Abstract:
A high speed input system for an inserter machine. The system controlling a guillotine cutter, a cutter transport, and an upstream web handler transport to increase throughput for mail production. The controller is programmed to control the high speed input module in accordance with a repeating cycle. The cycle time is determined as an amount of time between a first web feed request and an earliest possible time that a subsequent second web feed request can be acted upon. A cutter transport motion control profile initiates feeding of a document length of web after receiving the first feed request. The cutter motion control profile causes the cutter blade to begin descending when the cutter transport has moved the web a trigger distance, calculated such that the cutter blade will first make contact with the web immediately when the web has been halted by the cutter transport motion profile. A web handler transport profile moves the web the document length at velocities and accelerations less than the velocities and accelerations of the cutter transport. At the end of the cycle, the web handler transport causes the web to be transported at a nominal velocity selected to maintain an appropriate amount of the web loop in the web handler. Within the web handler a control loop expands and contracts as the downstream cutter transport stops and starts as the cutter blade cuts the web in each cycle.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to the input portion of a high speed inserter system in which individual sheets are cut from a continuous web of printed paper for use in mass-production of mail pieces.  
       BACKGROUND OF THE INVENTION  
       [0002]     Inserter systems, such as those applicable for use with the present invention, are typically used by organizations such as banks, insurance companies and utility companies for producing a large volume of specific mailings where the contents of each mail item are directed to a particular addressee. Also, other organizations, such as direct mailers, use inserts for producing a large volume of generic mailings where the contents of each mail item are substantially identical for each addressee. Examples of such inserter systems are the 8 series, 9 series, and APS™ inserter systems available from Pitney Bowes Inc. of Stamford, Conn.  
         [0003]     In many respects, the typical inserter system resembles a manufacturing assembly line. Sheets and other raw materials (other sheets, enclosures, and envelopes) enter the inserter system as inputs. Then, a plurality of different modules or workstations in the inserter system work cooperatively to process the sheets until a finished mail piece is produced. The exact configuration of each inserter system depends upon the needs of each particular customer or installation.  
         [0004]     Typically, inserter systems prepare mail pieces by gathering collations of documents on a conveyor. The collations are then transported on the conveyor to an insertion station where they are automatically stuffed into envelopes. After being stuffed with the collations, the envelopes are removed from the insertion station for further processing. Such further processing may include automated closing and sealing the envelope flap, weighing the envelope, applying postage to the envelope, and finally sorting and stacking the envelopes.  
         [0005]     The input stages of a typical inserter system are depicted in  FIG. 1 . At the input end of the inserter system, rolls or stacks of continuous printed documents, called a “web,” are fed into the inserter system by a web feeder  10 . The continuous web must be separated into individual document pages. This separation is typically carried out by a web cutter  20  that cuts the continuous web into individual document pages. In a typical web cutter  20 , a continuous web of material with sprocket holes on both side of the web is fed from a fanfold stack from web feeder  10  into the web cutter  20 . The web cutter  20  has a tractor with pins or a pair of moving belts with sprockets to move the web toward a guillotinecutting module  20  for cutting the web cross-wise into separate sheets. Perforations are provided on each side of the web so that the sprocket hole sections of the web can be removed from the sheets prior to moving the cut sheets to other components of the mailing inserting system. Downstream of the web cutter  20 , a right angle turn  30  may be used to reorient the documents, and/or to meet the inserter user&#39;s floor space requirements.  
         [0006]     The separated documents must subsequently be grouped into collations corresponding to the multi-page documents to be included in individual mail pieces. This gathering of related document pages occurs in the accumulator module  40  where individual pages are stacked on top of one another. The control system for the inserter senses markings on the individual pages to determine what pages are to be collated together in the accumulator module  40 .  
         [0007]     Downstream of the accumulator  40 , a folder  50  typically folds the accumulation of documents, so that they will fit in the desired envelopes. To allow the same inserter system to be used with different sized mailings, the folder  50  can typically be adjusted to make different sized folds on different sized paper. As a result, an inserter system must be capable of handling different lengths of accumulated and folded documents. Downstream of the folder  50 , a buffer transport  60  transports and stores accumulated and folded documents in series in preparation for transferring the documents to the synchronous inserter chassis  70 .  
         [0008]     In a typical embodiment of a web cutter  20 , the guillotine cutter arrangement requires that the web be stopped during the cutting process. As a result, the web cutter  20  transports the web in a sharp starting and stopping fashion and subjects the web to high accelerations and decelerations.  
         [0009]     With the guillotine cutter arrangement, the web feeder  10  may typically include a loop control module to provide a loop of slack web to be fed into the web cutter  20 . During high speed operation, the accelerations experienced by the web in the slack loop can be quite severe. The inertia experienced by the web from the sudden starting and stopping may cause it to tear or become damaged.  
         [0010]      FIG. 2  shows more details of an input portion of an inserter system. For purposes of the present invention it is not important whether a particular functionality be included one module or another, and the description of one module having a certain functionality is exemplary. A web  120  is drawn into the inserter input subsystem. Methods for transporting the web are known and may include rollers, or tractors pulling on holes along a perforated strip at the edges of the web. The web  120  is split into two side-by-side portions by a cutting device  11 . Cutting device  11  may be a stationary knife or a rotating cutting disc, or any other cutting device known in the art. While the embodiment in  FIG. 2  shows the web being split into two portions, one skilled in the art will understand that a plurality of cutting devices  11  may be used to create more than two strands of web from the original one.  
         [0011]     Sensors  12  and  13  scan a mark or code printed on the web. The mark or code identify which mail piece that particular portion of web belongs to, and provides instructions for processing and assembling the mail pieces. In addition to using the scanned information for providing assembling instructions, the scanning process is useful for tracking the documents&#39; progress through the mail piece assembly process. Once the location of a document is known based on a sensor reading, the document&#39;s position may be tracked throughout the system by monitoring the displacement of the transport system. In particular, encoders may be incorporated in the transport systems to give a reliable measurement of displacements that have occurred since a document was at a certain location.  
         [0012]     After the web  120  has been split into at least two portions, the web is then cut into individual sheets by cutter  21 . The cut is made across the web, transverse to the direction of transport. Downstream of the cutter  21  the individual cut sheets are transported by nips  23 . Nips  24  further serve to transport the sheets to the right angle turn  30  portion of the system.  
         [0013]     Right angle turn devices  30  are known in the art and will not be described in detail here. However, and exemplary right angle turn will comprise turn bars  32  and  33 . Of the two paper paths formed by the right angle turn  30 , turn bar  33  forms an inner paper path for transporting sheet  1 . Turn bar  32  forms a longer outer paper path on which sheet  2  travels.  
