Abstract:
The present invention is directed to a post print finishing device that incorporates a spiral binder module into the post print handling and finishing functions. In one exemplary embodiment of the invention, the binder module binds sheets together by inserting a metal piece that serves as the binder and then bends the metal so as to function as a spiral binder. An accumulator module is included to stack the sheets, present the sheets to the binder for binding and then discharges the bound stack to an output bin.

Description:
FIELD OF THE INVENTION 
     The present invention is directed to a post print finishing device in which a spiral binding is used to bind a printed documented. 
     BACKGROUND OF THE INVENTION 
     Current devices and methods for printing and binding media sheets involve printing the desired document on a plurality of media sheets, assembling the media sheets into a stack, and separately stapling, clamping, gluing and/or sewing the stack. In addition to imaging material used to print the document, each of these binding methods requires separate binding materials, increasing the cost and complexity of binding. Techniques for binding media sheets using imaging material are known in the art. These techniques generally involve applying imaging material such as toner to defined binding regions on multiple sheets, assembling the media sheets into a stack, and reactivating the imaging material, causing the media sheets to adhere to one another. 
     In addition, certain binding applications are prepared so that the spine of the binding is done in a loose manner that allows the stack to be opened to a flat position. Typically, spiral bound stacks are desirable to achieve this result. However, heretofore there has been no spiral binder device for use in the post print finishing stage of binding a stack of sheets with a desirable spiral binder. 
     Accordingly, what is needed is a post print finishing device that can perform spiral binding on a stack of sheets. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a post print finishing device that incorporates a spiral binder into the post print handling and finishing functions. In one exemplary embodiment of the invention, the finishing device includes an accumulator module and a binder module. The binder module binds sheets together utilizing a metal piece that serves as the binder and bending the metal so as to function as a spiral binder. The accumulator module stacks the sheets, presents the sheets to the binder for binding and then discharges the bound stack to the output bin. An automated method of binding the stack with a spiral binding is also disclosed. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a printer and attached stacker illustrating one type of document printing and finishing system in which the invention may be implemented. 
     FIG. 2 is a side elevation view of a modular stacker constructed according to one embodiment of the invention showing the flipper, paper path, accumulator and binder modules. 
     FIGS. 3-10 are side elevation views showing the routing of media sheets through the stacker of FIG.  2 . FIG. 3 shows a sheet routed to the upper/single sheet output bin. FIGS. 4-7 show a sheet routed to the stack of sheets in the accumulator in preparation for binding. FIGS. 8-10 show the stack routed to the binder, bound and then discharged to the lower/stacker output bin. 
     FIG. 11 is a detailed perspective view of an embodiment of the binder module according to the present invention. 
     FIG. 12 illustrates the operation of the spiral binder in accordance with the present invention. 
     FIG. 13 illustrates an embodiment of placement of the wire that serves as the spiral binder within a sheet stack in accordance with the present invention. 
     FIGS. 14 a  and  14   b  illustrate embodiments of the operation of achieving a spiral binder in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention will be described with reference to the printer  10  and attached stacker  12  shown in FIG.  1 . The invention may be implemented in any document production system in which it is necessary or desirable to use an inline spiral binder. Printer  10  and stacker  12 , therefore, represent generally any suitable printing device (e.g., printers, copiers, and multi-function peripherals) and associated post print finishing device in which an inline spiral binder is used to bind a printed document. 
     Referring to FIG. 1, printer  10  and stacker  12  together make up a document production system designated generally by reference number  14 . Printed sheets are output by printer  10  to stacker  12  where they are routed to an upper/loose sheet output bin  16  or to a lower/stacker output bin  18 . Unbound sheets are collected face up in loose sheet bin  16 . Bound documents are collected face down in stacker bin  18 . 
     A stacker  12  constructed according to one embodiment of the invention will now be described with reference to FIG.  2 . FIG. 2 is a side elevation view looking into stacker  12  showing the flipper module  20 , paper path module  22 , accumulator module  24  and binder module  26 . Each module is mounted to a frame  28 . Frame  28 , which forms the main body or “skeleton” of stacker  12 , is made from sheet metal or other suitable structurally stable materials. A power supply  30  and controller  32  are mounted to the lower portion of frame  28 . Power supply  30  and controller  32  are electrically connected to the operative components of modules  20 ,  22 ,  24  and  26 . Controller  32  contains the electronic circuitry and programming necessary to control and coordinate various functions of the components in stacker  12 . The details of the circuitry and programming of controller  32  are not particularly important to the invention as long as the controller design is sufficient to direct the desired functions as described below. 
     The modular design of stacker  12  shown in FIG. 2 is adapted from the Hewlett-Packard Company model C8085A stapler/stacker. Each module  20 ,  22 ,  24  and  26  is operatively coupled to but otherwise independent of the adjacent module. In the stacker of the present invention, the stapler module used in the C8085A stapler/stacker is replaced with binder module  26  and controller  32  is modified accordingly to control the operation of an inline spiral binder rather than a stapler. 
