearing plate. The connecting rod is provided with tensioning and adjustment means to adjust a defined draw tension (see also  FIGS. 2 and 3 ). 
     The last two cited solutions, matched to one another, form a compact transport device for franking machines with small to medium of mail items throughput; see also Design Patent registration with the Office of Harmonization for the Internal Market, file number 001292361-0001 and  FIGS. 1 through 3 . 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to increase the print quality and reliability with decreased technical cost in an arrangement to print strip-like print media, which also exhibits low wear and decreased need for maintenance. 
     A further object of the invention is to achieve an arrangement of the aforementioned type that operates without separate drive means and with an easily exchangeable strip dispenser module for strips of different lengths and thicknesses as well as different flexural strengths, and that achieves the same print quality in the transport path with the sensor technology for the otherwise typical print media. 
     Disadvantageous effects as a result of insertion errors given one or a few strips should be precluded by means of the application technology. A refilling of strips during the take-off should be possible. 
     The above object is achieved in accordance with the present invention by an arrangement for printing strip-like print media in a franking and/or addressing machine wherein the print media are transported by a revolving transport belt of a transport module, and are printed with a printhead that is located behind a printing window. A module that includes a magazine for the strip-like print media is located at the entrance region of the transport module in an engagement region of the transport belt thus also serves as a take-off device for removing individual items to be printed from the magazine. The module with the magazine is located laterally offset from the transport belt, so that the print media are captured by the transport belt only at an edge region thereof, and the transport belt is wider by this edge region than would be necessary for otherwise typical print media. The transport belt proceeds outside of and next to the print window. A remaining region, next to the edge region, of each item to be printed was thereby caused by the transport belt to be transported past and below the print window, for printing on this remaining region by the printhead. 
     Due to the laterally offset arrangement of the module relative to the transport module, the strip-like print media—strips in the following—are already aligned resting on their lateral edges upon removal from the magazine. The longitudinal edge of the strip and transport track are therefore parallel to one another, and the required print image clearance from the longitudinal edge of the strip is furthermore also ensured. The wider embodiment of the strips enables the typical print region, and the already present transport conditions (including sensor technology), to be maintained without changes. Based on empirical tests, the edge region of the strip that is provided for the transport (and therefore the module offset) is chosen to be so wide (at least one third of the print region width) that a safer transport is ensured by the transport module. The edge region can appropriately be provided with an identifier (arrow) in order to facilitate the correct filling of the magazine. The additional space is also suggested for advertising purposes. Given self-adhesive design of the strip, a subdivision of it matching the transport strips is advantageous; the later take-off of the printed part is thereby facilitated. 
     The special embodiment of the module according to the invention enables the optional configuration of the franking machine with or without strip printing and without additional space requirement. 
     The incorporation of the flap in the input region of the device housing into the strip magazine enables the opening for the strip input to be kept as small as possible, the housing to be sealed against access and the module to be adapted without any problems. 
     By adjusting the magazine from the pivoted-away position into the take-off position and back with the aid of a stepper motor with gearwheel and associated toothed segment on an axle with activation curve profile, a catch is reached for each position; a holding current is omitted. It is clear that a continuous adjustment of the exit conditions corresponding to the strip quality is thereby possible. 
     In the pivoted-away position of the magazine, the division of the floor of the magazine into a rigid, smooth part and a rotationally movable, elbowed part prevents individual strips from sliding through upon filling, and ensures a certain individualization afterward. In the take-off position, the rigid, flat part of the floor wall initially rests spring-loaded on the transport belt; the sluice is closed. The removed strip is subsequently pushed into the sluice. In this way an adapted, elastic sluice is formed for strips of different thicknesses, and the exit of only one strip is respectively enabled. Since only the contact region of the contact lever is significant for the take-off, a reloading can take place without any problems during the take-off operation. 
     In the take-off position, the combination of magazine with contact pressure lever and rigid, smooth resting part of the floor wall, as well as associated baffle plate with spring tabs above the letter thickness sluice, produces at least the triple contact of the strip with the transport belt, and therefore a high certainty of take-off and transport. 
