Abstract:
A method for binding together a plurality of paper sheets. The binding process comprises providing a book binding sheet coated on one side with hot-melt adhesive, orienting and securing sheets of paper that will comprise the book to be bound relative to the binding sheet, securing the leading edge of the binding sheet to the front of the book to be bound, severing the secured portion from the remaining binding sheet material, wrapping the binding severed strip around the spine and rear cover and heating the adhesive to produce a permanent bond with the edges of the spine and covers.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention provides a method and apparatus for binding a plurality of sheets together using a hot-melt adhesive, the adhesive being formed on a continuous roll of binding material. The sheet includes a resistive strip along the tail end of the roll for identifying the physical characteristics of the roll. The resistive strip is also used to indicate to the apparatus when the roll is consumed and needs to be replaced.  
           [0003]    2. Description of the Prior Art  
           [0004]    Techniques for binding sheets of material, such as paper, in a manner to form books have been widely available in the prior art. For example, U.S. Pat. Nos. 5,829,938 and 6,056,493 to Hartwig et al (the inventor of the present invention is a co-inventor on both the &#39;938 and &#39;493 patents) disclose a specific book binding apparatus using a L-shaped tape. Although the &#39;938 and &#39;493 patents disclose a useful book binding apparatus, the apparatus is relatively expensive to fabricate due to the number of mechanical components required. In addition, separate L-shaped binding tapes are utilized to bind sheets together.  
           [0005]    U.S. Pat. No. 4,898,506 to Lázár discloses a bonding system for securing a hot-melt strip material to an overlying sheet material and a grooving system for grooving the sheet material adjacent the opposite side edges of the strip material after it has been secured to the sheet. This patent is directed to a method and apparatus for producing the binding strips themselves, not a method for applying binding strips to sheets of paper. In addition, the above noted prior art patents do not disclose a technique wherein the binding material itself indicates to the processing apparatus, the physical characteristics thereof or, in the case of the Lázár patent, an indication when the roll is at the tail end.  
           [0006]    What is thus desired is to provide an improved method and apparatus for binding together a plurality of sheets and wherein the binding material roll includes means for indicating to the binding apparatus the physical characteristics of the material and when a replacement roll is required.  
         SUMMARY OF THE PRESENT INVENTION  
         [0007]    The present invention provides a method and apparatus for binding together a plurality of paper sheets. The binding process comprises providing a roll of book binding material coated on one side with hot-melt adhesive, orienting and securing sheets of paper, rear cover and spine that will comprise the book to be bound relative to the binding material, securing the leading edge of the binding material to the front of the book to be bound, severing the secured portion from the remaining binding material, wrapping the binding severed strip around the spine and rear cover and heating the adhesive to produce a permanent bond with the edges of the spine and covers. The binding material includes a strip of resistive material formed near the tail end of the roll to identify its physical characteristics to the microprocessor utilized in the apparatus. In addition to providing identification of the physical characteristics (this information is always available whenever the machine is turned on regardless of the amount of material consumed previously), the resistive strip applied to the binding material is physically wrapped around the core of the roll in such a way that when the material on the roll is consumed, the resistive strip becomes disconnected from the conductive edges of the core thus indicating to the microprocessor that the roll should be replaced to prevent partial or incomplete binding of the last document.  
           [0008]    The present invention thus provides an improved book binding apparatus that is more automated and faster than prior art book binding machines.  
         BRIEF DESCRIPTION OF THE DRAWINGS  
         [0009]    For a better understanding of the present invention as well as other objects and further features thereof, reference is made to the following description which is to be read in conjunction with the accompanying drawing therein:  
           [0010]    [0010]FIG. 1 is a simplified partial exploded perspective view of the book binding apparatus of the present invention;  
           [0011]    FIGS.  2 - 7  illustrate the steps for binding a plurality of paper sheets together to form a book; and  
           [0012]    [0012]FIG. 8 illustrates the novel binding material roll of the present invention.  
       
    
    
     DESCRIPTION OF THE INVENTION  
       [0013]    Referring now to FIGS. 1 and 2, the book binding apparatus  10  of the present invention is illustrated.  
         [0014]    Binding material roll  12  comprises a conventional continuous length binding sheet coated with hot-melt glue adhesive formed on one surface wound on spindle  13 . Roll  12  is selected to be the width of the pages to be bound together avoiding the need to be cut or trimmed along the width dimension. A tape feed roller system  14  comprising driver shaft  16  and rollers  18  advances the binding material roll  12  in discrete increments in order to position the binding material precisely along the lower edge of the front cover of the block of pages  36  to be bound. Cutter  20 , comprising leadscrew  22 , carriage, or carrier  24  for the cutter blade,and rotating cutter blade  26 , is positioned to sever a precise length from the binding material roll  12  necessary to wrap around the book spine  27 , the length of the cut strip portion being dependent on the number and thickness of the sheets presented into the binding cavity  25  for binding. Cutter  20  is advanced by rotating the lead screw  22  across the entire width of the binding material  12 , severing a binding strip  29  (FIG. 4) from the rest of the roll  12 . A paper shelf  31  is located at the bottom of binding cavily  25  and provides a flat smooth plenum surface along which the pages to be bound are accumulated and aligned prior to binding. The binding cavity  25  supports the sheets while they are accumulated prior to binding and is surrounded by perpendicular surfaces used to align the edges of the sheets as will be set forth hereinafter.  