     For sheets that will be stacked, bound and output to bin  18 , flipper  20  makes the leading edge of each sheet output by printer  10  the trailing edge for routing to paper path  22  and accumulator  24 . Flipping the sheets in this manner from face up to face down is necessary to properly stack the sheets in accumulator  24  prior to binding. Paper path  22  moves each sheet face down to accumulator  24  where the sheets are collected, registered, moved to binder  26  (when binding is desired) and then output to bin  18  (bound or unbound). Binder  26  performs the inline spiral binding of the sheets collected in accumulator  24  to bind the sheets together along a common edge. 
     The operation of flipper  20 , paper path  22 , accumulator  24  and binder  26  will now be described in more detail with reference to FIGS. 3-10. FIG. 3 shows a sheet routed to loose sheet bin  16 . FIGS. 4-7 show a sheet routed to accumulator  24  in preparation for binding. FIGS. 8-10 show the stack routed to binder  26 , bound and then ejected to stacker bin  18 . 
     Referring to FIG. 3, a sheet of paper or other print media  34  is output by printer  10  to stacker  12  through printer output rollers  35  and received into flipper  20  through flipper receiving port  37 . As flipper entry sensor  36  detects sheet  34  entering flipper  20 , flipper entry rollers  38  and flipper tray rollers  40  are driven forward as indicated by arrows  42  to move sheet  34  toward bin  16 . For sheets routed to loose sheet bin  16  through flipper discharge port  39 , rollers  38  and  40  are continually driven forward until sheet  34  reaches bin  16 . In the embodiment shown in the Figures, flipper entry rollers  38  and flipper out rollers  44  share the same drive roller  46 . Drive roller  46  is movable up or down to engage an opposing idler roller as necessary to move sheet  34  along one of two desired paper paths, as best seen by comparing FIGS. 3 and 4. 
     Referring now to FIG. 4, for sheets routed to accumulator  24 , flipper entry and tray rollers  38  and  40  are driven forward until just after the trailing edge of sheet  34  clears flipper entry rollers  38 , as detected by flipper middle sensor  48 , such that the trailing edge of sheet  34  clears directional guide  50 . Then, drive roller  46  is moved down to flipper out roller  44  and reversed along with flipper tray rollers  40  to route sheet  34  toward paper path  22  through flipper routing port  41  and paper path receiving port  53 . Paper path rollers  52  move sheet  34  through paper path  22  down to accumulator  24 . Flipper exit sensor  54  detects when sheet  34  has cleared the flipper module  20 . Paper path exit sensor  56  detects when sheet  34  has cleared the paper path module  22  through paper path discharge port  55 . Exit sensors  54  and  56  are used to control paper path rollers  52 . When paper path exit sensor  56  detects that sheet  34  is leaving the paper path module  22 , then paper path rollers  52  are stopped unless another sheet has cleared the flipper module  20  as detected by flipper exit sensor  54 . 
     Referring to FIGS. 5-7, sheet  34  is guided down from accumulator receiving port  59  through accumulator  24  to accumulator entry rollers  58  and on to accumulator eject rollers  60 . An accumulator entry sensor  62  is positioned immediately upstream from entry rollers  58 . As the trailing edge of sheet  34  passes through entry rollers  58 , as detected by entry sensor  62 , eject rollers  60  move the top sheet  34  back on to stack  64  in accumulator holding tray  66 , as best seen by comparing FIGS. 5,  6  and  7 . In the embodiment shown in the Figures, eject rollers  60  are configured as a pair of variably spaced rollers that are selectively driven as necessary to move top sheet  34  or stack  64 . As shown in FIGS. 5 and 6, eject rollers  60  are spaced apart or “open”to receive top sheet  34 . Then, the rollers come together and the top roller is driven counter-clockwise to move top sheet  34  on to stack  64 , as shown in FIG.  7 . Eject rollers  60  are driven together, as shown in FIGS. 8 and 10, counter-clockwise to move stack  64  into binder  26  (FIG. 8) or clockwise to move stack  64  into lower output bin  18  (FIG.  10 ). Although not shown, at the same time each sheet  34  is routed to holding tray  66 , sheet  34  is aligned with the other sheets in stack  66 . 
     A binding operation will now be described with reference to FIGS. 8-14. Referring to FIG. 8, once all the sheets in the document are accumulated in stack  64 , eject rollers  60  draw stack  64  back slightly from registration wall  68 , registration wall  68  is moved up and eject rollers  60  are reversed to move the edge of stack  64  into binder  26  through accumulator binding port  63 . Retainer  70  is then lowered against stack  64  to hold stack  64  in position during binding. 
     Referring now also to FIG. 11, binder  26  includes mounting brackets  72 , reversible motor  74  (not shown in FIG. 11) and press  76 . Press  76  includes base or platen  78 , carriage  80 , top support plate  82 , lead screw  84  and gear  86 . Motor  74  is operatively connected to carriage  80  through gear  86  and lead screw  84 . Carriage  80  moves alternately toward and away from platen  78  along guide posts  90  at the urging of motor  74 . 