     In the pivoted-away position, the equipment of the magazine with a touching lever with two switching plates and associated photoelectric barriers enables a simple fill level monitoring with regard to the empty state or overfilling. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a franking machine according to design patent registration 001292361-0001 with assembly for strip printing. 
         FIG. 2  is a perspective view of the transport device of a transport module according to DE 10 2008 032 804 A1 and  FIG. 2 , with a module for strip-like print media. 
         FIG. 3  is a perspective view of a counter-pressure device for the transport module according to DE 10 2007 060 789 A1 and  FIG. 3 , with a module for strip-like print media. 
         FIG. 4  is a detail of the input region with letter thickness sluice at the top, in perspective view. 
         FIG. 5  is a perspective view of a module for strip-like print media, counter to the transport direction, as seen from the rear right. 
         FIG. 6  shoed details of  FIGS. 4 and 5 , partially in section, 
         FIG. 7  is a perspective view of a module for strip-like print media with a stepper motor for defined adjustment of the module relative to the transport belt, as seen in the transport direction from the front left, 
         FIG. 8  is an exploded view of a module according to  FIG. 7 . 
         FIG. 9  is a side view of the module outside of (pivoted away) the engagement region of the transport belt in section. 
         FIG. 10  is a side view of the module in the engagement region (take-off position) of the transport belt in section. 
         FIG. 11  is a perspective view of a magazine in the transport direction, as viewed from the front left. 
         FIG. 12  is an exploded view (in part) of a magazine according to  FIG. 11  showing details regarding the fill level monitoring. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     According to  FIG. 1 , a franking machine  0  is laterally provided via the input region  02  in the apparatus housing  01  with a flap  011 . The flap  011  can be pivoted forward so that a filling opening (opening upward) of a magazine  21  (see  FIG. 5 ) for the strips  3  is created; see detail. The flap  011  is simultaneously the rear wall of the magazine  21  and is non-positively coupled with its u-shaped upper forward wall  2110  so that this is simultaneously pivoted inward upon closing the flap  011 . 
     If the franking machine  0  is not assembled for strip printing, the flap  11  remains permanently closed (and locked) so that manipulations of the franking machine  0  are not possible via this path. 
     The input region  02  of the franking machine  0  has what is known as a letter thickness sluice that is formed by an upper plate  021  and a lower plate  022 ; see also  FIG. 3 . The maximum letter thickness (10 mm, for example) is established by the separation of these two plates  021 ,  022 . An additional design of the input region  02  with means for letter thickness detection is possible. 
     The counter-pressure device  10  of the transport module  1  is apparent in outline in the lower part of the franking machine  0 ; see also  FIG. 3 . 
     A perspective plan view of a transport module  1  with a module  2  for strips  3  is shown according to  FIG. 2 . The transport module  1  has a revolving transport belt  11  directed over rollers. The drive roller—not designated specifically—is arranged in the output region of the franking machine  0 . Two printheads  15  are offset across a print window  14  so that printing can take place across the full width of the print region  32  of the strip  3 . The strip  3  is taken up with its edge region  31  (transport region) by the transport belt  11 . The revolution direction of the transport belt  11  travels in the counter-clockwise direction; see also the thick arrow. The upper letter travel guide  16  and the lateral letter travel guide  17  serve to guide the typical letters (see also  FIG. 3 ). 
     According to  FIG. 3 , the counter-pressure device  10  is arranged non-positively at the transport belt  11 . A circuit board  13  with transmitter-side letter travel sensors  131 ,  132  and  133  is attached below to the lateral letter travel guide  17 . The associated counterpart is a circuit board  12  with receiver-side letter travel sensors  121 ,  122 ,  123  (not shown) above at the letter travel guide  16  (see  FIG. 2  in this regard). 
     The upper forward wall  2110  of the magazine  21  is arranged spring-loaded so as to be movable in rotation around the axis  212  (see also  FIG. 7 ). The free end of the baffle flap  0232  of the baffle plate  023  for the module  2  protrudes out from the plate  021  (top of the letter thickness sluice) in the transport direction, next to the transport belt  11  (see also  FIG. 4 ). The module  2  has a module housing  20  to accommodate the magazine  21  (see also  FIG. 5 ). 
