Abstract:
An improved apparatus and method for applying labels to documents, such as mail pieces is provided. According to one aspect, a method and apparatus are provided for applying labels to documents, wherein labels are serially peeled from a liner along the width of the liner and then transported toward a document by a label transport. The labels are conveyed along the transport so that a short side of the label is the leading edge. In addition a method and apparatus are provided wherein labels are applied by removing a first label from a web, conveying the label along a label path to a staging position and then conveying the label toward a document path where the label is adhered to a document.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates of document processing devices. More specifically, the present invention relates to the field of mail processing devices including a labeler for applying labels to mail pieces.  
       BACKGROUND OF THE INVENTION  
       [0002]     In a variety of applications, when processing mail using high speed automated machinery, it is frequently desirable to apply a label to the pieces of mail. For instance, a label may be needed to cover an incorrect label if a piece requires forwarding, or if a POSTNET bar code is improperly printed, or an area on the envelope clear of printing is required. There are a variety of devices presently available for applying labels to mail pieces, however, the known devices suffer from one of several shortcomings. For instance, certain systems are limited in the speed at which the mail pieces can be conveyed when a label is applied. Therefore, the throughput of the overall mail processing system is slowed down to accommodate the labeling limitation.  
       SUMMARY OF THE INVENTION  
       [0003]     Accordingly, to overcome the limitations of the known mail processing devices, the present invention provides an improved apparatus and method for applying labels to documents, such as mail pieces. Although the present invention is particularly suited for use in processing pieces of mail, the present invention can also be applied to a variety of document processing applications. Accordingly, the term document as used herein includes any type of document, including mail pieces, including, but not limited to post cards and envelopes containing contents.  
         [0004]     According to one aspect, the present invention provides a device for applying labels to documents, comprising a transport for conveying documents along a transport path, a label peeler and a label transport. The label peeler is operable to serially peel the label from a liner, wherein the label is peeled along the width of the label. After the label is peeled from the liner, the label transport conveys the label to the document transport to apply the label to a document. The label transport conveys the label so that an edge other than the width of the label is the leading edge.  
         [0005]     According to another aspect, the present invention provides a method for applying labels to documents, comprising the steps of conveying a web of labels past a label remover to remove the labels from the web, whereby the labels are removed such that a first edge of each label is the leading edge as the labels are removed from the web. The method further comprises the step of conveying a removed label along a label path, whereby a second edge of the label is the leading edge as the label is conveyed, and the step of adhering the label to a document as the document is conveyed along a document path.  
         [0006]     In another aspect of the invention, a method for applying labels is provided, comprising the steps of providing a supply of labels on a length of web, removing a first label from the web and conveying the first label along a label path to a staging position. The label is then stopped at the staging position and subsequently advanced from the staging position toward a document path. The label is then adhered to a document as the document is conveyed along the document path.  
         [0007]     According to yet another aspect, the invention provides a method for applying labels, comprising the steps of removing a label from a web of labels, and conveying the label along a label path. The step of conveying the label comprises the step of accelerating the label to a speed that is similar to the speed that a document is conveyed along a document path. After the label is accelerated, the label is adhered to the document traveling along the document path. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The foregoing summary and the following detailed description of the preferred embodiments of the present invention will be best understood when read in conjunction with the appended drawings, in which:  
         [0009]      FIG. 1  is a side elevational view of a document processing device;  
         [0010]      FIG. 2  is a second side elevational view of the document processing device illustrated in  FIG. 1 ;  
         [0011]      FIG. 3  is an enlarged side elevation view of a label remover of the device illustrated in  FIG. 1 ;  
         [0012]      FIG. 4  is an enlarged perspective view of a label transport of the device illustrated in  FIG. 1 ;  
         [0013]      FIG. 5  is an enlarged perspective view of elements of the label transport illustrated in  FIG. 4 ;  
         [0014]      FIG. 6  is an enlarged fragmentary plan view of a portion of the device illustrated in  FIG. 1 , showing the intersection of the label transport and a document transport;  
         [0015]      FIG. 7  is a plan view of a length of web of label operable with the device illustrated in  FIG. 1 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]     Referring now to the drawings in general and to  FIGS. 1-6  specifically, a document processing apparatus is designated  10 . The apparatus  10  is operable to process mail, and is particularly suited for handling mail that has been rejected from other high-speed automated processing machines. The mail is serially fed from a stack of mail to a scanner that scans the mail to identify information about the piece of mail. For instance, the scanner may scan the piece of mail to scan the address of the recipient. After the piece of mail is scanned, a label may be applied to the piece at a labeler  20 . From the labeler  20 , the piece may be sorted into one of a number of output bins at a sorting station.  
