Abstract:
A rotary die cutting apparatus and method for removing scrap material from work pieces such as plastic or paperboard blanks. One of the dies of a pair of rotary cutting dies is provided with gripper elements that extend over at least a portion of the area of the die corresponding to the areas over which the scrap portions are generated. The gripper elements pierce, partially or completely, the scrap portions generated by the cutting operation of the dies. A stripping knife extends across the die carrying the scrap portions at a height above the gripper elements that provides clearance between the gripper elements and the stripping knife but contacts the scrap portions retained on the gripper elements.

Description:
[0001]     This application claims the benefit of U.S. Provisional Application No. 60/579,274, filed Jun. 14, 2004, which is hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to the field of rotary die cutting devices, and particularly to rotary die cutting machines used in high speed rotary cutting of a moving sheet or web of paper, paperboard, plastics and composite materials.  
       BACKGROUND OF THE INVENTION  
       [0003]     As one example, rotary die cutting machines are used for the high speed mass production of paperboard carton blanks that are subsequently folded into the shape of carton or box containers. In rotary die cutting, the cutting operations can occur by either of two methods, the first being referred to in the trade as rotary pressure (“RP”) cutting and the second as the “crush cut” method. In the rotary pressure cutting method, the paperboard material from which the carton blanks are generated is advanced at high speed between two rotary die cutting cylinders. The cylinders are provided with cutting elements on them which cooperate to form cutting dies to cut the desired shape of the carton blank as the material advances between the cylinders. The cylinders rotate at the same speed so as to maintain registration of the co-acting cutting surfaces. Each rotation of the cylinders generates a discrete series of one or more cartons depending upon the size of the cartons, diameters of the cylinders, etc. In the crush cut method, one of the cylinders, the cutting cylinder, is provided with knife blades that perform the cutting operation and the other cylinder, known as the anvil cylinder, provides a smooth surface against which the knife blades operate.  
         [0004]     In both the above described processes there is necessarily generated a certain amount of scrap material. This material needs to be separated from the carton blanks and removed from the dies as each revolution of the cylinders generates a new series of carton blanks. There are various ways in which the scrap removal process is performed. In one method, the scrap material is initially retained on one of the die cylinders by stripping pins that hold the scrap pieces onto that cylinder as the carton blanks are advanced away. Thereafter, the scrap pieces are removed from the die cylinder by a stripping comb. Alternatively, scrap removal is accomplished separately from the cutting operation. In this method, the carton blank and scrap pieces are retained as contiguous pieces by being left uncut during the cutting operation. The attached pieces are then carried to a stripping station. At the stripping station, the scrap material is removed from the carton blank by piercing the scrap portions with stripping pins carried on a rotating cylinder. As in the previous method, the scrap pieces are retained on the pins by the rotating cylinder until they are stripped off the pins by a stripping comb. A yet further alternative system employs a stripping station which removes the scrap pieces by rotatably registering male elements to “punch” the scrap from the moving web of pre-cut products.  
         [0005]     All of the above described methods of scrap removal add to the cost of rotary die cutting and require time and adjustments to optimize their operation in a coordinated fashion with the die cutting operation. For example, the location and number of stripping pins varies for each die and their installation can involve a certain amount of trial and error. Further, in some methods, the stripping pins are individually mounted to the die with a screw threaded base which mounts within complementary threaded mounting holes tapped into the portions of the die where the scrap material is generated. In addition, for each stripping pin a corresponding registration hole must be drilled or otherwise formed in the opposing die. These holes are located to register with the stripping pins.  
         [0006]     Thus, there remains the need for further improvement in this field. Various embodiments of the present invention do this in novel and unobvious ways.  
       SUMMARY OF THE INVENTION  
       [0007]     One aspect pertains to method and apparatus in retention and stripping of scrap portions of a web cut by rotary dies.  
         [0008]     Another aspect concerns stripping pins which are releasably captured between a removable die plate and the corresponding mandrel or cylinder.  
         [0009]     In yet another aspect a stripping pin projects from a lower rotary die. A distal tip of the stripping pin is received within a channel of an upper rotary die as the scrap portion is generated. The scrap portion is retained between walls surrounding the channel and a surface of the lower die as the tip penetrates into the scrap portion. In some embodiments, the channel is oval-shaped with the long direction of the oval being parallel to the direction of cylinder rotation.  
         [0010]     Another aspect relates to a stripping pin which is loosely retained in an underside cavity of a removable die plate. If a first pin wears out during operation during the die cutting apparatus, the first pin can be removed with little or no damage to the die plate and replaced with a second pin.  
