Patent Application
20130168914
The present invention relates to a system and method for handling sheet material, and more particularly, to a system and method for minimizing the conveyance feed path to reduce the spatial requirements of a sheet handling system.
Various apparatus are employed for arranging sheet material in a package suitable for use or sale in commerce. One such apparatus, useful for describing the teachings of the present invention, is a mailpiece inserter system employed in the fabrication of high volume mail communications, e.g., mass mailings. Such mailpiece inserter systems are typically used by organizations such as banks, insurance companies, and utility companies for producing a large volume of specific mail communications where the contents of each mailpiece are directed to a particular addressee. Also, other organizations, such as direct mailers, use mail inserters for producing mass mailings where the contents of each mail piece are substantially identical with respect to each addressee. Examples of inserter systems are the 8 series, 9 series, and APS™ inserter systems available from Pitney Bowes Inc. located in Stamford, Conn., USA.
In many respects, a typical inserter system resembles a manufacturing assembly line. Sheets and other raw materials (i.e., a web of paper stock, enclosures, and envelopes) enter the inserter system as inputs. Various modules or workstations in the inserter system work cooperatively to process the sheets until a finished mail piece is produced. For example, in a mailpiece inserter, an envelope is conveyed downstream to each processing module by a transport or conveyance including drive elements such as rollers or a series of belts. The processing modules may include, inter alia, (i) a web for feeding printed sheet material, i.e., material to be used as the content material for mailpiece creation, (ii) a module for cutting the printed sheet material to various lengths, (iii) a feed input assembly for accepting the printed sheet material from the cutting module, (iv) a folding module for folding mailpiece content material for subsequent insertion into the envelope, (v) a chassis module where sheet material and/or inserts, i.e., the content material, are combined to form a collation, (vi) an inserter module which opens an envelope for receipt of the content material, (vii) a moistening/sealing module for wetting the flap sealant to close the envelope, (viii) a weighing module for determining the weight of the mailpiece for postage, and (x) a metering module for printing the postage indicia based upon the weight and/or size of the envelope, i.e., applying evidence of postage on the mailpiece. While these are some of the more commonly used modules for mailpiece creation, it will be appreciated that the particular arrangement and/or need for specialty modules, are dependent upon the needs of the user/customer.
Inasmuch as a mailpiece inserter comprises a plurality of processing modules, it is oftentimes desirable to reduce the conveyance feed path, and, accordingly, the “foot-print” occupied by the inserter. That is, since the real-estate occupied by a mailpiece inserter translates into a “fixed expense” for an operator, it is desirable to reduce the space consumed by the inserter. As a result, savings can be achieved by reducing the length of the conveyance feed path.
Of the many challenges faced by designers of mailpiece inserters, one area which results in a requirement for greater space/length of the conveyance path is the transition between modules. That is, to accommodate sheets of variable length, or process certain mail run jobs, a threshold spacing must be maintained between modules to ensure that a downstream module does not prematurely begin processing/handling a sheet/collation before an upstream module has completed an operation. For example, it is common practice to lengthen the feed path, or include a buffer region between modules, to allow a larger sheet, e.g., 11×17 inch sheet, to be processed/handled by an upstream module without interference by a downstream module.
In the case of a print module, it will be appreciated that a blank sheet is fed past a printhead which prints from a leading to a trailing edge. As the sheet is fed and printed, the leading edge is conveyed downstream or “leads” as the sheet is printed along or near the trailing edge. No operation can be performed on the leading edge (which is now downstream of the printhead) while the trailing edge is being printed As a consequence, the conveyance feed path will typically include the full length of a sheet before a downstream module can accept and begin another operation.
Another example includes the transition between a cutting module and a feed input assembly of a mailpiece inserter. In this example, the length of content material can vary from a short insert, i.e., approximately four and one-half inches (4½″), to a double-length sheet, i.e., approximately seventeen inches (17″). As a result, the feed path between the cutting module and the feed input assembly can vary by more than twelve inches (12″) or one foot (1′). Stated in yet other terms, the point of entry/ingestion of the leading edge of a long sheet can lengthen the feed path of the inserter as compared to the entry point required by a short insert, e.g., the location of a nip for ingesting the leading edge of the insert.
