Abstract:
A method for operating an input sheet feeder coupled to an inserter system including the steps of providing an inserter system having a control system coupled to a sheet input station, wherein the sheet input station is coupled to a supply of continuous formed web and receiving a start command in the sheet input station to start operation of the sheet input station. The sheet input station then starts at an initial speed that is a fraction of its full operational speed and gradually increases the operational speed of the sheet input station from said initial speed to said full speed over a predetermined amount of time.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to devices for cutting sheets from a continuous web, and more particularly, to a method for initially varying the operating speed of a sheet cutter at startup.  
         BACKGROUND OF THE INVENTION  
         [0002]    Multi-station document inserting systems generally include a plurality of various stations that are configured for specific applications. Typically, such inserting systems, also known as console inserting machines, are manufactured to perform operations customized for a particular customer. Such machines are known in the art and are generally used by organizations, which produce a large volume of mailings where the content of each mail piece may vary.  
           [0003]    For instance, inserter systems are 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. Additionally, 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 and 9 series inserter systems available from Pitney Bowes Inc. of Stamford, Conn.  
           [0004]    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 mailpiece is produced. The exact configuration of each inserter system depends upon the needs of each particular customer or installation.  
           [0005]    For example, a typical inserter system includes a plurality of serially arranged stations including a sheet feeding station, a folding station, a plurality of insert feeder stations, an envelope feeder and insertion station and an output station for collecting the assembled mailpieces. As is conventional, the sheet feeder feeds one or a plurality of sheets to an accumulating station, which collects the fed sheets into a predefined collation packet. This collation is then preferably advanced to a folding station for folding the collation. Thereafter, the serially arranged insert feeder stations sequentially feed the necessary documents onto a transport deck at each insert station as the folded collation arrives at the respective station to form a precisely collated stack of documents which is transported to the envelope feeder-insert station where the stack is inserted into the envelope. The finished envelope is then conveyed to an output station for distribution into the mail stream. A typical modem inserter system also includes a control system to synchronize the operation of the overall inserter system to ensure that the mailpieces are properly assembled.  
           [0006]    One of the most important features of a modem inserter system concerns the reliability of providing a constant input of sheets into the inserter system. Since a sheet cutter is often the input module of the inserter system responsible for providing an input of sheets to the chassis of the inserter system, it is then of significant importance that the cutter provides a supply of sheets at a reliable high rate.  
           [0007]    A typical sheet cutter incorporates a sheet feeder which feeds a continuous web from either a roll or fan-folded stack into the sheet cutter. The web is driven into the sheet cutter by its sheet feeder via sprocket holes located on one or both sides of the web. In essence, there are two principal components to the force imparted on a paper web from its supply position to it&#39;s cutting position in the sheet cutter. The first are forces created by the acceleration of the web mass by the conveyor/tractor drive of the sheet cutter. The other predominant force is created by aerodynamic effects, forces generated from wind resistance against the motion of the web. When accelerations are high, the later forces can be enough to break the web at a perforation or cause the tractor pinfeed holes to tear. When high throughput (e.g., in excess of 20,000 cycles per hour) is desired, the acceleration forces on the tractor pin holes and the aerodynamically induced forces on the web become a limiting factor to the obtainable cycle rate. It is further noted that these forces on the web are significantly greater at system startup when the web comes to motion from rest. Once the feed “rhythm” is established, the “dances” in air and creates a “buffer” loop of web in the air to absorb acceleration induced shocks to the web. However, before this feed rhythm is established, the web is extremely vulnerable to breakage due to the initial startup forces of the sheet cutter as explained above.  
           [0008]    Thus, it is an object of the present invention to provide an improved sheet cutter that operates to reliably cut sheets without subjecting the web to breakage during the initial startup of the sheet cutter.  
         SUMMARY OF THE INVENTION  
         [0009]    Accordingly, the present invention relates to a method for operating an input sheet feeder coupled to an inserter system at a variable speed in which during startup of the sheet feeder it gradually increases its operational speed to its full operational speed. This method includes the steps of providing an inserter system having a control system coupled to a sheet input station, wherein the sheet input station is coupled to a supply of continuous formed web and receiving a start command in the sheet input station to start operation of the sheet input station. The sheet input station then starts at an initial speed that is a fraction of its full operational speed and gradually increases the operational speed of the sheet input station from said initial speed to said full speed over a predetermined amount of time.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The above and other objects and advantages of the present invention will become more readily apparent upon consideration of the following detailed description, taken in conjunction with accompanying drawings, in which like reference characters refer to like parts throughout the drawings and in which:  
         [0011]    [0011]FIG. 1 is a block diagram of a document inserting system in which the present invention is incorporated;  
         [0012]    [0012]FIG. 2 is a planar view of a web being fed into the cutter module of FIG. 1;  
         [0013]    FIGS.  3  is a flow chart depicting prior art steps for starting operation of the sheet cutter of FIG. 2; and  
         [0014]    [0014]FIG. 4 is a flow chart depicting the steps for starting operation of the sheet cutter of FIG. 2 in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0015]    In describing the preferred embodiment of the present invention, reference is made to the drawings, wherein there is seen in FIG. 1 a schematic of a typical document inserting system, generally designated  10 . A brief description of this typical inserting system  10  is given to set forth the operating environment for the present invention sheet feeder, generally designated  100  in FIGS. 1 and 2.  
         [0016]    In the following description, numerous paper handling stations implemented in a typically prior art inserter system  10  are set forth to provide a brief understanding of a typical inserter system. It is of course apparent to one skilled in the art that the present invention may be practiced without the specific details in regards to each of these paper-handling stations of inserter system  10 .  