         [0011]     Yet another aspect concerns a separable stripping pin which comprises a projection of a first, smaller diameter extending from a non-threaded base of a second, larger diameter.  
         [0012]     Another aspect relates to fabrication of a removable die plate having a plurality of stripping pins attached thereto by an adhesive.  
         [0013]     Further forms, objects, features, aspects, benefits, advantages, and embodiments of the present invention will become apparent from the detailed description and drawings provided herewith.  
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a side and top perspective view of a rotary die cutting apparatus according to one embodiment of the present invention.  
         [0015]      FIG. 2  is an enlarged cross sectional side view of the apparatus of  FIG. 1 .  
         [0016]      FIG. 3  is a scaled, cross sectional view of a portion of a rotary die cutting apparatus according to one embodiment of the present invention.  
         [0017]      FIG. 4  is top view of the apparatus of  FIG. 3 .  
         [0018]      FIG. 5  is a complete, rotated top view of  FIG. 4 .  
         [0019]      FIG. 6  is a top, plan view of a section of sheet material which includes a plurality of stripper pins according to one embodiment of the present invention.  
         [0020]      FIG. 7  is a top, plan view of a lower die plate according to one embodiment of the present invention.  
         [0021]      FIG. 8  is a bottom plan view of the opposite side of the apparatus of  FIG. 7 .  
         [0022]      FIG. 9  is a close-up of a portion of the apparatus of  FIG. 7 .  
         [0023]      FIG. 10  is a top, plan view of an upper die plate according to one embodiment of the present invention.  
         [0024]      FIG. 11  is an enlarged view of a portion of the apparatus of  FIG. 10 .  
         [0025]      FIG. 12  is a scaled, cross sectional view of a portion of a lower die according to one embodiment of the present invention.  
         [0026]      FIG. 13  is a top, plan view of the apparatus of  FIG. 12 .  
         [0027]      FIG. 14  is a side view of the apparatus of  FIG. 12 .  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0028]     This application incorporates by reference U.S. Pat. No. 6,681,666, METHOD AND APPARATUS FOR SCRAP REMOVAL FROM ROTARY DIES, issued Jan. 27, 2004.  
         [0029]     For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.  
         [0030]     Referring to  FIGS. 1 and 2 , there is shown a rotary die cutting apparatus  20  of a rotary pressure cutting type according to one embodiment of the present invention. The apparatus  20  comprises a pair of upper and lower rotary dieplates  30  and  40 , respectively, for cutting blank portions  26   a  and  26   b  and scrap portions  27  from web  26  passing between the dies. The upper and lower dieplates  30  and  40  are removably mounted to mandrels or carrier cylinders  22  and  24 , respectively. Although the dies and carrier cylinders are shown as separate elements, it is understood that in some embodiments die plates  30  and  40  can alternatively be integrally formed with their respective carrier cylinders  22  and  24 . In one embodiment, die plates  30  and  40  are chemically etched from a sheet of spring steel or stainless steel material, although die plates made of different material, and fabricated by other methods can be used. Separable stripping pins or gripping elements  50  are detachably attached to the lower dieplate  40 ; however, in other embodiments the stripping pins  50  may be detachably attached to the upper dieplate  30 .  
         [0031]     Referring again to  FIGS. 1 and 2 , upper die  30  includes a plurality of the cutting elements  32  and one or more receiving channels  34  in the areas of the upper die  30  where scrap portions  27  are generated by the cutting operation. Each of the cutting elements  32  surrounds one or more receiving channels  34 . Optionally, the receiving channels  34  have an oval shape; however, in other embodiments the receiving channels  34  can have another shape such as, rectangular or circular, to name a few. The receiving channels  34  can be integrally formed with the upper die  30 , or alternatively may be separately formed from the die  30  and mounted thereto by bolts or other suitable fastening means. The receiving channels  34  are located in an area of the die  30  that is to receive a scrap portion  27 . One purpose of the receiving channels  34  is to provide a surface against which the scrap portions  27  may bear and thereby be forced into engagement with stripper pins  50 . Receiving channel  34  is defined by fore and aft peripheral walls  34   a.  In some embodiments the fore and aft walls  34   a  are linked in an oval shape, as best seen in  FIG. 11 . In some embodiments, receiving channel  34  defines a hole through the thickness of upper die  30 . However, in other embodiments, the receiving channel  34  is a blind (non-through) channel.  