         [0014]     Because sheets  1  have a shorter path through the right angle turn  30 , a lead edge of sheet  1  will be in front of a lead edge of sheet  2  downstream of the right angle turn  30 . Also, the turn bars  32  and  33  are arranged such that sheet  2  will lay on top of sheet  1  downstream of the right angle turn, thus forming a shingled arrangement. Downstream of the right angle turn  30 , further sets of roller nips  36  transport the shingled arrangement of sheets.  
         [0015]     In a feed cycle, the paper is advanced past the blade of the guillotine cutter  21  by a distance equal to the length of the cut sheet and is stopped. In a cut cycle, the blade  21  lowers to shear off the sheet of paper, and then withdraws from the paper. As soon as the blade  21  withdraws from the paper path, the next feed cycle begins. The feed and cut cycles are carried out in such an alternate fashion over the entire operation.  
         [0016]     In some web cutters, it is desirable to achieve a cutting rate of 25,000 cuts per hour or more, for example. This means that the web cutter has a feed/cut cycle of 144 ms. Typically the length of the cut sheet is 11 inches (27.94 cm). If the time to complete a cut cycle is about 34 ms, then the total time in a feed cycle is 110 ms. This means that the web must be accelerated from a stop position to a predetermined velocity and then decelerated in order to stop again within 110 ms. As guillotine cutters are required to generate pages even faster (up to 36,000 cuts per hour), precise motion control coordinated over various mechanisms must be implemented in order to eliminate web breakage and to reliably cut sheets of proper length at high rates to provide to downstream devices.  
       SUMMARY OF THE INVENTION  
       [0017]     The present invention provides a high speed input system for an inserter machine that is capable of faster, more accurate, and more reliable high speed cutting. In particular, the manner of controlling the guillotine cutter, the cutter transport, and an upstream web handler transport provide a novel way to increase throughput for mail production. The system in accordance with the present invention is used for separating individual sheets from a continuous web for creating mail pieces in an inserter machine. A first component of the system is a guillotine cutter blade arranged to cyclically lower and raise to transversely cut the web transported below the cutter blade. A cutter transport is arranged to cyclically feed and stop the web in a path below the cutter blade for cutting by the cutter blade. A web handler transport is positioned upstream of the cutter transports and provides web to the cutter transport at lower peak velocities and accelerations than are experienced by the web at the cutter transport. The web handler transport includes a loop forming arrangement to act as a buffer between the drastic motion changes of the cutter transport and the steadier movement of the web handler transport.  
         [0018]     The system is controlled to maximize throughput with a controller. The controller is programmed to control the high speed input module in accordance with a repeating cycle. The cycles have cycle times that can vary in length. The cycle time is determined as an amount of time between a first web feed request and an earliest possible time that a subsequent second web feed request can be acted upon. At the beginning of each cycle, the controller controls the system in accordance with predetermined motion control profiles for the various components.  
         [0019]     In particular, a cutter transport motion control profile initiates feeding of a document length of web after receiving the first feed request. Under this profile, the cutter transport stops after the document length of web has been fed.  
         [0020]     A cutter motion control profile causes the cutter blade to begin descending when the cutter transport has moved the web a trigger distance, less than the document length, and while the web is still moving. The trigger distance is calculated such that the cutter blade will first make contact with the web as soon as it has been halted by the cutter transport motion profile. The cutter blade is raised back to its initial position after having completed its cutting of the web. Also, the cutter transport motion control profile begins moving the web in response to a second feed request, for a subsequent cycle, as soon as the cutter blade rises above a horizontal level of the web, and not waiting until the cutter blade is at a resting position above the web.  
         [0021]     A web handler transport motion control profile is also initiated during each cycle. The web handler transport profile moves the web the document length at velocities and accelerations less than the velocities and accelerations of the cutter transport. At the end of the cycle, the web handler transport causes the web to be transported at a nominal velocity selected to maintain an appropriate amount of the web loop in the web handler. The loop expands and contracts as the downstream cutter transport stops and starts as the cutter blade cuts the web in each cycle.  
         [0022]     In a preferred embodiment, the cutter transport motion control profile is comprised of a constant acceleration for half of the document length and a constant deceleration for the other half of the document length. Similarly, it is preferred that the web handler transport motion control profile comprises steady motion at the nominal velocity in steady state operation. In a non-steady state embodiment, if no feed request is present at the end of the cycle, the web handler transport motion control profile decelerates the web at a constant deceleration until the web comes to a stop, or until a subsequent feed request is received.  
         [0023]     Preferably, the web handler transport motion control profile also includes an intercept algorithm that is employed at the beginning of each cycle. The intercept algorithm calculates the appropriate web handler transport motion control profile to accomplish a displacement of the document length within the cycle time starting at a current velocity and ending at the nominal velocity. In a further preferred embodiment, the intercept algorithm calculates the web handler transport motion control profile as a constant acceleration and a constant deceleration during the cycle.  
         [0024]     Also in the preferred embodiment, the cutter blade is coupled by a cutter arm to a rotary motor. One full rotation of the rotary motor corresponds to one complete down and up movement of the cutter blade. The cutter blade motion control profile may be comprised of a constant rotary acceleration for a first half of the rotation while the cutter blade is descending and a constant deceleration for a second half of the rotation while the cutter blade is ascending.  
         [0025]     In a further embodiment, the controller includes a start-up profile for handling the web as it is first installed into the high speed input module. The start-up profile controls the cutter transport and the web handler transport to bring a lead edge of the web to a first cut location. The web handler is further controlled to execute a nominal loop displacement. The nominal loop displacement is a function of a differential displacement between the cutter transport and the web handler transport during a portion of the cycle while the cutter transport operates at a higher velocity than the web handler transport. Thus, the appropriate quantity of loop is provided for the system to begin steady-state operation.  
         [0026]     In the preferred embodiment, the system operates on a web having a 2-up sheet configuration having sheets side-by-side on the web. To separate the side-by-side sheets, the system includes a center cutting device positioned upstream of the guillotine cutter. The center cutting device splits the side-by-side portions of the web prior to cutting by the guillotine blade.  
         [0027]     Further details of the present invention are provided in the accompanying drawings, detailed description, and claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0028]      FIG. 1  depicts the initial stages of an inserter system for use with the present invention.  
         [0029]      FIG. 2  is a preferred embodiment of an input portion of an inserter system for use with the present invention.  
         [0030]      FIGS. 3   a  and  3   b  depict a preferred arrangement of the cutter transport and the web handling transport.  
         [0031]      FIGS. 4   a ,  4   b , and  4   c  depict a view of a guillotine cutter blade cutting across a sheet of web in varying stages.  
         [0032]      FIG. 5  is a diagrammatic representation of a preferred embodiment of rotary driven cutter blade.  
         [0033]      FIG. 6  depicts a graph of preferred motion control profiles for steady state operation of an inserter input module.  
         [0034]      FIG. 7  is a graph of an intercept profile used by the web handler transport during an exemplary operation cycle. 
     
