Abstract:
A mail processing system has an envelope-separating apparatus with a moistening apparatus for moistening and discharging an envelope in an open state. A franking device is disposed downstream of the envelope-separating apparatus and is optionally provided with weighing scales. In the franking device a moistened glued edge of the envelope flap is pressed against the envelope pocket by pressure-exerting elements also serving for transporting the envelope. A closing module is disposed downstream of the franking device and has a closing-roller pair that is configured in a manner adapted for mixed-mail operation. Because the entire sequence in the franking device takes place between the stages where the glued edge is moistened and the envelope is closed, sufficient time is gained, even at high transporting speeds, in order for the glue to begin to dissolve sufficiently and for the envelope to be reliably closed.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a configuration for closing envelopes in a mail-processing system once the glued edges of the envelope flaps have been moistened. 
     Mail-processing systems usually contain a letter/envelope-separating apparatus, in which the letters/envelopes are positioned in a stackwise manner, separated and closed as required. Downstream of this a franking and/or addressing machine with optional weighing scales, and a depositing apparatus are disposed (see German Geschmacksmuster DE 96 09 167.3 in the German Patent Office Design Journal dated 24.05.1997, Part 1a, goods class 18/02). The configuration according to the invention serves for reliably closing envelopes which run through such mail-processing systems. 
     A franking machine with devices for moistening the glued closing edges of the flaps of envelopes and then for closing the same is known, see Published, Non-Prosecuted German Patent Application DE 23 24 182 A1. The moistening apparatus for this essentially contains a water tank and a supporting arm along with a wick. 
     The envelopes are stacked such that the flaps are open. The flaps are turned against the envelopes by devices that are not described in any more detail. The envelopes rest flat on a table and are transported along the moistening apparatus by a transporting belt, which projects some way through a longitudinal slot in the table. In this case, the flaps of the envelopes are guided beneath the table. 
     The moistening apparatus is likewise disposed beneath the table, an open edge section of a supporting arm being located parallel, and transversely, to the table. The flap is pressed against the exposed section of the wick by a resiliently configured moistener casing, with the result that at least the glued closing edge is moistened as it passes. 
     The flap then passes through an opening in the table and, as the envelope runs through, the flap is pressed against the envelope by a pressure-exerting plate and a pressure mount feed plate, the envelope thus being sealed. 
     This apparatus allows only a relatively low transporting speed of horizontally located envelopes, since otherwise the capillary action from moistening the flaps is no longer sufficient. Added to this is the fact that the period of time from moistening up until the envelopes are closed is very brief. This results in the risk that the envelope glue does not begin to dissolve sufficiently in the moistening liquid and, consequently, the envelope is not reliably closed. 
     Meanwhile, the prior art already includes an apparatus which is intended for moistening the glued edges of the flaps of the envelopes and is the constituent part of a letter/envelope-separating apparatus. 
     SUMMARY OF THE INVENTION 
     It is accordingly an object of the invention to provide a configuration for closing envelopes that overcomes the above-mentioned disadvantages of the prior art devices of this general type, in which the application area and the functional reliability are increased. 
     With the foregoing and other objects in view there is provided, in accordance with the invention, a configuration for closing envelopes in a mail-processing system, including: 
     an envelope-separating apparatus having a moistening apparatus for moistening a glued edge of an envelope flap of an envelope and discharging the envelope in an open state with a moistened glued edge; 
     a franking device disposed downstream of the envelope-separating apparatus and receiving the envelope, the franking device having pressure-exerting elements for pressing the envelope flap with the moistened glued edge partially against an envelope pocket, the pressure-exerting elements further serving for transporting the envelope; and 
     a closing module with a closing-roller pair disposed downstream of the franking device and receiving the envelope. 
     The object of the invention is to provide a configuration of the type mentioned in the introduction in the case of which the envelopes can be transported at a high transporting speed and nevertheless reliably be closed and carefully deposited in a stackwise manner without any follow-up work by hand being necessary. 
