Patent Publication Number: US-8979723-B2

Title: Flat presser

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application Ser. No. 61/391,318, filed on Oct. 8, 2010, which is herein incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a blanking tool for making packaging and carton blanks and, more particularly, to a flat presser for supporting blanking scrap material during operation of the blanking tool. 
     BACKGROUND OF THE INVENTION 
     In the manufacture of cartons during a blanking operation, small sheets of paper material having specific profiles are cut out of larger sheets of paper material. These smaller sheets are known as carton blanks which are later formed into cartons and/or boxes. 
     As shown in  FIGS. 1 and 2 , in a die cutting machine  10 , the blanks are cut, but not removed from a large sheet  12  of paper material. After the blanks have been cut at a cutting station  14 , the large sheet layout  12  is pulled into a stripping station  15 , where small pieces of waste in between the blanks are removed, and then to the blanking station  16  where the sheet is positioned over a frame which includes openings which correspond in size, shape and position to the profile of the carton blank layout. 
     At the blanking station  16 , an upper tool is used in combination with the lower frame to knock the carton blanks from the sheet of paper material while holding the scrap material that surrounds the blanks. In particular, as shown in  FIG. 3 , a male blanker  20  includes a plurality of presser members  22 A,  22 B,  22 C,  22 D,  22 E secured to a support plate/board  24 , and the presser members  22 A- 22 E are dimensioned to be the same shape and slightly smaller than the blanks  26 A,  26 B,  26 C,  26 D,  26 E of a large sheet  12  supported upon a female blanker  28 . Next to and between the presser members  22 A- 22 E are a plurality of prior art standard pressers having presser rails  30 . (Only one of the identical six illustrated presser rails in  FIG. 3  is identified by the reference number  30  to avoid confusion.) Each prior art flat presser includes two mount housings  32 ,  34  that secure the presser rail  30  to the support plate  24 . Each mount housing  32 ,  34  includes a guide strut  36 ,  38  that is secured within the mount housing by a spring biasing mechanism such as a captured coil spring (not shown), and the guide struts  36 ,  38  are secured to the presser rail  30 . The spring biasing mechanism forces the presser rail  30  in a direction away from the support plate  24  and mount housings  32 ,  34 . 
     As is well known, in operation the support plate  24  is moved against the sheet  12  as shown in  FIG. 4  so that the presser rail  30  secures and stabilizes the carton blank scrap surrounding the blanks as the presser members  22 A- 22 E impact the blanks  26 A- 26 E to force them to break apart from the large sheet  12  and move with gravity assistance and guided by stationary joggers (not shown) to blank stacking piles  40 A,  40 B,  40 C,  40 D,  40 E. After the blanks  26 A- 26 E are removed from the large sheet  12 , the sheet is referred to as blanking scrap. As is apparent, the faster the large sheet  12  can be processed by the male and female blankers  20 ,  28 , the more cost efficient the blanking operation becomes. 
     As discussed above, in order to securely hold the carton blank scrap, known presser rails are interconnected to the support plate  24  by mount housings  32 ,  34  and guide struts  36 ,  38 . As shown in  FIGS. 3 and 4 , each guide cylinder  32 ,  34  biases the presser rail  30  downwardly away from the support plate  24 , and are mounted to the support plate  24  such that the mount housings  32 ,  34  project upwardly from the support plate.  24 . However, it is desirable to eliminate any components projecting above the support plate  24  and instead provide interior mounted flat pressers/presser assemblies for a number of reasons. First, for tool storage purposes, an upper tool having interior mounted pressers takes up less space. This is particularly advantageous in locations where storage space is limited. Secondly, many existing die cutting machines are built in such a manner that the upper tool slides into the blanking station of the machine. Any component projecting upwardly from the support plate would interfere with such sliding action. Therefore, only interior mounted flat pressers can be used with such systems. 