     The adjustment and fixing of the baffle plate  023  for the module  2  in the plate  021  (top of the letter thickness sluice) is shown in  FIG. 4 . The baffle plate  023  ends in two parallel tabs  0231 ,  0232 . A spring tab  0231  is non-positively applied on the transport belt  11 . The baffle flap  0232  deflects the strip  3  into the engagement region of the counter-pressure device  10 . The baffle flap  0232  is arranged near the transport belt  11  and is adapted to its curvature (see also  FIG. 10 ). The deflection roller  110  for the transport belt  11  is provided with an encoder wheel (not designated) that serves to measure distance for the print line to be printed. 
     Mounting holes  111  for the mounting pins  2011  (see also  FIG. 7 ) of the module  2  are provided in the support frame of the transport module  1 . A defined position of the module  2  relative to the transport module  1  is therefore achieved. 
     The offset position of the module  2  and the magazine  21  thereof relative to the transport belt  11  is clearly visible in  FIG. 5 . Only the narrower region (see stippling) of the transport belt  1  serves for the transport of the strips  3  with the edge region  31 . The front wall  211  of the magazine  21  is notched correspondingly (adapted to the transport module  1 ) for this. The magazine  21  is suspended with the pins  213  in the module housing  20  (see also  FIG. 8 ). 
     At least the part  2171  of the floor wall  217  of the magazine  21  that is situated in the engagement region of the transport belt  11  is executed as a rigid, smooth part (see Detail A). A metal plate with rounded facing profile with low coefficients of friction is advantageously glued on. A corresponding ceramic plate would also be possible. 
     Additional details regarding  FIGS. 4 and 5  are shown in  FIG. 6 . The magazine  21  is shown in the pivoted-away position relative to the transport belt  11 . In this position, the rear part of the elbowed part  2172  of the floor wall  217  is pressed against a contour  0211  in the upper plate  021  of the letter thickness sluice  02 . As a result of this, the front part of the elbowed part  2172  is pivoted upwardly. The magazine  21  is filled with a stack of strips  3  that is pressed by means of a contact pressure lever  214  against the front wall  211  of the magazine  21 . The fill level is monitored with the touching lever  215 . The strips stand with their lower facing edges on the smooth, rigid part  2171  of the floor wall  217 . With its raised leading edge, the elbowed part  2172  of the floor wall  217  prevents an exit of strips from the magazine  21 . A function support  218  for a circuit board  2180  is attached to the lower rear wall  216  of the magazine  21  (see  FIGS. 11 and 12 ). 
     A complete module  2  is shown in  FIG. 7  as viewed from the front left. The module housing  20  (see also  FIG. 2 ) is assembled from a right part  201  and a left part  202  and includes the magazine  21  (see also  FIG. 8 ). The upper, movable front wall  2110  of the magazine  21  is borne such that it can rotate around the axle  212  and is tensioned by means of a tension spring  2113 . The tension spring  2113  is suspended with one end in a tab  2114  of the front wall  2110  below the axle  212  and attached with the other end in a nose  2021  of the left part  202  of the module housing  20 . The contact pressure lever  214  with associated spiral torsion spring  2141  and the touching lever  215  with associated spiral torsion spring  2151  are likewise arranged next to one another on the axle  212 . The axle  212  itself is borne in side walls of the magazine  21 . A stepper motor  22  with gearwheel (not shown) is attached to the side at the left part  202  of the module housing  20 , which serves to drive a toothed segment  221 . 
     The design of the module  2  is more clearly apparent in  FIG. 8  in an exploded presentation. In particular, it is clear that the toothed segment  221  forms a unit with an axle  222  with activation curve profile that is borne between two parts  201 ,  202  of the module housing  20  parallel to the axle  212 . The axle  222  engages with its profile in an opposite contour  2112  of the outer front wall  211  of the magazine  21 . The distance of the rigid, smooth part  2171  of the base wall  217  of the magazine  21  from the transport belt  11  is continuously adjustable in this manner, and therefore the sluice opening for the strips  3  can be set (see also Detail A). 
