Abstract:
Methods and devices for folding a continuous web of material are provided. Systems can include a spiral folder assembly having first and second sets of rotatable spirals, a deflection means to guide the continuous web toward the first set of spirals and the second set of spirals, a beater assembly to urge the continuous web against the first set of spirals to form a first fold in the web against the second set of spirals to form a second fold in the web, and a conveyor assembly to receive and transport the folded continuous web as it exits the spiral folder assembly, the conveyor assembly providing a support between the first and second sets of spirals, the support modulating an amount of sag in the continuous web as the web is suspended between the first and second sets of spirals.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
       [0001]     This application is a divisional of U.S. patent application Ser. No. 11/182,510, entitled “FOLDER UNIT FOR PROCESSING SHEET-LIKE MATERIAL,” filed Jul. 14, 2005 by Michael J. Brunow et al., the entire disclosure of which is incorporated herein by reference for all purposes. 
     
    
     STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     NOT APPLICABLE  
       REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK  
       [0003]     NOT APPLICABLE  
       BACKGROUND OF THE INVENTION  
       [0004]     The invention relates generally to sheet processing equipment, and more specifically to systems and methods for folding sheets, statements, and/or inserts prior to mailing.  
         [0005]     Transactional printers, mail houses, and financial institutions such as credit card companies mail literally millions of documents within the United States each week. For example, credit card customers can expect to receive a monthly statement summarizing their charges for the prior month, or longer. The credit card companies, or other parties that prepare the mailings for them, are constantly on the lookout for improvements in efficiency, speed, and cost savings. Even incremental improvements in processing speed or efficiency can produce large benefits due to the huge number of mailings.  
         [0006]     Sheet processing modules such as spiral folders are useful for processing continuous webs of paper, and are frequently an important component of mail processing systems. Yet currently used spiral folder systems and methods often suffer from significant operational drawbacks. For example, excessive sagging may occur in the center of the folded sheet stack between the spirals. This is particularly true when a typically thin or flexible material is processed in the module. Such sagging can cause the sheet to become misaligned in the sheet processing module, and can lead to paper jams, damaged forms, and the like. These failures can be costly, due to hours of machine downtime and lost operator time. To address these issues, some have suggested shortening the form length of the folded sheet, however such solutions can result in the beater assembly colliding with the chute assembly, again leading to misalignment of the sheet. Relatedly, others have proposed adjusting the beater assembly timing, but this can cause problems when different forms are loaded in the folder module. What is more, in some cases these solutions are not effective due to operator error in adjusting the form length setting or the beater timing.  
         [0007]     In light of the above, it would be desirable to provide improved sheet processing systems and methods, particularly for processing components such as folding assemblies. The present invention addresses such needs.  
       BRIEF SUMMARY OF THE INVENTION  
       [0008]     The present invention provides sheet processing methods and systems that can be used with customer documents such as invoices and the like. These techniques may be particularly useful in preventing or reducing the frequency of unwanted system failures. Advantageously, the present invention provides sheet folding systems for continuous web materials having highly reliable folding configurations for long-lasting operation times with minimal downtime due to paper jams and other problems associated with paper misalignment.  
         [0009]     In a first aspect, the present invention provides a folder system for folding a continuous web of material. The system can include a spiral folder assembly having a first set of rotatable spirals and a second set of rotatable spirals, a chute assembly that alternates between a first position and a second position, the chute assembly configured to guide the continuous web toward the first set of spirals when in the first position and toward the second set of spirals when in the second position, a beater assembly having a first beater adapted to urge the continuous web against the first set of spirals to form a first fold in the web, and a second beater adapted to urge the continuous web against the second set of spirals to form a second fold in the web, and a conveyor assembly configured to receive and transport the folded continuous web as it exits the spiral folder assembly, the conveyor assembly providing a support disposed between a first vertical plane defined by the first set of spirals and a second vertical plane defined by the second set of spirals, the support adapted to modulate an amount of sagging in the continuous web as the web is suspended between the first set of spirals and the second set of spirals. In some embodiments, the conveyor assembly includes a plurality of support rollers coupled with a support frame, and a support belt circumferentially wrapped about the plurality of support rollers.  