     Since the envelopes are moistened on the glued edges immediately after they have been separated and are only fully closed immediately before they are deposited, this ensures, despite a high transport speed, sufficient time for softening the glued edges and, consequently, a reliable closure of the envelopes. 
     In specific terms, the fact that the pressure-exerting elements, originally provided just for transporting purposes, are utilized for partially closing the envelopes and that the actual closing operation is carried out by a specifically configured closing module with a closing-roller pair at the end of the mail-processing system. The closing module provides, despite a high transport speed, a sufficient amount of time for the glue to soften and thus a reliable closure of the envelopes. 
     The configuration of a runner-like pressure-exerting lever and the mounting of the input-driven closing roller, and also the positioning of the spindles of the closing-roller pair, result in that even thick envelopes are closed without creases and folds being formed. 
     Moreover, the closing-roller pair also assists in depositing the envelopes in the depositing box in a functionally appropriate manner since the run-through speed of the envelopes in this region is adjusted to be at least equal to or greater than that in the printing region of the franking/addressing machine. 
     Other features which are considered as characteristic for the invention are set forth in the appended claims. 
     Although the invention is illustrated and described herein as embodied in a configuration for closing envelopes, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
     The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagrammatic, perspective view of a mail-processing system according to the prior art; 
     FIG. 2 is a perspective, partly cut-away view of a letter/envelope-separating apparatus with a moistening device according to FIG. 1; 
     FIG. 3 is a perspective view of a pressure-exerting region of a franking machine according to FIG. 1; 
     FIG. 4 is a perspective view of the franking machine with a configuration in which it is possible to deposit envelopes according to the prior art; 
     FIG. 5 is a perspective view of the mail-processing system with a configuration according to the invention; 
     FIG. 6 is a partly exploded, perspective view relating to a closing region according to FIG. 5; 
     FIG. 7 is a perspective view of a drive in the closing region; 
     FIG. 8 is a partly broken-away, top plan view relating to a positioning of spindles of a closing-roller pair; and 
     FIGS. 9 a  and  9   b  are perspective views of details relating to depositing envelopes and letters. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In all the figures of the drawing, sub-features and integral parts that correspond to one another bear the same reference symbol in each case. Referring now to the figures of the drawing in detail and first, particularly, to FIG. 2 thereof, there are shown envelopes  1  that are disposed as a stack, standing with an edge of an envelope flap  11  on a bottom guide plate  22 , between a pressure-exerting bracket  27  and a rear guide plate  21  in a force-fitting manner of an envelope/letter separating apparatus  2 . In this case, the envelope flap  11  is directed upward. The envelopes  1  are transported away from the stack laterally and, in the process, butt against the slightly inclined rear guide plate  21 . In a movement path of the envelopes  1 , there is disposed in a resiliently adjustable manner a guide unit  23  which is intended for the envelope flap  11  and, on an outlet side, has a device  234  for moistening the glued edge. 
     Provided on the outlet side is an ejecting-roller pair  28  which is made up of an input-driven, stationary ejecting roller  281  and an output-driven, resiliently adjustable ejecting roller  282 . The output-driven ejecting roller  282  is shorter than the input-driven ejecting roller  281  by more than the maximum flap height of the envelopes, and is disposed flush at the top with the latter. 
     In this way, the envelopes leave the envelope-separating apparatus  2  with the glued edge moistened but still in an open state (i.e. the envelope is not glued shut). 
     Also known is an apparatus for printing a printing substrate standing on one edge, in particular the envelope  1  in a franking and/or addressing machine  3 , the printing substrate  1  being guided in a supported manner on an edge during the transporting operation and the printing operation, see Published, European Patent Application EP 0 788 073 A2 and FIG.  3 . 