    
     DETAILED DESCRIPTION  
       [0035]     A previously filed patent application titled METHOD AND DEVICE FOR REDUCING WEB BREAKAGE IN A WEB CUTTER, U.S. patent application Ser. No. 10/431,237 (Attorney Docket F-616) includes descriptions of components related to the present invention, and that application is hereby expressly incorporated by reference in its entirety.  
         [0036]     A preferred embodiment for arrangement of the components of the high speed web input system is illustrated in  FIGS. 3   a  and  3   b . As shown in  FIGS. 3   a  and  3   b , the input system arrangement comprises a cutter transport  90  and a web handler transport  80  for moving the web  120  from an upstream source to a cutter  21 . The preferred arrangement can effectively reduce the inertial forces acting on the web paper immediately upstream from the cutter transport  90 . The reduction in inertia is achieved by disposing the web handler transport  80  upstream from the cutter transport  90 , forming a partial paper loop  180  between the cutter transport  90  and the web handler transport  80 . Furthermore, the second tractor  80  is oriented such that the inertia acting on the loop  180  can be effectively reduced.  
         [0037]     In particular, when the cutter transport  90  moves the web in a direction substantially in a horizontal plane, the web handler transport  80  is oriented such that it moves the web in a direction substantially in a vertical plane. As such, the web is pushed upward when it enters the loop  180 . As shown in  FIGS. 3   a  and  3   b  a support deck  130  is used to support the loop  180  and a paper guide  132  is used to guide the web when the loop  180  is formed. A further paper guide  133  may be used to guide the paper path on the on the opposite side of the loop  180  from guide  132 .  
         [0038]     It is preferred that the control loop  180  be small so as to reduce the inertia acting on the web. In order to achieve a small control loop  180 , both the cutter transport  90  and the web handler transport  80  are set in motion in a coordinated way. In particular, both the cutter transport  90  and the web handler transport  80  are designed to accelerate and decelerated in a related operation cycle. Because only the cutter transport  90  must stop to allow for the cutting cycle, the web handler transport  80  can accelerate and decelerate differently from the cutter transport  90 . Thus, while the cutter transport  90  operates at full acceleration and advances the web  120  as quickly as possible, the web handler transport  80  operates at a lower acceleration rate. This lower acceleration rate reduces the breakage of the web as the web paper is pulled by the web handler transport  80  from the upstream source. At the same time, because the paper at the control loop  180  is moved by the web handler transport  80  toward the cutter transport  90 , the stop-and-start motion of the cutter transport  90  does not produce as severe a pull on the paper.  
         [0039]      FIGS. 4   a - 4   c  depict the guillotine cutter  21  through a downward cutting motion, starting at a beginning position in  4   a , to a finished cut position in  4   c . Guillotine cutter blade  21  preferably has an edge that is vertically inclined at an angle above the path of web  120 . As the blade  21  is lowered ( FIG. 4   b ) the blade  21  edge comes into contact with the web  120  and cuts across its width (from right to left in  FIGS. 4   a - c ). In  FIG. 4   c , the blade has reached its bottom position, and the whole width of the web  120  has been cut. In an alternative scenario, blade  21  can be stopped at the position shown in  FIG. 4   b , and only the right half of the web  120  has been cut. This technique is used when the web  120  is comprised of side-by-side sets of sheets, and where only one of the sheets belongs to the mailpiece that is currently being processed. The other half of the web  120  can be cut when the system is ready to start processing the collection of sheets for the next mailpiece.  
         [0040]      FIG. 5  is a diagram depicting a preferred embodiment for driving the motion of the cutter blade  21 . Cutter blade  21  is linked to a rotary motor  22  by an arm (or crank)  25 . As the motor  22  makes a  360  degree rotation in the clockwise direction, the cutter blade  21  undergoes a complete down and up cutting cycle. When the arm  25  is rotated to point TDC, the blade  21  is positioned at top-dead-center above the web  120 . When the motor  22  has rotated the arm  25  to position BDC, the blade will be at bottom-dead-center of its cutting cycle.  
         [0041]     It will be understood by those skilled in the art that motor  22  may also be coupled to the crank  25  through a coupling ratio other than unity. Thus a complete  360  degree cutting cycle may actually correspond to more or less than a full rotation of a motor, or even multiple rotations. Accordingly, the term “rotary motor” in this application shall be understood to mean the motor and any corresponding coupling that results in movement of the crank  25 .  
         [0042]     Positions A-H of the rotary motor  22  in  FIG. 5  are other key positions in the cutting cycle. Position A represents the point on the rotation where the blade  21  first comes into contact with the web. Position A in  FIG. 5  would roughly correspond to the position of the blade  21  depicted in  FIG. 4   a . Position D in  FIG. 5  represents a half-cut position that corresponds to the blade  21  position in  FIG. 4   b . Rotary position E represents the position in the rotary cycle of motor  22  where the web  120  has been completely cut ( FIG. 4   c ). The blade  21  completes its downward movement at BDC in the rotary cycle, and rises back up from BDC to TDC. At position H, while rising, the blade  21  rises above the horizontal position of the web  120 . In the preferred embodiment, as will be described further below, the cutter transport  90  resumes transport of the web after point H in the rotary cutting cycle has passed.  