         [0032]     As shown in  FIG. 2 , the lower die plate  40  includes a plurality of cutting elements  42  arranged to cut a desired shape of blank portions  26   a  and  26   b  and scrap portions  27 . The cutting elements  42  substantially surround one or more pockets or locating lands  44 . The locating land  44  is configured to form a relief cavity or counterbore  46 . In this form, the locating land  44  has a substantially circular shape; however, in other embodiments the locating land  44  may be shaped differently. Locating land  44  includes an outermost surface  41 . In one embodiment, the outermost surface  41  is located at an elevation similar to an elevation of the cutting elements  42 . In other embodiments, the outermost surface  41  is located at an elevation different than an elevation of the cutting elements  42 . Locating land  44  also defines a through hole  48 . As shown, the hole  48  is located in the center of the locating lands  44 . Hole  48  is preferably larger than the diameter of the projection  54  of the stripping pin  50  so that the projection  54  is loose within the hole  48 . In other embodiments, the hole  48  is sized to form a light press fit with the projection  54  of the stripping pin  50 .  
         [0033]     Lower die  40  includes an underside  49 . The underside  49  defines a relief cavity or counterbore  46  which is approximately centered within a corresponding locating land  44 . As shown, relief cavity  46  has a shape similar to the shape of a base  52  of the stripping pin  50  as described below. In other forms, the relief cavity  46  and the base  52  may each have a different shape.  
         [0034]     Web  26  is formed from various workpiece materials, such as paperboard or plastic. The blank portions  26   a  and  26   b  are generated by cutting the moving web  26  between co-acting edges of cutting elements  32  and  42  located on the upper and lower dies  30  and  40 , respectively, as the cylinders  22  and  24  are rotated in synchronicity in opposite directions of rotation by a suitable drive mechanism (not shown). Separable stripping pins or gripping elements  50  are captured by the lower die  40  in those areas where scrap portions  27  are generated by the cutting process. The upper die  30  is provided with receiving channels  34  that register with each of the pins  50  as the pins  50  reach the cutting position of the upper and lower dies  30  and  40 . Additionally, the receiving channels  34  provide a surface against which the scrap portions  27  may rest against and thereby be forced into engagement with the pins  50 . In other embodiments, the stripping pins are captured by the upper die and the lower die is provided with receiving channels that register with each of the pins as the pins reach the cutting position of the upper and lower dies.  
         [0035]      FIGS. 2 and 3  show details of stripper pins  50  in cross section to reveal its shape. The stripping pins or gripping elements  50  are preferably formed with any of several conventional metal removal techniques such as electrical discharge machining, photo-etching, or chemical etching techniques. The stripping pins  50  can be made of various metals, such as steel, stainless steel, aluminum, or any other metal. Optionally, the stripping pins  50  are made with other methods and materials. Example materials for the stripping pins  50  include plastics, ceramics, or composite materials such as fiberglass reinforced materials. Additionally, an example method for fabricating the stripping pins  50  includes injection molding material into a die in the shape of the stripping pins  50 .  
         [0036]     As shown in  FIG. 2 , the stripper pin  50  includes a base  52 . In this embodiment, the base  52  is a circular shape; however, in other embodiments the base  52  may be shaped differently such as rectangular, triangular, or elliptical to name a few. The stripper pin  50  also includes a projection  54  extending from the base  52 . The projection  54  includes a top surface  55  at the distal end. The projection  54  has the general shape of a cylinder except that the projection  54  includes the barbed tip  56  which gives the projection  54  a cylindrical shape with a flared end tip. In other embodiments, the projection  54  has the general shape of a truncated cone except that the upper portion is modified to incorporate an undercut or reverse taper proximate to tip  56  which gives it a sort of mushroom shaped appearance. Yet in other embodiments, the projection  54  can be shaped differently such as rectangular, triangular, or elliptical to name a few. One purpose of the undercut or barbed tip  56  in some embodiments is to provide for increased gripping force on the scrap portion  27 . Beneficially, the barbed tip  56  assists the projection  54  to retain the scrap portion  27  while the lower rotary die  40  and mandrel or carrier cylinder  24  rotate.  