     In addition, during the cutting operation, perimeters of the blanks are cut out using a continuous steel knife configuration of the blank profile. The blanks are usually held in the sheet  12  with nicks. Nicks are small areas around the perimeter where the knife is removed, usually with a small grinding wheel or chisel. Multiple nicks are usually placed around the blanks to carry the sheet into the blanking station  16  where the nicks are pulled apart during the blanking cycle. As the machine speed increases, more nicks may have to be added to the existing cutting tool to help hold the blanks in place. More nicks may hold the sheet together but they can also cause problems when the sheet is transferred to the blanking station  16 . Therefore, it is desirable for a machine operator to have the ability to easily add a flat presser to the support plate  24  while the board is still on press. Prior art pressers, however, make it difficult to add pressers onto a support board without cutting a custom profile into the support plate  24  for mounting. In addition, prior art pressers are usually large, not customizable, and there is often insufficient space on the support plate for mounting any additional pressers to increase support and stabilization of the carton blank scrap during the blanking operation. In particular, known presser assemblies are often arranged in static rows, which allow for limited, if any, customization of presser geometry, i.e., the arrangement of pressers on the support plate. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, it is an object of the present invention to provide a flat presser for supporting blanking scrap material during operation of a blanking tool for making packaging blanks. 
     It is another object of the present invention to provide a flat presser that is surface mountable with a support board of a blanking tool. 
     It is another object of the present invention to provide a flat presser that is easy to assembly, inexpensive to manufacture and that utilizes strong materials with low friction. 
     It is another object of the present invention to provide a flat presser that is easy to mount to standard blanking operation machinery. 
     It is another object of the present invention to provide a flat presser that provides consistent pressure to the blank scrap throughout the blanking operation. 
     It is another object of the present invention to provide a flat presser that is small in size and which can be positioned almost anywhere on the support board. 
     It is another object of the present invention to provide a flat presser that can easily be utilized in combination with a presser rail to provide a linear pressing surface. 
     In accordance with an embodiment of the present invention, a flat presser includes a plurality of coaxially oriented, concentric wall sections of progressively different interior areas and being collapsible from an extended position wherein the wall sections partially overlap in an axial direction to a collapsed position wherein the wall sections substantially completely overlap in the axial direction, and a biasing mechanism for biasing the wall sections to the extended position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below: 
         FIG. 1  is a perspective view of a prior art die cutting machine for manufacturing carton blanks. 
         FIG. 2  is a schematic illustration of the interior of the prior art die cutting machine of  FIG. 1  showing cutting station and a blanking station. 
         FIG. 3  is a partial perspective view of a prior art male blanker and female blanker cooperatively positioned to knock blanks out of a large sheet of packaging material. 
         FIG. 4  is a partial perspective view of the  FIG. 3  prior art male and female blanker showing usage of a prior art presser rail in knocking out packaging blanks. 
         FIG. 5  is a perspective view of a flat presser for use with a male blanker of a die cutting machine in accordance the present invention, shown in an extending position. 
         FIG. 6  is a front elevational view of the flat presser of  FIG. 5 . 
         FIG. 7  is a bottom perspective view of the flat presser of  FIG. 5 . 
         FIG. 8  is an exploded perspective view of the flat presser of  FIG. 5 . 
         FIG. 9  is a perspective view of the flat presser of  FIG. 5  shown in a partially collapsed position. 
         FIG. 10  is a perspective view of the flat presser of  FIG. 5  shown in a fully-collapsed position. 
         FIG. 11  is a bottom perspective view of the flat presser of  FIG. 5  in a partially collapsed position. 
         FIG. 12  is a bottom perspective view of the flat presser of  FIG. 5  in a fully-collapsed position. 
         FIG. 13  is a top plan view of a conical spring for use in the flat presser of  FIG. 5 . 
         FIG. 14  is a front elevational view of the conical spring of  FIG. 13  illustrating movement of the spring under applied load. 
         FIG. 15  is a top perspective, exploded view of the flat presser of  FIG. 5  illustrating position stops. 
         FIG. 16  is a bottom perspective, exploded view of the flat presser of  FIG. 5  illustrating position stops. 
         FIG. 17  is a perspective view of a flat presser rail assembly utilizing a plurality of the flat pressers of  FIG. 5  and a presser rail in accordance with another embodiment of the present invention. 
