Abstract:
A binder strip cassette including a binder strip roll disposed within a cassette housing, with the roll including a multiplicity of elongated binder strips, each of said binder strips including a flexible substrate and an adhesive disposed on the substrate. The roll further includes a flexible elongated carrier supporting said binder strips, with said binder strips being disposed along a length of the elongated carrier in an end-to-end arrangement; with said elongated carrier and said binder strips being wound to form a binder strip roll. The binder strip roll is rotatably mounted within the housing. The cassette is further provided with a drive apparatus for unwinding the binder strip roll to provide an unwound portion of the binder strip roll together with a separating apparatus disposed within the cassette housing for separating the binder strips from the elongated carrier of the unwound portion of the binder strip roll to produce a separated binder strip. The unwinding by the drive apparatus causes the separated binder strip to be at least partially ejected through a binder strip eject opening in the cassette housing.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates generally to the field of bookbinding and, in particular, to container for dispensing adhesive binder strips.  
         [0003]     2. Description of the Related Art  
         [0004]     Binder strips having a paper substrate covered with a heat activated adhesive layer have become increasing popular for use in bookbinding. This method of bookbinding has become a low cost alternative to commercial bookbinding. An exemplary binder strip is disclosed in USPNo. 4,496,617, the contents of which are incorporated herein by reference. An exemplary desktop binding machine for binding books using the binder strips is disclosed in USPNo. 5,052,873, the contents of which are also incorporated herewith by reference. Referring to the drawings,  FIG. 1  shows a binder strip  20  disposed adjacent the insertion point  30 A of a conventional binding machine  30 . A user first places a stack of sheets  32  to be bound in an upper opening of the machine. Controls  30 B are then activated to commence the binding process.  
         [0005]     The binding machine operates to sense the thickness of the stack  32  and indicates on a machine display  30 C the width of binder strip  20  to be used.  
         [0006]     Typically, three widths can be used, including wide, medium and narrow. The binder strip includes a flexible substrate  20 A having a length that corresponds to the length of the edge of the stack  32  to be bound and a width somewhat greater than the thickness of the stack. A layer of heat-activated adhesive is disposed on one side of the substrate, including a low viscosity, low tack central adhesive band  20 C and a pair of high viscosity, high tack outer adhesive bands  20 B.  
         [0007]     Once the user has selected a binder strip  20  of appropriate width, the user manually inserts the strip  20  into the strip loading port  30 A of the machine. The end of the strip, which is positioned with the adhesive side up, is sensed by the machine and is drawing into the machine using an internal strip handling mechanism. The machine then operates to apply the strip to the edge of the stack to be bound. The strip is essentially folded around the edge of the stack, with heat and pressure being applied so as to activate the adhesive. Once the adhesive has cooled to some extent, the bound book is removed from the binding machine so that additional books can be bound.  
         [0008]      FIG. 2  depicts a partial end view of the bound stack  32 . As can be seen, the binder strip substrate  20 A is folded around the bound edge of the stack. The high tack, high viscosity outer adhesive bands  20 B function to secure the strip to the front and back sheets of the stack. These sheets, which function as the front and rear covers, can be made of heavy paper or the like. The central low viscosity adhesive band  20 C functions to secure the individual sheets of the stack by flowing up slightly between the sheets during the binding process.  
         [0009]     Although manual feeding of the binder strip permits books to be bound at a fairly high rate, there is a need for an apparatus that can feed binder strips to binding machines at a higher rate. Such apparatus preferably could be used with a wide variety of binder machines and binder strips. Further, such apparatus would preferably be capable of storing a relatively large number of binder strips and be capable of fabrication using materials that are recyclable. As will be apparent from a reading of the following Detailed Description of the Invention together with the drawings, the present invention provides the above-described features.  
       SUMMARY OF THE INVENTION  
       [0010]     A binder strip cassette comprising a roll of binder strips rotatably mounted within a cassette housing is disclosed. The roll includes a multiplicity of elongated binder strips, with each of the binder strips including a flexible substrate and an adhesive disposed on the substrate. The roll further includes a flexible elongated carrier supporting the binder strips, with the binder strips being disposed along a length of the elongated carrier in an end-to-end arrangement.  