         [0037]     The size of the stripper pins  50  can vary with the thickness and type of material for web  26  being used to generate the blanks  26   a  and  26   b.  In some embodiments, the base  52  has a thickness of from about 0.01″ to about 0.02″. Generally, it is anticipated that the diameter of the projection  54  of the stripper pins  50  will be in a range of 0.01″ to about 0.1″ and the overall height will range from about 0.020″ to about 0.060″. Base  52  has a diameter larger than hole  48  of die plate  40  and preferably smaller than the internal diameter of cavity  46 . Therefore, securement of die plate  40  to mandrel  24  (such as by magnetic or other means) also releasably captures pins  50  in their corresponding cavities  46 . In those embodiments in which die plate  40  is releasably attached to mandrel  24 , the pins  50  can be replaced by removal of the die plate  40  and removal of the separable pins  50 .  
         [0038]     As shown in  FIG. 2 , a section of the paper board or plastic web  26  is shown passing between upper and lower mandrels  22  and  24 . The feedstock or blank portion  26   a  of the web  26  has passed by the upper and lower cutting elements  32  and  42 . A blank portion  26   b  is shown exiting from between a pair of cutting elements  32  and  42 . A scrap portion  27  is located between upstream and downstream cutting elements  32  and  42 , and is shown pierced by a projection  54  of a stripper pin  50 . Stripper pin  50  is preferably a separable pin which is releasably captured within a relief cavity or counterbore  46  of lower dieplate  40 . Preferably, the height or thickness of the base  52  is less than the height of the cavity  46  so that pin  50  fits loosely within cavity  46 . Projection  54  extends through the hole  48  which has been milled or formed from dieplate  40 . Preferably, the barbed tip  56  at the distal most end of projection  54  is spaced higher than the outermost surface  41  of locating land  44 . In some embodiments, outermost surface  41  of locating land  44  is roughly the same elevation as the cutting elements  42 . In yet other embodiments, outermost surface  41  substantially represents the original, unmilled thickness of the sheet material from which lower dieplate  40  was fabricated.  
         [0039]     In one form, pin  50  is adapted and configured such that the length of projection  54  extends to a location within a receiving channel  34  defined by fore and aft peripheral walls  34   a  of upper die  30  as shown in  FIG. 2 . In this form, the projection  54  has pierced both the top and bottom surfaces of scrap portion  27 . In other forms, the pin  50  is adapted and configured such that the length of projection  54  extends to a location near receiving channel  34 ; however, the projection  54  pierces the bottom surface of scrap portion  27  but the projection  54  does not enter the receiving channel  34 .  
         [0040]      FIG. 3  is an enlarged sectional view of apparatus  20  similar to that of  FIG. 2  but without blank portions  26   a,    26   b,  and scrap portion  27  being shown.  FIG. 3  is a scaled drawing of one embodiment. As best seen in  FIGS. 2 and 3 , the stripping pins  50  are preferably provided with a barbed tip  56  adapted to pierce the scrap portions  27  and thereby retain the scrap portions  27  as the blank portions  26   a  and  26   b  advance through the space between the dies  30  and  40 . In addition, the pins  20  can include a barb or undercut to facilitate retention of the scrap portions  27  thereon. Preferably, the barbed tip  56  of pin  50  pierces through the thickness of the scrap portion  27 . In other embodiments, the tip  56  of the stripping pin  50  pierces through one side of the scrap portion  27  but not the other side of the scrap portion  27 . In other embodiments, the projection  54  does not include a barbed tip  56 .  
         [0041]     As shown in  FIG. 1 , the rotary die cutting apparatus  20  includes a stripping comb  28  attached to the lower rotary die  40 . In another embodiment wherein the pin  50  is attached to the upper rotary die  30 , the stripping comb  28  is attached to the upper rotary die  30 . Yet in other embodiments, the stripping comb  28  is placed adjacent the appropriate rotary die to remove the scrap portions  27  from the stripper pins  50 . The stripping comb  28  includes a plurality of teeth  29  spaced along a contact edge of the stripping comb  28 . As shown, the teeth  29  are rectangular in shape; however, in other embodiments the teeth  29  may have a different shape such as triangular, curvilinear, or trapezoidal to name a few.  
         [0042]     Referring to  FIG. 2 , it can be seen that the tips  56  of the stripping pins  50  preferably extend locally above the outermost surface of the lower dieplate  40 . As shown in  FIG. 1 , as the lower cylinder  24  rotates, scrap portions  27  retained on the lower die  40  by the stripping pins  50  come into contact with the teeth  29  of stripping comb  28 . The pins  50  do not contact the teeth  29  of the stripping comb  28  because the projections  54  of the pins  50  pass through the spaces between the teeth  29  of the comb  28 . As the lower cylinder  24  continues to rotate, the scrap portions  27  slide or continue over the teeth  29  and the scrap portions  27  are removed from the pins  50 .  