     In FIG. 3, the franking machine  3  has a guide plate  31 , which is inclined in relation to the vertical and is intended for a slidable abutment of the envelope  1 , and a circulating transporting belt  32  for applying an advancement force to the envelope  1  for advancement along the guide plate  31 . Fastened on the transporting belt  32  are pressure-exerting elements  33  for pressing the envelope  1  onto the guide plate  31 . The pressure-exerting elements  33  are disposed such that they can be moved toward the guide plate  31  and away from the same, such that, during the transportation and the printing operations, the envelope  1  is gripped in a force-fitting manner by the pressure-exerting elements  33  on a side of the envelope that is directed away from the guide plate  31 . 
     Finally, a configuration in which it is possible to deposit envelopes for the above-mentioned franking machine  3  and in the case of which the envelopes are deposited in a stackwise manner one above the other in an adjusted box is also known, see German Patent DE 197 05 089 C1 and FIG. 1. 
     According to FIG. 1, the configuration contains an insert  5  and a box  6 . These two form the termination of a mail-processing system, which also contains the letter/envelop-separating apparatus  2  and the franking machine  3 . 
     The insert  5  is connected releasably to the franking machine  3 , which, adjoining the guide surface for a bottom edge of the envelope  1  in the franking machine  3 , has a channel  531 , which slopes down in the transporting direction, and a pivotable, resilient rocker SI parallel to a front edge of the insert  5 . 
     At the same time, in the left-hand rear corner region of the box  6 , the insert  5  is placed at a small distance from the same, the two being adapted to one another. 
     As a supplement to the above-mentioned depositing apparatus, the prior art as shown in FIG. 4 has also been found to include a solution in which the angled insert  5  is attached to the franking machine  3  by way of its side wall  54 , and has the downwardly sloping channel  531  formed in its front wall  53 , and the open angled box  6  is guided adjustably by way of its front wall  61 . 
     The channel  531  adjoins the guide plane for the bottom edge of the letter/envelop in the franking machine  3 . The side wall  62  of the box  6  is configured as a resilient deflecting wall and is disposed at an adjustable distance downstream of the channel  531  and orthogonally to the transporting direction. 
     The distance between the side wall  62  and the outlet of the franking machine  3  is adjusted to be somewhat greater than the largest letter format which is to be processed. 
     Optionally, the franking device  3  shown in FIG. 4 has a weighing scale  100  for weighing the envelope  1  for determining the postage. 
     With a mail-processing system which is made up of the four last-mentioned devices (FIGS.  1 - 4 )—it being possible to chose one of two optional depositing apparatuses—the envelopes  1  will be closed more or less appropriately on account of the weight of the stack, in which the envelopes are located one above the other. In this device it is possible to avoid the situation where at least the envelopes  1  at the top of the stack have to be closed by hand. In mail-processing systems with throughput figures of 5000 envelopes and above, this situation is not satisfactory. 
     In FIG. 5, a closing module  4  is added in between the franking machine  3  and the insert  5  with the depositing box  6 . The essential constituent part of the closing module  4  is a closing-roller pair  42  containing an input-driven closing roller  421  and an output-driven closing roller  422  (see FIG.  6 ). The closing module  4  is attached to the franking machine  3  such that its guide plate  41  forms a continuation of the guide plate  31  of the franking machine  3 , which in turn constitutes a continuation of the guide plate  21  of the letter/envelope-separating apparatus  2 . In other words, all three guide plates  21 ,  31  and  41  are in alignment. 
     The envelopes  1  pass into the franking machine  3  from the separating apparatus  2  in the open state, but with the moistened envelope flap  11  disposed in front of an envelope pocket  12 . The envelope flaps  1  are gripped in a force-fitting manner, in the franking machine  3 , by the pressure-exerting elements  33  for transportation in the franking machine  3  (see FIG.  3 ), and are partially closed in the process, and, following the franking, are transferred to the closing module  4  and are fully closed in the latter by the closing-roller pair  42 . 
     For this purpose, the pressure-exerting elements  33  extend up to such a height, and the closing rollers  421 ,  422  are of such a length, that the envelope flaps  11  are gripped fully over a maximum height of the envelope flaps  11 . 