         [0010]     In related embodiments, the support can be defined by at least one of the plurality of support rollers. The plurality of support rollers may define a horizontal path that extends at least one half of a horizontal distance between the first vertical plane defined by the first set of spirals and the second vertical plane defined by the second set of spirals. In some embodiments, the conveyor assembly includes a plurality of support rollers that define a substantially horizontal plane, and a support belt circumferentially wrapped about the plurality of support rollers. The conveyor assembly may also include a ramp roller, a plurality of exit rollers, a ramp belt circumferentially wrapped about the ramp roller and at least one of the plurality of exit rollers, and an exit belt circumferentially wrapped about the plurality of exit rollers. The plurality of support rollers and the ramp roller can be coupled with a support frame, and the support can be defined by at least one of the plurality of support rollers and the ramp roller. In some embodiments, the conveyor assembly may include a drive belt coupled with the ramp roller and a drive means, and a transfer belt coupled with the ramp roller and a support roller adjacent to the ramp roller. In still further embodiments, the folder system can include a first stop bar configured to restrain movement of the continuous web when the web is urged against the first set of spirals by the first beater, and a second stop bar configured to restrain movement of the continuous web when the web is urged against the second set of spirals by the second beater.  
         [0011]     In another embodiment, the present invention provides a method for folding a continuous web of material. The method can include directing the continuous web of material with a chute assembly that alternates between a first position and a second position, guiding the continuous web toward a first set of rotatable spirals of a spiral folder assembly when the chute assembly is in the first position, guiding the continuous web toward a second set of rotatable spirals of the spiral folder assembly when the chute assembly is in the second position, urging the continuous web against the first set of spirals with a first beater of a beater assembly to form a first fold in the web, and urging the continuous web against the second set of spirals with a second beater of the beater assembly to form a second fold in the web, advancing the folded continuous web from the spiral folder assembly toward a conveyor assembly, and supporting the folded continuous web with a support of the conveyor assembly to modulate an amount of sagging in the continuous web as the web is suspended between the first set of spirals and the second set of spirals. In some embodiments, the method includes transporting the folded continuous web with the conveyor assembly by rotating a support belt circumferentially wrapped about a plurality of support rollers. The method may also include supporting the folded continuous web with at least one of the plurality of support rollers as the web is suspended between the first set of spirals and the second set of spirals.  
         [0012]     In related embodiments, the plurality of support rollers may define a horizontal path that extends at least one half of a horizontal distance between a first vertical plane defined by the first set of spirals and a second vertical plane defined by the second set of spirals. The method may also include transporting the folded continuous web with the conveyor assembly in a downstream direction from the support rollers by rotating a ramp belt circumferentially wrapped about a ramp roller and at least one of a plurality of exit rollers. In some embodiments, the method may include advancing the folded continuous web from the spiral folder assembly onto a support belt circumferentially wrapped about a plurality of support rollers, the plurality of support rollers that define a substantially horizontal plane, rotating the support belt to advance the folded continuous web from the support belt onto a ramp belt circumferentially wrapped about a ramp roller and at least one of a plurality of exit rollers, and rotating the ramp belt to advance the folded continuous web from the ramp belt onto an exit belt circumferentially wrapped about the plurality of exit rollers.  
         [0013]     The method may also include activating a drive means to rotate the ramp roller, and rotating a support roller adjacent to the ramp roller via a transfer belt coupled with the ramp roller and the support roller adjacent to the ramp roller. In some embodiments, the method includes restraining movement of the continuous web with a first stop bar when the web is urged against the first set of spirals by the first beater, and restraining movement of the continuous web with a second stop bar when the web is urged against the second set of spirals by the second beater. In related embodiments, the continuous web may include a sheet having a plurality of perforations, and the method may include folding the sheet along each of the plurality of perforations.  