Finally, the initial set-up and anticipated processing of a sheet/collation can adversely impact the length of the conveyance feed path. For example, it is common practice to include a symbol/mark/scan code on one or more sheets of a collation to provide information concerning the processing of the collation. When accumulating a collation of sheets, a scanner disposed upstream of the accumulator, reads the symbol/mark/scan code so that the inserter may know when a collation begins or ends. That is, the mailpiece processor interprets the symbol/mark/scan code such that it may determine which sheet, of the stream of sheets being fed along a conveyance path, is the first sheet of the next collation.
As a result, information is obtained concerning when the Beginning Of the next Collation (BOC) begins and/or when the end of the current collation ends. Depending upon the location of this symbol/mark/scan code, the length of the conveyance feed path (between an upstream singulating module, i.e., a module which singulates/feeds sheets, and a downstream accumulator), must accommodate the longest sheet anticipated to be processed. If, for example, the symbol/mark/scan code is located along a trailing edge of a sheet to be processed, then the length of the conveyance path must be at least as long as the distance between the leading edge of the sheet and the BOC plus a threshold pitch distance (i.e., the distance between the trailing edge of one sheet and the leading edge of the subsequent sheet as determined by the throughput requirements/speed of the mailpiece inserter).
In each of the above examples, it will be appreciated that conveyance systems of the prior art are constrained by a requirement to accommodate processing of the largest sheet, whether dictated by the length dimension of the sheet, or the location/position of a symbol/mark/scan code on the face of the sheet. As a result, the overall foot-print/size of the sheet handling system, e.g., a mailpiece inserter, is increased by the limitation to maintain a minimum spacing, or threshold distance, between modules.
A need, therefore, exists for a conveyance system which processes sheets without the limitations necessitated by the variations in sheet length or sheet processing requirements.
A method is provided for operating a sheet handling system which includes the processing steps of feeding singulated sheets from a stack of sheet material and accumulating select sheets into a completed collation of sheets along a conveyance feed path. The method includes the steps of: determining a location of a next collation mark on select sheets of the stack of material to be processed, selecting an operating mode based upon the proximity of the next collation mark relative to a leading or trailing edge of each of the select sheets, processing the singulated sheets in a first operating mode when the next collation mark is proximal to the leading edge of each of the select sheets, and in a second operating mode, when the next collation mark is proximal to a trailing edge of each of the select sheets. When processed each of the select sheets along the conveyance feed path is buffered to change the spatial relationship between each of the select sheet and each completed collation of sheets along the feed path. By selectively operating the sheet handling system based upon the location of the next collation mark and buffering the select sheets, the conveyance feed path is minimized.
Further details of the present invention are provided in the accompanying drawings, detailed description, and claims.
a is an isolated perspective view of a vacuum roller assembly for a singulating apparatus which improves the reliability of sheet feeding while minimizing audible noise levels for improved workstation comfort.
b is an exploded view of the vacuum roller assembly depicted in
a though 5e depict schematic views of the accumulator module according to the present invention, in a first operating mode, wherein a BOC/EOC mark is printed proximal to the leading edge of selected sheets and wherein each of the
a though 6g depict schematic views of the accumulator module according to the present invention, in a second operating mode, wherein a BOC/EOC mark is printed proximal to the leading edge of selected sheets and wherein each of the
The invention described herein is directed to an improved sheet handling system. Firstly, the invention describes a feed apparatus having an improved vacuum roller which reliably singulates sheet material for delivery to the accumulator while reducing the audible noise levels generated by the vacuum pump for increased operator comfort. Additionally, the invention describes an improved sheet material accumulator including an auxiliary conveyance which accumulator improves throughput by selectively operating one of at least two operating modes Finally, a method of operating a sheet handling system is described to reduce the conveyance feed path and decrease the overall envelope/foot-print occupied by the sheet handling system.