         [0017]     Turning now to  FIGS. 1-2 , the details of the labeler  20  will be discussed in greater detail. The labeler  20  is operable to remove a label from a roll of labels and convey the label to the document path so that the label can be applied to a piece of mail being conveyed along the document path. The labeler  20  includes a feeder  30  that includes a roll  32  of labels  34  adhered to a liner  35 . A tensioner  40  maintains the liner in intension as the labels are fed to a label remover  50 , which removes the labels from the liner. From the label remover  50 , a label transport  70  conveys the removed labels to the documents path. After the labels are removed, the empty backing is wound onto a spool by a take-up system  80 .  
         [0018]     The apparatus  10  includes a system controller  120  that monitors the progress of each envelope as the envelopes are processed. The system controller tracks the sequence and location of each piece of mail, and controls various gates along the document path to control the processing of each piece of mail. The system controller receives signals from various sensors along the document path and from the various stations along the document path. The system controller controls the processing of each piece of mail in response to these signals.  
         [0000]     Feeder  
         [0019]     Referring now to  FIGS. 1-2 , the details of the feeder assembly  30  will be discussed in greater detail. The feeder  30  is configured to feed a web of labels from a roll  32 . Referring to  FIG. 8 , the web comprises a series of labels  34  that are releasably adhered to a length of backing material or liner  35 . The liner  35  may be any of a variety of materials, such as paper or plastic. In the present instance, the liner  35  is formed of clear polyester.  
         [0020]     The labeler  20  can be utilized in connection with labels of various sizes and configurations. However, the labeler is particularly suited for use with labels that meet the U.S. Postal specifications for Letter Mail Labeling Machines, sometime referred to a LMLM standards. In the present instance, the labels have a width W that is significantly larger than the height H of the labels. For instance, the labels may be approximately 4½″-6½″ wide and approximately ⅝″ high.  
         [0021]     The labels  34  may be adhered to the liner  35  so that the edges of the labels are adjacent the preceding and trailing labels. However, in the present instance, there is a gap between successive labels. Further, the labels are adhered to the liner so that the width of the labels extend across the width of the liner, as shown in  FIG. 7 . In other words, the width-wise edges W of a first label are adjacent the width-wise edges of the preceding and trailing labels. In this way, the web of labels is rolled into a roll of labels wherein the width of each label is parallel to the axis of the roll. By spooling the labels in this orientation, a spool of labels approximately 11 inches in diameter can accommodate approximately 21,000 labels, and the web need only be advanced a distance approximating the height of the labels in order to remove a label, as discussed further below.  
         [0022]     The feeder  30  comprises a shaft  37  configured to receive the roll  32  of labels. The roll  32  is mounted onto the shaft  37  so that the roll is rotated clockwise when the web of labels is pulled forwardly. An end cap or plate  38  attached to the shaft  37  retains the roll  32  on the shaft. The shaft  37  may be driven by a motor to advance a length of labels. However, as discussed further below, the take-up  90  is driven by a motor, so that the web  32  is pulled off of the roll  32  to advance the labels.  
         [0023]     As discussed further below, the web is repeatedly advanced and then stopped during operation of the labeler  20 . In addition, it is desirable to maintain the web under tension during use. However, when the web is stopped, the inertia of the moving roll will tend to continue to turn the roll even after the pulling force from the web stops. Accordingly, it is desirable to incorporate a brake to prevent the roll  32  from turning forwardly after the web is stopped. In the present instance, the brake comprises a friction belt that cooperates with a hub connected to the shaft  37  on which the roll  32  of labels is mounted. As discussed below, the tensioner  40  comprises a biasing arm  48 . Preferably, one end of the friction belt is attached to the arm  48  so that the biasing arm biases the friction belt against the hub to brake the roll  32 .  
         [0000]     Tensioner  
         [0024]     From the feeder  30 , the web of labels passes over a tensioner  40  to retain the web in tension. The tensioner  40  comprises one or more rollers that are biased to tension the web. In the present instance, the tensioner includes two upper rollers  42 ,  43 , that are biased away from two lower rollers  46 ,  47 . The web  33  of labels is threaded over the first upper roller  42 , then under the first lower roller  46 . From the first lower roller, the web extends upwardly, passing over the second upper roller  43 , which it passes over. The web then extends downwardly under the second lower roller  46  toward the label remover  50 .  