         [0011]     The cassette further includes a drive apparatus for unwinding the binder strip roll to provide an unwound portion of the binder strip roll. A separating apparatus is provided which is disposed within the cassette housing for separating the binder strips from the elongated carrier of the unwound portion of the binder strip roll to produce a separated binder strip, with the unwinding by the drive apparatus causing the separated binder strip to be at least partially ejected through a binder strip eject opening in the cassette housing. In one embodiment of the subject invention, the cassette includes apparatus for maintaining the unwound carrier and binder strips in contact with one another thereby reducing or eliminating the need for adhesives to secure the carrier and strips together.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  depicts prior art binding machine receiving a thermal adhesive binder strip.  
         [0013]      FIG. 2  is a partial elevational side view of the edge of a stack of sheets bound by the  FIG. 1  binding machine using the  FIG. 1  binder strip.  
         [0014]      FIG. 3  is an elevational view side view of a binder strip cassette in accordance with a first embodiment of the present invention.  
         [0015]      FIG. 4  is a perspective view of the subject binder strip cassette showing the outer case.  
         [0016]      FIG. 5  is a perspective view of the internal frame member of the subject binder strip cassette.  
         [0017]      FIG. 6  is an end view of the internal frame member of the subject binder strip cassette.  
         [0018]      FIG. 7  is an end view of the subject binder strip cassette.  
         [0019]      FIGS. 8A-8C  are schematic representations of a binder strip ejection sequence for the subject binder strip cassette.  
         [0020]      FIG. 9  is a side elevational view of the take up roller of the subject binder strip cassette.  
         [0021]      FIGS. 10A-10C  are end views of the subject binder strip cassette showing the encoding present on the elongated carrier being displayed through an opening in the cassette housing.  
         [0022]      FIGS. 11A-11D  show various exemplary encoding indicia which can be used in connection with the subject binder strip cassette.  
         [0023]      FIG. 12  is a table showing the manner in which the indicia of  FIGS. 11A-11D  are decoded.  
         [0024]      FIGS. 13, 14  and  15  depict the subject binder strip cassette in combination with a prior art binding machine.  
         [0025]      FIGS. 16A-16B  show one type of cassette holding apparatus for use in connection with the subject binder strip cassette.  
         [0026]      FIGS. 17A-17B  show a second type of cassette holding apparatus for use in connection with the subject binder strip cassette.  
         [0027]      FIG. 18  is a cut away perspective view of a binder strip cassette in accordance with the second embodiment of the subject invention.  
         [0028]      FIG. 19  is a cut away elevational view of the second embodiment binder strip cassette.  
         [0029]      FIG. 20  is an enlarged potion of  FIG. 19  showing details of the primary guide of the cassette for guiding the binder strips and carrier.  
         [0030]      FIG. 21  is a schematic representation comparing certain aspects of the first and second embodiments of the subject binder strip cassette.  
         [0031]      FIGS. 22 and 23  are respective perspective and elevational views of the primary guide of the second embodiment binder strip cassette.  
         [0032]      FIG. 24  is a cut away view showing a binder strip being ejected from the second embodiment binder strip cassette into a binding machine.  
         [0033]      FIGS. 25A and 25B  are cut away views of the second embodiment binder strip cassettes illustrating the pivoting of the binder strip primary guide as the binder strip roll is depleted.  
         [0034]      FIGS. 26 and 27  depict further examples of encoding patterns that can be incorporated into the elongated carriers.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0035]     Referring again to the drawings, a first embodiment of the present invention, a binder strip cassette, is shown in  FIGS. 3, 4  and  5 . The cassette, generally designated by the numeral  36 , includes a roll  38  of individual adhesive binder strips  42  supported on a continuous elongated carrier  40 . A very low tack adhesive is used to secure the substrate side of the strip to the carrier, with the strip being disposed on the inner surface of the carrier. One suitable adhesive for this application is type HL2268, from H. B. Fuller of St. Paul, Minn. In that the continuous carrier  40  is disposed on the exterior side of the roll, the carrier functions to hold the roll together. Roll  38  is rotatably mounted on a main roller  44 , which is preferably made of heavy paper tubing. As shown in  FIG. 5 , the cassette includes an inner frame member  52 , preferably manufactured from a single sheet of corrugated cardboard or other semi-rigid recyclable material. The inner frame member  52  is disposed within an outer case  50  as can be seen in  FIG. 4 . Case  50  is also preferably made of recyclable material, with a rigid paper such as 30-point chip board, being found suitable for the present application. Frame member  52  is preferably fabricated from a single sheet of material that is folded in two places to provide a pair of facing side members  52 H and  52 I as shown in  FIGS. 5 and 6  which are interconnected by web members  52 B and  52 C.  FIG. 6  does not show the main roller  44  or the binder strip roll  38  for purposes of clarity.  
