Abstract:
A system for the automated insertion of documents into envelopes. The system includes a plurality of individual document feeding devices that feed individual documents from an assembled stack onto a moving document conveyor. Each of the document feeding devices includes a suction device that pulls the lowermost document into contact with a discharge nip formed between a pair of opposed rotating belts. After being deposited onto the document conveyor, each of the documents enters into a pusher assembly in which each of the documents is accelerated and pushed into an open envelope positioned adjacent to the discharge end of the document conveyor. The stack of opened envelopes is fed by the combination of an envelope feeding device and an envelope conveyor section. The envelope feeding device receives a stack of closed envelopes and feeds and opens each envelope before it is stacked adjacent to the discharge of the document conveyor.

Description:
BACKGROUND OF THE INVENTION 
     The present invention generally relates to the unloading of documents from a stack or stacks and the subsequent insertion of such documents into envelopes. More specifically, the present invention relates to an automated system that discharges a single document or several documents onto to a discharge conveyor and loads the documents into an open envelope while maintaining the required control over the documents to reduce mishandling. 
     Currently, many systems exist for the automated insertion of documents into envelopes and the subsequent processing of the envelopes for automated mailing. For envelope insertion operations, it is generally necessary to provide a stack of envelopes which have had the envelope flap opened so that the materials to be inserted may be inserted therein. In typical prior art systems, such as shown in U.S. Pat. Nos. 4,020,615; 4,888,938; and 5,247,780, opening fingers or blades are inserted into the envelope to allow documents or articles to be slid into the opened envelope. 
     An inherent drawback in envelope inserting systems that includes blades or fingers to open the envelopes is that at higher speeds, the blades or fingers that come into contact with the envelope will tear or otherwise damage the envelope, thereby resulting in system shutdowns and delays. Additionally, high speed operation requires the mechanical fingers to continuously operate, which results in wear and mechanical breakdowns. 
     Along with the inherent problems that result from the use of insertion fingers or blades is the lack of control over the product as it moves at high speeds throughout the system. A primary reason for the lack of control of articles being inserted into the envelopes is the continual starting and stopping of both the articles and the envelopes throughout the entire production process. Additionally, in many currently available machines and systems, both the documents and envelopes change directions several times during the insertion process. During each of the direction changes, the articles and envelopes suffer from a lack of control which tends to restrict the speed of the production process. 
     An additional problem with currently available systems running at higher speeds is the deterioration of the gears and cams that are used to operate the unloading devices and the devices used to insert the documents into envelopes. Therefore, a need currently exists for an improved system for the automated insertion of documents and other articles into envelopes that maintains the required control over the documents and envelopes to allow for the high speed stuffing of envelopes. Further, it is an object of the present invention to provide a system that maintains the required amount of control over the articles as the individual articles move in a single direction from accumulated stacks of documents to finally being placed within the desired envelope. Further, it is an object of the present invention to provide an outfeed conveyor assembly that allows multiple envelope insertion lines to be accumulated on a common conveyor system. 
     SUMMARY OF THE INVENTION 
     The present invention is a system for the high speed and automated insertion of documents into envelopes. The system operates to maintain control over the documents throughout the process and operates in a single, first direction such that the envelopes and documents do not change direction. 
     The envelope inserter of the present invention includes a document conveyor that extends in a first direction. The document conveyor terminates at a discharge end and includes an endless drive chain having a plurality of tabs. Each of the tabs are spaced along the length of the drive chain and function to engage and move the documents along the length of the document conveyor. 
     The envelope inserter further includes a plurality of individual document feeding devices spaced along the length of the document conveyor. Each of the document feeding devices includes a stacking bin that receives a stack of documents to be dispensed. The stack of documents contained within the stacking bin can be folded or flat documents, depending upon the type of material to be inserted into the envelopes. 