         [0043]      FIG. 6  depicts the motion control profiles for the cutter transport  90 , the web handler transport  80 , and the rotary motor  22  of cutter  21 . This graph shows time on the x-axis and velocity on the y-axis. Cutter transport profile  61  has a triangular shape indicating constant acceleration and deceleration for its controlled motion. In steady state operation web handler profile  62  is preferably a straight line, indicating constant velocity feeding a loop  180  that is expanded and contracted while the cutter transport  90  undergoes the accelerations of profile  61 . Blade profile  63  represents the rotary motion of the motor  22  for driving the blade  21 . As seen in this preferred embodiment, the blade profile  63  is triangular, indicating constant acceleration during the downward stroke to BDC, and decelerating a constant rate while returning back to TDC.  
         [0044]     To facilitate description of the proposed control method, this description assumes a guillotine cutter system  1  that executes an ‘Advance then Cut’ sequence triggered by a feed request  64 . A feed request  64  is a command from the system controller to provide a next sheet for cutting and processing. Feed requests  64  will typically be received by the system periodically, but there may be pauses between feed requests  64  as downstream conditions indicate that the devices there are not ready to receive more sheets. One of skill in the art will understand that the control method described herein is adaptable for a ‘Cut then Advance’ sequence triggered by a Feed Request  64 .  
         [0045]     The present invention provides for precise displacement-based motion for cutter transport  90 , blade motor  22  and web-handler transport  80  axes for a guillotine cutter system  1 . For steady state operation, i.e. where a feed request  64  is always present, both the cutter transport  90  and blade motors follow triangular velocity profiles and the web-handler  80  motor follows a constant velocity profile.  
         [0046]     If practical velocity limitations emerge for the cutter transport profile  61  or blade motion profile  63  (i.e. paper handling, scanning or motor/drive constraints), other profile types such as trapezoidal profiles can be substituted, however use of the triangular waveform minimizes accelerations for a given cut rate performance. Also, nominal web-handler motions  62  could be made more complex than constant velocity, i.e. periodic trapezoidal or sinusoidal profiles could be used. These more complex profiles may provide some incremental improvement for web control. However, constant velocity motion will significantly reduce the accelerations and forces as seen by the web and is the most straightforward motion to implement when the complexities of stopping and starting conditions are taken into consideration.  
         [0047]     In the preferred embodiment, the driving parameter that determines the cut generation rate of the system is Cycle Time as illustrated in  FIG. 6 . Cycle Time is defined as the time between an actual feed request  64  and the earliest possible time that the next feed request  64  can be acted upon. If a new feed request  64  arrives before the end of the current Cycle Time, the feed request  64  is acted upon at the end of the current cycle. The Cycle Time value can be effectively changed to any value greater than or equal to a predetermined minimum allowable cycle time.  
         [0048]     By way of example, motors and coupling ratios preferably accommodate a  36 K cut/hr performance goal (72 K sheets/hr in 2-up mode) while generating 11 inch cut sheets. 36 K cut/hr equates to a minimum allowable cycle time of 100 ms. The commanded speed ratio parameter, k, is defined as the minimum allowable cycle time divided by the desired commanded cycle time where 0&lt;=k&lt;=1. Therefore, for 11 inch cut sheets when consecutive feed requests  64  are generated periodically every 100 ms, the corresponding speed ratio is 100%. The system rate is effectively controlled by changing the value of the speed ratio parameter. Since this parameter drives the Cycle Time, it can be changed to any value between 0 and 1 (100%) per cycle but also only takes effect at cycle boundaries.  
         [0049]     Maximum accelerations and decelerations for the cutter transport  90 , blade  21  and web-handler transport  80  axes are pre-determined based on the 36 K, 11 inch sheet condition in conjunction with predetermined motion overlap displacements between cutter transport  90  and blade  21  resulting from geometrical constraints and actual servo motion tolerances (includes accuracy and settle time). These same maximum acceleration and decelerations are used when cutting longer and shorter sheets, thereby resulting in lower and higher maximum cut sheet generation rates, respectively.  
         [0050]     Motion profiles, as depicted in  FIG. 6 , for the cutter transport  90 , blade  21  and web-handler transport  80  are displacement moves and all are determined at the feed request  64  and are executed using forward integration methods. For the preferred, ‘Advance then Cut’ implementation described herein, the cutter transport  90  motor begins its motion at the feed request  64 .  
         [0051]     As seen in  FIG. 6 , the cutter transport profile  61  is a triangular velocity motion profile executing a displacement move that begins at the feed request  64 . It is computed based on the document length, speed rate, maximum cutter transport  90  acceleration and deceleration according to the following equations:  
         [0000]     (In the following equations the term “tractor” refers to the preferred embodiment of cutter transport  90 .)  
         [0000]    
       