         [0036]     A pair of openings (not designated) are formed in the opposite spaced-apart side members  52 H and  52 I of the frame member  52  to receive the main roller  44  of the binder strip roll  38 . The spacing between the facing side members  52 H and  52 I of the frame member is equal to the width of the web members  52 B and  52 C of the frame and is also substantially equal to the width of the binder strip roll  38 . The roll  38  thus contributes to the overall rigidity of the cassette until the roll is essentially completed. As will be described, another roller takes up the elongated carrier  40  so that the wound up carrier also contributes to the rigidity, particularly when the binder strip roll  38  is substantially depleted. Note that the thickness of the cassette is adjusted to conform to the width of the binder strips and associated elongated carrier  40 . The roller  44  is captured by the opposing inner surfaces of the outer case  50 . An unwound portion  38 A of the binder strip roll is guided to be proximate a binder strip ejection opening  50 A formed in the outer case  50  by way of a rotatably mounted idler roller  46 . Roller  46 , which is also preferably made of heavy paper tubing, is rotatably mounted within opposing openings (not designated) in the frame member  52  and is also secured in place or captured by the inner surfaces of outer case  50 .  
         [0037]     The unrolled segment  38 A of the binder strip roll  38  extends to edge  521  ( FIGS. 3 and 6 ) of web member  52 B of the frame member. The elongated carrier  40  is then drawn around edge  52 J and along the surface of the web member  52 B. A pair of extensions  52 A in the frame member  52  define a passage way between outer case  50  and web member  52 B through which carrier  40  passes. The action of carrier  40  making a relatively sharp turn over edge  523  and down the face of web member  52 B causes the carrier  40  and the leading edge of the individual binder strip  42 A to begin to separate as shown in  FIG. 3  thereby starting the binder strip ejection sequence.  FIGS. 8A-8C  illustrate the complete ejection sequence, with the outer case  50  and frame member  52  not depicted. The somewhat rigid binder strip  42 A will tend to continue moving in a linear path through the strip ejection opening  50 A in cover  50  as can best be seen in  FIG. 3  and in  FIG. 4 .  
         [0038]     The underlying elongated carrier  40  is drawn through an opening  52 K in the frame member intermediate web members  52 B and  52 C to a driven take up roller  48 . The elongated carrier  40  is wound around take up roller  48 , with roller  48  being rotatably driven through an access opening formed in cover  50  as shown in  FIG. 4 . Roller  48  is preferably made of heavy paper tubing and includes a pair on opposing cutouts  48 A that can be used to key the roller to an external drive mechanism. In that roller  48  is not captured on both sides by outer case  50 , roller  48  includes a center section  48 B of exterior paper tubing to slightly increase the exterior diameter of the roller as shown in  FIG. 9 . The center section  48 B has a diameter greater than the access opening in frame member  52  so that roller  48  will be captured between frame members  52 H and  52 I of the frame. Idler roller  46  can be identical to roller  48 , including the presence of the non-functional cutouts, so as to reduce fabrication costs.  
         [0039]     Referring to  FIG. 8A , the binder strip  42 A is shown approximately one-half way through the ejection sequence. Idler roller  46  functions to position segment  38 A relative to edge  523  to ensure that the underlying elongated carrier  40  will be forced to make the above-described sharp turn. Preferably, a guide member  50 D ( FIG. 3 ) is formed in outer case  50 , which is positioned adjacent eject opening  50 A and intermediate the two facing sides  52 H and  52 I of the frame member. Guide member  50 D functions to control, to some extent, the direction which the binder strip  42 A takes exiting the cassette  36 .  