     In the closing module  4 , the letter-transporting speed is adjusted to be somewhat higher—up to 13%—than in the printing region of the franking machine  3 . The adjoining insert  5  with the depositing box  6  is accordingly adapted and optimized. 
     The maximum stacking depth in the envelope-separating apparatus  2  and a height of the transporting plane in the same, and accordingly also in the franking machine  3 , are coordinated with one another such that, when the largest possible stack of letters is being processed from the separating apparatus  2 , the maximum possible stacking height in the depositing box  6  that corresponds more or less to the top edge of the channel  531 —is not exceeded. 
     It can be seen in FIG. 6 how the closing module  4 , the insert  5  and the depositing box  6  are connected to one another and the envelopes/letters run through within these structural units. The envelope  1  passes from the franking machine  3  into the closing module  4  and is guided by a wedge-shaped narrowing to the two closing rollers  421 ,  422 . The wedge-shaped narrowing is formed, toward a front side, by a toothed belt  48  and, at the rear, by the guide plate  41 , see also FIG.  8 . 
     The envelope  1  passes first of all into a region of a resiliently mounted, runner-like pressure-exerting lever  44 . A free end of the pressure-exerting lever  44  is spaced apart from the guide plate  41  by a small distance—about 5 mm with the result that thin envelopes can pass through the pressure-exerting lever  44  without obstruction. In the case of thick envelopes  1 , the pressure-exerting lever  44  butts against the same right from the beginning, with the result that the envelope flap  11  is positioned against the pocket  12  of the envelope  1 . 
     Following passage through the pressure-exerting lever  44 , the envelopes  1  pass onto the toothed belt  48 . Via the toothed belt  48 , the envelope  1  is directed to the guide plate  41  and then, between the closing rollers  421 ,  422 , is pushed with contact pressure onto the channel  531  in the insert  5  in order to tip from the channel  531 , via rear guide slopes  5313 , into the depositing box  6 . 
     The channel  531  runs horizontally in adaptation to the plane on which the envelopes  1  stand in the franking machine  3  and the horizontal guidance of the envelopes in the closing module  4 . 
     On account of the inclination of the guide plate  41  and of the parallel configuration of the closing rollers  421 ,  422  in relation to the guide plate  41 , the envelopes  1  have a clearly predetermined orientation, this ensuring that they are deposited in the direction of the depositing box  6 . The envelopes  1  are stacked one above the other on a base of the depositing box  6 . The right-hand side wall  62  prevents the envelopes  1  from moving out laterally. A front wall  61  of the depositing box  6  is guided in a slit  532  (se e also FIGS. 9 a  and  9   b ) of the front wall  53  of the insert  5  such that it can be adjusted in accordance with the largest letter/envelope format which is to be processed in each case. 
     The closing module  4  is attached by way of its left-hand side wall  46 , in the region of the guide plate  41 , to the right-hand side wall of the franking machine  3 . The closing module  4  has, in a front region, a front covering  40  for the closing-roller pair  42  and a reinforcing angle  401  for inner support. 
     In an inlet region for the envelopes  1 , the side wall  46  is provided with an angled lug  460  for guiding the envelopes  1  at the bottom. Furthermore, the side wall  46  is configured as a retaining angle for the pressure-exerting lever  44  and its spindle  441  and for a carrying lever  45  and its spindle  451 , and is provided with correspondingly angled lugs  461  to  464 . 
     The spindle  441  for the runner-like pressure-exerting lever  44  is fastened in the parallel lugs  462  and  463 . The pressure-exerting lever  44  is disposed, a small distance from the guide plate  41 , such that it can be rotated against a spring  442  likewise pushed onto the spindle  441 . The spring  442  is supported, at one end, on the pressure-exerting lever  44  and, by its other end, on the lug  464  of the side wall  46 . The distance from the guide plate  41  may be dispensed with if the spring force is of correspondingly small dimension in an entry region. 