          Atractor=Tractor acceleration=k 2 (Atractor_max)  
          Dtractor=Tractor deceleration=k 2 (Dtractor_max), where Dtractor_max is always a negative value  
             Xtractor_accel   =     Tractor   ⁢           ⁢   accel   ⁢           ⁢   displacement                 =     Ldoc     (       Atractor_max     -   Dtractor_max       +   1     )                 
 
          Xtractor_decel=Tractor decel displacement=(Ldoc−Xtractor_accel) 
 
 where: 
 
          Ldoc=the document length  
          k=the speed ratio  
          Atractor_max=the maximum tractor acceleration (predetermined)  
          Dtractor_max=the maximum tractor deceleration (predetermined)  
       
     
         [0059]     As previously mentioned, if practical considerations warrant, this cutter transport profile  61  could also be a trapezoidal profile. For this case, an additional variable must be added to the above equations to limit the maximum velocity.  
         [0060]     The blade profile  63  is a triangular velocity motion profile executing a 360-degree displacement move that begins when the cutter transport  90  has reached a pre-calculated displacement. The blade profile  63  is computed based on the speed rate, maximum blade acceleration and maximum blade deceleration according to the following equations: 
    Ablade=Blade acceleration=k 2 (Ablade_max)     Dblade=Blade deceleration=k 2 (Dblade_max), where Dblade_max is always a negative value  
             Xblade_accel   =     Blade   ⁢           ⁢   accel   ⁢           ⁢   displacement                 =     360     (       Ablade_max     -   Dblade_max       +   1     )                 
    Xblade_decel=Blade decel displacement=(360−Xblade_accel) 
 
 where: 
    Ablade_max=the maximum tractor acceleration (predetermined)     Dblade_max=the maximum tractor deceleration (predetermined)    
 
         [0066]     The blade  21  begins its motion profile  63  when the displacement of the cutter transport  90  is such that after the blade  21  has reached displacement, A (see  FIGS. 5&amp;6 ), the cutter transport  90  will have come to rest. Blade displacement, A, is the blade position from TDC where the blade just contacts the inner sheet of web  120  minus some amount for margin (includes servo settle time). The value of this cutter transport  90  displacement to begin the blade profile  63  is called Position Sense and is defined by:  
         Position   ⁢           ⁢   Sense     =     Ldoc   -     A   ⁡     (     Dtractor_max   Dblade_max     )             
 