         FIG. 18  is a perspective view of a portion of the flat presser rail assembly of  FIG. 17 , showing a mounting bracket disconnected from the flat presser. 
         FIG. 19  is a perspective view of a portion of the flat presser rail assembly of  FIG. 17 , showing the mounting bracket connected to the flat presser. 
         FIG. 20  is a perspective, exploded view of the flat presser rail assembly of  FIG. 17 . 
         FIG. 21  is a perspective, exploded view of the flat presser rail assembly of  FIG. 17  in a partially assembled state. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings,  FIGS. 5-8  illustrate a flat presser  100  for use with a male blanker of a die cutting machine for converting or processing a sheet of paper material into a carton blank. These machines are well known in the art and are used to cut one or several blanks into each sheet of paper material which, after folding and gluing, may be formed into cartons or boxes. As is conventional, the sheets of paper material within the machine are carried through various sequences of printing, cutting, embossing, creasing, waste stripping and/or blank stations. 
     As shown in  FIG. 5 , the flat presser  100  includes a base  102  and plurality of coaxially oriented, concentric wall sections  104   a - f , each wall section generally taking the shape of a rhombus or diamond and having progressively different diagonal lengths (and different inner areas).  FIG. 8  shows an exploded view of the flat presser including the base  102  and six wall sections  104   a - f , although the invention may include more or fewer wall sections without departing from the broader aspects of the present invention. The wall sections  104   a - f  are nested within one another and are collapsible from an extended position ( FIGS. 5 and 6 ) wherein the wall sections  104   a - f  partially overlap in the axial direction to a collapsed position ( FIGS. 10 and 12 ) wherein the walls sections  104   a - f  substantially completely overlap in the axial direction.  FIGS. 9 and 11  illustrates the flat presser  100  in an intermediate, partially collapsed position. As best shown in  FIGS. 10 and 12 , in the fully collapsed position, the sidewall sections  104   a - f  are all housed within the diamond shaped opening in the base  102  such that the full height of the flat presser  100  is substantially equal to the height of the base  102 . An elastomeric cap  106  having a substantially planar surface is received in the smallest wall section  104   a . In the preferred embodiment, the elastomeric cap  106  may be made of rubber or like material having a coefficient of friction high enough to grip and hold the sheet of material during the blanking operation, as discussed in detail below. 
     As best shown in  FIGS. 7 and 11 , in the extended position, the flat presser  100  defines a generally open cavity  108  in the bottom thereof. A conical spring  110  is housed within the cavity  108 . The conical spring  110  is positioned generally coaxially with the wall sections  104   a - f  within the cavity  108 . The spring  110  is retained in place within the cavity  108  by a locating protrusion  112  formed in the underside of sidewall section  104   a  that is received by a small diameter end of the spring  110 , and by a locking plate  114  secured to the base  102 . Importantly, the spring  110  biases the flat presser  100  to its extended position, i.e., it biases wall sections  104   a - f  away from the base  102  when the spring  110  is retained within the cavity  108 . As shown in  FIG. 8 , locking plate  114  has a plurality of legs that engage complimentary recesses in the base to secure the locking plate  114  to the base. The locking plate  114  may also be secured to the base  102  by other means known in the art, such as by fasteners, adhesive and the like, without departing from the broader aspects of the present invention. 
       FIGS. 13 and 14  illustrate the configuration of the conical spring  110 . As shown therein, the spring has a small diameter end and a large diameter base. As force is applied to the small diameter end of the spring  110 , the spring collapses to a substantially flat configuration (see right-most drawing of  FIG. 14 ). This position of the spring  110  corresponds to the fully-collapsed position of the flat presser  100 . 
