Patent Publication Number: US-8540235-B2

Title: Conveying apparatus for envelopes and related methods

Description:
CROSS-REFERENCE 
     This application is generally related to the following co-pending U.S. patent applications: Ser. No. 12/231,739, entitled “Apparatus for Guiding and Cutting Web Products and Related Methods;” U.S. Pat. No. 7,717,418, entitled “Envelope Conveying and Positioning Apparatus and Related Methods;” Ser. No. 12/231,753, entitled “Inserting Apparatus for Discrete Objects into Envelopes and Related Methods;” Ser. No. 12/231,754, entitled “Transporting Apparatus for Discrete Sheets into Envelopes and Related Methods;” and Ser. No. 12/231,749, entitled “Transporting Apparatus for Web Products and Related Methods”, all being filed on even date herewith and expressly incorporated herein by reference in their entirety. 
     TECHNICAL FIELD 
     The present invention generally relates to converting equipment and, more particularly, to apparatus for converting paper into sheets, collating and automatic envelope stuffing operations. 
     BACKGROUND 
     Converting equipment is known for automatically stuffing envelopes. Such equipment may include components for feeding a pre-printed web of paper, for cutting such web into one or more discrete sheets for collating sheets, and for feeding such discrete sheet collations into envelopes. Such equipment may further include components to convey the stuffed envelopes to a specified location. The industry has long known apparatus which accomplish these and other functions. However, improvements are needed where high volumes of paper piece count and high speeds are required without sacrificing reliability accuracy and quality of end product. 
     More particularly, a large roll of paper is typically printed in discrete areas with piece specific information. That is, the initial roll of paper comprises vast numbers of discrete areas of already-printed indicia-specific information with each discrete area defining what is to eventually comprise a single page or sheet of indicia specific information. To complicate the process, a variable number of sheets with related indicia must be placed into the envelopes so that the content of one envelope varies from the content of another by sheet count and, of course, by the specific indicia on the included sheets. As one example, financial reports of multiple customers or account specifics may require a varied number of customer or account specific sheets to be cut, respectively collated, stuffed and discharged for delivery. Thus, the contents of each envelope include either a single sheet or a “collation” of from two to many sheets, each “collation” being specific to a mailing to an addressee. 
     In such an exemplary operation, a financial institution might send billing or invoice information to each of its customers. The billing information or “indicia” for one customer may require anywhere from one final sheet to a number of sheets which must be collated, then placed in that customer&#39;s envelope. While all this information can be printed in sheet size discrete areas, on a single roll, these areas must be well defined, cut, merged or collated into sheets for the same addressee or destination, placed into envelopes, treated and discharged. Thus, a system for conducting this process has in the past included certain typical components, such as a paper roll stand, drive, sheet cutter, merge unit, accumulate or collate unit, folder, envelope feeder, envelope inserter, and finishing and discharge units. Electronic controls are used to operate the system to correlate the functions so correct sheets are collated and placed in correct destination envelopes. 
     In such multi-component systems, the pass-through rate from paper roll to finished envelope is dependent on the speed of each component, and overall production speed is a function of the slowest or weakest link component. Overall reliability is similarly limited. Moreover, the mean down time from any malfunction or failure to repair is limited by the most repair-prone, most maintenance consumptive component. Such systems are capital intensive, requiring significant floor plan or footprint, and require significant labor, materials and maintenance capabilities and facilities. 
     In such a system, it is sometimes necessary to convey envelopes toward a stuffing station. In conventional systems of this type, operation may require a user to load envelopes on the conveyor in a continuous fashion, with a gap between envelopes sometimes interrupting the flow of envelopes to the stuffing station. 
     Accordingly, it is desirable to provide an improved envelope conveying system and methods in a high speed handling machine. It is also desirable to provide an envelope conveying system and related methods that address inherent problems observed with conventional paper systems. Moreover, it is also desirable to provide a converting apparatus in the form of an automatic envelope stuffing machine that address the problems with conventional machines used to automatically stuff envelopes. 