         [0067]     The web handler profile  62  is computed based on a positional move relative to the desired position of the web-handler transport  80  at the most previous cycle boundary. The final position is the desired position of the web-handler transport  80  at the most previous cycle boundary plus the cut sheet length. The initial velocity of the displacement move is the current desired velocity and the final velocity is the nominal desired web velocity, Vweb_nom.  
         [0068]     An intercept algorithm is used to calculate the necessary motion profile  62  to accomplish this displacement in a time equal to the current value of Cycle Time using the initial and final desired velocities. Details of one possible algorithm are described in more detail below.  
         [0069]     If a feed request  64  is not present at the end of a Cycle Time (i.e. a cycle boundary), the web-handler  80  will begin an immediate deceleration equal to Dweb. If the time from the cycle boundary to the next feed request  64  is sufficiently long, the web-handler  80  will come to rest. Velocities and accelerations for the web-handler  80  are defined as follows: 
    Vweb_nom=Web-handler velocity=k(Vweb_nom_max)     Aweb=Web-handler acceleration=k 2 (Aweb_max)     Dweb=Web-handler deceleration=k 2 (Dweb_max), where Dweb_max is always a negative value 
 
 where: 
    Vweb_nom_max=(Ldoc)/(minimum allowable cycle time).     Aweb_max=the maximum web-handler acceleration (predetermined)     Dweb_max=the maximum web-handler deceleration (predetermined)    
 
         [0076]     When the web-handler  80  does decelerate to rest, the resulting deceleration displacement is equal to Xloopstop. Xloopstop is the additional displacement added to the control loop  180  between the web-handler  80  and cutter transport  90  during a stopping condition and is computed as follows:  
       Xloopstop   =         (   Vweb_nom   )     2       (       -   2     ⁢     (   Dweb   )       )           
 
         [0077]     Since the velocities and accelerations are appropriately scaled, when the web-handler  80  does go to rest due to the absence of a feed request  64 , the value of Xloopstop is a constant regardless of the value of the speed ratio, k, for any given cycle.  
         [0078]     By virtue of the displacement move being referenced to the desired position of the web-handler  80  at the last cycle boundary, the web-handler  80  will resynchronize itself at every cycle boundary, even if a feed request  64  is received during or after a deceleration to rest.  
         [0079]     The system also includes a routine for initial paper loading and startup. The blade mechanism  21  is homed such that its crankshaft  25  resides at TDC of the stroke. During the web loading all motors are deactivated for operator safety. The web  120  is installed into the cutter transport  90  with the lead edge of the web  120  upstream of the sensors  12  and  13 . Then the web  120  is installed into the web-handler  80  tractors and the web  120  is pulled tight by manually moving the web-handler  80  tractors without deforming the holes in the paper. The cover is closed and all three devices  22 ,  80 , and  90  are activated to servo in place. Next the blade  21  mechanism is homed to TDC (top dead center). Next both cutter transport  90  and web-handler  80  motors execute a displacement move together to bring the lead edge to the cut location.  
         [0080]     Next the web-handler  80  executes a displacement move equal to (Xloopnom+Xloopextra). Xloopnom is a calculated loop  180  displacement required at the start of the cutter transport profile  61  to ensure that the loop  180  size always remains a positive value during steady state operation. This displacement is calculated based on the smallest loop size condition, which occurs at the instant that the cutter transport velocity profile  61  falls below the web-handler velocity profile  62  during cutter transport  90  deceleration and is calculated as follows: 
 
 Xloopnom=Xtractor   —   accel+Xdecel−Xweb  
 
 where: 
    Xtractor_accel=the displacement of the tractors during the entire acceleration.     Xdecel=the displacement of the tractors from the beginning of the deceleration to the point at which the velocity of the tractors equals the velocity of the web-handler.     Xweb=the displacement of the web during Xaccel and Xdecel. 
 
 where:  
       Xdecel   =         2   ⁢     (   Atractor   )     ⁢     (   Xtractor_accel   )       -       (   Vweb_nom   )     2         (       -   2     ⁢     (   Dtractor   )       )           
             Xweb   =       ⁢     Vweb_nom   [             (   2   )     ⁢     (   Xtractor_accel   )       Atractor       ±                       ⁢       (         2   ⁢     (   Atractor   )     ⁢     (   Xtractor_accel   )         -   Vweb_nom     )       -   Dtractor       ]             
   
 
         [0084]     Xloopextra is a design parameter that adds margin on the initial loop  180  size to ensure that the loop  180  size never gets close to zero during operation or to generally increase loop  180  size if a reliability benefit is realized from such. For example, this value can be about ½ inch. Therefore the actual initial loop  180  size before starting a cutter transport profile  61  is (Xloopnom+Xloopextra). Once this (Xloopnom+Xloopextra) displacement move is completed, the loading sequence is complete and the cutter  21  is now ready to execute full speed operation or operation at any speed ratio, k, upon receipt of a feed request  64 . Recalling from previous discussion, in the absence of a feed request  64 , the loop  180  size will increase further by displacement, Xloopstop.  
         [0085]     The resulting total loop  180  size during a stopping condition is therefore: 
 
