Abstract:
A multi-row punch die for punching pages permits a single die to accommodate a plurality of lines of pins. The multi-row punch die reduces the need for multiple punch dies. This allows for quick engagement and disengagement of rows of punch pins being used to punch the pages. The multi-row punch die preferably floats pins not being used out of the way from contact with pages being punched, or allows for their removal.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to double-sided punch die which permits a single die to accommodate two or more lines of pins for different sized punch hole patterns, each to put holes in stacks of pages. 
       BACKGROUND OF THE INVENTION 
       [0002]    Paper punches for punching sheets for loose leaf, perforated or mechanically (spiral, metal or plastic, double loop or twin wire binding and comb binding) bound books are well known in the art. Since mechanically bound books or other stacks of sheets of any material, such as paper, metal or synthetic materials, come in a variety of sizes and require a large variety of binding elements, hole sizes, shapes and pitches, some method for accommodating two permutations with a single punch die was sought. The solution is a punch design which accepts two or more punch patterns, rows of set pins, which fit into and are engaged by the punch ram mechanism of the punch machine. Each of the punch patterns would accommodate a single line of punches (commonly called pins) to punch a stack of sheets, such as book pages or other stacked sheets with holes of the proper size and shape at the proper pitch and distance from the edge to accept the mechanical binding element being used. So another die is required for each permutation. The die is an expensive part and it must withstand substantial force and must maintain precision hole punching of the paper stack. Dies for a variety of jobs therefore represent a significant capital investment; they also require space for storage. 
         [0003]    In the past there were dies made where one could engage or disengage an individual punch pin from the row of pins by loosening a screw above the pin within the pin bar retainer or by pulling a rod above the pin there by allowing the pin to float and preventing it from punching the paper when the pin bar pushes the other pins through the paper and into a female plate located in the base. The preferred embodiment allows for the quick engagement and disengagement of an entire row of pins at once without the time and expense of making an engage/disengage mechanism for each pin, saving money and change over time as well. 
       OBJECTS OF THE INVENTION 
       [0004]    It is therefore an object of the present invention to provide a single die to accommodate two or more lines of pins. 
         [0005]    It is also an object of the present invention to provide a die which reduces the need for multiple punch dies. 
         [0006]    It is a further object of the present invention to provide for quick engagement and disengagement of a row of punch pins. 
         [0007]    It is yet another object to provide a punch die which swings and floats pins not being used out of the way from contact with pages being punched. 
         [0008]    Other objects which become apparent from the following description of the present invention. 
       SUMMARY OF THE INVENTION 
       [0009]    A typical punch die has a heavy steel base with a side slot to accept a stack of book pages or other sheets of any material, and locate them with a stop member to locate the pages or other kind of sheets relative to the stripper plate above, so the edge of the sheets is at the proper distance from the center of the line of holes through which the pins will emerge. The pin retaining bar above the base is engaged by the punch ram when the die is inserted in the punch. This bar is guided over the stripper plate such that all of the pins are in registration with the line of holes. The pins are retained in the pin retaining bar by a pin bar cover which is removable to permit exchange or sharpening of the pins as they wear. The stripper often guides the pins into their respective holes. 
         [0010]    The double-sided punch die of this invention permits a single die to accommodate two lines of pins, each with particular pin size and shape, pitch, and distance from the sheet&#39;s spine edge. Thus the number of separate dies to accommodate a given set of permutations can be reduced by 50% or more through the use of this invention. Great cost savings can therefore be obtained since a single double-sided die or other multi-row die would be substantially less costly than two single dies because major subassemblies with minor modifications are now used for two or more different book designs. Storage is also reduced since a double-sided die requires no more space than a prior art single die. 
         [0011]    In the preferred embodiment, a half-width pin bar cover is used with the double-sided die of this invention. This would cover only one line of pins. It would be placed over the heads of the pins to be used in a particular run prior to insertion in the punch, but the unused pins would not have to be removed. In operation, the unused pins would just float harmlessly upward as their cutting ends impact the paper stacks, since there is no cover above them to keep them pushing down through the paper during the downward excursion of the pin retaining bar while the covered set of pins are actually punching holes in the paper stack. 