     SUMMARY 
     To these ends, in one particular embodiment of the invention an apparatus is provided for conveying envelopes traveling in a travel direction in a generally upright orientation. The apparatus includes a first pair of conveyor assemblies disposed opposite one another and configured to engage lateral edges of the envelopes, and configured to move the envelopes in the travel direction. The apparatus includes a second pair of conveyor assemblies disposed opposite one another and positioned downstream of the first pair of conveyor assemblies in the travel direction, with the second pair of conveyor assemblies being configured to move the envelopes in the travel direction independently of the first pair of conveyor assemblies. 
     At least a portion of the first pair of conveyor assemblies may overlap the second pair of conveyor assemblies in the travel direction. At least one of the first or second pairs of conveyor assemblies may include deflectable elements for engaging the lateral edges of the envelopes. The deflectable elements may flex in response to the respective thicknesses of the envelopes to allow the envelope edges to reside slightly between individual bristles. The deflectable elements may be configured to flex in a direction opposite the travel direction to thereby permit movement of the first pair of conveyor assemblies relative to envelopes held by the second pair of conveyor assemblies. The deflectable elements may, for example, include bristles. 
     The first and second pairs of conveyor assemblies may be configured to respectively hold first and second envelopes in generally upright orientations, with the first and second pairs of conveyor assemblies being configured to move the first and second envelopes at respective first and second speeds that are substantially equal to one another. The apparatus may include a drive apparatus for driving the first pair of conveyor assemblies and at least one sensor that is operatively coupled to the drive apparatus and configured to detect a gap in front of a first envelope carried by the first pair of conveyor assemblies in the travel direction and send a corresponding signal to the drive apparatus. The drive apparatus is responsive to the signal to advance the first pair of conveyor assemblies and move the first envelope at a first speed greater than a second speed associated with the second pair of conveyor assemblies. The drive apparatus may be configured, in response to the signal, to accelerate the first pair of conveyor assemblies to thereby close the gap detected by the at least one sensor. 
     In another embodiment, an apparatus is provided for conveying envelopes traveling in a travel direction in a generally upright orientation. The apparatus includes a first pair of conveyor assemblies disposed opposite one another and including deflectable elements for engaging lateral edges of the envelopes, with the first pair of conveyor assemblies being configured to move the envelopes in the travel direction. A second pair of conveyor assemblies are disposed opposite one another and include deflectable elements for engaging lateral edges of the envelopes, and are positioned downstream of the first pair of conveyor assemblies, with the second pair of conveyor assemblies being configured to move the envelopes in the travel direction independently of the first pair of conveyor assemblies. A drive apparatus drives the first pair of conveyor assemblies. At least one sensor is operatively coupled to the drive apparatus and is configured to detect a gap in front of a first envelope carried by the first pair of conveyor assemblies in the travel direction, with the drive apparatus being responsive to a signal received from the at least one sensor to accelerate the first envelope and thereby close the gap detected by the at least one sensor. 
     In yet another embodiment, an automatic envelope stuffing machine is provided. The machine includes a first end associated with feeding of a roll of paper and a processing apparatus for converting the roll of paper into discrete sheets. A stuffing apparatus feeds the discrete sheets into envelopes, with a second end having a conveying apparatus for conveying the envelopes toward the stuffing apparatus in a travel direction. The conveying apparatus includes a first pair of conveyor assemblies that are disposed opposite one another and which are configured for engaging lateral edges of the envelopes, with the first pair of conveyor assemblies being configured to move the envelopes in the travel direction. The conveying apparatus also includes a second pair of conveyor assemblies that are disposed opposite one another and that are positioned downstream of the first pair of conveyor assemblies in the travel direction, with the second pair of conveyor assemblies being configured to move the envelopes in the travel direction independently of the first pair of conveyor assemblies. At least one of the first and second pairs of conveyor assemblies may include a plurality of deflectable elements for engaging the lateral edges of the envelopes. 