     Each of the document feeding devices includes a suction device positioned beneath the bottom end of the stacking bin and is operable to remove the lowermost document from the accumulated stack. The suction device includes a suction cup and support arm that are movable between a grasping position, a discharge position, and a retracted position. When the suction device is in the grasping position, a source of negative air pressure is applied to the lowermost document through a suction cup contained on the suction device. After the supply of negative air pressure is applied to the lowermost document, the suction device can be moved to the discharge position to pull the lowermost document out of the accumulated stack in the stacking bin. 
     As the suction device pulls the lowermost document from the accumulated stack, the document is pulled into contact with a discharge nip formed between a pair of rotating discharge belts. The discharge belts are operated at substantially the same speed such that when the document enters into the discharge nip and the supply of negative air pressure is removed, the pair of rotating discharge belts act to direct the document onto the document conveyor. One of the discharge belts passes around a drive member that is operable to adjust the position of the discharge nip. Specifically, the drive member operates to move the discharge nip upward to pull the document from the suction device when the suction device is in the discharge position. As the discharge belts engage the document, the suction device moves to the fully retracted position that is completely out of the way of the document as it is pulled from the stack. The operation of each document feeding device is controlled by a control unit that times the discharge of each document such that each document is positioned in contact with one of the moving tabs on the document conveyor. 
     As the discharged documents are moved along the document conveyor, the discharged documents pass beneath a document insertion device. The document insertion device is positioned near the discharge end of the document conveyor and operates to act upon the documents as the documents approach the discharge end of the document conveyor. The document insertion device includes a continuous belt that operates in-line with the document conveyor in the first direction. 
     The continuous belt of the document insertion device includes a plurality of pusher members that contact the individual documents supported along the document conveyor. Each of the pusher members contacts the document and pushes the document off of the discharge end of the document conveyor and onto a support platform. The endless belt of the document insertion device is operated at a speed slightly faster than the speed of the document conveyor such that the documents are accelerated by the pusher members of the document insertion device. 
     A stacking device that includes a stack of opened envelopes is positioned immediately adjacent to the discharge end of the document insertion device such that the pusher members of the document insertion device push the documents into the uppermost envelope of the opened envelope stack. A blast of air is directed into the uppermost envelope of the opened envelope stack to open the envelope prior to insertion of the document by the document insertion device. 
     The stack of opened envelopes in the stacking device is created by the combination of an envelope feeding device and an envelope conveyor. The envelope feeding device is generally identical to the plurality of document feeding devices and thus includes a stacking bin including a supply of unopened envelopes. The unopened envelopes contained within the stack in the storage bin are fed individually into a discharge nip by a suction device. As the unopened envelopes are fed from the stack, a powerful air blast is used to open the envelope flap prior to the envelope entering into the discharge nip. 
     The now opened envelopes are fed from the envelope feeding device to an envelope conveyor where a continuous string of opened envelopes are shingled. The shingled, opened envelopes are fed from the envelope conveyor to the bottom of the opened envelope stack contained within the stacking device. The stacking device includes a photoeye that communicates with a control unit such that the control unit can control the operation of both the envelope conveyor and the envelope feeding device to feed envelopes to the stacking device as the height of the opened envelope stack decreases. 
     After the uppermost envelope in the opened envelope stack is stuffed with a document by the document insertion device, the envelope is lifted off of the stack by a suction device. The envelope is fed by a transfer device to an outfeed conveyor. While on the outfeed conveyor, the envelope flap is wetted and pressed into a closed position. The outfeed conveyor extends in a second direction that is different from the first direction of the document conveyor. From the outfeed conveyor, the closed envelopes are fed to conventional processing equipment, such as mailing and sorting machines. 
     Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings illustrate the best mode presently contemplated of carrying out the invention. 