         [0025]     The two lower rollers  46 ,  47  are mounted on the vertical plate  22  so that the roller are fixed against vertical displacement. In contrast, the two upper rollers  42 ,  43  are vertically displaceable. Specifically, upper rollers  42 ,  43  are mounted onto a biasing arm  48  that is pivotably connected to the vertical plate  22 . The upper rollers  42 ,  43  are connected to a first end of the arm, and a spring  45  is connected to a second end of the arm. The spring  45  biases the first end of the arm downwardly, which in turn, biases the second end of the arm upwardly, along with the roller  42 ,  43 . In this way, the upper roller  42 ,  43  are biased upwardly, away from the lower rollers  46 ,  47 . Accordingly, slack in the web is taken up by the upper roller  42 ,  43  pivoting upwardly to maintain the web under tension.  
         [0000]     Label Remover  
         [0026]     Referring to  FIGS. 1 and 3 , the label remover  50  is operable to remove the labels  34  from the liner  35  so that the labels can be applied to documents. The label remover  50  operates by peeling the labels off of the liner. As discussed further below, the peeling operation is accomplished by passing the web  33  over a peel plate  55 , which progressively peels each label off of the liner.  
         [0027]     The label remover  50  comprises an entry roller  53  that extends between a pair of end plates  52 . Below the entry roller  53  is the peel plate  55 , which is a substantially flat plate extending between the end plate  52 . The peel plate  55  is positioned so that the plate projects toward label transport  70  at an angle so that the lower edge of the peel plate is adjacent the label transport. A hold down roller  57  is positioned adjacent the top face of the peel plate  55 , and is biased downwardly into contact to hold the web down against the peel plate.  
         [0028]     In the present instance, the label remover  50  is pivotable so that the web  33  can be more easily threaded through the label remover prior to use. Specifically, the label remover  50  comprises a shaft  51  that is mounted between two mounting brackets that are fixed in place. The end plates  52 , along with the peel plate  55  and roller  53 ,  57 , pivot about the shaft  51 .  
         [0029]     During use, it is desirable to lock the label remover in place to impede upward displacement, which could produce slack in the web adjacent the peel plate, thereby hampering the label removal. Accordingly, the label remover  50  includes a lock  60  for locking the label remover against pivotable motion. The lock may be in any of a number of configurations. In the present instance, the lock  60  is a toggle clamp having a plunger  61  that is vertically displaceable. In the retracted position, the label remover may be pivoted by lifting the peel plate upwardly, which in turn pivots the plunger downwardly. In the retracted position, the plunger is sufficiently spaced from the surface below so that the peel plate can be lifted a sufficient distance before the plunger engages the surface below. The lock  60  is locked by pivoting the toggle clamp, which in turn extends the plunger  61  downwardly. When the plunger  61  is extended, the plunger engages a surface below the lock. Since the plunger  61  engages the surface, the plunger cannot be displaced downwardly by lifting the peeler plate. In this way, the lock  60  is operable between an unlocked position in which the peel plate can be displaced relative to the label transport  70 , and a locked position in which the peel plate cannot be displaced away from the label transport.  
         [0030]     The labels  34  are removed from the liner  35  by pulling the web  33  over the lower edge of the label peeler  55 . Preferably, the lower end of the peel plate has a sharp corner forming a sharp lower edge used to peel the labels. The web  33  passes over the entry roller  53  and under the hold down roller  57 , which holds the web against the top surface of the peel plate. The web  33  then passes over the lower edge of the peel plate, and back upwardly toward rollers in the take-up section. By maintaining the web  33  in tension, the web is pulled against the sharp lower edge of the peel plate. Since the liner  35  is continuous, the liner is retained in tension around the lower edge of the peel plate  55 . However, the labels  34  are not. As the leading edge of a label  34  passes the lower edge of the peel plate  55 , the leading edge separates from the liner, rather than turning around the edge, as the liner does. As the liner  35  continues to be pulled around the lower edge of the peel plate, the label  34  progressively separates, or peels, from the liner. When the trailing edge of the label passes the lower edge of the peel plate, the label completely releases from the liner. The removed label is then entrained by the label transport  70 , as discussed further below.  