     In another embodiment, a method is provided for conveying envelopes traveling in a travel direction. The method includes sliding an envelope in a generally upright orientation between a first set of deflectable elements engaging opposite lateral edges of the envelope and moving the deflectable elements to thereby move the envelope in the travel direction. The envelope is transferred in the generally upright orientation to a second set of deflectable elements and the second set of deflectable elements is moved independently of the first set of deflectable elements to thereby move the envelope in the travel direction. 
     The method may include flexing the deflectable elements of the first set in response to a thickness of the envelope. The method may additionally or alternatively include detecting a gap in front of the envelope in the travel direction and accelerating movement of the first set of deflectable elements in the travel direction in response to detection of the gap. The first set of deflectable elements may be accelerated to close the gap. Sliding the envelope in the generally upright orientation may include moving the envelope in a direction transverse to the travel direction. Transferring the envelope in the generally upright orientation to the second set of deflectable elements may include moving the envelope in the travel direction. The method may include simultaneously engaging the envelope with the first and second sets of deflectable elements. The first set of deflectable elements may be moved relative to an envelope held by the second set of deflectable elements. 
     Such apparatus and methods are particularly useful in a paper converting and envelope stuffing system contemplating improved paper converting and sheet inserting apparatus and methods, modular based, and having improved paper handling apparatus, servo driven components, improved sensor density and improved control concepts controlling the system operation. One or more of the embodiments of the invention contemplate the provision of an improved envelope conveying apparatus which can be used as a module of a modular paper converting and sheet insertion system where human capital, required space, required equipment, maintenance, labor and materials and facilities therefore are reduced compared to conventional systems of similar throughput. 
     More specifically, such improved apparatus and methods contemplate a plurality of functional modules providing the following functions in a series of modules of like or dissimilar modules where a specific module is multi-functional. The functions comprise:
         a printed paper roll handling/unwinding;   paper slitting and cutting;   sheet collation and accumulation;   sheet folding;   transportation for interfacing with inserts;   envelope feeding;   collation interfacing and insertion; and   envelope treating and discharge.       

     More particularly, one or more aspects of the invention may contemplate, without limitation, new and unique apparatus and methods for:
         (a) guiding a web of the paper or film containing the printed indicia into a cutter apparatus;   (b) processing the web through slitting and transverse-cutting operation;   (c) transporting and merging discrete pieces of the insert;   (d) accumulating predefined stacks of discrete pieces of the insert;   (e) guiding and transporting a stack of discrete pieces of the insert toward an envelope-filling station;   (f) transporting individual envelopes toward the envelope-filling station;   (g) creating and processing a stack of the envelopes prior to the envelope-filling process; and   (h) processing an individual envelope from the stack of envelopes and through the envelope-filling station.       

     While the combination of the particular functions in the particular modules are unique combinations, the invention of this application lies primarily in the paper transporting apparatus and methods described herein. 
    
    
     
       BRIEF DESCRIPTION OF FIGURES 
         FIG. 1  is a perspective view illustrating a portion of a converter for stuffing envelopes with selected paper or film objects; 
         FIG. 2  is a cross-sectional view taken along line  2 - 2  of  FIG. 4A ; 
         FIG. 2A  is a view similar to  FIG. 2 , illustrating an alternative relative positioning of a conveying module; 
         FIG. 3  is an enlarged view of the encircled area  3  of  FIG. 4A ; 
         FIG. 4A  is a perspective view of a portion of the conveying module of the converter of  FIG. 1 ; and 
         FIG. 4B  is a perspective view similar to  FIG. 4A  showing an exemplary operation of the conveying module; 
         FIG. 5  is a view similar to  FIG. 3 , illustrating another embodiment of a conveying module; and 
         FIG. 6  is a top schematic view of another embodiment of a conveying module. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the figures and, more particularly to  FIG. 1 , a portion of an exemplary converter  10  is illustrated for processing a web  12  of paper or film. Although not shown, the web  12  processed by the converter  10  originates, for example, from a roll (not shown) of material containing such web. The roll is generally associated with a first end  14  of the converter  10  and is unwound in ways known in the art, for example, by driving a spindle receiving a core of the roll or by contacting a surface of the roll with a belt or similar apparatus. Typically, the web  12  is pre-printed with indicia in discrete areas. 