         [0014]     In yet another aspect, the present invention provides a method of constructing a folder system for folding a continuous web of material. The method may include coupling a system frame with a spiral folder assembly having a first set of rotatable spirals and a second set of rotatable spirals, coupling the system frame with a chute assembly that alternates between a first position and a second position, the chute assembly configured to guide the continuous web toward the first set of spirals when in the first position and toward the second set of spirals when in the second position, coupling the system frame with a beater assembly having a first beater adapted to urge the continuous web against the first set of spirals to form a first fold in the web, and a second beater adapted to urge the continuous web against the second set of spirals to form a second fold in the web, and coupling the system frame with a conveyor assembly configured to receive and transport the folded continuous web as it exits the spiral folder assembly, the conveyor assembly providing a support disposed between a first vertical plane defined by the first set of spirals and a second vertical plane defined by the second set of spirals, the support adapted to modulate an amount of sagging in the continuous web as the web is suspended between the first set of spirals and the second set of spirals. In a related embodiment, the method of constructing the conveyor assembly can include coupling a plurality of support rollers with a support frame, and circumferentially wrapping a support belt about the plurality of support rollers, the plurality of support rollers defining a horizontal path that extends at least one half of a horizontal distance between a first vertical plane defined by the first set of spirals and a second vertical plane defined by the second set of spirals. In some embodiments, the method can include coupling a plurality of support rollers with a support frame, and circumferentially wrapping a support belt about the plurality of support rollers, coupling a ramp roller with the support frame, coupling a plurality of exit rollers with the system frame, circumferentially wrapping a ramp belt about the ramp roller and at least one of the plurality of exit rollers, and circumferentially wrapping an exit belt about the plurality of exit rollers. In related embodiments, the method can include coupling the system frame with a first stop bar configured to restrain movement of the continuous web when it is urged against the first set of spirals, and a second stop bar configured to restrain movement of the continuous web when it is urged against the second set of spirals. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  illustrates a cut-away side view of a known sheet folder system.  
         [0016]      FIG. 2  illustrates a cut-away side view of a sheet folder system according to one embodiment of the present invention.  
         [0017]      FIG. 3  illustrates a perspective view of a sheet folder system according to one embodiment of the present invention.  
         [0018]      FIG. 4  illustrates a perspective view of a sheet folder system according to one embodiment of the present invention.  
         [0019]     FIGS.  5 A-F illustrate spiral folder configurations according to various embodiments of the present invention.  
         [0020]      FIG. 6  illustrates a support assembly end plate according to one embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]     The present invention will find application in a wide variety of web processing environments. The systems and methods disclosed herein are useful for preventing, inhibiting, or otherwise addressing excessive or unwanted sag in sheet-like materials as they are advanced through processing systems. For example, the present invention can effectively process lightweight grades of paper ( 161   b ) with a large distance between perforations (14 in.) which may otherwise exhibit unwanted sag when processed using currently known systems. Advantageously, the present techniques can prevent or inhibit the exit side of a folded stack from pulling away from the stops during stack processing, and can also prevent or inhibit placement of the perforated line behind the exit beaters, both of which may occur with other known approaches for dealing with excessive sag. Relatedly, the present invention is also useful for preventing the beaters from colliding with the swing chute, and for preventing the entrance side of the folded stack from buckling against the entrance stops, which are drawbacks of present systems when they are adjusted to a different form length setting in an attempt to deal with excessive sag. Relatedly, the present invention is useful for preventing timing problems when different forms are loaded, which occurs, for example, when the exit beater timing is adjusted to help catch the perforated line.  
         [0022]     The instant invention can provide greater support to a folded stack when compared to known systems. The instant invention can also help to maintain the perforated lines or folds closer to the folder stops. It can reduce the need to adjust form length setting and beater timing, the time needed to set-up the folder module, and the amount of damaged forms due to paper jams.  
         [0023]     Turning now to the figures,  FIG. 1  shows a known sheet folder system  100  adapted for folding a continuous web of paper  104 . System  100  includes a spiral folder assembly  110 , a chute assembly  120 , a beater assembly  130 , and a conveyor assembly  140 . In operation, chute assembly  120  swings back and forth between a first set of spirals  112  and a second set of spirals  114 . When in a first position indicated by arrow  1 A, chute assembly  120  feeds continuous web  104  toward first set of spirals  112 . A first beater  132  acts to urge web  104  against first set of spirals  112  so as to form a first fold in web  104  as it engages spiral blade  113 . Thereafter, when in a second position indicated by arrow  1 B, chute assembly  120  feeds continuous web  104  toward second set of spirals  114 . A second beater  134  acts to urge web  104  against second set of spirals  114  so as to form a second fold in web  104  as it engages spiral blade  115 . Often, first and second folds correspond to perforations that are present in web  104 . During this process, web  104  is continuously advanced through chute assembly  120  as it swings back and forth between positions  1 A and  1 B, and spirals  112  and  114  are rotated about their own axes to advance the paper folds in a downward direction, such that an accordion-type fold is created in web  104 . Companies that market such known folders include Energy Saving Products (ESP) of Burlington, Conn. (e.g. Model No. ESP500 Forms Fold Processor) and B. Bunch Co., Inc. of Phoenix, Ariz.  