         [0040]     During the binder strip ejection sequence shown in  FIGS. 8A-8C , the binder strip is being fed into the binding machine at a controlled rate. The state of the binder strip ejection sequence can be monitored by the binding machine  30  using encoded indicia present on elongated carrier  40 . Preferably, the encoded indicia are sensed by sensors disposed within a cassette holding apparatus to be described, with the sensor outputs being forwarded to the binding machine. The processing of the sensed indicia can be divided, as desired, between a controller present in the cassette holding apparatus and the controller of the binding machine  30 . The encoded indicia can be printed on or punched though selected locations on the carrier  40  since the position of the carrier correlates very well with the actual position of the binder strip  42 A during ejection. Preferably, the encoded indicia is positioned on the face of the elongated carrier positioned adjacent the binder strip. By way of example, as can be seen in  FIG. 8A , indicia  54  is located on the surface of carrier  40  which is contacting the binder strip  42 A.  
         [0041]     As the strip continues in the ejection sequence, the indicia will eventually pass over edge  52 J and down across web member  52 B where the indicia is viewable through opening  50 B ( FIG. 7 ). In one instance, when an optical sensor on the binding machine detects the presence of the indicia through opening  50 B, the binder strip is essentially at the point where the strip is being separated from the carrier  40 . At that point, the conventional binding machine  30  strip loading mechanism is free to complete loading of the strip by drawing the strip into the binding machine. Further, the drive to take up roller  48  can be stopped so that no further binder strip feeding takes place while the binder is completing a binding operation. In this example, the there would be encoded indicia  54  for every binder strip on the binder strip roll  38 , as will be further described in connection with  FIGS. 11A-11D .  
         [0042]     Encoded indicia can also be used to indicate that the binder strip roll  38  has almost been used up. In that case, the indicia would be placed on the carrier  40  near the end of the roll. Indicia performing differing functions can be distinguished from one another based upon the lateral location of the indicia on the carrier  40 . In that event, two separate laterally spaced optical sensors A and B that are disposed external to the cassette on a cassette holding apparatus are used. By way of example,  FIG. 10A  shows a cassette  36  where the binder strip  42 A is at the point of being released from the carrier  40  as also shown and described in connection with  FIG. 8C . Indicia  54 A on one side of carrier  40  is shown in opening  50 A indicating the strip is at the release point.  FIG. 10B  shows another state of the binder strip roll  381  where indicia  54 A again indicates that a binder strip  42 A is being released. In addition, a second indicia  54 B, laterally spaced from indicia  54 A, is used to indicate that the roll is about completed, with only a few strips remaining. Indicia  54 B is detected with the second sensor. Finally.  FIG. 10C  shows the roll when empty, with the first sensor detecting indicia  54 A again indicating that the strip is being releases and with the second sensor detecting indicia  54 C that the strip being released is the last strip on the roll. Indicia  54 C is longer than indicia  54 B so that the second sensor is able to determine that the indicia is indicating an end of roll rather than a near end of roll. A fourth condition not depicted exits when no indicia is present in opening  50 A thereby indicating the a strip is in the middle of a feeding sequence.  
         [0043]     Alternatively, indicia may be printed in more complex patterns similar to conventional bar codes. With a higher information density, the code may change throughout the roll  38  to indicate the number of strips remaining on the roll. Encoded indicia in the form of simple bar codes could also be used to identify the type of binder strip present in the cassette. A number of types of bind can be done with thermal binder strips, including conventional strip-bind, perfectback binding and padding. In addition, there may be variations with special strip finishes and for binding specialized page stocks. Each bind type may require a different binder strip type that would be detected by the binding machine for proper operation. Additionally, indicia could identify the binder strip length, which will vary, for example, from 11 inches for standard letter size or 297 mm for standard A4 size. Further, the indicia could be used to identify the width, color or other characteristics of the binder strip.  
         [0044]     Another possible application for the indicia is shown in  FIG. 26 . In this design, alternating low and high reflectivity marks having a uniform spacing L are printed along the length of the carrier  40 . There is n number of marks for each binder strip  42 . Alternatively, the carrier could be punched to produce a similar result. A controller can detect the rate at which the marks pass by opening  50 B of the cassette and adjust the speed of the motor as needed. This allows for velocity control without need for an additional tachometer system.  
         [0045]     In yet another implementation, a repeating bar code may be printed or punched on carrier  40  as shown in  FIG. 27 . Because the bar code contains elements repeated with constant dimensions, the rate of the strip can be detected, as in the  FIG. 26  implementation. In addition, other information can be readily encoded as desired using conventional bar coding techniques. The  FIG. 27  implementation shows an exemplary pattern based on a constant module dimension M. Light bar  108 A and dark bar  108 B are both one module dimension M wide. Dark bar  108 C is two module dimensions M wide and dark bar  108 D is three module dimensions M wide. In this example, the bar  108 D, which is three module dimensions M wide, serves as a divider between identical patterns R which are repeated three times ( 3 R). Each of the patterns R is fourteen module dimensions M in length. The remainder of each of the repeating patterns encodes the desired detailed information and is comprised of an arrangement of dark bars that are one ( 108 B) and two ( 108 C) modules wide.  