         [0031]     The label remover  50  also includes a sensor  62  for detecting the position of a label as it passes through the label remover. The sensor  62  is a reflective sensor that is operable to detect the leading and/or trailing edges of each label to determine the length of web that is to be advanced to advance a label past the lower edge of the peel plate. In addition, the label remover  50  comprises a plurality of brushes  64  that engage the web as the web passes through the label remover. The brushes  64  are operable to diffuse static electricity that may build up on the liner  35 .  
         [0032]     As described previously, in the present instance the labels are positioned on the web so that the width of the labels extends across the width of the liner  35 , as shown in  FIG. 7 . Therefore, the labels are advanced toward the lower edge of the peel plate so that the width of the label is parallel to the lower edge of the peel plate, and the leading edge of the label is a width-wise edge W that is transverse the direction of travel of the web. In other words, one of the longest edges of the label is the leading edge and it is parallel to the lower edge of the peel plate. In this way, the label is progressively peeled across the entire length of the side W, and once the leading edge of a label begins to peel, the label can be removed from the liner by advancing the web a distance equal to approximately the height H of the label. For example, in the present instance, a label can be removed by advancing the web approximately ⅝″.  
         [0000]     Take-up Assembly  
         [0033]     After the labels  34  are removed from the liner, the liner is wound into a roll by the take-up assembly  80 . The take-up assembly performs two functions. The take-up assembly winds the empty liner onto a take-up spool after the labels are removed. In addition, the take-up assembly operates to pull the liner though the labeler. In other words, the take-up assembly  80  operates as the drive control for the web, providing the driving force for the web as the web advances through the labeler.  
         [0034]     Turning first to the drive control aspect, the take-up assembly comprises a tight nip formed between two rollers  82 ,  84  that project generally horizontally. One of the rollers  82 ,  84  is a high friction roller, and the roller are biased toward one another to form a tight nip. The liner  35  extends over the top of the first take-up roller  82 , then downwardly, wrapping under the second take-up roller  84 , and finally, over the top of the take-up spool  90 .  
         [0035]     The tight nip formed by the two take-up roller  82 ,  84  is operable to frictionally engage the liner with sufficient grip to pull the liner through the tight nip. In addition, the grip at the tight nip is sufficient to overcome the load from the drag of the liner through the label remover  50  and the tensioner  40 , as well as overcoming the inertia of the roll to pull the web off of the roll.  
         [0036]     One or both of the rollers  82 ,  84  is driven by a motor  88 . In the present instance, the motor  88  is a stepper motor so that the displacement of the take-up rollers can be precisely controlled, thereby precisely controlling the displacement of the liner  35 , as discussed further below. The motor  88  rotates one or both of the take-up rollers. As the rollers  82 ,  84  turn, the rollers pull the liner through the tight nip, which in turn advances the web from the roll  32  of labels  34  on the feeder  30 . By using a pulling force from the take-up roller  82 ,  84 , the web/liner is more readily maintained in tension.  
         [0037]     The motor  88  also drives the take-up spool  90 , so that when the motor drives the rollers  82 ,  84  to pull the liner through the tight nip, the motor turns the spool to wind up the liner. In the present instance, the power transfer to the spool is controlled so that the spool rotates faster than the rollers  82 ,  84 . Turning the spool  90  faster than the take-up rollers  82  and/or  84  ensures that the liner is maintained in tension. A clutching mechanism allows the spool to rotate freely if the spool is rotated but there is no slack in the liner to wind up. As the liner  35  is pulled onto the spool, the liner is wound around the spool  90  to create a roll of empty liner. After the entire roll  32  of labels is used, the roll of liner  35  is removed from the take-up spool  90 .  
         [0000]     Label Transport  
         [0038]     As described previously, the label remover  50  is operable to serially peel labels from the web  33  so that each label is separated from the liner  35  adjacent the label transport  70 . Referring to  FIGS. 3-6 , the label transport  70  is operable to transport the removed label to the document path  110 , where the label is applied to a document.  
         [0039]     The label transport comprises a vacuum belt that is operable to apply vacuum to the label to retain the label against the belt as the label is conveyed along the label transport. As a label  34  is peeled off of the liner  35  a vacuum pulls the label up against the belt  72 . Subsequently, the belt conveys the label toward the document path.  