         [0024]     When the folded web  104  leaves the spiral folder assembly  110 , it falls to rest on one or more rotating ramp belts  164  of ramp arrangement  160 , which are wrapped circumferentially about a ramp roller  162  and an exit roller  172 . As seen from this perspective, ramp belt  164  rotates in a counter-clockwise direction, illustrated by arrow  164   a . Typically, rotation of exit roller  172 ′ is driven by a drive chain  177  which is coupled with a drive motor  175  via a drive sprocket  176 . Drive motor  175  can be any of a variety of motors, such as those marketed by Zero-Max, Inc. of Plymouth, Minn. Rotation of exit roller  172 ′ causes exit belt to circumferentially rotate about exit rollers  172 ,  172 ′. One of the exit rollers  172  is coupled with ramp roller via ramp belt  164 . Rotating ramp belt  164  operates to advance the folded web  104  from spiral folder assembly  110  toward one or more rotating exit belts  174  of exit arrangement  170 . As seen from this perspective, exit belt  174 , which is wrapped circumferentially about a plurality of exit rollers  172 ,  172 ′, rotates in a counter-clockwise direction, illustrated by arrow  174   a . Typically, exit belt  174  of conveyor assembly  140  acts to advance the folded web  104  toward another downstream processing location as indicated by arrow  104   a.    
         [0025]      FIG. 2  illustrates a sheet folder system  200  according to one embodiment of the present invention. Folder system  200  is provided for folding a continuous web of sheet-like material  204 . System  200  includes a spiral folder assembly  210 , a chute assembly  220 , a beater assembly  230 , and a conveyor assembly  240 . According to some embodiments, conveyor assembly may include a support arrangement  250 , a ramp arrangement  260 , and an exit arrangement  270 . In operation, chute assembly  220  swings back and forth between a first set of spirals  212  and a second set of spirals  214 . It is appreciated that chute assembly  220  represents one of a variety of deflection means contemplated by the present invention, whereby the deflection means operates to steer, direct, or otherwise move web  204  in the desired direction. When in a first position indicated by arrow  2 A, chute assembly  220  feeds continuous web  204  toward first set of spirals  212 . A first beater  232  acts to urge web  204  against first set of spirals  212  so as to form a first fold in the web. Thereafter, when in a second position indicated by arrow  2 B, chute assembly  220  feeds continuous web  204  toward second set of spirals  214 . A second beater  234  acts to urge web  204  against second set of spirals  214  so as to form a second fold in the web. Often, the continuous web is prepared so as to provide perforations where the folds are to be made. System  200  often includes one or more first stop bars  106  configured to restrain movement of continuous web  204  when it is urged against first set of spirals  212  by first beater  232 , and one or more second stop bars  108  configured to restrain movement of continuous web  204  when it is urged against second set of spirals  214  by second beater  234 .  
         [0026]     As noted previously, the present invention can prevent or inhibit the folded stack from pulling away from stops  206  and/or  208 , such that web folds/perforations are kept close to or at stops  206 ,  208 . Often, beater timing involves a leading edge of beater  232 ,  234  being disposed about 0.75 inches from its respective stop  206 ,  208 , so beater  232 ,  234  will have ample time to force the perforated line to collapse and create a fold. Accordingly, the present invention can inhibit or prevent the perforations and/or folds from being placed at inappropriate locations relative to beaters  232  and/or  234  during web processing. For example, without the necessary support at the lower center of the folded stack, the sagging will shorten the overall horizontal distance between the perforated lines at spirals  212  and perforated lines at spirals  214 . If the perforated lines are not close enough to stops  206 ,  208 , then beater  232 ,  234  may not be able to effectively collapse the perforated line to cause a fold. In known systems, such as those shown in  FIG. 1 , this can be a significant problem because ramp roller  162  at best supports the very end of the folded stack, at spirals  114 , and therefore the perforations are not kept sufficiently close to the stop (not shown) located at spirals  112 , or are otherwise not sufficiently engaged with spirals  112  to allow for proper beater folding. In this sense, the present invention provides devices and methods for ensuring that the web is appropriately engaged with spirals  212 ,  214 , beaters  232 ,  234 , and/or stops  206 ,  208  so as to correctly create folds in web  204 .  