     Referring to  FIGS. 8 ,  15  and  16 , assembly of the flat presser  100  will now be discussed. During assembly, wall section  104   a  may first be inserted through the bottom of wall section  104   b . Once wall section  104   a  is nested within wall section  104   b , wall section  104   b  can be nested in the same manner within wall section  104   c , and so on. Finally, wall section  104   f  can be inserted through the bottom of base  102  in a similar manner such that all wall sections  104   a - f  are in a nested configuration. In this extended configuration, the conical spring  110  may then be inserted into cavity  108  and retained in place by locking plate  114 , as discussed above. Elastomeric cap  106  may be inserted into wall section  104   a  either first, or after the flat presser  100  is assembled. Importantly, locking plate  114  provides a flat surface on the bottom of the flat presser  100 , allowing the flat presser  100  to be surface mounted to the bottom of a support board, such as support plate  24  of male blanker  20  of  FIGS. 3 and 4 . 
     With further reference to  FIGS. 15 and 16 , the specific configuration of the wall sections  104   a - f  is shown. As shown therein, wall sections  104   a - e  each have a pair of protrusions  116   a - e  on opposing outer walls thereof. The protrusions  116   a - e  are angled downward and terminate in outwardly extending shoulders (shoulders extend substantially perpendicular from outer walls of wall sections  104   a - e ). In addition, wall sections  104   b - f  each have a pair of channels or grooves  118   b - f  on opposing inner walls thereof. The channels  118   b - f  are sized to slidingly receive complimentary protrusions  116   a - e  therein. For example, opposing channels  118   b  in the inner walls of wall section  104   b  are sized to slidably receive opposing protrusions  116   a  of wall section  104   a . Likewise, opposing channels  118   e  in the inner walls of wall section  104   e  are sized to slidably receive opposing protrusions  116   d  on wall section  104   d.    
     As further shown in  FIGS. 15 and 16 , each of the channels  118   b - f  has an abutment  120   b - f  adjacent the bottom thereof. Each abutment is sized and positioned so as to be complimentary with the shoulders of protrusions  116   a - e  on wall sections  104   a - e . During assembly, for example, wall section  104   a  is inserted through the bottom of wall section  104   b . The angled portion of the protrusions  116   a  of wall section  104   a  permit the protrusions  116   a  to slide past abutments  120   b  and into channels  118   b  such that wall section  104   a  is received within wall section  104   b . Once received, wall section  104   a  cannot be retracted from wall section  104   b  because of the abutments  120   b  on the inner walls of wall section  104   b . In particular, any attempt to retract wall section  104   a  (in a collapsed direction) from wall section  104   b  causes the shoulder of protrusions  116   a  to come into contact with abutments  120   b . In this respect, downwards movement of wall section  104   a  with respect to wall section  104   b  is directly limited by abutments  120   b  on the inner walls of wall section  104   b.    
     As further shown therein, each wall section  104   a - f  includes a plurality of raised surfaces  122   a - f  on the outer walls thereof adjacent the bottom walls thereof. These surfaces  122   a - f  are complimentary in size and shape to relieved portions  124   b - f  in the inner walls of wall sections  104   b - f . When, for example, wall section  104   e  is inserted into the bottom of wall section  104   f , upward movement of wall section  104   e  with respect to wall section  104   f  is limited by the length of relieved portion  122   f . In particular, raised surface  122   e  is slidably received in relieved portion  124   f  and is limited in its upward travel by the extent of relieved portion  124 , i.e., raised surface  122   e  eventually abuts the end of the relieved portion  124   f . As will be readily appreciated, base  102  also has relieved portions  126  on inner walls thereof that are sized and shaped so as to slidably receive raised surfaces  122   f  of wall section  104   f , thereby limiting upwards movement of wall section  104   f  with respect to the base  102 . 
     Importantly, the contact between the shoulders of protrusions  116   a - e  with abutments  120   b - f  prevents each wall section  104   a - f  from being removed (in a collapsed/retracted direction) from the wall section  104   a - f  within which it is nested. Likewise, the contact between the raised surfaces  122   a - f  and the ends of the relieved portions  124   b - f ,  126  prevents each wall section  104   a - f  from being removed (in an extended/expanded direction) from the wall section  104   a - f  (or base  102 ) within which it is nested. 