The system, apparatus and method of the present invention will be discussed in the context of a mailpiece inserter including a feed module disposed upstream of a sheet accumulating module, although, the teachings described herein are equally applicable to other sheet handling equipment and systems. Consequently, the described embodiment is merely an exemplary arrangement of the present invention and the appended claims should be broadly interpreted in view thereof.
In
A processor or controller 20 (see
In
In the described embodiment, and referring to
The stationary inner plenum 32 defines a longitudinal plenum slot 38 (see
The outer vacuum roller 36 is disposed over the inner plenum 32 and includes a plurality of apertures 44 which are in fluid communication with the plenum slot 38 for the purpose of producing a negative pressure differential, i.e., a singulating vacuum, along the surface of the roller assembly 30. More specifically, the apertures 44 are arranged in three distinct regions of the vacuum roller 30 to facilitate the directed passage of air while maintaining low audible noise levels for operator comfort.
In the described embodiment, the rotating vacuum roller 36 includes a central region 44a having circular-shaped apertures 44O and outboard regions 44b, 44c having substantially slot-shaped apertures 44S to either side of the central region 44a. With respect to the central region 44a, the circular apertures 44O are aligned in a plurality of cross-sectional planes which are orthogonal to the rotational axis RA of the vacuum roller 36. Furthermore, the apertures 44O within each plane are staggered, or rotated several degrees in a helical pattern about the axis RA. Furthermore, the central region 44a defines a concave surface 46a about the circumference of the vacuum roller 36 to facilitate singulation of sheet material 16S. The import of these geometric features will be described in greater detail when discussing the operation of the vacuum roller assembly 30.
With respect to the outboard regions 44b, 44c, the slot-shaped apertures 44S are similarly aligned, i.e., the geometric center GC of each are aligned relative to an orthogonal plane, however, the orientation of each slot-shaped aperture is off-axis relative to the rotational axis RA of the vacuum roller 36. In the context used herein, “aligned” means that the locus of points defined by the geometric center GC of each aperture 44O lies within a plane orthogonal to the rotational axis RA. Furthermore, in the context used herein, “off-axis” means that the elongate or major axis of each aperture 44S defines an acute angle θ relative to the rotational axis RA. Finally, the external surface or periphery of the vacuum roller 36 in each of the outboard regions 44b, 44c is substantially cylindrical to facilitate initial separation of the lowermost sheet 16LM from the stack 16S of sheet material. The import of these geometric features will be also discussed when describing the operation of the vacuum roller assembly 30.
The geometry of the vacuum roller 36 may be best understood by referring to a two-dimensional flat pattern perspective thereof depicted in
As mentioned earlier, the geometry and arrangement of apertures 44 of the vacuum roller 36 serves to reliably singulate sheet material 16S while reducing audible noise levels produced by the flow of air when drawing a pressure differential/vacuum across the sheets 16S. These features are best understood by discussing the operation of the vacuum roller assembly 30.
Operationally, the outer vacuum roller 36 rotates over the inner plenum 32 such that the apertures 44O, 44S rotate over the elongate slot 38. As the sheet material 16S is fed to the vacuum roller assembly 30, a negative pressure differential develops along the surface of the vacuum roller 36. More specifically, a pressure differential is first developed in the outboard regions 44b, 44c to draw the lowermost sheet 16LM from the shingled stack 16S. Inasmuch as the cylindrical external surface of the outboard regions 44b, 44c compliments the planar contour of the sheet material 16S, the outboard regions 44b, 44c and the slot-shaped apertures 44S, are principally responsible for drawing the lowermost sheets 16LM from the stack 16S. Inasmuch as frictional forces are developed between the sheets 16, the upper sheets 16U follow the lowermost sheet 16LM, but are shingled when engaging the separating guide 24.