Xlooptotal=(Xloopstop+Xloopnom+Xloopextra) 
 
         [0086]     The following are exemplary parameters for the above equations for a preferred embodiment of the system for performing 36,000 cuts per hour:  
         [0000]     For job parameter:  
         [0000]    
       
          Ldoc=11.0 inches 
 
 Design parameters: 
 
          Atractor_max=6383 in/s 2 =+16.5 G&#39;s  
          Dtractor_max=−6383 in/s 2 =−16.5 G&#39;s  
          Aweb_max=2200 in/s2=+5.7 G&#39;s  
          Dweb_max=−2200 in/s 2 =−5.7 G&#39;s  
          Ablade_max=1,000,000 degrees/s 2    
          Dblade_max=−1,000,000 degrees/s 2    
          A=55 degrees (the position from TDC where the blade just contacts the inner sheet, minus a little for margin)  
          C=305 degrees (the position from TDC where the blade just clears the inner sheet, plus a little for margin, Normally C=360−A)  
          Xloopextra=0.50 inches 
 
 Results in the following values: 
 
          Tractor Time=0.083 s  
          Blade Time=0.038 s  
          Tractor Dwell Time=0.017 s  
          Total Cycle Time=0.100 s (36 Kcuts/hr)  
          Xloopstop=2.750 inches  
          Xloopnom=2.815 inches  
          Xlooptotal=6.065 inches (total loop size during a stoppage)  
       
     
         [0104]     As described above in connection with web handler profile  62 , an intercept algorithm is used to define the velocity of the web handler transport  80  as a function of time from an initial velocity to a final velocity over a fixed time period with the axis experiencing a fixed displacement. The following is a preferred embodiment of the intercept algorithm, although it will be understood by one of ordinary skill in the art that other intercept algorithms may be used. Given:  
         [0105]     vi=initial velocity  
         [0106]     vf=final velocity  
         [0107]     tx=time for the profile to execute  
         [0108]     dx=displacement incurred during the profile  
         [0109]     The intercept algorithm determines an acceleration that may be applied from vi to an intermediate vm and then reversed (multiplied by −1.0), and applied from vm to the given vf The intercept algorithm calculates the values for a (the acceleration) and vm without bound.  
         [0110]      FIG. 7  an exemplary solution of the preferred intercept algorithm for the web handler profile  62  where the initial velocity vi is less then the desired final velocity vf. It will be understood that such a situation would arise when web handler transport  80  has decelerated as a result of the previous cycle ending without a feed request  64  being immediately present.  
         [0111]     t1=time at which the changing velocity reaches vf the 1 st  time  
         [0112]     t2 time to accelerate from vi to vm  
         [0113]     Let d1 be the displacement from t0 to t2.  
         [0114]     Let d2 be the displacement from t2 to tx  
         [0115]     Therefore: 
 
 dx=d 1 +d 2 
 
 The expressions d1 and d2 may be expressed in terms of vm,vi,vf, and a.  
         d   ⁢           ⁢   1     =         vm   2     -     vi   2         2   ⁢   a           
         d   ⁢           ⁢   2     =     -         vf   2     -     vm   2         2   ⁢   a             
 
 So dx in terms of vm,vi,vf and a results in the equation:  
       dx   =           vm   2     -     vi   2         2   ⁢   a       -         vf   2     -     vm   2         2   ⁢   a             
 
 Solving for vm:  
           1   2     ⁢         4   ⁢   dxa     +     2   ⁢     vi   2       +     2   ⁢     vf   2             ,       -     1   2       ⁢         4   ⁢   dxa     +     2   ⁢     vi   2       +     2   ⁢     vf   2                 
 
 Solve for a . . . call this equation 1 
           2   ⁢     vm   2       -     vi   2     -     vf   2         2   ⁢   dx         
 
         [0116]     Referring to the velocity graph of  FIG. 7 , since the acceleration from vi to vm has the inverse slope (decel=accel*−1.0) of the acceleration from vm to vf, then t2−t1 must equal tx−t2, or  
         t   ⁢           ⁢   2     =         1   2     ⁢   tx     +       1   2     ⁢   t   ⁢           ⁢   1           
 
 The similar triangles gives us  
           t   ⁢           ⁢   1       vf   -   vi       =       t   ⁢           ⁢   2       vm   -   vi           
 
 Substituting t2 from the previous equation results in:  
           t   ⁢           ⁢   1       vf   -   vi       =       tx   +     t   ⁢           ⁢   1           2   ⁢           ⁢   vm     -     2   ⁢           ⁢   vi             
 
 And solve for t1 
       -       tx   ⁡     (     vf   -   vi     )             -   2     ⁢           ⁢   vm     +   vi   +   vf           
 
 Now using the equation: 
 
 vf=vi+αt 1 
 
 and substitute what we concluded about t1 previously:  
       vf   =     vi   -       a   ⁢           ⁢   tx   ⁢           ⁢     (     vf   -   vi     )             -   2     ⁢           ⁢   vm     +   vi   +   vf             
 
 and solve for α . . . call this equation 2 
       -           -   2     ⁢           ⁢   vm     +   vi   +   vf     tx         
 