         [0046]     Certain other information regarding binder strip types can also be provided on the outer case  50 . Printed encoded indicia can be applied to the case. Further, outer case  50  could include a selectable collapsible segment, such as segment  50 C as shown in  FIG. 4 . That portion of the frame member  52  underlying segment  50 C is provided with a notch  52 E as shown in  FIG. 5 . This permits segment  50 C to be selectively formed in the case  50 . If, for example, A4 size binder strips are located in the cassette  36 , the region of case  50  overlying notch  50 C can pressed inward to form an indentation which can be sensed by the binding machine using a sensing switch or the like. If, for example, 11-inch size binder strips are in the cassette, no notch is formed in the case  50 . Parallel cuts can be formed in case  50  over notch  52 E to facilitate this process.  
         [0047]      FIG. 11A  shows of segment  38 A of the binder strip roll  38 . As previously described, the individual binder strips  42  are positioned along the length of the elongated carrier  40 , with the substrate of the strip contacting the carrier. Thus, the thermal adhesives on the strips are facing toward the center of the binder strip roll  38 . A typical roll may contain 100 or more binder strips  42 , this being a large number of strips relative to the overall size of the subject binder strip cassette  36 . This number can be increased significantly while maintaining a cassette size compatible with desktop binding machines. It is preferred that the strips be spaced a distance apart, such as distance X shown in  FIG. 11A . Among other things, it has been found that when the strips and carrier are wound in roll form, the strips and carrier have a tendency to form wrinkles during the manufacturing process and over time. This is due to relatively thick combination of carrier and strip thickness that resists being wound around a relatively small radius of curvature. To avoid such wrinkling, which can mar the appearance of the bound book, the spacing between the strips functions to provide a form of relief, so that the strips can move slightly relative to the overlying carrier. It has been found that a spacing X on the individual strips should be at least 0.040 inches.  
         [0048]     Typically, the binder strips are manufactured as a single long strip and then cut to the individual lengths. This can result in the production of debris that needs to be removed. Preferably, the adhesive securing the strips  42  to the carrier  40  is not present in the regions near the ends of the strip adjacent spacing X so that the debris can be easily removed. This region Y where adhesive is absent from the leading edge of the binder strip is typically 0.06 to 0.25 inches in length. A similar region lacking adhesive is disposed at the trailing edge of the binder strip for the same purpose of facilitating debris removal. However, it is preferable, that the adhesive between the binder strips  42  and carrier  40  be absent in the region along length Z along the trailing end of the binder strip for reasons other than debris removal. This is because, when the strip is driven in the direction indicated by arrow  56  over edge  52 J ( FIGS. 3 and 6 ), as the strip begins to separate from the carrier  40 , the strip extending out of the cassette will be captured by the strip transfer mechanism of the associated binding machine  30  and pulled into the machine. At this point, the binder strip drive function provided by carrier  40  is no longer needed to eject the strip from the cassette. Thus, the adhesive is no longer needed to secure the strip to the carrier. The binder strip will then be essentially free of the carrier  40 , so that the binder strip feed mechanism of the binding machine can continue to pull the strip out of the cassette at a rate somewhat greater than the rate at which the carrier  40  is driven to eject the strip from the cassette. This reduces the degree to which the binder strip feed mechanism of the binder machine  30  needs to be synchronized with the drive to the take up roller  48 . If an adhesive were present in region Z and if the binder strip feed mechanism were to take up the strip faster than it was being fed by the take up roller, the strip feed mechanism would advance the carrier at a rate faster than roller  48  could take up the carrier  40 . This would most likely cause the cassette mechanism to malfunction. Preferably, region Z, the region adjacent the trailing end of the strip, be free on adhesive. Region Z preferably comprises at least 20% of the total length of the binder strip.  