         [0017]    As will be described in greater detail below, document inserter system  10  preferably includes an input station  100  that feeds paper sheets from a paper web to an accumulating station  11  that accumulates the sheets of paper in collation packets. Preferably, only a single sheet of a collation is coded (the control document), which coded information enables the control system  14  of inserter system  10  to control the processing of documents in the various stations of the mass mailing inserter system. The code can comprise a bar code, UPC code or the like.  
         [0018]    Essentially, input station  100  feeds sheets in a paper path, as indicated by arrow “a,” along what is commonly termed the “deck” of inserter system  10 . After sheets are accumulated into collations by an accumulating station  11 , the collations are folded in folding station  16  and the folded collations are then conveyed to a insert feeder station  18 . An example of such an accumulating station  11  can be found in U.S. Pat. No. 5,083,769, which is hereby incorporated by reference. It is to be appreciated that a typical inserter system  10  includes a plurality of insert feeder stations, but for clarity of illustration only a single insert feeder  18  is shown.  
         [0019]    Insert feeder station  18  is operational to convey an insert (e.g., an advertisement) from a supply tray to the main deck of inserter system  10  so as to be nested with the aforesaid sheet collation conveying along the main deck. The sheet collation, along with the nested insert(s), are next conveyed to an envelope insertion station  20  that is operative to insert the collation into an open envelope.  
         [0020]    After the envelope exits the envelope insertion station  20 , it then preferably conveys to an envelope sealer station  24  for sealing. After the envelope is sealed, it is then preferably conveyed to a postage station  26  having at least one postage meter for affixing appropriate postage to the envelope. Finally, the envelope is preferably conveyed to an output station  28  that collects the envelopes for postal distribution.  
         [0021]    As previously mentioned, inserter system  10  includes the input station  100  which causes sheets to be inputted into the inserter system  10 . Typically, the input station  100  is associated with a supply of sheets  208  (FIG. 2), which sheet supply consists of continuously coupled sheets, otherwise known of in the art as a web supply. This web supply  208  can be either a continuous spool of sheets or may be sheets formed in a fan folded format.  
         [0022]    In either event, the web is driven into input station  100 , via sprocket holes located on one or both sides of the web. It is to be appreciated, and as illustrated in FIG. 2, the input station  100  includes a web feeder component  202  and a web cutting component  204 . The web feeder component is operational to fed a web  206  from its supply  208  (e.g., via sprocket holes) into the web cutting component  204 . The web cutting component  204 , in turn, is operational to separate the web  206  into individual sheets for further processing in the inserter system  10 . As is well known in the art, this can be accomplished through either a cutting component (e.g., cutting blade) or sheet burster.  
         [0023]    In operation, and as stated above, when the web  206  is fed from the web supply  208  into the web feeder  202  of the input station  100 , there are two principal components to the force imparted on a paper web  206  from its supply position  208  to it&#39;s cutting position in the input station  100 . The first are forces created by the acceleration of the web mass by the conveyor/tractor drive of the web feeder component  202  of the input station  100 . The other predominant force is created by aerodynamic effects, forces generated from wind resistance against the motion of the web  206 . When accelerations are high, the later forces can be enough to break the web  206  at a perforation or cause the tractor pinfeed holes to tear. When high throughput (e.g., in excess of 20,000 cycles per hour) is desired, the acceleration forces on the tractor pin holes and the aerodynamically induced forces on the web  206  become a limiting factor to the obtainable cycle rate. It is further noted that these forces on the web  206  are significantly greater at system startup when the web  206  comes to motion from rest. Once the feed “rhythm” is established, the “dances” in air and creates a “buffer” loop of web  206  in the air to absorb acceleration induced shocks to the web  206 . However, before this feed rhythm is established, the web is extremely vulnerable to breakage due to the initial startup forces of the sheet cutter as explained above.  
         [0024]    In order to mitigate this likelihood of web breakage during startup of the input station  100 , and in accordance with the present invention, the input station  100  is now operative during initial startup to gradually reach its full operational speed. As mentioned above, in the prior art (and with reference to FIG. 3) when input station  100  initial receives its ON command (step  300 ) the web-feeding component  202  would then be caused to startup at its full speed (step  302 ) making the input station prone to web breakage as explained above.  
         [0025]    In accordance with the present invention, and as illustrated in the flow chart of FIG. 4, when the input station  100  now receives an ON command from the control system (step  400 ) the web feeding component  202  of the input station  100  starts at a reduced speed (step  402 ) which is a percentage of the full operational speed of the web feeding component  202 . Preferably, this percentage is around 60% of the full operational speed of the web-feeding component  204 . The web feeding component  202 , during a prescribed amount of time, gradually increases its speed from the reduced initial speed of step  402  to its full operational speed (step  404 ). Once the web feeding component  202  reaches it full speed, it maintains this speed for continued operation thereof (step  406 ).  
         [0026]    Thus an advantage of this gradual method for start-up of the input station  100  is that it will not impart the significant acceleration and aerodynamic forces on the web  206  subjecting it to breakage during initial start-up of the input station  100 . Rather, during startup of the input station  100 , reduced acceleration and aerodynamic forces are imparted on the web  206  in order to mitigate the likelihood of web breakage during this initial startup. Perferably, the initial speed of the input station is preferably 60% of its full speed but this initial speed may be prescribed by a user to be any fractional amount of its full operational speed. Further, the acceleration of the operating speed of the input station  100  can also be adjusted by a user such that the time period between the initial speed and the full speed is also controllable by a user.  
         [0027]    In summary, a sheet input station for an inserter system having a gradual startup has been described. Although the present invention has been described with emphasis on particular embodiments, it should be understood that the figures are for illustration of the exemplary embodiment of the invention and should not be taken as limitations or thought to be the only means of carrying out the invention. Further, it is contemplated that many changes and modifications may be made to the invention without departing from the scope and spirit of the invention as disclosed.