     In the drawings: 
     FIG. 1 is a schematic top plan view of a system for the automated insertion of documents into envelopes in accordance with the present invention; 
     FIG. 2 is a side view of the system of the present invention as seen along line  2 — 2  of FIG. 1 further illustrating the operational components of the system; 
     FIG. 3 is a side view of an outfeed conveyor portion of the system of the present invention, as viewed along line  3 — 3  of FIG. 1; 
     FIG. 4 is a detailed side view of a document feeding device that forms part of the system of the present invention; 
     FIG. 5 is a partial side view similar to FIG. 4, further illustrating the operational steps of the document feeding device in discharging a document from the accumulated stack of documents; 
     FIG. 6 is a further operational sequence diagram illustrating the document feeding device of the present invention; 
     FIG. 7 is a partial section view taken along line  7 — 7  of FIG. 6; 
     FIG. 8 is a partial side view of a document insertion device of the present invention, illustrating the loading of an individual document into an opened envelope; 
     FIG. 9 is a further operational sequence diagram illustrating the insertion of a document into an opened envelope; and 
     FIG. 10 is a operational sequence diagram illustrating the removal of a stuffed envelope from the stack of open envelopes accumulated near the discharge end of the document conveyor. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The envelope inserter  10  of the present invention in schematically illustrated in FIG.  1  and shown in operational detail in FIG.  2 . The envelope inserter  10  generally feeds articles or documents from individual stacks and stuffs the documents into individual envelopes, which are then sealed and distributed to a downstream processing system, such as a conventional mail addressing, stamping and sorting system. 
     The envelope inserter  10  of the present invention generally includes a plurality of document feeding devices  12  sequentially spaced along the longitudinal length of a documents conveyor  14 . Each of the document feeding devices  12  includes a stack of documents  16  and operates to sequentially unload the stack of documents one by one onto the moving document conveyor  14 . As can be understood in FIG. 1, the document conveyor  14  extends in a first direction along which the documents move. Although the present invention illustrates only two documents feeding devices  12  positioned along the length of the document conveyor  14 , it is contemplated by the inventor that any number of document feeding devices  12  could be placed sequentially along the operative length of the document conveyor  14 . The plurality of document feeding devices  12  can be configured to either dispense the same documents, or the document feeding devices  12  can each include a different document depending upon the selected user configuration for the envelope inserter  10 . 
     As the documents  16  are dispensed onto the document conveyor  14 , one of the spaced tabs  18  (FIG. 2) contacts the document and moves the document towards a discharge end  20  of the document conveyor. Each of the tabs  18  is spaced along the length of a rotating, endless chain  22  driven at a constant speed by a drive motor (not shown). In the preferred embodiment of the invention, the drive chain  22  is preferably driven at a speed such that approximately 100 envelopes per minute can be stuffed, although other speeds of operation are clearly within the scope of the present invention. 
     As the individual documents move along the document conveyor  14 , the documents continue to move in the first direction until the documents reach a document insertion device  24 . The document insertion device  24  generally includes a rotating, endless belt  26  that includes a plurality of spaced pusher members  28 . As can best be seen in FIG. 2, the document insertion device  24  is positioned slightly above the document conveyor  14  and operates in-line with the document conveyor  14 . The document insertion device  24  operates to accelerate the speed of each individual document  16  as it reaches the discharge end  20  of the document conveyor  14 . 
     From the document insertion device  24 , each individual document or stack of documents  16  is inserted into the topmost envelope of an accumulated opened envelope stack  30 . Each envelope of the envelope stack  30  has been previously opened such that the documents can be readily fed into the envelope by the document insertion device  24 . 
     After the top envelope of the opened envelope stack  30  has been loaded with the required document or documents, the stuffed envelope is transferred away from the stack  30  by a transfer device  32  to an outfeed conveyor  34 , which then transfers the envelope to a sorting conveyor for further downstream processing. As can be understood in FIG. 1, the documents  16  travel in only the first direction until they are inserted into the top envelope of the opened envelope stack  30 . After the envelope has been stuffed, the stuffed envelope is placed on the outfeed conveyor, which extends in a direction different from the first direction. 