         [0049]     As previously described, encoded indicia  54  can be used to provide various information regarding the state of the subject binder strip cassette including the type of binder strip present in the cassette, the amount of binder strips remaining in the cassette and the location of the binder strips during feeding of the strips into the binding machine. One approach is to use a pair of optical sensors A and B, shown schematically in  FIGS. 11B through 11D , that are disposed within a cassette holding apparatus to be described. The sensors A and B are positioned along the path  56  taken by the elongated carrier  40  as the carrier passes by opening  50 B of the cassette, and on opposite sides of the center axis of the carrier. Referring to  FIG. 11B , the depicted indicia  54 A on only one side of the path will be sensed by sensor A when that indicia passes by the sensor. There is an indicia  54 A at this location for each of the binder strips  42  on the roll. There is no corresponding indicia on the other side of the axis, so that sensor B senses nothing when sensor A detects indicia  54 A. These conditions indicate that the feeding of a binder strip into the binding machine is sufficiently completed such that the drive to the drive cassette take up roller  48  is to be stopped. This is also shown in the table of  FIG. 12 . When neither indicia being detected, the strip is in a strip feeding position as also shown in  FIG. 12 .  
         [0050]      FIG. 11C  shows exemplary indicia indicating the cassette is running low, with indicia  54 A being repeated as in  FIG. 11B  and with an additional indicia  54 B being added. This pair of indicia is positioned as shown for the last few strips on the roll. Detection of this condition, also shown in the table of  FIG. 12 , can be used to cause a warning indication to be shown on the display  30 C of the binding machine ( FIG. 1 ) notifying the user that the cassette is almost empty. Indicia  54 A of  FIG. 11C  further functions as a stop feed indication as previously described in connection with  FIG. 11A . Finally,  FIG. 11D , shows the indicia  54 A and  54 C indicating the last strip of the roll. Indicia  54 C begins at the same location relative to the last strip as does indicia  54 B of  FIG. 11C  and continues along the full length of the last binder strip and a substantial distance past the last strip. Indicia  54 A terminates at the usual location thereby indicating that the strip feed has been completed. After a small additional drive, indicia  54 A is not longer detected. Detection of this condition where sensor B detects indicia  54 C and sensor A detects nothing can be used to display a further message on display  30 C to the user, indicating that the cassette is empty. This condition is also shown in the table of  FIG. 12 .  
         [0051]     The above-described indicia and the information provided by such indicia are intended to be exemplary only. Conventional bar codes and other more sophisticated encoding techniques could also be used to provide a greater range of information useful in the binding process. By way of example, coding could be used to uniquely identify each strip of a roll so if a cassette is removed for some reason, such as to permit another cassette to be used, the replaced cassette can be readily recognized and the remaining number of binder strips displayed.  
         [0052]      FIG. 14  depicts an exemplary cassette holding apparatus  58  for receiving the subject cassette  36  and for interfacing the cassette with a prior art binding machine  30 .  FIG. 13  shows the orientation of the cassette  36  relative to binding machine achieved by the holding apparatus  58 , with the holding apparatus itself not being depicted. The binder strip ejection opening  50 A of the cassette is positioned opposite the binder strip input opening  30 A of the binding machine.  FIG. 15  shows a cassette  36  inserted in the cassette holding apparatus  58 , with the holding apparatus being positioned relative to the binding machine  30  for carrying out a binding operation.  FIGS. 16A and 16B  are cutaway views of the cassette holding apparatus  58  showing details of the apparatus construction. An electrical interface  70  is provided between the holding apparatus  58  and the binding machine  30 . An existing binding machine interface connector, used for controlling a conventional binder strip printer, can be readily adapted for this purpose. Among other things, the interface  70  can be used to provide power to the holding apparatus  58  and to provide control signal paths between the holding apparatus and the binding machine. By way of example, interface  70  could carry information to be displayed by the binding machine based upon the indicia  54  indicating the cassette  36  is near empty.  
         [0053]     The holding apparatus  58  includes a drive motor  72  which drives the cassette take up roller  48  through drive pulleys  74  and  76  and drive belt  78 . The previously described optical sensors A and B are positioned so that they are disposed opposite opening  50 B and can sense the presence or absence of the indicia on the elongated carrier  40 . Each sensor includes an optical transmitter for illuminating the carrier  40  and an optical detector for detecting the reflected light, with the reflective light magnitude being indicative of the presence or absence of an indicia. Only sensor A is depicted for sensing indicia on one side of the carrier, with sensor B being positioned for sensing indicia on another side of the carrier and with sensor B being offset from sensor A as illustrated schematically in  FIGS. 11B through 11D .  