     The carrying lever  45  for the input-driven closing roller  421  is mounted in a resiliently rotatable manner on the spindle  451  which is fastened in the two parallel lugs  461  and  463 . The carrying lever  45  is angled at top and bottom ends for the purpose of receiving the spindles  451  and  4211 . A spring  454  is likewise pushed onto the spindle  451 . The spring  454  is supported, by one end, on the carrying lever  45  and, by its other end, on the lug  461 . Moreover, a gear wheel  452  is fastened at a bottom end of the spindle  451  and a pinion  453  is fastened at a top end of the spindle  451 , see FIG.  7 . 
     The spindle  4211 , with the closing roller  421  fastened on it, is mounted rotatably in an outer pivot region of the carrying lever  45 . A gear wheel  4212  is also fastened at a top end of the spindle  4211 . The gear wheel  4212  is coupled kinematically to a pinion  453  on the spindle  451  by the toothed belt  48 . 
     The output-driven closing roller  422  is disposed behind the guide plate  41 , in an opening  411  of the same, such that the closing roller  422  is flush on the outside with a front plane—which, as is known, is the abutment plane for the envelope  1 —of the guide plate  41 , see also FIG.  8 . 
     As can be seen in FIG. 7, the gear wheel  452  is coupled kinematically to a pinion  431  by a toothed belt  47 . The pinion  431  is fastened on a spindle  430  of a motor  43 , which is connected, via a power-supply line  432 , to the same power source, and consequently also to the same control devices in the franking machine  3 , which serves for driving the transporting belt  32 , see also FIG.  3 . In other words, when the transporting belt  32  operates, the closing rollers  421 ,  422  also rotate, to be precise such that the transportation in the closing module  4  is synchronous with, but somewhat quicker—more or less up to 13%—than, the transportation in the franking machine  3 . This prevents any jamming. 
     The motor  43  is flanged onto a lug  466  of the side wall  46 . A spindle  4221  of the output-driven closing roller  422  is fastened in the parallel lugs  46  S and  466 . The closing roller  422  is disposed rotatably on the spindle  4221 . 
     In the case illustrated, that is to say as seen from beneath, when the motor  43  is operating the pinion  431  is rotated in the counterclockwise direction and the movement is transmitted to the gear wheel  452  via the toothed belt  47 . Since the gear wheel  452  is fixed on the spindle  451  and the latter can be rotated, the rotary movement of the gear wheel  452  is transmitted to the pinion  453  via the spindle  451 , the pinion  453  likewise being fixed on the spindle  451 . The pinion  453  drives the gear wheel  4212  via the toothed belt  48 , the gear wheel  4212 , together with the closing roller  421 , being fixed on the rotatable spindle  4211 . In this way, the closing roller  421  is then driven by the gear wheel  4212  via the spindle  4211 . 
     The rotary movement of the input-driven closing roller  421  is transmitted to the other closing roller  422  in a force-fitting manner by friction via the envelope  1  or directly. In order to have favorable static friction, the input-driven closing roller  421 , or the closing roller  421  which drives the envelope, has a grooved outer covering  4210 , see also FIG.  8 . In this case, the grooves run parallel to the spindle  4211  and have a shark-tooth-shaped contour. The elastic positioning of the teeth achieves both highly elastic adaptation to unevennesses in envelopes and an increase in the carry-along surface area and thus good adherence properties. The effect is increased further if a suitable silicone rubber is used. 
     For the outer covering  4220  for the output-driven closing roller  422 , use is made of a flexible, highly absorbent foam rubber or open-microcell foamed polyurethane. In this way, the closing roller  422  acts as a blotting roller for pressure points which are still moist; smearing is thus avoided. 
     FIG. 8 shows the positions of the input-driven closing roller  421  and the output-driven closing roller  422  in relation to one another. 
     In the rest state, the two closing rollers  421 ,  422  butt against one another in an axis-parallel manner on a line which is orthogonal—chain-dotted—to the front side of the guide plate  41  and/or to the abutment plane for the envelope  1 . 
     This state is also largely maintained for thin letters and envelopes. 