     Although FIG. 1 is illustrated as including a single document conveyor  14 , including a plurality of aligned document feeding devices  12  feeding stuffed envelopes onto the single outfeed conveyor  34 , it is contemplated by the inventor that several document conveyors  14  could be aligned next to each other and operated to feed stuffed envelopes onto the single outfeed conveyor  34 . The single outfeed conveyor  34  would then transfer the series of envelopes from the multiple document conveyors to the single sorting conveyor  36 . 
     Referring now to FIGS. 4-7, thereshown is the detailed construction of one the document feeding devices  12  that forms part of the envelope inserter  10  of the present invention. As can be seen in FIG. 4, the document feeding device  12  includes a stacking bin  38  that receives and supports a stack of documents  16 . The stack of documents  16  can include either folded or unfolded material depending on the preference of the user. The stacking bin  38  includes a bottom support plate  40  that extends over a substantial portion of the width of each document  16 . 
     Referring now to FIGS. 4 and 7, the document feeding device  12  includes a pair of spaced upper discharge belts  42  and a pair of spaced lower discharge belts  44 . The upper discharge belts  42  are each a continuous belt entrained around one of the primary drive roller  46  and a discharge roller  48 . As can be seen in FIG. 7, each of the primary drive rollers  46  is attached to a rotating drive shaft  50 . The drive shaft  50 , in turn, is connected to a drive motor  52 . The operation of the drive motor  52 , as well as the drive means for the document conveyor  14 , are controlled by a central control unit (not shown). 
     The central control unit receives a signal from an encoder coupled to the drive shaft for the rotating, endless chain  22  of the document conveyor  14 . The encoder generates a series of pulses as the drive shaft for the endless conveyor  14  rotates. By counting the number of pulses generated by the encoder, the central control unit can accurately monitor and determine the position of each of the tabs  18  along the length of the document conveyor  14 . Based upon the position of the tabs, the central control unit can operate each of the document feeding devices  12  such that documents are dispensed from the accumulated stack at the right time to be received by one of the tabs  18  of the drive chain  22  that forms a part of the documents conveyor  14 . 
     Through use of the encoder pulses generated by the drive motor for the document conveyor  14 , the central control unit can accurately control the firing of each of the document feeding devices  12 . If the envelope inserter  10  of the present invention is utilized with smaller documents that are being inserted into letter-sized envelopes, the number of tabs  18  on the endless chain  22  can be doubled and the firing of each document feeding device  12  also doubled. In this manner, a significantly larger number of envelopes can be loaded per minute without increasing the actual speed of the document conveyor  14 . 
     As can be seen in FIG. 7, the drive rollers  46  and thus the upper discharge belts  42  are spaced along the width of the documents  16  contained within the stacking bin  38 . As can be seen in FIGS. 4 and 7, the lower discharge belts  44  are directly aligned beneath the upper discharge belts  42  such that the upper discharge belts  42  and the lower discharge belts  44  form a discharge nip  54 . The lower discharge belts  44  are entrained and supported by a series of individual rollers  56  such that a portion of each lower discharge belt  44  wraps around the primary drive roller  46  for the respective upper discharge belt  42 . The speed of each lower discharge belts  44  is also controlled by the drive motor  52 , such that the upper discharge belts  42  and the lower discharge belts  44  operate at substantially the same speed. 
     As can be seen in FIGS. 4-6, the wrap angle of the lower discharge belts  44  along the primary drive roller  46  is controlled by a drive member  58  attached to a roller  60  about which the lower discharge belt  44  is entrained. When the drive member  58  is fully retracted, as shown in FIG. 5, the discharge nip  54  is effectively moved downward from the stacking bin  38 . When the drive member  58  is extended, as sown in FIG. 6, the wrap angle increases such that discharge nip  54  moves upward toward the stacking bin  38 , the significance of which will be made clear in the following discussion. In the preferred embodiment of the invention, the drive member  58  is an air cylinder having an extendable cylinder rod  62  attached to the roller  60 , the operation of which is controlled by the central control unit. 