     Platen  78  and carriage  80 , which also serves as a binder platen, form an opening immediately adjacent to accumulator holding tray  66 . Preferably, holding tray  66  and base  78  and carriage  80 , which also serves as a platen, are aligned at substantially the same angle to allow stack  64  to move easily into the opening between platens  78  and  80 . Once the edge of stack  64  is positioned in binder  26 , motor  74  is energized to close press  76  by driving carriage  80  against stack  64  and platen  78 , as shown in FIG.  9 . Pressure is thereby applied to the stack  64  and the binding operation is performed. Motor  74  is then reversed to open press  76  by driving carriage  80  away from stack  64  and platen  78 . Press  76  is raised off the now bound stack  64 , ejector rollers  60  are reversed again to route the bound stack  64  through accumulator discharge port  61  to stacker bin  18 , and registration wall  68  is raised in preparation for stacking the next print job, as shown in FIG.  10 . 
     FIGS. 12-14 illustrate an exemplary embodiment of the spiral binder  26  and its method of mechanical and automated operation in accordance with the present invention. Spiral binder includes a wire dispenser  102  to dispense a wire element  104  that serves as the spiral binding element. A wire cutter  106  is utilized to cut wire element  104  to a selected length that is long enough to provide a suitable spiral binder for stack  64 . Alternatively, the wire element  104  can be precut to a desired length so that the cutting step may be omitted. Wire dispenser  102  draws wire element  104  using either hooks or a magnetic catch. Other wire transport systems are also contemplated. 
     Spiral binder  26  further includes a plurality of bottom wire benders  108  and a plurality of top wire benders  110 . Each wire bender  108  and  110  includes a hole punch portion  113  and  112 , respectively, which, when urged together, punch a hole through stack  64  where the wire element is to be inserted. The hole punches  112  and  113  are removed from the stack  64  after the holes  122  are formed and moved sufficiently laterally away from the holes so that wire element  104  can be inserted into holes  122  without interference. The dashed lines show the alignment of hole punches  112  and  113  in performing the hole punch step and how wire element  104  is aligned for insertion into holes  122 . Alternatively, the holes in the media sheets may be pre-punched, thus allowing the hole punch step to be omitted. 
     Each top wire bender  110  further includes a wire bending cam  114 , which pivots about an axis and includes a rolling surface  115  that engages the wire while pivoting so as to cause the wire element to curve about itself. Each bottom wire bender  108  includes a bending anvil  116 , which pivots about an axis so as to engage the bottom portion of the wire element and bend it in a generally curved manner to meet the tips of the bent top wire portion. The method of bending wire element  104  is not limited to the use of cams  114  and anvils  116 , but can also be performed by mechanical fingers that hook the ends  118  and bend the wire in a spiral fashion. What is important is that the mechanism for bending wire  104  operates to provide a uniform spiral shape as well as close the ends sufficiently so as to prevent the sheets in the stack from coming loose. 
     During the binding step, also known as the bending step, cams  114  are rotated by a mechanical device such as a directly coupled drive shaft that rotates, a camshaft, hydraulic or piston drive, or pulleys. Anvils  116  are rotated via a press or a mechanical device such as a direct drive shaft, camshaft, hydraulic or piston drive, or pulleys. 
     After the holes are punched, and as illustrated in FIGS. 13,  14   a  and  14   b , platens  78  and  80  press towards stack  64  to hold it in place and to cause wire element  104  to guide through holes  122 . Wire element  104  is inserted sufficiently so that top wire portions  118  can engage and be bent by cams  114  and bottom wire portions  120  can engage and be bent by anvils  116 . Wire benders  108  and  110  can be moved relative to the inserted wire element to facilitate cams  114  and anvils  116  properly engaging wire portions  118  and  120 , respectively. Alternatively, only the top or bottom wire portions need be bent, instead of both. In such an operation, the wire portion being bent must be closed sufficiently close to the opposite portion so that the sheets within the stack  64  cannot come loose. 
     Once the wire is in place, cams  114  and anvils  116  are rotated by their drive mechanisms to cause top wire portion  118  and bottom wire portion  120  to close together forming a circular or spiral binding. Cams  114  and anvils  116  move about their axis from a first position as shown in FIG. 14 a  to a second position as shown in FIG. 14 b . Cams  114  can pivot 360 degrees (see arrow in FIG. 12) to complete the bending of wire portion  118 . After completion of the spiral binding step, the bound stack  64  is ejected via ejector rollers  60  to stacker bin  18 . 
     It is to be understood that the above-referenced arrangements are only illustrative of the application for the principles of the present invention. Numerous modifications and alternative arrangements can be devised without departing from the spirit and scope of the present invention while the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiments(s) of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications can be made without departing from the principles and concepts of the invention as set forth in the claims.