     As the envelope thickness increases, the carrying lever  45  for the closing roller  421  is rotated resiliently to the front side, in the forward direction, about its spindle  451 . In this case, the spindle  4211  moves along over a circular path—dashed lines—with the result that the input-driven closing roller  421  comes to be located downstream of the output-driven closing roller  422 , as seen in the transporting direction of the envelope  1 . On the one hand, this results in the envelope  1  being bent slightly around the closing roller  422  by the closing roller  421 , while, on the other hand, the runner-like pressure-exerting lever  44  acts as abutment. This enforced curvature of the envelope  1  achieves the situation where the envelope flap  11  is already positioned closely against the pocket  12  of the envelope  1  even before it passes through the closing-roller pair  42 . 
     The output-driven closing roller  422  is somewhat longer than the input-driven closing roller  421  and is disposed such that the bottom edge is located at least at as low a level as the bottom edge of the envelope. The input-driven closing roller  421  is disposed such that its bottom edge is located at a somewhat higher level—more or less 5 mm—than the bottom edge of the letter. This achieves the situation where all the contact pressure acts, in the region of the glued edge, on the flap  11  of the envelope  1  and uneven or bumpy envelope contents do not have a disadvantageous influence on the gluing process. 
     In order to assist a successful closing operation further, the two closing rollers  421 ,  422  and their spindles  4211 ,  4221  are inclined slightly—that is to say less than 3°, preferably 1.7°—in the envelope-transporting direction. This avoids creases and folds from being formed in particular. This problem is difficult to solve particularly in the case of thick and partly irregularly filled envelopes. The positive effect is assisted further by the specific configuration of the outer covering  4210  of the input-driven closing roller  421 . 
     The closing operation can also be adversely affected by the way in which envelopes are deposited. In particular when thickly filled envelopes  1  drop forcibly onto the edge or, worst still, onto a corner, there is the risk of the closure splitting open again. The insert  5  is configured appropriately in order to avoid this effect, and this is described here-in-below. 
     FIGS. 9 a  and  9   b  illustrate in more detail the construction of the insert  5  and the movement sequence of the envelopes  1  as they are deposited from the insert  5  into the depositing box  6 . The configuration of the channel  531  and of the rear side  532  of the front wall  53  have particular influence here. 
     As has already been mentioned above, the channel  531  runs horizontally overall, but sloping slightly rearwardly, in the transporting direction behind the front plane of the guide plate  41 . 
     At the entry, the channel  531  has a nose  5310  (FIG. 6) which projects beyond the side wall  54  of the insert  5  into the closing module  4 . The nose  5310  is configured as a slanting plane which slopes down in the outward direction, in order to prevent the envelopes  1  from catching during transfer to the channel  531 . The channel  531  also has at the entry, in a rear region, a supporting plate  5314  which is adapted to the inclination of the guide plate  41  in the closing module  4 . The supporting plate  5314  prevents thin, lightweight envelopes  1  from fluttering about and, as a result, not being deposited correctly, see also FIG.  6 . 
     The channel  531  has a front top guide slope  5311 , a front bottom guide slope  5312  and a rear guide slope  5313 . This gives, in transverse profile, a wedge-shaped depression that is bent on one side. An envelope  1  running into the channel  531  slides down to the base of the guide slopes  5311 ,  5312 ,  5313  to the extent permitted by the thickness of the envelope edge which is being placed in position. 
     A rear side  533  of the front wall  53  undercuts the channel  531  and/or the rear guide slope  5313 . 
     When the entire envelope  1  has left the closing module  4 , it tips via the rear guide slope  5313  first of all, in order then, by way of the edge which is located opposite the envelope flap  11 , to come into contact, at an oblique angle, with the base  63  of the depositing box  6  or the previously deposited envelope  1 . The envelope  1  then slides downward with the edge of the envelope flap  12  on the rear side  533  of the front wall  53 . 
     In this way, the envelope  1  slides into the depositing box  6  and impact loading is thus avoided.