         [0027]     During the web processing operation, web  204  can be continuously advanced through chute assembly  220  as it swings back and forth between position  2 A and position  2 B, and spirals  212  and  214  can be rotated about their own individual axes so that spiral blades  213  and  215  operate to advance the paper folds in a downward direction. This process effectively creates an accordion-type fold or fan fold in web  204 . When the folded web  204  leaves the spiral folder assembly  210 , it can be supported by a support  251  defined at least in part by a support assembly  250  of conveyor assembly  240 . Support assembly  250  can include one or more support rollers  252 ,  252 ′ and one or more support belts  254 , where support belts  254  are wrapped circumferentially about one or more support rollers  252 ,  252 ′. In some embodiments, support belts  254  are about 1.5 inches wide and about 0.0625 inches thick, and support rollers  252  are made of aluminum. Often, support  251  will be disposed between a first vertical plane  280  defined by first set of spirals  212  and a second vertical plane  290  defined by second set of spirals  214 . Support  251  can be configured so as to prevent or reduce sagging of continuous web  204  as it is suspended between first set of spirals  212  and second set of spirals  214 . It is appreciated that the position or orientation of support  251  can be configured in any of a variety of ways. By setting the orientation of various components of conveyor assembly  240 , an operator can modulate or adjust the amount of sagging present in folded web  204 . In some cases, the conveyor assembly  240  configuration will be a pre-set configuration, based on parameters such as spiral blade depth, web thickness, distance between folds or perforations in the web, and the like. Factors such as these are further discussed below in reference to FIGS.  5 A-F.  
         [0028]     What is more, the present invention contemplates a wide variety of different configurations for any of the system components, including, but not limited to, spiral folder assembly  210 , chute assembly  220 , assembly  230 , and conveyor assembly  240 . For example, conveyor assembly  240  often includes one or more support rollers  252 ,  252 ′, although in some embodiments a support roller may not be present. Ramp roller  262  may be adapted so as to provide achieve a desired effect of the invention, in the absence of a support roller  252 ,  252 ′. Relatedly, an operator may configure support arrangement  250 , ramp arrangement  262 , and exit arrangement  240  with any desired combination or belts and rollers. As noted previously, such configurations will often provide support  251  so as to reduce or inhibit an amount of sagging present in continuous web  204  as it is suspended or otherwise processed through first set of spirals  212  and second set of spirals  214 . In some embodiments, support  251  is disposed along a horizontal plane defined by bottom ends  216  and  218 , respectively, of spiral blades  213  and  215 . Support  251  may be present in any of a variety of orientations and/or locations at or near this plane, so long as it provides the desired effect on the sag in continuous web  204 . In many embodiments, continuous web  204  is processed along a cascade-like web processing path defined by conveyor assembly  240 .  
         [0029]     As seen from the perspective shown in  FIG. 2 , support belt  254  rotates in a counter-clockwise direction, illustrated by arrow  254   a . Similarly, ramp belt  264 , which is wrapped circumferentially about a ramp roller  262  and an exit roller  272 , rotates in a counter-clockwise direction, illustrated by arrow  264   a . In some embodiments, rotation of exit roller  272 ′ is driven by a drive chain  277  which is coupled with a drive motor  275  via a drive sprocket  276 . Rotation of exit roller  272 ′ causes exit belt to circumferentially rotate about exit rollers  272 ,  272 ′. One or more of the exit rollers  272  can be coupled with ramp roller via ramp belt  264 . Transfer belt  258  can transfer rotational force from ramp roller  262  to support roller  252 . Support belt  254  can transfer rotational force from support roller  252  to other support rollers  252 ′. Support belt  254  can operate to advance folded web  204  from spiral folder assembly  210  toward one or more ramp belts  264 . Ramp belts  264  can operate to advance the folded web  204  from support arrangement  250  toward one or more rotating exit belts  274  of exit arrangement  270 . As seen from this perspective, exit belt  274 , which is wrapped circumferentially about a plurality of exit rollers  272 ,  272 ′, rotates in a counter-clockwise direction, illustrated by arrow  274   a . Typically, exit belt  274  of conveyor assembly  240  acts to advance the folded web  204  toward another downstream processing location.  