As the sheets 16LM is singulated/drawn from the stack 16S, the stationary roller/finger 26 guides the lowermost sheet 16LM into the concave curvature 46 of the central region 44a. More specifically, the stationary roller/finger 26 includes a convex guide surface 26a which opposes and compliments the concave surface 46a of the vacuum roller 36. As the sheet 16LM follows the contour of the convex guide surface 26a, additional vacuum pressure is applied across the sheet 16LM, in the area immediately opposing the concave surface 46a of the roller 36. As the lowermost sheet 16LM is drawn into the concave surface 46a of vacuum roller 36, it is also drawn away from a sheet 16U immediately adjacent to and above the lowermost sheet. Accordingly, frictional forces developed between the lowermost and upper sheets 16LM, 16U are reduced in this region, i.e., in the region immediately above the concave surface 46a. Inasmuch as the friction forces are reduced while the vacuum forces are increased, the lowermost sheet is reliably singulated from the stack 16S. It will be appreciated, therefore, that the vacuum roller 36 of the present reliably singulates the lowermost sheet 16LM without a “miss-feed”, i.e., without feeding a sheet from the stack 16S, or “double-feeds”, i.e., two or more sheets being fed from the stack.
In addition to enhanced reliability, audible noise levels are reduced by the angular orientation of the slot-shaped apertures 44S. More specifically, the inventors of the present invention discovered that a conventional arrangement of large apertures, i.e., three uniformly-spaced openings along the length of the vacuum roller assembly, produced audible noise levels which were highly uncomfortable to an operator. Upon further study and examination, it was determined that elongate openings provided a degree of relief, however, the level of audible noise continued to be problematic. Finally, it was discovered that the noise levels could be reduced by orienting the apertures 44O, 44S such that airflow was not abruptly ingested by the longitudinal slot 38 of the inner plenum 32. To achieve this effect, the apertures 44O in the central region 44a are staggered or off-set such that, at any time, a full compliment cannot flow through all of the apertures 44O at the same time. That is, the apertures 44O are arranged in a helical pattern, i.e., slope downwardly or upwardly, at an acute angle β relative to the rotational axis RA. Similarly, the slot-shaped apertures 44S associated with the outboard regions 44b, 44c are disposed at an acute angle (i.e., cut across the longitudinal slot 38 of the inner plenum) such that a full compliment of air cannot flow through any one slot-shaped aperture 44S. It was also discovered that the acute angle must within a relatively narrow range, i.e., less than ten (10) degrees, to prevent the loss of air or suction and greater than five (5) degrees to mitigate noise levels.
As sheets are singulated by the feed module 12, they are conveyed in series along a conveyance path FP and dispensed downstream toward the accumulator module 14. In the described embodiment, a sheet feed sensor 48 is disposed downstream of the singulating assembly 22 to sense whether each sheet has been successfully singulated and fed by the feed module 12. More specifically, the sheet feed sensor 48 senses the leading edge of each sheet and provides a signal to the processor 20 for determining whether a miss-feed has occurred. In the event of a miss-feed, the processor 20 may discontinues sheet feed operations or provide a cue to an operator.
In
Information concerning processing of the singulated sheets 16 may be obtained by one or more optical scanners 50 operative to read scan codes/symbols disposed on the singulated sheets (generally within the margins thereof), directly from the mail run data file MRDF, or from other upstream or downstream modules IM of the mailpiece inserter 10. Additionally, optical position detectors 48, 52, 54, 56 may be employed to determine the instantaneous location of a sheet 16 as the leading or trailing edge of a sheet passes one of the detectors 48, 52, 54, 56, Furthermore, it should be appreciated that a number of rotary encoders (not shown) are disposed on at least one shaft of each of the conveyance rollers, (e.g., the drive shaft 60 of the vacuum roller assembly 30, the drive shaft 60 of the feed motor FM which drives the exit rollers 64, 66 of the feed module 12, etc.). This information is fed to the processor 20 such that, inter alia, the location of each sheet 16 along the feed path FP can be determined at nearly any point along the conveyance feed path FP.