     The web  12  thus travels in a machine direction, generally indicated by arrow  15 , through several modules that make up the converter  10 . In the exemplary embodiment of  FIG. 1 , converter  10  cuts the web material into discrete sheets (corresponding to the “areas”) of material (“inserts”) and feeds them into envelopes fed generally from an opposite end  16  of converter  10 . Converter  10  may further convey the envelopes containing the inserts away from the shown portion of the converter  10  for subsequent processing or disposition. The exemplary converter  10  includes, as noted above, several modules for effecting different steps in the processing of the web and the inserts resulting therefrom, as well as processing of the envelopes. Those of ordinary skill in the art will readily appreciate that converter  10  may include other modules in addition or instead of those shown herein. 
     A first of the shown modules, for example, is a cutting module  30  relatively proximate first end  14  of the converter  10  and which cuts the web  12  into discrete objects such as inserts (not shown) for subsequent processing. A conveying module  40  controls and transports the discrete inserts received from the cutting module and feeds them into a folding and buffering module  50 . Module  50  may, if necessary, form stacks of the discrete inserts for subsequent processing, for example, if the intended production requires stuffing the envelopes with inserts defined by more than one discrete sheet. Module  50  folds the discrete inserts, if required by the intended production, along a longitudinal axis of the discrete inserts disposed generally along the machine direction. Moreover, module  50  accumulates, collates or buffers sets of the discrete sheets into individually handled stacks, if the particular production so requires. 
     With continued reference to  FIG. 1 , an uptake module  60  takes the inserts from folding and buffering module  50  and cooperates with components of a stuffing module  70  to transport the inserts and feed them into envelopes. The envelopes, in turn, are handled and fed toward the stuffing module  70  by an envelope conveyor  80 . A conveying assembly  90  is operatively coupled to the stuffing module  70  and the envelope conveyor  80  for conveying the stuffed or filled envelopes away from the shown portion of converter  10  for subsequent processing or disposition. 
     With reference to  FIG. 2 , a portion of conveying module  80  is illustrated. Conveying module  80  includes a first pair on conveyor assemblies  112  (only one shown) that are disposed opposite one another and a second pair of conveyor assemblies  114  (only one shown), also disposed opposite one another and which cooperate to convey envelopes  120  in a travel direction  130  in an generally upright orientation. As used herein, the term “upright,” when used to describe the orientation of the envelopes  120 , is not intended to be limiting but rather exemplary. The term is therefore intended to apply to deviations from a vertical orientation and still fall within the scope of the present disclosure. 
     A frame  132  of module  80  supports the conveyor assemblies  112 ,  114 , as well as a set of guiding rails  116  and bottom surface or floor  118  ( FIGS. 4A-4B ) that guide and support the envelopes  120 . In this exemplary embodiment, the travel direction  130  is opposite the machine direction (arrow  15  of  FIG. 1 ) although this is merely exemplary rather than limiting. In this regard, therefore, the travel direction defined by the conveying module  80  may instead by transverse or, alternatively, parallel to the machine direction (arrow  15 ), so long as the travel direction conveys the envelopes  120  towards a stuffing operation, such as that provided by stuffing module  70 . 
     The first and second pairs of conveyor assemblies are driven by respective schematically-depicted drive apparatus  140 ,  144  which, for example, may include servo apparatus (not shown). While this embodiment schematically depicts two independent drive apparatus  140 ,  144 , it is understood that a single drive apparatus may instead drive both pairs  112 ,  114  of conveyor assemblies, so long as such drive apparatus permits independent movement of the first and second pairs  112 ,  114  of conveyor assemblies relative to one another. 