         [0030]      FIG. 3  illustrates a sheet folder system  300  according to one embodiment of the present invention. Folder system  300  is provided for folding a continuous web of sheet-like material  304 . In some embodiments, web  304  may include a pre-printed roll of paper material, or the like, as produced by a printer system  305  which is operative association with folder system  300 . System  300  includes a spiral folder assembly  310 , a chute assembly  320 , a beater assembly  330 , and a conveyor assembly  340 . In operation, web  304  is fed into folder system  300  from printer system  305 , and chute assembly  320  swings back and forth between a first set of spirals  312  and a second set of spirals  314 . When in a first position indicated by arrow  3 A, chute assembly  320  feeds continuous web  304  toward first set of spirals  312 . A first beater (not shown) acts to urge web  304  against first set of spirals  312  so as to form a first fold in the web. Thereafter, when in a second position indicated by arrow  3 B, chute assembly  320  feeds continuous web  304  toward second set of spirals  314 . A second beater  334  acts to urge web  304  against second set of spirals  314  so as to form a second fold in the web. During this process, web  304  can be continuously advanced through chute assembly  320  as it swings back and forth between position  3 A and position  3 B, and spirals  312  and  314  can be rotated about their own individual axes to advance the paper folds in a downward direction, such that an accordion-type fold or fan fold is created in web  304 .  
         [0031]     When the folded web  304  leaves the spiral folder assembly  310 , it can be supported by a support  351  defined at least in part by a support assembly  350  of conveyor assembly  340 . Support assembly  350  can include one or more support rollers  352  and one or more support belts  354 , where support belts  354  are wrapped circumferentially about one or more support rollers  352 . Support assembly  350  may also include a transfer belt  358  wrapped circumferentially about a ramp roller  362  and a support roller  352 , configured to transmit rotational force from ramp roller  362  to support roller  352 . In some embodiments, transfer belt  358  is made of urethane, and is about 0.5 inches wide and about 0.0625 inches thick.  
         [0032]     As seen from the perspective shown in  FIG. 3 , support belt  354  rotates in a counter-clockwise direction, illustrated by arrow  354   a . Similarly, ramp belt  364 , which is wrapped circumferentially about a ramp roller  362  and an exit roller  372  rotates in a counter-clockwise direction. Support belt  354  can operate to help advance folded web  304  from spiral folder assembly  310  toward one or more ramp belts  364 . Ramp belts  364  can operate to advance the folded web  304  from support arrangement  350  toward one or more rotating exit belts  374  of exit assembly  370 . As seen from this perspective, exit belt  374 , which is wrapped circumferentially about a plurality of exit rollers  372 , rotates in a counter-clockwise direction, illustrated by arrow  374   a . Typically, exit belt  374  of conveyor assembly  340  acts to advance the folded web  304  toward another downstream processing location.  
         [0033]      FIG. 4  illustrates a sheet folder system  400  according to one embodiment of the present invention. Folder system  400  is provided for folding a continuous web of sheet-like material (not shown). System  400  includes a spiral folder assembly  410 , a chute assembly (not shown), a beater assembly  430 , and a conveyor assembly  440 . When the folded web leaves the spiral folder assembly  410 , it can be supported by a support  451  defined by various components of conveyor assembly  440 . Conveyor assembly  440  can include a support arrangement  450 , a ramp arrangement  460 , and an exit arrangement  470 . Support assembly  450  can include one or more support rollers  452 , two end plates  453 , and one or more support belts  454 , where support belts  454  are wrapped circumferentially about one or more support rollers  452 . Often, support  451  will be disposed between a first vertical plane defined by first set of spirals  412  and a second vertical plane defined by second set of spirals  414 . Support  451  can be configured so as to prevent or reduce sagging of continuous web  404  as it is suspended between first set of spirals  412  and second set of spirals  414 .  