         [0015]    The opening of binding cavity  25  is flanked on two sides by clamps  32  and  34 , the clamps securing the sheets after the edges are aligned to maintain the alignment during the binding process. Clamps  32  and  34  are adjacent the lower edge of the block of pages  36  to be bound to secure the block as well as the corners. The lower edges of clamps  32  and  34  are mounted in a way as to allow them to be rotated out of the way during the binding process without disturbing the alignment of the clamped block of pages  36 . Three heaters  38 ,  40  and  42  (FIG. 3) are positioned to heat the three adjacent surfaces to which binding strip  29  is to be applied (heater  38  is formed on the lower edge  39  of clamp  34 ). Each heater is regulated independently by a conventional microprocessor  44 , allowing heat to be applied at the appropriate time and also controlling the temperature and pressure required to apply the binding strip  29  to the front and back edges and to the spine of the block of sheets  36  during the binding process. The use of heaters to heat and melt the adhesive to bind the book pages is conventional and is not, by itself, a part of the present invention and the use of microprocessor  44  to provide the signals to control the heaters  38 ,  40  and  42 , the cutter  20  and other components are also well known and not part of the present invention.  
         [0016]    Referring to FIG. 2, the process is initiated when the pages  36  are introduced into the binding cavity  25 . These may be assembled outside the binding cavity  25  and introduced as a block of pages, the likely case if used manually to bind sheets into books. The sheets may also be introduced into the binding cavity individually until the complete set is accumulated; typically the case if apparatus  10  was integrated with a printer or copier producing sheets one at a time and delivering them to binding cavity  25 . The edges of the sheets in binding cavity  25  are aligned either manually or by means of the clamps  32  and  34 . After the complete set of sheets, including front and rear covers are assembled, the next step is to clamp the sheets together.  
         [0017]    During the clamping step, the block of sheets  36  is positioned to align with the binding material roll  12  as shown in FIG. 3. The lower edge  39  of clamp  34  is rotated out of the way and the feed rollers  14  and  18  advance the binding roll  12  to the prescribed location along the front edge, or front cover,  15  of the block of sheet  36 .  
         [0018]    With the binding roll  12  in position along the lower edge of the front of the block of sheets  36 , heater  38  is brought to bear against the binding sheet portion  27 , applying heat and pressure to secure it to the front cover  15  as shown in FIG. 4.  
         [0019]    After the leading edge of the binding sheet portion  29  is secured to the front cover  15  and while maintaining the integrity of the block pages  36 , the block  36  is moved to the right as shown in FIG. 4, in the direction of arrow  35 , drawing out a prescribed amount of sheet  29  proportional to the thickness of the block of pages while wrapping the sheet  29  around the spine portion  17  of the block  36 . At the predetermined position, knife  20 D is transported along the lateral width of the sheet  29  in the direction of arrow  80  severing it from roll  12 .  
         [0020]    The block  36  and sheet portion  29  are transported further in the direction of arrow  39  and positioned over spine heater  40  as shown in FIG. 5. Heat and pressure are then applied to the spine portion  17  of the block of sheets  36  causing the sheets to be bonded together by the liquefied hot-melt glue on sheet portion  29 . At this step, two of the three sides of block  36  are now adhered into position.  
         [0021]    With the block of sheets  36  positioned to the right of the axis of rotation of heater  40 , the lower edge  50  of clamp  32  is rotated out of the way in the direction of arrow  51  as shown in FIG. 6. Heater  40  is then rotated clockwise in the direction of arrow  53  wrapping the protruding portion of the binding strip portion  29  around the back cover  52  of the block of sheets  36  as shown in FIG. 7. Heat and pressure are again applied to secure the last portion of the strip portion  29 . All three surfaces of the binding strip  29  are secured for a period of time sufficient to insure good binding results.  
         [0022]    The bound document is then transported back to the original starting position over the paper shelf  31  (transport mechanism is not shown but is of a conventional design) in the direction of arrow  60  as shown in FIG. 2 and allowed to cool sufficiently.  
         [0023]    After cooling, the clamps  32  and  34  are moved apart in the direction of arrow  62  and the finished bound document is removed from binding cavity and the process is ready to start over.  
         [0024]    [0024]FIG. 8 illustrates a binding material roll  12  in accordance with the teachings of the present invention. Roll  12  includes a strip of resistive material  70  formed on the inner surface  72  of the roll near the tail end (the resistive strip  70  applied to the binding material is physically wrapped around the inner core  73  of the roll  12  as illustrated). Resistive strip  70  has a resistance value coded to correspond to the physical characteristics of the roll itself, i.e. the type of paper, the width of the roll, the heating levels required to melt the adhesive coating, etc. Sensors on the spindle  13  detect the resistance level and couple the information to microprocessor  44  which in turn controls the apparatus components.  
         [0025]    When the material on the roll is consumed, the resistive strip  70  becomes disconnected from the conductive edges  74  of the core  73 , exposing the conductive edges  74  on spindle  13 . This condition is detected by sensors (not shown) which then generate a signal indicating that no further binding can take place until the roll is replaced, thus preventing partial or incomplete binding of the last block of pages. Microprocessor  44 , in response to this signal, essentially turns the apparatus off. When the roll is replaced, microprocessor  44  turns the apparatus on.  
         [0026]    The present invention thus provides a new and improved book binding method that is more automated and faster than book binding apparatus currently available.  
         [0027]    While the invention has been described with reference to its preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its essential teachings.