         [0012]    To switch patterns in the preferred embodiment one does the following. Remove the die from the machine, switch the pin bar cover screwed over one row of pins to the other side. Then put the die into the punch the other way. The original paper entrance slot is now the exit slot and visa versa. 
         [0013]    It is possible to make a multi-row punch with more than two rows in the die. This would save more money and eliminate the need to turn the die around. One method is to just cover the pins with the pin bar cover of the row in use and stop the paper with the correct distance of the row and the spine edge of the paper or synthetic sheets to be punched. 
         [0014]    In an alternate embodiment, a pin locking rod is used to lock the pins in the desired row of the pin retaining bar by sliding the rod through a hole centered on each row of the bar and through transverse holes in each of the pins. 
         [0015]    In yet another variation on the use of a locking rod, the rod rests on the top surface of the pin head instead of going through a transverse hole in each pin. 
         [0016]    While, in general, the rows in a multi-row die have different configurations of pins and/or pitch, two or more rows can be made identical to increase the longevity of the die before a row of pins would need sharpening or replacement. 
         [0017]    Therefore, a multi-row punch die for punching a stack of sheets includes in general: 
         [0018]    a) a female member for accepting a stack of sheets to be punched to form a row of holes of a specific configuration and pitch; 
         [0019]    b) the female member has at least two rows of holes, whereby the holes in one row may differ in configuration and pitch from holes in the other respective rows; 
         [0020]    c) a pin retaining bar has two or more rows of holes, in registration with corresponding holes in said female member, for accepting pins, and 
         [0021]    d) a pin row selection means for insuring that pins in only one selected row of holes in the retaining bar are enabled to enter the holes in the corresponding row of the female member so as to punch holes in the stack of sheets. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    The present invention can best be understood in connection with the accompanying drawings. It is noted that the invention is not limited to the precise embodiments shown in drawings, in which: 
           [0023]      FIG. 1  is a perspective view of a prior art single-sided punch die with the pin retaining bar moved out of the base to show the pins and the line of holes in the stripper plate. 
           [0024]      FIG. 2  is a perspective view of a double-sided multi-row punch die of this invention with the pin retaining bar pulled away from the base to show the two parallel lines of pins as well as the two parallel lines of holes in the stripper plate. 
           [0025]      FIG. 3  is a top view detail of a portion of a pin retaining bar of the preferred embodiment showing the half-width pin bar cover covering the selected row of pins used to punch a selected row of holes in a stack of sheets being punched. 
           [0026]      FIG. 4  is an end view crossection view of the pin retaining bar of  FIG. 3  illustrating the floating position of the unused pins and the alignment with book page stacks. 
           [0027]      FIG. 5  is a top view detail of an alternate embodiment for a pin retaining bar showing a narrow pin bar cover covering the center row of a three row punch. 
           [0028]      FIG. 6  is a perspective view of a further alternate embodiment for a three row pin retaining bar using a locking rod to select a row of pins for punching holes. 
           [0029]      FIG. 7  is a perspective view of an alternate embodiment for a pin with rectangular shank and a transverse hole, for use in the embodiment of  FIG. 6 . 
           [0030]      FIG. 8  is a side crossectional detail of a pin retaining bar with a locking rod securing a row of pins with transverse holes. 
           [0031]      FIG. 9  is a side crossectional detail similar to  FIG. 8  showing a detail of an alternate embodiment with a locking rod resting on top of a row of pins being secured. 
           [0032]      FIG. 10  is a perspective view of a pin with a flat top which may be used with the embodiment of  FIG. 9 . 
           [0033]      FIG. 11  is a perspective view of an alternate type pin with a concave recess on top which is also compatible with the embodiment of  FIG. 9 . 
           [0034]      FIG. 12  is a perspective view of a punch pin with a round side notch. 
           [0035]      FIG. 13  is an end view detail with locking rod and pin retaining bar in crossection showing the locking fit of the punch pin of  FIG. 12 . 