         [0040]     The vacuum belt  72  is a conveyor belt having a plurality of perforations. The vacuum belt rides against a manifold  77  having a plurality of ports that distribute the vacuum along the length of the label transport. The belt is entrained around the manifold so that the belt confronts the manifold along the length of the label path. Specifically, the vacuum belt  72  rides against a face of the manifold along the length of the label path. The belt may be perforated in a number of different configurations. In the present instance, the belt comprises a single row of perforation extending along the length of the belt.  
         [0041]     The vacuum belt rides against the front face of the manifold  77 , which is generally flat so that the vacuum belt can lie flat against the manifold. The manifold includes a row of ports through the front face. The row of ports are positioned so that the ports are generally aligned with the perforations in the belt when the belt is entrained about the manifold. Optionally, the front face of the manifold  77  comprises an elongated recess aligned with the row of ports. In this way, when the belt lies against the front face of the manifold, the belt and the recess form a plenum so that the vacuum from the ports is dispersed throughout the plenum along the front face of the manifold. In addition, the perforations in the belt are configured so that the perforations align with the plenum. By distributing the vacuum throughout the plenum, a generally constant vacuum is applied to the labels through the perforated belt as the belt travels along the label transport.  
         [0042]     Optionally, the label transport  70  may include a guide rail  75  for supporting the label when it falls from the peel plate. The guide rail  75  projects outwardly from the manifold and provides a generally horizontal surface along the length of the loading area  73  adjacent the peel plate. To prevent the lower edge of the label from adhering to the guide rail, the guide rail is formed of a low friction material, such as Teflon. The guide rail  75  operates as a stop or justifier so that the bottom edge of the label is positioned at a predetermined position. In addition, the guide rail can be adjusted vertically, so that the vertical position at which the label is applied to a document can be varied by adjusting the height of the guide bar  75 .  
         [0043]     The label transport  70  may be configured so that it only accommodates a single label at the time. In such a configuration, the label transport conveys the label directly from the peeler to the document transport. However, in the present instance, the label transport  70  is configured to accommodate two labels at a time, as discussed further below.  
         [0044]     The label transport  70  comprises a loading area  73  adjacent the label remover  50 . Specifically, the loading area  73  is positioned adjacent the lower edge of the peel plate. Therefore, as a label  34  separates from the liner  35 , the vacuum from the vacuum belt  72  pulls the label up against the belt.  
         [0045]     The label transport  70  also includes a staging area  74  positioned downstream from the loading area. The staging area is configured to accommodate a label while another label is being loaded onto the belt  72  at the loading area  73 . Accordingly, the staging area  73  is sufficiently spaced from the loading area to ensure that a label being loaded onto the belt  72  at the loading area does not overlap a label in the staging area  74 . In addition, the staging area is positioned adjacent the document path so that a label is positioned adjacent the document path, ready to be applied to a document on the document path when necessary. A sensor  76  in the staging area  74  is operable to detect the label as it is conveyed to the staging area. The staging sensor  76  is operable to detect the leading edge and/or the trailing edge of a label as the label enters the staging area, and when the label exits the staging area.  
         [0046]     The manifold  77  may be formed of one or more air chambers. In the present instance, the manifold includes two separate air chambers. The first air chamber is a first vacuum block that extends along the length of the label loading area  73 . The second air chamber is a second vacuum block that extends along the length of the staging area  74 . Each vacuum block includes one or more air fittings for connecting the vacuum blocks to a vacuum pump. In the present instance each vacuum block is connected to the vacuum pump via two vacuum lines.  
         [0047]     Referring to  FIGS. 4, 6 , the intersection between the document transport  110  and the label transport  70  can be seen. The document transport  110  comprises opposing rollers  102 ,  104  that convey the documents along the document path. A sensor  106  positioned downstream from the rollers  102 ,  104  is operable to detect the leading edge and/or the trailing edge of a document as the document passes the sensor. Downstream from the sensor  106  is a pivoting guide  108  at the intersection of the document transport and the label transport. The guide  108  is pivotable between a retracted position in which the guide is pulled away from the label transport and an extended position in which the guide is pivoted toward the label transport. In the extended position, the guide directs the document against the end of the label transport, so that the document intersects the label transport to contact the label on the end of the label transport. As the document is conveyed forwardly, the label on the end of the label transport is also conveyed forwardly, so that the label is progressively applied to the length of the document.  
         [0048]     If the label and the document are moving at different speeds, the label may not be properly applied to document. Accordingly, it is desirable to control the speed of the label transport and the document transport so that the label and document are moving at approximately the same speed when the two intersect. Specifically, in the present instance, the document transport conveys the documents at approximately 75 inches per second. As mentioned above, at the staging area  74 , the label is stationary. From this stationary position, the label transport accelerates the label so that the label is conveyed at approximately 75 inches per second when the label intersects the document path.  