     Referring back to  FIGS. 5 and 6 , base  102  includes a plurality of mounting throughbores  128 . In the preferred embodiment, there are four mounting throughbores in the base  102 , although more or fewer throughbores may be utilized without departing from the broader embodiments of the present invention. As will be readily appreciated, the flat presser  100  may be secured to the bottom of a support board of a male blanker, such as support plate  24  of male blanker  20 , shown in  FIGS. 3 and 4 , by screws or the like. 
     As further shown in  FIGS. 5 and 6 , the base  102  includes a pair of vent holes  130  in the sidewall thereof, which facilitate smooth operation of the flat presser  100 . In particular, during operation, the compression of the conical spring may create a slight pressure differential within the cavity  108  of the flat presser  100  itself, and therefore vent apertures  130  formed in the housing allow for venting and the quick and smooth action of the flat presser  100 . 
     In an embodiment, one or more of the wall sections  104   a - f  includes a notch  131  or cutout which provides a clearance for the presser members  22 A-E in situations where the flat presser  100  may be mounted in close association with the presser members  22 A-E. 
     In the preferred embodiment, the flat presser  100  is approximately 2½ inches tall from base to the tip of the elastomeric member  106  in the fully extended position, and collapses to approximately ⅝ inches tall. In addition, in the preferred embodiment, the flat presser  100  has a major width of approximately 2 inches and a minor width of approximately 1 inch. Moreover, the wall sections  104   a - f  and the base  102  are preferably formed from a suitably durable material having a suitably low coefficient of friction, such as plastic including, but not limited to, polyethylene and the like. 
     As will be readily appreciated, the flat presser  100  of the present invention is easy to assemble, inexpensive to manufacture and is formed from lasting materials with a low or very low coefficient of friction. As will be readily appreciated, this provides for a long lasting, lower cost flat presser  100 . 
     With reference to  FIGS. 3 ,  4  and  5 , in operation, a plurality of flat pressers  100  are surface mounted to the bottom of a support plate  24  of a blanking tool  50  in predetermined locations (they are utilized in place of presser rails  30  and mount housings  32 ,  34 ). Under the bias of the conical spring  110 , the flat pressers  100  are each in a fully extended position. As the male blanker  20 , and thus the support plate  24 , move downwardly, flat pressers  100  engage the top surface of the sheet  12  of paper material and retract/collapse, as previously described, to hold the scrap. The presser members  22 A-E then push the blanks  26 A-E from the sheet  12 , and thereafter, the male blanker  20 , including support plate  24  then moves upwardly to its initial starting position where the flat pressers  100  again return to their fully extended positions. 
     Notably, during downward movement of the blanking tool, it is necessary to securely stabilize the carton blank scrap surrounding the blanks by frictionally holding the scrap with the plurality of flat pressers  100  positioned around the carton blanks throughout the layout. The spring  110  in the flat presser  100  allows for consistent pressure applied to the blank scrap throughout the complete vertical motion of the support board during the blanking cycle. 
     As discussed above, the utilization of a conical spring that compresses to a completely flat configuration, as shown in  FIG. 14 , allows the flat presser  100  to fully collapse (see  FIG. 10 ), thereby providing a minimum protrusion distance from the lower surface of the support board  24 . Notably, the design of the flat presser  100  allows for quick and easy surface mounting to the underside of the support board  24  using screws or other suitable fastening means. In addition, the small size of the flat presser  100  allows it to be quickly and easily mounted to the support board  24  in almost any location, thereby allowing for a level of customization of presser arrangement heretofore unseen in the art. In particular, as a result of the small size and quick mounting capabilities of the flat presser  100 , flat pressers  100  can be quickly and easily mounted at almost any location on the support board  24  by an operator without substantial down-time, thereby providing a precise, pointed stabilization of the sheet of material that is simply not possible with prior art presser devices. In contrast to the present invention, there often will not exist sufficient space on the support board for additional conventional presser assemblies. 
     Turning now to  FIGS. 17-21 , an alternative embodiment of the present invention is shown. As shown therein, in an embodiment, a flat presser rail assembly  200  utilizes flat pressers  100  in combination with presser rails to achieve a pressing arrangement substantially similar to that achieved by the presser rails  30  and mount housings  32 ,  34  known in the art, but which also provides the advantages hereinbefore disclosed. 