With respect to the accumulator module 14, an important source of information is the Beginning- or End-Of-Collation symbol or mark Nn disposed on select sheets, i.e., a next collation sheet 16NC (see
In one operating mode, a BOC/EOC mark NnLE is located proximal to the leading edge of the next collation sheet 16NC, and in a second operating mode, a BOC/EOC symbol NnTE is located proximal to the trailing edge of the next collation sheet 16NC. The general position of the BOC/EOC mark, i.e., near the leading or trailing edges, may be input by an operator assist processing of the mark. Alternatively, the optical sensors 52, 54, 56 may be used in conjunction with the rotary encoders of the conveyance system, to locate the mark NnLE, NnTE on each of the select sheets 16.
In the described embodiment, the scanner 50 searches for the location of, the mark NnLE, NnTE from signals acquired by the leading edge sensor 48, upstream of the scanner 50. The scanner 50 issues a next collation signal NCS to the processor 20 to determine which sheet, in a series of consecutively fed sheets, is the first sheet of the next collation, or the last sheet of the current collation.
In the broadest sense of the invention and referring to
More specifically, the processor 20 controls the conveyances C1, C2, AC such that in the second operating mode, the first conveyance C1 feeds a first sheet of the next collation into a buffer region BR of the accumulator 14, and, the auxiliary conveyance AC feeds the completed collation CC to the second conveyance C2 while the first conveyance C1 is deactivated to hold the first sheet of the next collation in the buffer region BR. As will be discussed in greater detail hereinafter, the buffering of the first sheet of the next collation, minimizes the conveyance feed path between the accumulator and an upstream module of the sheet handling system to reduce the overall size envelope of the accumulator 14.
In
The mechanism for driving the transport elements includes a motor M1, a drive belt 78 for rotationally coupling the motor M1 to a first of the drive/suspension shafts, e.g., the lower suspension shaft 76S, and a gear drive mechanism (not shown) rotationally coupling a second of the drive shafts, e.g., the upper suspension shaft 74S, to the first suspension/drive shaft 76S. With respect to the latter, the gear drive mechanism drives the shafts 74S, 76S at the same speed and in opposite directions such that the O-ring elements 70, 72 are driven from an upstream to a downstream location along the conveyance feed path FP.
Accordingly, sheets are accepted between the upper and lower transport elements, i.e., between the O-ring elements 70, 72 and are conveyed to the accumulator station AS (described in greater detail in subsequent paragraphs) along the feed path FP. The operation of the first conveyance C1 is discussed in greater detail below when discussing the operation of the accumulator and method for minimizing the conveyance feed path of a mailpiece inserter.
The second conveyance C2 is adapted to accept a completed collation CC from the accumulator station AS and dispense a completed collation CC (see
Each of the rollers 84R, 86R of the second conveyance C2 are rotationally coupled by a drive shaft 86S to a drive motor M2. In the described embodiment, the motor M2 is rotationally coupled to the drive shaft 86S by a drive belt 88. Furthermore, the nip rollers 84R, 86R of the second conveyance C2 are co-axially aligned with the rotational axis of the downstream pulley rollers 74R, 76R of the first conveyance C1, however, the nip rollers 84R, 86R may be independently, and differentially, driven relative to the pulley rollers 74R, 76R. For example, the downstream pulley rollers 74R, 76R may rotate while the nip rollers 84R, 86R are motionless. Conversely, the nip rollers 84R, 86R of the second conveyance C2 may be driven while the pulley rollers 74R, 76R of the first conveyance C1 are stopped. Additionally, or alternatively, the nip rollers 84R, 86R of the second conveyance C2 may be driven at a higher/lower rotational speed than the pulley rollers 74R, 76R of the first conveyance C1. With respect to the latter, the first and second conveyances C1, C2 may be operated at different speeds to match the throughput of other modules of the sheet handling system.