         [0000]     Method of Use  
         [0049]     Configured as discussed above, the device operates as follows. In one mode of operation, a label is applied to every document. In a second mode of operation, the labels are selectively applied. For instance, the document may be scanned to determine if a bar code is readable. If the bar code is not readable, the document is tagged as requiring a label, and a label is applied at the labeling station  20 .  
         [0050]     Prior to use, a roll of labels  32  is mounted onto the shaft  37  of the feeder  30  and the end cap  38  is the mounted onto the shaft to retain the roll on the shaft. The web  33  is fed through the tensioner  40 , label remover  50  and take-up section  80 , and then attached to the take-up spool  90 . When feeding the web  33  through the take-up section  80 , the web cannot be manually fed between the tight nip roller  82 ,  84 . Instead, the web is placed into the nip of the rollers  82 ,  84  and the hand wheel  83  is turned by hand, which rotates the nip rollers, thereby pulling the web through the rollers.  
         [0051]     The labels  34  are fed as follows. The web is advanced by the motor  88  that drives the tight nip, which pulls the web. The sensor  62  in the label remover  50  monitor the labels as the web is advanced. Specifically, the sensor  62  is a reflective sensor that monitor the leading edge of a label in the label remover and the trailing edge. After the sensor detects the trailing edge of the label, the sensor sends a signal to the controller  120  indicating that the trailing edge has passed. In response to the signals received from the sensor, the controller controls the operation of the motor  88  so that the web continues to advance until the trailing edge passes the sensor. The web is then advanced a further amount based on the gap between adjacent labels.  
         [0052]     As the web is advanced, the label adjacent the bottom edge of the peel plate is peeled from the web, so that the label is released from the liner. As the label is released, the lower edge of the label falls onto the guide rail  75  and the vacuum of the vacuum belt  72  pulls the front face of the label (i.e. the non-adhesive side) up against the belt. At this point, the label is stationary up against the belt in the loading section  73  of the label transport. The label transport then conveys the label forwardly to the staging area  74 , where the label is stopped. After the label stops in the staging area, the web  33  is advanced to peel the next label from the liner so that it falls to the loading section of the label transport. Now the belt holds two labels. The first label is in the loading section, the second label is in the staging section. The staging sensor  76  detects the leading edge of the label as the label enters the staging section, and sends a signal to the controller  120  indicative of the leading edge of the label. Based on the signals received from the sensor  76 , the controller controls the operation of the label transport to advance the label so that the leading edge is positioned at a pre-determined location.  
         [0053]     To apply a label to a document, the label is conveyed from the staging area toward the document path. The operation of the document transport and the label transport are controlled to apply the label at a predetermined position along the length of the document. Specifically, sensors along the length of the document path monitor the position of the document as the document is conveyed along the document path. As the document approaches the intersection with the label transport, the controller receives a signal from sensor  106  indicating the presence of the leading edge of the document. The controller  120  then controls the pivoting guide  108  so that the guide pivots toward the label transport  70 . In addition, in response to signals that the controller receives regarding the position of the document, the controller controls the label transport, starting the label at the appropriate time so that the leading edge of the label contacts the document as the document passes through the intersection with the label transport.  
         [0054]     By controlling the timing of the start of the label transport, the position that the label is applied along the length of the envelope can be controlled. Specifically, the sooner the label transport is started relative to the time the leading edge of the document passes a particular position, the closer the label will be applied to the leading edge of the document. Conversely, delaying the start of the label transport will cause the label to be applied along the document farther from the leading edge of the document. In this way, by controlling the start of the label transport relative to the position of the leading edge of the document, the position that the label is applied along the length of a document may be controlled without varying the speed of the document being conveyed along the document path.  
         [0055]     In certain situations, it may be desirable to purge the labels from the label transport without transporting the labels to the document transport. For instance, at the end of a batch of mail, if there are labels on the label transport, the labels should be disposed of. Otherwise, the adhesive may dry out so that they do not adhere to the documents when the next batch of mail is processed. Accordingly, in the present instance, the label transport is operable in a reverse direction so that the labels are discharged into a receptacle  78  adjacent the loading area  74 .  
         [0056]     It will be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. It should therefore be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention as set forth in the claims.