     With reference to  FIGS. 2 and 2A , the second pair of conveyor assemblies  114  is positioned generally downstream, in the travel direction  130 , of the first pair of conveyor assemblies  112 . More specifically, the first pair of conveyor assemblies  112  extends generally from an upstream end  80   a  ( FIG. 1 ) of module  80  to an interior portion of module  80 , while the second pair of conveyor assemblies  114  extends generally from an opposite downstream end  80   b  to the interior portion of module  80 . It is contemplated that one or both of the pairs of conveyor assemblies  112 ,  114  may alternatively extend into adjoining modules. For example, and without limitation, the second pair of conveyor assemblies  114  may extend into stuffing module  70  (as shown in the alternative embodiment of  FIG. 2A ). The extension of the first and second pairs of conveyor assemblies  112 ,  114  of this exemplary embodiment into the interior portion of module  80  is such that they define an overlap region  136  between them having a suitably chosen distance. Alternatively, it is contemplated that no overlap region may exist between the first and second pairs of conveyor assemblies  112 ,  114 . 
     The overlap region  136  between the first and second pairs of conveyor assemblies  112 ,  114  is facilitated by the vertical arrangement if these two pairs of assemblies  112 ,  114 . More particularly, in this embodiment, the first pair of conveyor assemblies  112  is disposed on a first horizontal plane that is lower relative to a second horizontal plane associated with the second pair of conveyor assemblies  114 . As used herein, the terms “horizontal,” “vertical,” “up,” “down,” “top,” “bottom,” and derivatives thereof refer to the exemplary orientations of the figures and are therefore not intended to be limiting. 
     With continued reference to  FIGS. 2 and 2A , and as discussed above, the first and second pairs of conveyor assemblies  112 ,  114  are driven by one or more drive apparatus  140 ,  144 . In this regard, in this particular embodiment, the drive apparatus  140  is operatively coupled to a power shaft  186  (shown in phantom) disposed proximate the upstream end  80   a  of module  80  and which drives a belt  188  of one of the first pair of conveyor assemblies  112 . Likewise, drive apparatus  144  is operatively coupled to a second power shaft  192  disposed proximate downstream end  80   b  and which drives a set of second belts  196 , of one of the second pair of conveyor assemblies  114 . Belts  188 ,  196  are supported in the interior portion of module  80 , by a set of coaxial idler rollers  152 ,  154  coupled to frame  132  through a common shaft  198 . Accordingly, the power shafts  186 ,  192  and the coaxial idler rollers  152 ,  154  define a generally closed-loop path of travel for each of the belts  188 ,  196 . 
     As discussed above, drive apparatus  140 ,  144  permit controlling movement of the first and second pairs of conveyor assemblies  112 ,  114  independent from one another. To this end, the coaxial idler rollers  152 ,  154  are, though mounted on common shaft  198 , rotatable independent from one another, for example, at different speeds. Accordingly, belts  188 ,  196  can travel in the travel direction  130  at speeds that are different from one another, thereby permitting envelopes  120  held by the first and second pairs of conveyor assemblies  112 ,  114  respectively at first and second speeds that are also different from or substantially equal to one another. 
     With continued reference to  FIG. 2 , a plurality of sensors  200  are positioned along the travel direction, for example, below each of the belts  188 ,  196  of the first and second pairs of conveyor assemblies  112 ,  114 . The sensors  200  which may, for example be light-type sensors, are operatively coupled to a schematically depicted control apparatus  204  of module  80  to permit, as explained in further detail below, a steady stream of envelopes  120  to the stuffing module  70 , regardless of gaps between the envelopes  120 . 
     While the exemplary embodiment of the figures includes a pair of belts  196  defining the second pair of conveyor assemblies  112 , it is contemplated that only on such belt  196  or belts in any other number may be present and still fall within the scope of the present disclosure. 