           [0036]      FIG. 14  is a perspective view of a punch pin with a v-shaped side notch. 
           [0037]      FIG. 15  is an end view detail with locking rod and pin retaining bar in crossection showing the locking fit of the punch pin of  FIG. 14 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0038]      FIG. 1  shows a prior art die  1  with female base  2  and pin retaining bar  3  with pin cover  9 . When assembled, a single row of pins  8  remain in a single row of holes  7  in stripper plate  6 . Pin bar assembly  3  is guided through its excursion relative to female base  2  by linear shafts  4  within bearing holes  5 . Slot  20  enters and exits a stack of sheets being punched such as a stack of book sheets or other sheets, in a transverse direction. 
         [0039]      FIGS. 2 through 4  describe a double-sided punch die with only two rows of pins.  FIGS. 5-11  relate to dies of two or more rows of pins, generally illustrating three rows of pins. 
         [0040]      FIG. 2  shows a double-sided punch die  10  of this invention with female base  12  and pin retaining bar  13  with removable pin cover  9 . A double line of pins  18  and  22  of different diameters and pitch are shown mounted in pin retaining bar  13 . These are in registration with holes  17  and  21  of female base  12  respectively when die  10  is assembled. Note that with full width pin bar cover  9 , one set of pins, either  22  or  18  (whichever is not used in a run) is removed prior to the run, otherwise two sets of punch holes would be punched in the sheets. The sheet stack slot  24  is shown, which can be used for entering or exiting paper. Entrance slot  24  is for use of pins  22 ; the sheet slot for use by pins  18  (not shown) is on the opposite side of base  12 . Then slot  24  is an exiting slot. 
         [0041]      FIG. 3  is a partial top view of pin retaining bar  13  fitted with a removable half-width pin bar cover  30  of the preferred embodiment of the paper punch die of the present invention. 
         [0042]    Companion  FIG. 4  is an end crossection of bar  13 . 
         [0043]    In  FIG. 3 , the heads of pins  18  are covered by bar  30 , but the heads of pins  22  are not. Bar cover  30  has a set of fastener holes that are symmetrically placed relative to the longitudinal centerline such that it can be rotated or flipped over to cover punches  22  instead of  18  if the run would require the use of punches  22  instead. One or more fasteners  31  and/or  32  are used to fasten bar cover  30  to pin retaining bar  13 . For example, in a preferred embodiment, fasteners  31  located at the respective outer edges are screwed into threaded holes  32  while one or more near center fasteners  33  are screwed into one or more threaded holes  34  in pin retaining bar  13 . Other means of removably attaching bar cover  30  to pin retaining bar  13  may be used, such as clips or magnets can be used. 
         [0044]    As shown in  FIG. 4 , as pin retaining bar  13  is moved through a punch cycle (downward) pins  18  punch holes in sheet stack  43  (entered traversely through the opposite slot not shown on  FIG. 2 ) which is stopped at stop  42  put within female base  12 . Pins  18  are constrained to punch due to the position of pin bar cover  30 . However, as bar  13  is pushed down and pins  22  impinge on stack  43 , they simply move upward to position  40  without punching stack  43 . 
         [0045]    Stack  45 , which is stopped by stop  44  put within female base  12 , enters through slot  24  of female base  12 . To punch using punches  22  on this run, pin bar cover  30  is simply be moved over pins  22  with no need to remove pins  18 . 
         [0046]    While  FIGS. 2-4  show two rows of pins  18  and  22 , it is contemplated that more than two rows of pins can be used. For example, if three or more rows of pins are used, as shown in  FIG. 2 , then two or more of the rows of pins can be removed. Likewise, if three or more rows of pins are used with pin bar cover  30  of  FIGS. 3 and 4 , then two or more rows of pins can be exposed. 
         [0047]      FIG. 5  shows a section of pin retaining bar  50  with three rows of pins,  51 ,  52 , and  53  respectively. A narrow pin bar cover  60  is shown over center row  52  thereby selecting this row for a run. Threaded holes  54  are dispersed at distal ends of the pin row spaces and at points between the rows to accept flat head screws  55  used to secure cover  60  over the desired row. Cover  60  is preferably notched on the sides to receive screws  55  which serve more than one row; this can be seen on the top right screw hole  54  adjacent cover  60  since the illustration does not show the screw  55  in place. 