         [0034]     As seen from the perspective shown in  FIG. 4 , support belt  454  rotates in a counter-clockwise direction, illustrated by arrow  454   a . Similarly, ramp belt  464 , which is wrapped circumferentially about a ramp roller  462  and an exit roller  472  rotates in a counter-clockwise direction, illustrated by arrow  464   a . Support belt  454  can operate to help advance folded web  404  from spiral folder assembly  410  toward one or more ramp belts  464 . Ramp belts  464  can operate to advance the folded web  404  from support arrangement  450  toward one or more rotating exit belts  474  of exit assembly  470 . As seen from this perspective, exit belt  474 , which is wrapped circumferentially about a plurality of exit rollers  472 , rotates in a counter-clockwise direction, illustrated by arrow  474   a . Typically, exit belt  474  of conveyor assembly  440  acts to advance the folded web  404  toward another downstream processing location.  
         [0035]     As illustrated in FIGS.  5 A-F, the configuration of certain system components may depend on not only the nature of the material being processed but also the nature of other components in the system. As seen in  FIG. 5A , distance d a  represents the distance between (i) a portion of support  551   a  and (ii) a horizontal plane defined by bottom ends  516   a  and  518   a , respectively, of spiral blades  513   a  and  515   a . A corresponding distance d b  is shown in  FIG. 5B . A comparison of  FIGS. 5A and 5B  reveals that distance d a  is greater than distance d b . Here, the difference may correlate with the fact that the web material  504   a  is thicker than the web material  504   b  and is less likely to sag, and therefore requires less support than web material  504   b . For example, web material  504   a  may be 20 pound paper stock, whereas web material  504   b  may be 16 pound paper stock. The difference may also correlate with the fact that the distance pa between perforations and/or folds is less than the distance p b  between perforations and/or folds. For example, distance pa between perforations and/or folds may be about 10 inches, and distance p b  between perforations and/or folds may be about 14 inches. Table 1 illustrates these associations, as well as other similar associations between the web material and the configuration of certain system components. In many respects,  FIGS. 5A  and B (side view) correspond with  FIGS. 5C  and D (top view), respectively.  
                                                         TABLE 1                                                    distance d a     greater   distance d b             than       thickness of web 504a   greater   thickness of web           than   504b       distance w a  between spiral   less   distance w b  between       sets 512a and 514a   than   spiral sets 512b and               514b       radius of spiral blades 513a   greater   radius of spiral blades       and 515a   than   513b and 515b       distance p a  between folds   less   distance p b  between       and/or perforations   than   folds and/or perforations       contact area between web 504a   greater   contact area between web       and spiral blades 513a and 515a   than   504b and spiral blades               513b and 515b                                             radius of spiral blades 513c   greater   radius of spiral blades       and 515c   than   513d and 515d       portion of web length p c  that   less   portion of web length p d         is unsupported by spiral blades   than   that is unsupported by       513c and 515c (where p c  is       spiral blades 513d and       distance between folds and/or       515d (where p d  is distance       perforations)       between folds and/or               perforations)       portion of web span s c  that is   less   portion of web span s d  that       unsupported by spiral blades   than   is unsupported by spiral       513c and 515c (where s c  is       blades 513d and 515d (where       width of web)       s d  is width of web)       distance w c  between spiral sets   less   distance w d  between spiral       512c and 514c   than   sets 512d and 514d       contact area between web 504c   greater   contact area between web       and spiral blades 513c/515c   than   504d and spiral blades               513d/515d                  
 
         [0036]     In some embodiments, the width of the continuous web (e.g. width s c  of web  504   c  shown in  FIG. 5C ) is about 8.5 inches, about 11 inches, about 14 inches, or about 18 inches. In other embodiments, the width of the continuous web is within a range between about 3.5 inches and about 20 inches. In some embodiments, the distance between perforations and/or folds in the continuous web (e.g. distance p c  of web  504   c  shown in  FIG. 5C ) is about 8.5 inches, about 10 inches, about 12 inches, or about 14 inches. In some embodiments, the distance between perforations and/or folds in the continuous web is within a range between about 7 inches and about 17 inches. In some embodiments, the paper weight of the continuous web is about 18 pounds or about 24 pounds. In some embodiments, the paper weight of the continuous web is within a range between about 9 pounds and about 200 pounds. In some cases, paper weights can be determined by measuring paper thickness.  