In the described embodiment, the accumulator station AS is integrated with the first and second conveyances C1, C2, however, it should be appreciated that the accumulator station AS may be an independent module, i.e., may not share components of the conveyances C1, C2. In the broadest sense of the invention, the accumulator station AS includes a means for stacking a select group of sheets, e.g., a group intended for subsequent insertion into a mailpiece envelope, to produce a collation. In the described embodiment, the accumulator station AS includes (i) a means for changing the plane of one sheet 16 relative to another sheet 16 such that the sheets may be stacked vertically, i.e., one atop the other, (ii) a support deck for collecting the vertically stacked sheets, i.e., sheets which comprise the same collation, and (iii) a device for momentarily retarding the motion of select sheets to produce a completed collation.
In the described embodiment, the means for changing the plane of a sheet 16 is effected by creating a vertical step 80 in the lower transport element 72 of the first conveyance C1. More specifically, the vertical step 80 is produced by changing the path of the lower O-ring members 72 around several guide rollers 80a, 80b, 80c. This same arrangement, i.e., of O-ring members 72 and guide rollers 80a, 80b, 80c, also facilitates the creation of the deck for supporting the completed collation CC. More specifically, the deck is defined by a combination of the lower O-ring members 72 and a pair of guide elements 82. The guide elements 82 are disposed on each side of the O-ring members and in combination with the sidewalls 14SW of the accumulator 14. The O-ring members 72 provide support for a center portion of a completed collation CC while the side guides elements 82 support/guide the lateral edges of a collation CC.
In the described embodiment, the means for changing the plane of a sheet 16 is assisted by a plurality of ramps members 83 having ramp surfaces 83R disposed on each side of an O-ring element 72. The illustrated embodiment depicts ten (10) ramp members 83 which are laterally aligned across the width of the accumulator 14.
To accumulate sheet material, the accumulator 14 retards the motion of each sheet 16 in the accumulator station AS. Apparatus to perform this function may include any of one of a variety of know mechanisms to retain a sheet at a select location along a feed path FP. For example, a simple rotating finger, or group of fingers, may extend vertically upward into the feed path to retard the motion of one sheet while a subsequent sheet is stacked over the current sheet. In the described embodiment, this function is, however, integrated with the nip rollers 84R, 86R of the second conveyance C2. More specifically, selected sheets 16 are retained in the accumulator station AS by fixing the rotational position of the nip rollers 84R, 86R as the first conveyance C1 drives additional sheets 16 into the accumulator station AS. The need to lock the rotational position of the nip rollers 84R, 86R is particularly evident inasmuch as the nip rollers 86R of the second conveyance C2 share the same rotational axis as the pulley rollers 76R of the first conveyance C1, (albeit the shafts are rotationally independent from each other).
The auxiliary conveyance AC is adapted to convey a completed collation CC to the second conveyance C2 by engaging and disengaging the collation based upon the selected operating mode. The auxiliary conveyance AC includes at least one upper idler roller 94R adapted to engage and disengage an uppermost sheet 16UM (see
In the described embodiment, a pair of lower drive rollers 96R mount to a shaft 96S which rotationally mounts to the sidewall structure 14SW of the accumulator 14. Furthermore, each of the drive rollers 96R is aligned with an upper idler roller 94R such that, when engaged, an auxiliary drive nip AN is created therebetween. Moreover, the same motor M2 and drive belt 88 used to drive the lower nip roller 86R of the second conveyance C2. That is, the mechanisms for driving the lower drive roller 96R of the auxiliary conveyance AC and the lower nip roller 86R of the second conveyance C2 are integrated, or common to both conveyances AC, C2, to reduce the number of component parts and the cost associated therewith. While these drive mechanisms are integrated, it should be appreciated that each roller 86R, 96R may be driven independently, i.e., by separate drive motors and belts. The operation of the auxiliary conveyance AC, is discussed in greater detail in the subsequent paragraphs when discussing the operation of the accumulator.
The following describes the operation of the accumulator 14 and the method for controlling the sheet handling system, i.e., the mailpiece inserter 10, for minimizing the overall conveyance path required to process sheet material, i.e., prepare the sheet material for insertion into a mailpiece envelope.