     Referring back the FIG. 4, the document feeding device  12  includes a suction device  64  rotatably positioned beneath the bottom support plate  40 . The suction device  64  includes a support arm  66  having a first end  67  positioned beneath the bottom support plate  40  and having suction cup  68  attached to its outer end  69 . The suction device  64  is connected to a supply of negative air pressure, such that a vacuum is created within the suction cup  68 . The vacuum created in the suction cup  68  can be used to grasp the lowermost document  16  within the document stack in the stacking bin  38 . As can be seen in FIGS. 4 and 5, the suction device  64  is moveable between the grasping position of FIG.  4  and the discharge position of FIG.  5 . Although not shown in the drawings, the suction device  64  rotates further in the counter-clockwise direction from the position shown in FIG. 5 to a completely retracted position. When in the retracted position, the suction device  64  is moved away from the document  16  being discharged to prevent contact therewith. The movement of the suction drive  64  between the grasping position, the discharge position, and the retracted position is controlled by the control unit and is carried out by an air cylinder (not shown) coupled to the suction device  64 . 
     In operation, the control unit for the envelope inserter  10  times the operation of each of the document feeding devices  12  to discharge individual documents  16  based upon the encoder pulses received from the drive shaft for the document conveyor  14 . The sequence in which the document feeding devices  12  are operated depends upon whether each device  12  is unloading the same document  16  onto the discharge conveyor  14  or whether each device  12  is unloading different documents so that multiple articles can be inserted into a single envelope. If multiple articles are to be inserted into each element, each of the devices  12  is operated for each tab  18  such that multiple documents are moved along the document conveyor  14  by each tab  18 . 
     Based upon the position of each tab  18 , the drive member  58  retracts the cylinder rod  62  such that roller  60  is moved away from the primary drive roll  46  to decrease the wrap angle of the lower discharge belt  44  and move the discharge nip  54  away from the bottom of the stacking bin  38 . At the same time, the source of negative air pressure is applied to the suction device  64  such that the suction cup  68  engages the lowermost document  16 . Once the lowermost document  16  has been attracted to the suction cup  68 , the suction device  64  is moved to its discharge position, as illustrated in FIG.  5 . As can be seen in FIG. 5, when the suction device  64  is in the discharge position, the document  16  is pulled into contact with the rotating upper discharge belts  42 . 
     Once the suction device  64  is in the discharged position, the source of negative air pressure is removed and the drive member  58  operated to extend the cylinder rod  62 . As the cylinder rod  62  is extended, the lower discharge belts  44  entraps the document  16  between the upper discharge belts  42  and the lower discharge belts  44 , as best illustrated in FIG.  6 . As the document  16  is entrapped between the two sets of discharge belts, the suction device is rotated to the retracted position and the document is moved in the direction illustrated by arrows  70  and discharged from the discharged end  72  of the document feeding device  12  onto the moving document conveyor  14 . After the lowermost document has been discharged, the suction device  64  returns to its engaged position for dispensing of the next document in the assembled stack, as illustrated in FIG.  6 . 
     After the individual documents  16  have been dispensed by the respective document feeding devices  12 , the documents  16  continue to proceed in the first direction along the document conveyor  14  until they come into contact with the document insertion device  24 . As can be seen in FIG. 2, the document insertion device  24  operates in-line with and slightly above the document conveyor  14  in order to move the documents off of the document conveyor  14  and insert them into an envelope. 
     Referring now to FIGS. 8-10, thereshown are the operational details and steps performed by the document insertion device  24  for inserting one of the documents  16  into an opened envelope  70 . As can be seen in FIGS. 2 and 8, the document insertion device  24  includes the continuous belt  26  entrained around a series of gears  72 . The lowermost gears  72  define an operative path  73  for the continuous belt  26  that is parallel to the document conveyor  14  and spaced slightly above the document conveyor  14 . In the preferred embodiment of the invention, the continuous belt  26  is operated slightly faster than the speed of the document conveyor  14  for reasons to be discussed below. 