         [0043]     Mandrel  24  and lower die plate  40  preferably releasably capture stripper pins  50  that serve to grip, either with or without piercing substantially through, the scrap portions  27 . In other embodiments, mandrel  22  and upper die plate  30  releasably capture stripper pins  50 . As best seen in  FIGS. 4 and 5 , locating land  44  and through hole  48  are located on lower die  40  such that projection  54  projects within receiving channel  34  during rotation of mandrels  22  and  24 . In these embodiments, receiving channel  34  is oval shaped and surrounded by an oval-shaped peripheral wall  34   a.  As shown in  FIGS. 3 and 4 , the long dimension of the oval receiving channel  34  is preferably parallel to the direction of rotation. In other forms, the receiving channel  34  can be other shapes as mentioned above.  
         [0044]     While the invention is described in connection with a rotary pressure cutting method where there are cutting elements on both the upper and lower dies, the invention is also useful with “crush cut” methods which employ cutting elements on only one of the dies (e.g., the “carrier” die) and co-act against an anvil cylinder.  
         [0045]      FIGS. 6, 7 ,  8 ,  9 ,  10 , and  11  are plan views of various aspects according to a particular embodiment.  FIGS. 6, 7 ,  8 ,  9 ,  10 , and  11  are generated from photographs.  
         [0046]      FIG. 6  shows a plurality of stripper pins  50  prior to complete fabrication of the stripping pin according to one embodiment. In this embodiment, a plurality of stripping pins  50  are shown chemically milled from a portion of sheet material  50 . As mentioned previously, the stripping pins  50  may be fabricated in other manners. For example, the stripping pins  50  may be formed from sheet material  50  with other metal removal techniques such as electrical discharge machining or photo-etching techniques. The top view shown in  FIG. 6  shows the projection  54  extending from a circular base  52 . In this embodiment, the chem milling procedure is controlled such that a retention member  59  is retained, which secures the semi-finished pins shown in  FIG. 6  to the sheet material  58 . Each pin  50  is further processed to a final stage by grinding away the retention member  59  and thereby generating a loose, separate pin  50 .  
         [0047]      FIGS. 7, 8 , and  9  depict views of an unwrapped lower die plate  40  according to one embodiment of the present invention.  FIG. 7  shows the outer side of die plate  40 . Die plate  40  includes a plurality of cutting elements  42  arranged in a pattern to cut a desired shape of blank portions  26   a  and  26   b.  The cutting elements  42  generally surround one or more locating lands  44 . Die plate  40  is prepared from a portion of sheet material having an initial thickness. In some embodiments, the pattern of cutting elements  42  and locating lands  44  (as well as other surface features shown in  FIG. 7 ) are covered with a coating that resists chemical milling in a desired pattern. In these embodiments, the outermost surface  41  of locating lands  44  are roughly representative of the original surface and original thickness of the sheet material. However, in other embodiments, the locating lands  44  have an outermost surface  41  which is at a different elevation than the outmost surface of cutting elements  42 . Although not shown, lower die plate  40  is wrapped around mandrel  24  for use.  
         [0048]     Referring to  FIG. 8 , the reverse side or underside  49  of die  40  includes a relief cavity or counterbore  46  which is roughly centered within a corresponding locating land  44 .  FIGS. 7 and 8  show five locating lands  44  and five relief cavities  46 , respectively. Preferably, relief cavity  46  has a shape which is complementary to the shape of base  52  of pin  50 . In a preferred embodiment, both cavity  46  and base  52  are circular. However, in other embodiments different shapes such as square, triangular, oval, or other shapes, are used. Preferably, the inner diameter and inner height of relief cavity  46  are greater than the outer diameter and outer height of base  52 , so that a pin  50  is loosely received within the cavity  46 .  
         [0049]      FIG. 9  is a close-up of a portion of lower die  40 . In this embodiment, locating lands  44  are generally circular. A through hole  48  is fabricated preferably through the center of each locating land  44 . Hole  48  is preferably larger than the diameter of the projection  54  of the pin  50 , so that the projection  54  is loose within the corresponding hole  48 . In other forms, the projection  54  of the pin  50  is a light press fit in the hole  48 . In some embodiments, individual, separate pins  50  are placed within the corresponding cavities  46  of a lower die  40  and held in place by an adhesive to prevent the pin  50  from falling out as the lower die plate  40  is wrapped around the lower mandrel  24 .  