     With reference to  FIG. 3 , an enlarged view of an exemplary portion of a conveyor assembly of the first pair of conveyor assemblies  112  is illustrated. It is contemplated that the structure shown in  FIG. 3  may additionally or alternatively apply to one or both of the conveyor assemblies of the second pair of conveyor assemblies  114 . A plurality of deflectable elements in the form, in this embodiment, of bristles  230 , extend from the surface of belt  188  toward the space provided for the envelopes  120 . As used herein, the term “deflectable elements” and derivatives thereof refer to solid or solid structures that flex or bend upon the action of a force. Accordingly, while this embodiment depicts deflectable elements in the form of bristles, it is contemplated that they may alternatively take on other forms such as, without limitation, flexible straps. 
     With reference to  FIGS. 4A-4B , a pair of motors  240  ( FIG. 4B ) are operatively coupled to each of the conveyor assemblies  112   a ,  112   b  defining the first pair of conveyor assemblies  112  to permit accommodation of envelopes  120  having different widths. Motors  240  may, for example, be stepper motors such as model HRA08C available from Sick Stegmann GmbH, a member of the Sick AG Group of Waldkirch, Germany. Motors  240  cooperate with jack screws (not shown) to selectively move the conveyor assemblies  112   a ,  112   b  inwardly (i.e., toward one another) and outwardly (i.e., away from one another) along the direction of arrow  242  ( FIG. 4B ). In this regard, for example, both of the conveyor assemblies  112   a ,  112   b  may be selectively and/or automatically moved inwardly to accommodate an envelope  120  of relatively small width, thereby enabling engagement of the envelopes  120  by bristles  230 . It is contemplated that, alternatively, only one of the conveyor assemblies  114   a ,  114   b  may be movable inwardly and outwardly relative to the other conveyor assembly. It is also contemplated that the conveyor assemblies  112   a ,  112   b  may instead have fixed positions relative to one another and therefore include other apparatus to facilitate engagement of envelopes  120  having different widths or include no such apparatus at all. As used herein, the term “width” in regard to envelopes  120  refers to the dimension of the envelopes  120  generally along the direction of arrow  242 . 
     While the exemplary embodiment of the figures includes a pair of motors  240 , each controlling movement of one of the conveyor assemblies  112   a ,  112   b , it is contemplated that a single motor  240  or alternatively motors in any number may control one or both of the conveyor assemblies  112   a ,  112   b . It is also contemplated that one or both of the conveyor assemblies  114   a ,  114   b  defining the second pair of conveyor assemblies  114  may be inwardly and outwardly movable to accommodate envelopes  120  of different widths. 
     Bristles  230  are made of a suitably flexible material such as, for example, nylon, such that they may flex and thereby accommodate envelopes  120  of different thicknesses inserted between the bristles  230 . Moreover, the material making up bristles  230  is chosen to have some level of sturdiness, capable of closely pressing against the lateral edges  120   a  of the envelopes  120  and thereby maintain the envelopes  120  in a generally upright orientation. The flexible and sturdy characteristics of bristles  230  further permit driving of the envelopes  120  in the travel direction  130 , as belt  188  moves in the same direction, while minimizing the likelihood of damaging the envelopes  120 . Accordingly, bristles  230  move the envelopes  120  toward the second pair of conveyor assemblies  114  ( FIG. 2 ). 
     Referring again to  FIG. 2 , the bristles  230 , schematically represented in that figure by a dot pattern, permit insertion of envelopes  120  in a general vertical orientation, for example, by sliding the envelopes  120  between bristles  230  in the direction of arrow  280  (e.g., transverse to the travel direction  130 ). In this regard, therefore, the envelopes  120  may be inserted between bristles  230  of the first pair of conveyor assemblies  112  in a generally upright orientation. In operation, the envelopes  120  are carried by the first pair of conveyor assemblies  112  as they travel in the travel direction  130  and are subsequently transferred from the first pair of conveyor assemblies  112  to the second pair of conveyor assemblies  114  in the overlap region  136 . To this end, in this exemplary embodiment, the belts  196  of the second pair of conveyor assemblies  114  are fitted with bristles  232  that may be of the same type and/or arrangement of bristles  230  of the first pair of conveyor assemblies  112  or of any other type and/or arrangement. In this embodiment, moreover, the belts  196  of the second pair of conveyor assemblies  114  are fitted with bristles  232  similar to the bristles  230  of the first pair of conveyor assemblies  112 . 