     The continuous belt  26  includes a plurality of pusher members  28  that are spaced along the continuous length of the belt  26 . The individual pusher members  28  are spaced from each other by a length that is slightly greater than the distance between the tabs  18  on the document conveyor  14  in order to compensate for the increased speed of the belt  26  relative to the speed of the document conveyor  14 . The document insertion device  24  extends past the discharge end  20  of the document conveyor  14  such that the document insertion device  24  retains control of each of the documents  16  as the documents pass off of the discharge end  20  of the document conveyor  14 . 
     As discussed previously, it is contemplated by the inventor that twice as many tabs  18  can be installed on the drive chain  22  of document conveyor  14  when the envelope insertion device  10  is used with small documents and letter sized envelopes to increase the rate at which envelopes are stuffed by the envelope insertion device  10 . If the number of tabs  18  are increased on the document conveyor  14 , the number of pusher members  28  spaced along the continuous length of the belt  26  also must be doubled. By doubling the number of tabs  18  and pusher members  28 , the envelope insertion device  10  of the present invention can significantly increase the number of envelopes stuffed per minute without increasing the running speed of the document conveyor  14 . 
     As an individual document passes beneath the document insertion device  24 , one of the pusher members  28  contacts the trailing edge of the document  16 , as illustrated in FIG.  8 . Since the belt  26  of the document insertion device  24  is operated at a speed greater than the linear speed of the drive chain  22 , the individual pusher member  28  accelerates the document  16  such that the document  16  is moved away from the individual tab  18  that was moving the document  16  along the document conveyor  14 . As shown in FIG. 8, the pusher member  28  accelerates the document  16  such that a relatively significant amount of space exists between the trailing edge of the document  16  and the tab  18 . 
     As the pusher member  28  accelerates the document and pushes the document from the discharge end  20  of the document conveyor  14 , the document  16  is supported by a guide plate  74 . The guide plate  74  is positioned next the envelope stack  30 , which includes a series of individual envelopes  70  assembled such that the envelope flap  76  is positioned downward, as can be seen in FIG.  8 . Although not shown, an air blast is used to open the uppermost envelope  70  as the document  16  is being pushed toward the envelope by the individual pusher member  28 . 
     After the document  16  has been inserted into the uppermost envelope  70  by the pusher member  28 , the pusher member  28  travels upward and around the downstream roller  72  and away from the now stuffed envelope. As can be seen in FIG. 9, the pusher member  28  of the present invention includes a pair of pusher fingers  78  connected to a support rail  80  by a spring member  82 . The spring member  82  allows the pusher finger  78  to fully insert the document  16  into the open envelope  70  before the spring  82  snaps the fingers  78  upward, as illustrated in FIG.  10 . As the pusher member  28  moves upward around the downstream gear  72 , the spring  82  first moves the fingers  78  away from the envelope prior to the fingers  78  moving in the upward direction. In this manner, the pusher member  78  can fully insert the document  16  into the open envelope  70  and be subsequently moved away from the envelope to prevent damage to the envelope. 
     After the envelope has been stuffed with the document  16 , a suction device  84  is operated to lift the stuffed envelope into contact with a discharge nip  86  between a pair of rotating belts  88  and  90 . As can be seen in FIG. 10, the suction device  84  includes a suction cup  92  connected to a support arm  94 . The support arm  94  is moveable between the grasping position of FIG.  9  and the discharge position of FIG.  10 . When in the discharge position shown in FIG. 10, the stuffed envelope  70  is pressed into contact with the rotating belt  88  by a pinch roller  95 . The pinch roller  95  is connected to a drive cylinder  97  that moves the pinch roller  95  toward and away from the belt  88 . When the drive cylinder  97  is operated, the supply of negative air pressure to the suction cup  92  is terminated and the stuffed envelope  70  is caught within the discharge nip  86  between the pair of belts  88  and  90  and discharged from the envelope stack  30  for further downstream processing, as will be discussed in greater detail below. 