     With specific reference to  FIG. 17 , the flat presser rail assembly  200  includes a plurality of flat pressers  100  with the elastomeric cap  106  not included or removed. In the preferred embodiment, the assembly  200  utilizes three linearly spaced flat pressers  100 . A center rail mounting bracket  202  is secured to the distal end of wall section  104   a  of the middle flat presser  100 . The center rail mounting bracket  202  is generally U-shaped and has a plurality of outwardly extending arms  204 , as best shown in  FIGS. 18-20 . Similarly, end rail mounting brackets  206  are secured to the distal ends of walls sections  104   a  of the respective end flat pressers  100 . The rail mounting brackets  206  are generally L-shaped and have an arm  208  extending towards the middle flat presser  100 . The rail mounting brackets  202 ,  206  may be attached to the respective flat pressers  100  by means known in the art, such as by fasters and the like. In an embodiment, the mounting brackets  202 ,  206  may be secured to the flat pressers  100  by means similar to how the elastomeric cap  106  is secured, i.e., friction fit. 
     As best shown in  FIGS. 20 and 21 , the flat presser rail assembly  200  further includes presser rail sections  210 . The presser rail sections  210  are preferably formed from a durable material such as extruded aluminum or the like, although other materials are certainly possible without departing from the broader aspects of the present invention. The presser rails  210  each include a pair of guide rails  212  defining a channel therebetween for slidably receiving arms  204 ,  208  of the mounting brackets  202 ,  206 .  FIG. 21  illustrates the arms  204 ,  208  received in presser rails  210 . A plurality of retaining clips  214  are also included and enclose the remaining space between the presser rails  210  and the mounting brackets  202 ,  206 . As shown therein, the retaining clips  214  snap over a portion of the arms  204 ,  208  of the mounting brackets  202 ,  206 . Referring back to  FIG. 17 , the presser rails  210  and the mounting brackets  202 ,  206  form a generally planar presser surface. As with the flat pressers  100  discussed above, presser assembly  200  may be flush mounted to the underside of a support board of a male blanking tool by screws or other means known in the art. 
     In operation, the flat presser rail assembly  200  is surface mounted to the bottom of a support plate, such as support plate  24  shown in  FIGS. 3 and 4  in a predetermined location. Under the bias of the conical spring  110 , the flat pressers  100 , and thus the presser rails  210 , are in an extended position away from the under surface of the support board  24 . As the blanking tool  20 , and thus the support plate move downwardly, the planar surface of the presser assembly  200  defined by the presser rails and the mounting brackets  202 ,  206  engage the top surface of the sheet  12  of paper material and the flat pressers  100  retract/collapse in the manner described above. The presser members  22 A-E then push the blanks  26 A-E from the sheet  12 , and thereafter, the blanking tool  20 , including support plate  24  then moves upwardly to its initial starting position wherein the flat pressers  100 , and thus the flat presser rail assembly  200 , again return to their fully extended positions. 
     In an embodiment, a shorter flat presser rail assembly may be constructed using two end flat pressers. Similarly, a longer presser rail may be constructed using two middle and two end flat pressers. Indeed, as will be readily appreciated, a flat presser rail assembly of almost any size may be constructed by using any number of flat pressers  100  and any combination of mounting brackets and presser rails, without departing from the broader aspects of the present invention. 
     In an embodiment, multiple presser assemblies  200  may be surface mounted to the bottom of the support board. In yet another embodiment, individual flat pressers  100  may be utilized in combination with one or more flat presser rail assemblies  200  to provide an even more tailored support and stabilization system for the sheet of material. In particular, additional flat pressers  100  may be added to the support board  24  to more specifically tailor the presser arrangement to the specific geometry of the carton/packaging blanks. 
     Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those of skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. Particularly, the present invention is not limited to a particular structure and arrangement of the slide components surrounding the extractor mechanism. 
     In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed in the above detailed description, but that the invention will include all embodiments falling within the scope of the above description.