         [0054]     Operation of the drive motor  72  is controlled by a suitably programmed micro-controller  64 , primarily in response to the outputs of sensors A and B and control signals from the binding machine indicating that a binder strip is needed. The implementation of the micro-controller is straightforward and will not be described so as not to obscure the description of the invention in unnecessary detail. Basically, when the binding machine has started up or has completed a binding operation and is ready for a further binding operation, the binding machine  30  will send a command to the cassette holding apparatus  58  by way of interface  70  that a binder strip of a certain width is needed. If the cassette  36  contains a binder strip of incorrect width, the holding apparatus  58  will signal the binding machine that another cassette must be loaded in the holding apparatus. Assuming that cassette type is proper, micro-controller  64  can signal motor  72  to proceed to load a binder strip  42 A into the binding machine. As can be seen in  FIG. 16B , a binder strip is fed through the strip opening  50 A of the cassette, with the strip being separated from the carrier  40  in the process. As also shown in  FIG. 16B , the strip  42 A exiting the cassette will pass through a strip exit port  68  of the holding apparatus into the strip input opening  30 A of the binding machine. As the strip is being fed into the binding machine, the indicia  54  associated with the strip being loaded will pass by opening  50 B so that the indicia can be sensed by sensors A and B. When sensor A senses an indicia  54 A such as shown in  FIGS. 11B through 11C , the associated binder strip is essentially free of the underlying elongated carrier  40  so that micro-controller  64  can command the drive motor  74  to halt. The binder strip loading mechanism of the binding machine will have sensed the presence of the binder strip and will draw the remainder of the strip into the binding machine. Once a binding operation is completed, the binding machine can then request a further binder strip. In the event that the cassette does not utilize encoding, optical sensors  62 A and  62 B can be used to detect the presence and absence of a binder strip disposed in the strip exit port  68  of the cassette holding apparatus. Although this approach is not preferred, these optical sensors, together with the sensors located within the binding machine itself, will provide sufficient information to permit the micro-controller  64  to control the operation of the drive motor  74 .  
         [0055]      FIGS. 17A and 17B  show an alternative arrangement for the cassette holding apparatus which provides a further alternative to encoding the carrier  40  or strip  42  itself. A roller  80  is provided which is positioned to engage the elongated carrier  40  as the carrier passes by opening  50 B. The roller  80  is biased against the carrier  40  by a spring mechanism (not depicted) so that linear movement of the carrier translates to rotational movement of the roller. Roller  80 , in turn, drives a conventional optical encoder  84  by way of a belt  82 . By using a stepper motor or servomotor for the drive, the rotational speed of drive motor  72  is determined. Comparing the output of the encoder  84  to the speed of the drive motor indicates the diameter of the take-up roll  48  in the cassette. Given that the thickness of the carrier  40  is known, the diameter of the take-up roller indicates the length of the carrier  40  that has been driven thereby providing sufficient information to ascertain the number of binder strips  42  remaining in the cassette. This information is processed by micro-controller  64  and forwarded to the binding machine for display and other possible action.  
         [0056]     A second embodiment of the subject binder strip cassette  36  is shown in  FIGS. 18 and 19 . One advantage of this embodiment over the first embodiment is that the need for an adhesive to secure the binder strips  42  to the elongated carrier  40  is reduced or eliminated altogether. The cassette includes a pivoting primary guide  88  which, as will be described in greater detail, functions to deflect the normal path of the carrier  40  and binder strips  42  so as to slightly force the binder strip  42  in the process of being unwound against the overlying carrier  40 . This force will tend to maintain the carrier  40  in contact with the overlying binder strips  42  in the region between the point where the carrier  40  and strips  42  leave the roll  38  and where the separated strips  42 A exit the cassette. Given the slight degree of tackiness of the carrier  40 , this action is sufficient to substantially reduce or eliminate the need for an adhesive to secure the strips  42  to the carrier  40 .  