     Referring back to FIG. 2, the assembled stack of opened envelopes  30  is created as follows. Initially, a stack of unopened envelopes  95  is assembled within an envelope feeding device  96 . Since the construction of the envelope feeding device  96  is identical to the construction of document feeding devices  12  discussed in detail above with reference being made to FIGS. 4-7, a complete description of the envelope feeding device  96  can be omitted. The stack of unopened envelopes  95  is positioned in the stacking bin  38  with the envelope flap  76  facing up and away from a discharge nip  97 . As the lowermost envelope in the unopened envelope stack  95  is fed into the discharge nip  97 , an air blast blows open the envelope flap such that lowermost envelope is fed into the discharge nip  97  in an opened condition. 
     From the envelope feeding device  96 , the opened individual envelopes are fed to an envelope conveyor section  98 . The envelope conveyor section  98  includes an upper conveyor belt  100  and a lower conveyor belt  102  operating at substantially the same speed. The individual envelopes are supported on the lower conveyor belt  102  and captured between the lower conveyor belt  102  and the upper belt  100 . Both the upper conveyor belt  100  and the lower conveyor  102  are operated at a speed less than the discharge speed of the envelope feeding device  96  such that the envelopes fed from the envelope feeding device  96  are shingled within the envelope conveyor section  98 . 
     The shingled envelopes pass through the envelope conveyor section  98  and are fed into the bottom of the stack of opened envelopes  30 . The stack of opened envelopes  30  is accumulated within a stacking device  103  that is sized to adequately support the stack of opened envelopes  30 . The stacking device  103  includes an open bottom that allows additional opened envelopes to be fed into the stack  30  by the envelope conveyor section  98 . In the preferred embodiment of the invention, the stacking device  103  includes a photoeye that detects the height of the opened envelope stack  30 . The operation of both envelope feeding device  96  and the envelop conveyor section  98  is controlled by the height of the stack of opened envelopes  30 . As the height of the stack  30  decrease, both the envelope feeding device  96  and the envelope conveyor section  98  operates to supply additional envelopes to the stack  30 . 
     Referring now to FIG. 3, after each envelope has been stuffed with the required documents, the stuffed envelope is deposited onto the outfeed conveyor  34  by the transfer device  32 . The position of the transfer device  32  relative to the document insertion device  24  can be adjusted to compensate for envelopes of differing sizes. When the transfer device  32  is moved either toward or away from the document insertion device  24 , the upper and lower rotating belts  88  and  90  compensate for the movement and remain entrained around the series of rollers. In addition to the movement of the transfer device to compensate for the envelope size, the back support plate for the stacking device  103  is movable to adjust for the envelope size. In this manner, the envelope insertion device of the present invention can be easily configured to stuff envelopes of different sizes. 
     As can be seen in FIG. 1, the outfeed conveyor  34  extends in a second direction that is different from the first direction of the document conveyor  14 . In the embodiment in the invention illustrated, the outfeed conveyor  34  extends at a right angle to the document conveyer  14 . While each individual stuffed envelope is moved along the length of the outfeed conveyor  34 , the glue on the envelope flap  76  is wetted by a spray nozzle  104 . After the glue on the envelope flap  76  has been wetted by the spray nozzle  104 , the envelope flap  76  is closed, as illustrated by arrow  106 . After the envelope flap  76  is closed, a pressure roller  108  seals the envelope in a conventional manner. 
     After each envelope has been sealed, a second transfer conveyor system  110  transfers each individual envelope to a sorting a conveyor  112  where the individual stuffed envelopes can be processed downstream as desired. For example, the envelopes on the sorting conveyor  112  can be sorted in a conventional manner and postage applied as desired. 
     As previously discussed, the outfeed conveyor  34  is configured such that more than one document conveyor  14  can be aligned therewith. In this manner, the signal outfeed conveyor  34  can be used to accumulate stuffed envelopes from more than one source of documents. 
     Various alternatives and embodiments are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.