         [0050]      FIGS. 10 and 11  show plan views of the outer surface of an unwrapped, upper die plate  30 . Upper die plate  30  includes cutting elements  32  which are shaped and located in a manner to correspond with cutting elements  42  of lower die plate  40 . Together cutting elements  32  and  42  provide cutting action of web  26  passed therebetween. Each cutting element  32  surrounds one or more receiving channels  34 . The receiving channels  34  are located within the area of die plate  30  which will define a scrap portion  27  of the web  26 . As best seen in  FIG. 11 , in a preferred embodiment the receiving channel  34  has an oblong or oval shape, with the long direction being parallel to the direction of rotation of the assembled die. In another form, the receiving channel  34  may be shaped differently, as mentioned above.  
         [0051]     As best seen in both  FIGS. 2 and 3 , the peripheral walls  34   a  which surround receiving channel  34  project downward such that tip  56  of a corresponding pin  50  extends past the outermost surface of the peripheral walls  34   a  and into receiving channel  34 . Preferably, the scrap portion  27  is trapped between the outermost surface  41  of a locating land  44  and the outermost surface of the corresponding peripheral wall  34   a.  By trapping the scrap portion  27  therebetween, the material is prevented from simply deforming when it comes into contact projection  54 , and instead tip  56  is forced to pierce into the scrap portion  27 . It is to be appreciated that the distance between the outermost surface or bearing surfaces of receiving channels  34  and the top surfaces  55  of the stripper pins  50  determine the distance to which the stripper pins  50  pierce into the scrap portions  27 . In some embodiments, the pin has a total height, from the bottom of the base to the top of the tip, of 0.06″ to 0.07″. In some embodiments, plate  40  has an initial thickness of 0.035″. In the described embodiment, the barbed tip  56  protrudes nominally 0.035″ above the outermost surface of the locating land  44 . In that embodiment, the minimum clearance between the assembled upper die plate  30  and the assembled lower die plate  40  is nominally 0.002″ greater than the caliper thickness of the web  26  being cut. Although specific dimensions have been shown and described, the present invention is not so limited and contemplates embodiments having other dimensional features.  
         [0052]      FIGS. 12, 13 , and  14  show various aspects of a particular embodiment.  FIGS. 12, 13 , and  14  are scaled drawings with dimensions. The use of a hundred-series prefix (NXX) in front of an element number (XX) indicates an element that is the same as the non-prefixed element number, except for those changes shown or described hereafter. As shown in  FIG. 12 , the lower die plate  140  includes a locating land  144 . Locating land  144  is similar to locating land  44  as previously discussed. In this form, locating land  144  surrounds five stripping pins  150 . Stripping pins  150  are similar to stripping pins  50  as previously discussed. In other embodiments, locating land  144  may surround any number of stripping pins  150 . Yet in other embodiments, the locating land  144  is configured to surround stripping pins  150 , stripping pins  50 , and/or any other stripping pin.  
         [0053]     The locating land  144  is configured to form a relief cavity or counterbore  146 . As shown, the locating land  144  has a substantially rectangular shape; however, in other embodiments the locating land  144  may be shaped differently. Locating land  144  includes an outermost surface  141 . Locating land  144  also defines a through hole  148 . As shown, the hole  148  is a rectangular shape; however, in other embodiments the hole  148  may be shaped differently. Hole  148  preferably surrounds all of the diameters of the projections  154  of the stripping pins  150  located within the hole  148 . In this form, hole  148  is sized so that the projections  154  are loose within the hole  148 . In other forms, hole  148  is sized so that the projections  154  are tightly retained within the hole  148 .  
         [0054]     As mentioned previously, stripping pins  150  are similar to stripping pins  50 . Stripping pins  150  include a continuous base  152 . In this embodiment, the base  152  is a rectangular shape; however, in other embodiments the base  152  may be shaped differently. In one form, the stripping pins  150  and the continuous base  152  are separable from the lower die plate  140 . In this form, multiple stripping pins formed with continuous base  152  allows any number of stripping pins to be attached to and detached from lower die plate  140  as one common piece. Each of the stripping pins  150  also includes a projection  154  extending from the continuous base  152 . In other forms, the base  152  may be separate individual supports for each of the projections  154 . The projection  154  includes a top surface  155  at the distal end. The projection  154  has the general cross sectional shape of a tear drop. The projection  154  includes a barbed tip  156  having a tear drop shape. In other embodiments, the projection  154  and/or the barbed tip  156  can be shaped differently or the projection  154  and barbed tip  156  can be shaped different from each other.  
         [0055]     While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.