         [0048]      FIG. 6  shows a different embodiment using locking rod  80  instead of a narrow pin bar cover  60  for retaining pins  85  (see  FIG. 7 ) which have a transverse hole  87 . Pin retaining bar  70  is shown with three rows of countersunk pin holes  71 ,  72  and  73 . In registration with the centerline of each row are longitudinal holes  75 ,  76  and  77  respectively through pin retaining bar  70 . One, and only one, locking rod  80  is used in each punching run to secure the pins in only the desired row by inserting in one of the three holes  75 ,  76  or  77 . Locking rod  80  is secured by fastening means in pin retaining bar  70 , for example, by screwing the male threaded end  81  into mating female threads at the end of holes  75 - 77 . Note that an alternate embodiment for pins  85  are shown with a rectangular shank. As these pins  85  are guided by rectangular holes in pin bar  70 , they would be automatically aligned to accept locking rod  80  to penetrate transverse pin holes  87  when rod  80  is inserted. Round shank pins with transverse holes can also be used, but may have to be rotated a few degrees to lock in place to align in the direction of rod  80 . 
         [0049]      FIG. 8  is a side crossection detail showing pins  85  in row  71  locked to pin retaining bar  70  by rod  80  in hole  75 . 
         [0050]      FIG. 9  shows a side crossection comparable to  FIG. 8  but illustrating a variation of the embodiment of  FIGS. 6-8 . In this embodiment, pins  95  (see  FIG. 10 ) are locked to pin retaining bar  90  by locking rod  80  which is guided through a longitudinal hole just above the flat top surface of pins  95  so as to touch. In this case, no transverse holes are needed in pins  95 . Pins  95  are inserted through straight holes  91  which end in a recessed countersink before a transition to shank clearance diameter. In this embodiment, any type shank can be accommodated without any need for alignment with locking pin  80 . 
         [0051]    If more intimate contact than a line contact is desired between rod  80  and each of the pin heads is desired, the pin heads  97  can be made concave as in pins  96  shown in  FIG. 11 . 
         [0052]      FIGS. 12-15  illustrate yet another embodiment using locking rod  80  to selectively lock in place punch pins with a side notch or slot. 
         [0053]      FIG. 12  shows pin  100  with a round side notch  101 . 
         [0054]    In  FIG. 13 , the crossectional end view shows locking rod  80  engaging with round notch  101  thereby preventing pin  100  from floating up during a punch cycle. 
         [0055]    In  FIG. 14  punch pin  105  is shown with a v-shaped side notch or groove  106 . 
         [0056]      FIG. 15  shows the fit of locking rod  80  in v-notch  106  locking pin  105  to retaining bar  70 . It is noted that in this embodiment, the longitudinal holes for locking rod  80  within retaining bar  70  are now offset from the centerline of the row of pins. 
         [0057]    A tighter circular groove can also be used instead (not shown). With the concave or grooved pin heads, some alignment rotation will be required to insert rod  80  in the desired row. Other pin head configurations (not shown) can also be retained by retaining rod  80 . For example, if a pin head has an “F” or “S” shaped configuration, retaining rod  80  can engage in the recesses of the “F” or “S” shaped head to retain these fasteners with other pin head configurations. The rod can be mounted along the edge of grooved or slotted pins, or under the heads of each pin. Any fastener pin head with any kind of geometric configuration forming a cantilever or recess can be retained by retaining rod  80 . 
         [0058]    In the foregoing description, certain terms and visual depictions are used to illustrate the preferred embodiment. However, no unnecessary limitations are to be construed by the terms used or illustrations depicted, beyond what is shown in the prior art, since the terms and illustrations are exemplary only, and are not meant to limit the scope of the present invention. 
         [0059]    It is further known that other modifications may be made to the present invention, without departing the scope of the invention, as noted in the appended Claims.