     The relationships given a pivoted-away magazine  21  are shown in section in side view in  FIG. 9 , in particular Detail A. In the magazine  21  (see also  FIG. 8 ), the stack of strips  3  rests non-positively (as a result of contact pressure lever  214 ) with the front-most strip on the lower front wall  211 . The facing side of the elbowed part  2172  of the floor wall  217 , the exit end of the tab spring  0231  and of the baffle flap  022  of the baffle plate  023  are normally distanced from the transport belt  11 . As an exception, it can be desired to leave the tab spring  0231  in contact with the transport belt  11  in order to securely transport away the end of the currently taken strip  3 . The facing part of the tab spring  0231  is then advantageously to be provided with a sliding layer. 
     The interaction of axle  222  with activation profile and opposite contour  2112  of the front wall  211  is easily recognizable in Detail B. As long as the projecting part of the eccentric axle  222  strikes the bead of the opposite contour  2112  of the front wall  211 , the magazine  21  remains pivoted away. The translation relationships between gearwheel of the step motor  22 , toothed segment  221  and axle  222  can be selected so that a less powerful motor is sufficient and a catch is present; a holding current is consequently done away with. 
     As a supplement to  FIG. 3 , the arrangement of the circuit boards  12  and  13  with the associated letter travel sensors  121 ,  122 ,  123  and  131 ,  132 ,  133  relative to the transport belt  11  and counter-pressure device  10  is visible. 
     The relationships given a pivot-forward magazine  21  in a side view in section are shown in  FIG. 10  (in particular Detail A); that is the take-off position. The magazine  21  is pivoted so far forward that the deflection roller  110  with the transport belt  11  protrudes into the recess  2111  of the lower front wall of the magazine  21  (see  FIG. 8 , Detail A). As a result of this, the forward-most strip  3  rests positively on the transport belt  11  and is taken along by this by static friction, is deflected at the magazine floor and consequently matches the curvature of the deflection roller  110 . The elbowed part  2172  of the floor wall  217  has left the contour  0211  of the plate  021 , so its free end falls downwardly and releases the strip  3 . The exit end of the spring tab  0231  of the baffle plate  023  initially rests on the transport belt  11  before the strip  3  arrives between them. With its rounded front profile and the transport belt  11 , the smooth part  2171  initially forms a wedge-shaped, closed intake angle into which the front-most strip  3  is securely pressed due to the static friction with the transport belt  11 . Since the magazine  21  is elastically spring-loaded, the now open intake angle or the strip sluice is flexibly adapted to different strip thicknesses. The strip  3  presses the sluice only until this is passed through. The static friction required for the take-off (and consequently the feed force) is not sufficient for the strip situated after this. 
     If the start of the strip  3  is located in the region of the first sensor pair (the input sensor  121 ,  131 ), strip take-off is signaled. The second sensor pair is the print image sensor  122 ,  132  and the third sensor pair is the print start sensor  123 ,  133 . The print image sensor  122 ,  132  is used both for the preparation of the print image and the control of the magazine position. If the start of the strip arrives at the print image sensor  122 , the signal to pivot the magazine  21  away is emitted to the step motor  22  with a delay (see also  FIG. 7 ). 
     Since the thickness fluctuations of the strips are far less in comparison to typical letters, a significantly higher print quality is achieved given unmodified transport conditions. 
     The arrangement of the touching lever  215  for the fill level monitoring and the function support  218  with the circuit board  2180  relative to one another is shown in the view according to  FIG. 11 . The free leg of the touching lever  215  is provided at its end with two elbowed switching plates  2152 ,  2153  of different lengths that act on associated photoelectric barriers  2181 ,  2182  depending on the position of the touching lever  215 . The photoelectric barriers  2181 ,  2182  are designed as forked photoelectric barriers with aperture and are attached on the circuit board  2180 . 
     The size ratios of the two switching plates  2152 ,  2153  are easily seen in  FIG. 12 . If too many strips  3  are slid into the magazine  21 , the shorter switching plate  2152  interrupts the photoelectric barrier  2182 . Enough strips  3  must be removed so that the photoelectric barrier  2182  is free again. Given an empty state, the touching lever  215  is pivoted so far forward into a recess (not designated in detail) of the front wall  211  that, due to this path relationship, the longer switching plate  2153  securely triggers the photoelectric barrier  2181  even given thin strips  3 . 
     Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art.