Returning briefly to
a though 5e illustrate the operation of the sheet handling system in a first operating mode, wherein a BOC/EOC mark NnLE has been printed proximal to the leading edge of selected sheets 16. It should be appreciated that the sheet handling system of the present invention is adapted to process sheet material irrespective the location of the BOC/EOC mark Nn while, at the same time, minimizing the length of the conveyance path, i.e., the distance between modules 12, 14. Each of the
The operation of the sheet handling system described in
In
In
In
In
In
a though 6g illustrate the operation of the sheet handling system, in a second operating mode, wherein a BOC/EOC mark has been printed proximal to the trailing edge of selected sheets 16. Each of the
In
In
In
Stated in yet other terms, the first conveyance C1 continues to drive the first sheet of the next collation to effect a change in the spatial relationship between the first sheet of the next collation 16NC and the last sheet of the current collation 16LS next collation sheet. In the context used herein, the “change in spatial relationship” means that the first sheet of the next collation 16NC moves closer to the last sheet of the current collation. Additionally, the change in spatial relationship may result in a portion of the next collation sheet 16NC overlapping a portion of the last sheet of the current collation 16LS.
To better understand the potential length or breadth of the buffer region BR,
In each of the embodiments illustrated in
In
In
In
As mentioned previously, the timing and coordination of various actions impacts the throughput of the feed input and accumulator modules 12, 14 and, consequently, the overall operation mailpiece inserter 10. While information from each of the position sensors 48, 52, 54, 56 can be used exclusively to operate/coordinate the modules 12, 14, in the described embodiment rotary encoders are used in combination with the sensors 48, 52, 54, 56, i.e., (disposed on at least one shaft rotational axis of each conveyance C1, C2, AC) to obtain additional, more accurate, sheet location information. Accordingly, the processor 20 uses both position sensors and rotary encoders to track the position of each sheet 16 and each collation CC.
The accumulator 14 is controlled to maximize throughput of the mailpiece inserter. In one embodiment of the invention, an operator provides the processor 20 information regarding the location of the BOC/EOC mark Nn, i.e., proximal to the leading or trailing edges. Based upon this information, the accumulator 14 operates in one of the first or second operating modes to accumulate the sheets 16 of a particular mail run job. Alternatively, information regarding the location of the BOC/EOC mark Nn may be obtained from the mail run data file MRDF, i.e., an electronic file having information regarding the processing requirements of a job.
The sheet handling system of the present invention is also adapted to maximize throughput by the independent control of the first and second conveyances C1, C2. For example, the accumulator module 14 may obtain data input from a downstream module, e.g., the chassis module (not shown), to timely dispense a completed collation or change the pitch distance PD, i.e., the spacing between the trailing edge of the sheets or between the trailing edge of a completed collation and a next collation sheet 16NC.
In summary, the sheet handling system of the present invention is adapted to minimize the conveyance feed path thereof while maximizing throughput. The conveyance feed path is reduced by a buffer region adapted to accept at least a portion of a next collation sheet, i.e., within the accumulator. More specifically, the accumulator provides a buffer region, disposed internally of the accumulator, and control algorithms for moving sheets into and out of the buffer region, to accept and overlap a portion of a sheet from an upstream module, e.g., a feed module, with the sheets of a downstream module, e.g., an accumulator module. Furthermore, the invention provides a single deck accumulator module which provides throughput levels commensurate with dual deck accumulators while maintaining a similar foot-print, i.e., without increasing the space requirements between the accumulator and an upstream module.
It is to be understood that the present invention is not to be considered as limited to the specific embodiments described above and shown in the accompanying drawings. The illustrations merely show the best mode presently contemplated for carrying out the invention, and which is susceptible to such changes as may be obvious to one skilled in the art. The invention is intended to cover all such variations, modifications and equivalents thereof as may be deemed to be within the scope of the claims appended hereto.