         [0117]     Using, equation 1 and equation 2 here are both expressions for the acceleration derived 
 
 from different approaches . . . and they must be equal  
             2   ⁢           ⁢   vm     -   vi   -   vf     tx     =         2   ⁢           ⁢     vm   2       -     vi   2     -     vf   2         2   ⁢           ⁢   dx           
 
 So now we have an equation with one unknown . . . vm 
 
 Solving for vm:  
             4   ⁢           ⁢   dx     +     2   ⁢         4   ⁢           ⁢     dx   2       +     2   ⁢           ⁢     tx   2     ⁢     vi   2       -     4   ⁢           ⁢   tx   ⁢           ⁢   dx   ⁢           ⁢   vi     -     4   ⁢           ⁢   tx   ⁢           ⁢   dx   ⁢           ⁢   vf     +     2   ⁢           ⁢     tx   2     ⁢     vf   2                 4   ⁢           ⁢   tx       ,     
     ⁢         4   ⁢           ⁢   dx     -     2   ⁢         4   ⁢           ⁢     dx   2       +     2   ⁢           ⁢     tx   2     ⁢     vi   2       -     4   ⁢           ⁢   tx   ⁢           ⁢   dx   ⁢           ⁢   vi     -     4   ⁢           ⁢   tx   ⁢           ⁢   dx   ⁢           ⁢   vf     +     2   ⁢           ⁢     tx   2     ⁢     vf   2                 4   ⁢           ⁢   tx           
 
 Once vm is determined, use equation 2 to solve for a 
 
 Test the results produced by both roots (plus or minus 2 times the radical) . . . one will be correct. 
 
         [0118]     The following is exemplary embodiment of the intercept algorithm in computer code:  
                                                                                                                                                                                                                                                                                                       // InterceptProfile . . . accels from vi to vf in a given time and creating a       given displacement       //       // vi = initial velocity vf = final velocity tx = the profile must       reach vf from inception in tx seconds       // dx = the displacement experienced during the profile must be dx.       //       // returns:       // true/false for success/failure       // *pa = acceleration       // *pm = velocity       //       // The path accels/decels from vi to *pm and then decels/accels       ( . . . −1.0 * (*pa)) to vf. The time will be tx.       //       BOOL CInterceptProfileDlg::InterceptProfile(double vi, double vf,       double tx, double dx, double *pa, double *pv)       {                BOOL bret = FALSE;           if ((NULL ! = pa) &amp;&amp; (NULL ! = pv) &amp;&amp; (0.0 &lt; tx))           {                double y = 4*dx*dx + 2*tx*tx* (vi*vi + vf*vf) − 4*tx*dx*           (vf + vi); if (0.0 &lt;= y)           {                bret = TRUE;           double x = 2 * sqrt (y);           double vp = (4*dx + x) / (4*tx);           double ap = (2*vp−vi−vf) / tx;           double vn = (4*dx − x) / (4*tx);           double an = (2*vn−vi−vf) / tx;           double tpos = (0.0 != ap)? ((vp−vi) / ap) : 0.0;           double tneg = (0.0 != an)? ((vn−vi) / an) : 0.0;           int f = ((0.0 &lt; tpos) &amp;&amp; (tx &gt;= tpos) &amp;&amp; (0.0 != ap))?            1 : 0; // if the pos root is possible f =1                f |= ((0.0 &lt; tneg) &amp;&amp; (tx &gt;= tneg) &amp;&amp; (0.0 != an))?            2 : 0; // if the neg root is possible f |=2       if both possible f = 3 //                switch (f)           {           case 1: *pv = vp;// Positive Root (only)           *pa = ap;           break;           case 2: *pV = vn;// Negative Root (only)           *pa = an;           break;           case3:                {                // both possible . . . one correct           double dn = ((vn*vn) − (vi*vi)) / (2*an) +            ((vf*vf) − (vn*vn)) / (−2.0*an)                double dp = ((vp*vp) − (vi*vi)) / (2*ap) +            ((vf*vf) − (vp*vp)) / (−2.0*ap)                if (fabs (dx−dn) &lt; fabs (dx−dp))           {                *pv = vn; // Negative Root (best)           *pa = an;                }           else           {                *pv = vp; // Positive Root (best)           *pa = ap;                {                {           break;                default:                if ((vi == vf) &amp;&amp; (dx == (vi*tx)))           {                *pv = vi; // No Accel           *pa = 0.0;                }                else bret = FALSE; // can&#39;t solve (?)                break;                }                }                }           return bret;            }                  
 
         [0119]     Throughout this application the preferred web moving mechanisms have been described as tractors. However, it is also possible to use wheels and rollers to move the web. This is known in the industry as pinless tractors. With wheels and rollers, it is not necessary to provide sprocket holes of the web.  
         [0120]     Although the invention has been described with respect to a preferred embodiment thereof, it will be understood by those skilled in the art that the foregoing and various other changes, omissions and deviations in the form and detail thereof may be made without departing from the scope of this invention.