     During transfer of the envelopes  120  from the first pair of conveyor assemblies  112  to the second pair of conveyor assemblies  114 , the bristles  232  of the second pair of conveyor assemblies  114  flex in the travel direction (i.e., toward the downstream end  80   b  of module  80 ) to permit the envelopes  120  to be engaged between the plurality of bristles  232 . Once engaged, the envelopes  120  are carried in the travel direction  130  by the bristles  232  toward the downstream end  80   b  and, in this particular embodiment, toward the stuffing module  70 . During travel of the envelopes  120  through the overlap region  310 , the envelopes  120  are carried simultaneously by bristles  230  and  232 . The envelopes  120  are transferred to and carried by the second pair of conveyor assemblies  114  in a generally upright orientation. 
     Referring again to  FIGS. 4A-4B , an exemplary operation of the envelope conveying module  80  is illustrated.  FIG. 4A , in particular, depicts the presence of a gap  310  downstream of a leading envelope  120   f  of a stack of envelopes  120  carried by the first pair of conveyor assemblies  112 . One or more of the sensors  200  ( FIG. 2 ) detect the gap  310 . For example, and without limitation, a sensor  200  may include a light-emitting component and a cooperating light-receiving component such that, only in the absence of an envelope or group of envelopes  120 , light is received by the light-receiving component, thereby triggering a signal. In such instance, the signal may be sent to the control apparatus  204 . 
     Control apparatus  204  is operatively coupled to drive apparatus  140  controlling movement of the first pair of conveyor assemblies  112 . In this regard, when control apparatus  204  receives a signal associated with detection of the gap  310  by a sensor  200 , control apparatus  204  accelerates movement of the belts  188  and bristles  230  of the first pair of conveyor assemblies  112 . This acceleration results in the first pair of conveyor assemblies  112  moving in the travel direction  130  at a first speed that is greater relative to a second speed associated with the second pair of conveyor assemblies  114 . This acceleration may close the gap  310  detected by the sensor(s)  200 . Once the sensor(s)  200  no longer detect the gap  310 , the control apparatus  204  may decelerate the first pair of conveyor assemblies  112  to thereby cause the first and second pairs of conveyor assemblies  112 ,  114  to travel at substantially equal speeds relative to one another. The ability of this exemplary embodiment to permit minimization or even closure of the gap  310  obviates the need by a user to continuously feed envelopes to the first pair of conveyor assemblies  112  without gaps or interruptions. 
     With continued reference to  FIGS. 4A-4B  and with further reference to  FIG. 3 , the flexibility of bristles  230  of the first pair of conveyor assemblies  112  permit the bristles  230  to flex in a direction opposite the travel direction  130 . More specifically, movement of the first pair of conveyor assemblies  112  in the travel direction  130  may require contact between the bristles  230  with envelopes  120  held by the second pair of conveyor assemblies  114  in the overlap region  136 . In this regard, the first pair of conveyor assemblies  112  travel relative to the envelopes  120  held by the second pair of conveyor assemblies, which is facilitated by flexing of the bristles  230  in the direction opposite the travel direction  130 , in a clutching fashion. 
     With reference to  FIG. 5 , in which like reference numerals refer to like features of  FIGS. 1-4B , another embodiment of an envelope-conveying apparatus  300  is illustrated. Conveying apparatus  300  includes, in addition to the first and second pairs of conveyor assemblies  112 ,  114 , a third pair of conveyor assemblies  316  positioned downstream, in the travel direction (arrow  130 ), of the second pair of conveyor assemblies  114 . In this particular embodiment, the third pair of conveyor assemblies  316  includes a pair of belts  317  generally parallel to and generally abutting the belts  196  of the second pair of conveyor assemblies  114 . The belts  317  may be similar to belts  196  and therefore may include deflectable elements such as bristles. It is contemplated that the third pair of conveyor assemblies  316  may include a single belt or belts in any number other than the two depicted here. Transfer of envelopes  120  from the second pair  114  to the third pair of conveyor assemblies  316  maintains the envelopes in a generally upright orientation. Moreover, the third pair of conveyor assemblies  316  in this exemplary embodiment extends into the inserting or stuffing module  70  (shown in phantom). 