         [0057]      FIG. 21  is a schematic representation of the path taken by carrier/strip in the first embodiment cassette ( FIG. 3 ) and the second embodiment cassette ( FIGS. 18 and 19 ). The primary guide  88  is not shown in  FIG. 21 . As previously described, binder strip roll  38  includes an elongated carrier  40  which supports the individual binder strips  42 . The roll  38  is formed so that the carrier  40  is disposed on the exterior of the roll. Thus, carrier  40  functions to secure the strips  42  in place when the strips are in roll form. When the roll is unwound, this compression force applied by the carrier  40  is no longer present. The carrier  40  and strips  42  of the first embodiment cassette will follow a path indicated by line  94  between a point C at binder strip roll  38  and point D at the idler roller  46 , so that line  94  forms a tangent line with respect to the outer circumference of each of these elements. As a strip  42  comes off the roll  38 , there is a tendency for the leading edge of the strip to separate from the carrier  40 , especially if there is no adhesive present at this leading edge. The pivoting primary guide  88  of the second embodiment prevents this separation by causing the path taken by the carrier/binder strips to change from line  94  to line  98 . The magnitude in the change in paths is somewhat exaggerated for purposes of illustration. The force applied to the binder strips  42  against the carrier  40  as a result of this path change functions to maintain the carrier in contact with the strips  42  as desired. As will be explained, this force can be well controlled and tends to be substantially independent of the amount of binder strips remaining on roll  38 .  
         [0058]     Referring again to  FIGS. 18 and 19 , primary guide  88  can be seen, pivotally mounted on pivot mount  86 . As can be seen in  FIGS. 22 and 23 , pivot mount  86  is basically a paper tube much like idler roller  46  of the first embodiment cassette. Mount  86  is secured in corresponding openings in frame member  52  so that the mount can rotate in the openings. As was the case of idler roller  46 , outer case  50  extends over the frame openings and thus captures the mount  86  in place. Primary guide  88  is secured to the periphery of mount  86  by an adhesive  102  as can be seen in  FIG. 23 . Primary guide  88  includes an elongated main member  88 A and a bent member  88 B. Both members  88 A and  88 B are made of recyclable materials such as cardboard. A thin contact member  88 C made, for example, from a sheet of polyester plastic, is secured to the end of bent member  88 B.  
         [0059]      FIG. 20  is an expanded view of the region of the binder strip roll  38  of  FIG. 19  where the roll is unwound. As can be seen, the outer edge of the thin contact member  88 C is disposed near the point where the binder strips  42  and overlying carrier  40  separate from the roll  38 . The bent member  88 B of the primary guide  88  is captured between the wound portion of the roll  38  and a short segment of the unwound portion of the roll. The force applied by the unrolled portion gently forces the bent portion  88 B and the thin plastic contact member  88 C against the smooth surface of the carrier  40  still wound on the roll. The unwound portion of the roll passes over the outer surface  100  of the bent member  88 B ( FIG. 22 ) and of main member  88 A of the primary guide  88  thereby directing the unwound portion along the non-linear path  98  shown in  FIG. 21 . The thin contact member  88 C insures that the primary guide  88  does not catch on the ends of the binder strips  42  passing over the primary guide. This action causes the binder strips  42  passing over surface  100  to be forced against the overlying carrier  40  thereby permitting the carrier to carry out the desired function of transporting the binder strips out of the cassette as shown in  FIG. 24 . Note that  FIG. 24  also shows the cassette  36  positioned adjacent a binding machine  30  (the cassette holding apparatus  58  is not shown) feeding a strip into a pair of pinch rollers  90 A,  90 B of the binding machine. The pinch rollers function to draw the binder strip  42 A into the binding machine.  
         [0060]     The geometry of the primary guide  88  and the location of the pivot mount  86  relative to the binder strip roll  38  will vary depending upon various factors, including the desired amount of non-linearity of the path  98  ( FIG. 21 ). If the non-linearity is too great, the resultant friction will cause the drive force applied to the take up roller  48  to be excessive. The geometry should also be selected to ensure that the contact member  88 C can engage the roll  38  even when the roll is substantially completely unwound. This is illustrated in  FIGS. 25A and 25B . In  FIG. 25A , the roll  38  is substantially full, with contact member  88 C contacting the roll as shown. In  FIG. 25B , the roll is substantially depleted thereby causing the captured primary guide  88  to pivot about the center of pivot mount  86  in the direction shown by arrow  104  so that the contact member  88 C continues to engage the roll.  
         [0061]     Thus, various embodiments of a binder strip cassette have been disclosed. Although these embodiments have been described in some detail, it is to be understood that various changes can be made by those skilled in the art without departing from the spirit and scope of the present invention as defined by the appended claims.