         [0037]     There are a variety of ways in which folds and/or perforations in the continuous web may engage the spiral blades. For example, as shown in  FIG. 5E , each consecutive fold at spiral  512   e  is separated by spiral blade  513   e . In comparison, as shown in  FIG. 5F , each individual fold envelopes spiral blade  513   f , so the top half of the fold is above the blade, and the bottom half of the fold is below the blade.  
         [0038]     In many instances conveyor assembly  540   a  will be configured to inhibit sagging that occurs perpendicular to the direction in which web  504   a  travels through the system, as shown in  FIG. 5A  (e.g. sag between first set spirals  512   a  and second set of spirals  514   a ). It appreciated that conveyor assembly  540   a  may also be configured to inhibit sagging that occurs parallel to the direction in which web  504   a  travels. Various manifestations of web sag can occur depending on the configuration of the folding system and characteristics of the web. The present invention provides means and techniques for addressing any of these types of sag. As noted previously, support  551   a  may be present in any of a variety of orientations and/or locations at or near the horizontal plane defined by bottom ends  516   a  and  518   a  of spiral blades  513   a  and  515   a , respectively, so long as it provides the desired effect on the sag in continuous web  504   a.    
         [0039]      FIG. 6  illustrates a support assembly end plate  653  according to one embodiment of the present invention. Dimensions of end plate  653  can be adapted in any of a variety of ways in order to achieve the desired effect of inhibiting sag in a continuous web. Here, a dimension C represents the distance between a first support roller holder  653   a  and a second support roller holder  653   b . In some embodiments, dimension C is about 5.25 inches. In some embodiments, dimension C is within a range between about 4.25 inches and about 6.25 inches. In other embodiments, dimension C is within a range between about 3.25 inches and about 7.25 inches. In some embodiments, dimension A is about 10 inches. In some embodiments, dimension A is within a range between about 8 inches and about 12 inches. In other embodiments, dimension A is within a range between about 6 inches and about 14 inches. In some embodiments, dimension B is about 3.75 inches. In some embodiments, dimension B is within a range between about 2.75 inches and about 4.75 inches. In other embodiments, dimension B is within a range between about 1.75 inches and about 5.75 inches.  
         [0040]     In some embodiments, dimension D is about 2 inches. In some embodiments, dimension D is within a range between about 1 inch and about 3 inches. In other embodiments, dimension D is within a range between about 0.5 inches and about 3.5 inches. In some embodiments, dimension E is about 4.875 inches. In some embodiments, dimension E is within a range between about 3.875 inches and about 5.875 inches. In other embodiments, dimension E within a range between about 2.875 inches and about 6.875 inches. In some embodiments, dimensions F and G are about 3 inches. In some embodiments, dimensions F and G are within a range between about 2 inches and about 4 inches. In other embodiments, dimensions F and G are within a range between about 1 inch and about 5 inches. In some embodiments, dimension H is about 8 inches. In some embodiments, dimension H is within a range between about 6 inches and about 10 inches. In other embodiments, dimension H is within a range between about 4 inches and about 12 inches. In some embodiments, dimension I is about 2 inches. In some embodiments, dimension I is within a range between about 1 inch and about 3 inches. In other embodiments, dimension I is within a range between about 0.5 inches and about 3.5 inches.  
         [0041]     Systems of the present invention often include two end plates  653  for supporting ramp rollers, support rollers, or both. In some embodiments, the distance between end plates  653  is about 20 inches. In some embodiments, the distance between end plates  653  is within a range between about 15 inches and about 25 inches. In other embodiments, the distance between end plates  653  is within a range between about 10 inches and about 30 inches. It is appreciated that end plate  653  can be manufactured from any of a variety of suitable materials. In some embodiments, end plate  653  is made of aluminum, and is about 0.25 inches thick.  
         [0042]     While the above provides a full and complete disclosure of certain embodiments of the present invention, various modifications, alternate constructions and equivalents may be employed as desired. Therefore, the above description and illustrations should not be construed as limiting the invention, which is defined by the appended claims.