     The third pair of conveyor assemblies  316  is driven by a drive apparatus  320  operatively coupled to control apparatus  204 , although it is contemplated that the third pair of conveyor assemblies  316  may instead be driven by one of the drive apparatus  140 ,  144  associated with the first and second pairs of conveyor assemblies  112 ,  114 . Drive apparatus  320  permits controlling movement of the third pair of conveyor assemblies  316  independently from the first and second pairs of conveyor assemblies  112 ,  114 . In this regard, for example, the third pair of conveyor assemblies  316  may be selectively driven at speeds that are different from those associated with the first and/or second pairs of conveyor assemblies  112 ,  114 . 
     A plurality of sensors  318  are associated with the third pair of conveyor assemblies  316  and are similar in relative location, type, structure, and/or function to the sensors  200  associated with the first and second pairs of conveyor assemblies  112 ,  114 , the description of which may be referred to for an understanding of sensor(s)  318  as well. Sensors  318  are configured to detect any gaps upstream of a group of envelopes  120  carried by the third pair of conveyor assemblies  316 . When control apparatus  204  receives a signal associated with detection of such gap by a sensor  318 , control apparatus  204  accelerates movement of the belts  196  of the second pair of conveyor assemblies  114 . This acceleration results in the second pair of conveyor assemblies  114  moving in the travel direction  130  at a second speed that is greater relative to a third speed associated with the third pair of conveyor assemblies  316 . This acceleration may close the gap detected by the sensor(s)  318 . 
     Once the sensor(s)  318  no longer detect the gap, the control apparatus  204  may decelerate the second pair of conveyor assemblies  114  to thereby cause the second and third pairs of conveyor assemblies  114 ,  316  to travel at substantially equal speeds relative to one another. The ability of this exemplary embodiment to permit minimization or even closure of the gap upstream of envelopes  120  carried by the third pair of conveyor assemblies  316  obviates the need for the second pair of conveyor assemblies  114  to have a continuous flow of envelopes  120  i.e., a flow without gaps or interruptions. 
     With reference to  FIG. 6 , in which like reference numerals refer to like features of  FIGS. 1-5 , another embodiment of an envelope-conveying apparatus  400  is illustrated. Envelope-conveying apparatus  400  is similar to envelope-conveying apparatus  300  of  FIG. 5 , the description of which may be referred to for an understanding of envelope-conveying apparatus  300  as well. Envelope-conveying apparatus  400  includes a second pair of conveyor assemblies  114  oriented at an angle transverse to the third pair of conveyor assemblies  316  and therefore transverse to the travel direction (arrow  130 ) associated with the third pair of conveyor assemblies  316 . In this particular embodiment, the second and third pairs of conveyor assemblies  114 ,  316  are oriented generally orthogonal to one another although this is merely illustrative of the transverse orientation discussed above, and therefore is not intended to be limiting. A schematically-depicted transition section  404  is operatively coupled to the second and third pairs of conveyor assemblies  114 ,  316  and is configured to retrieve envelopes  120  from the second pair  114 , re-orient them, and transfer them onto the third pair of conveyor assemblies  316 . Accordingly, transition section  404  transfers envelopes  120  from the second pair of conveyor assemblies  114  to the third pair of conveyor assemblies  316 . 
     While the present invention has been illustrated by a description of various embodiments and while these embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. For example, and without limitation, other alternatives structures may replace bristles  230 ,  232 , so long as they provide the ability to engage envelopes and carry them in a generally upright orientation. For example, and also without limitation, such structures may be in the form of flexible flaps. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept.