Patent Publication Number: US-2021170620-A1

Title: Method and apparatus for processing cutting-creasing rules of die-cutters

Description:
FIELD OF THE INVENTION 
     The present invention relates to the field of die-cutters and in particular refers to a method and an apparatus for making cutting-creasing rules to be used for assembling die-cutters. 
     STATE OF THE ART 
     As known, a die-cutter used in die-cutting machines comprises a flat or cylindrical support, normally made of multilayer wood, in which metal rules provided with a cutting and/or bending (creasing) profile are assembled; the rules are inserted by interference fit into corresponding seats obtained in the support and are arranged so as to reproduce the shape of a product to be made by die-cutting a sheet of paper or cardboard, for example a box. The seats in the support are generally obtained by laser cutting techniques. The insertion of the rules in the corresponding seats is usually manually carried out by an operator, often with the aid of a hammer. 
     Raw metal rules are initially unwound and machined, e.g. punched, milled, rounded, bent several times to obtain the desired shapes, and finally cut to size. 
     Structurally, a typical die-cutter rule comprises a base, which can be orthogonally inserted into the support in a corresponding seat, and an edge facing the side opposite the support, i.e. facing the sheet to be die-cut. The rules have heights extending between the base and the edge facing the sheet to be die-cut. On the support of the die cutter, further elements combined with the rules are also provided, for example elastic elements which facilitate the detachment and separating of the die cut portion of the sheet from the die cutter itself. 
     The rules are mainly subdivided into cutting rules (blades) and bending or creasing rules (creasing profiles). 
     In the first type, the rule has a cutting edge, typically with a triangular section, able to cut the sheet to be die-cut when pushed into abutment against the latter and against a counter-male die positioned on the opposite side with respect to the sheet. Cutting rules are used, for example, to make cutting lines that define the perimeter profile of a box. 
     The bending or creasing rules, on the other hand, have a rounded edge shaped to press, without severing, the sheet against a seat of a counter-male die positioned on the opposite side with respect to the sheet to be die cut. This way, a trace is obtained along which the bending of the sheet is easy. This is the case, for example, of the creasing lines on the flaps of a paper or cardboard box. 
     Other rules allow the so-named weakening or tear-off lines to be made, i.e. dashed lines which alternate cut lengths with uncut lengths. 
     A manufacturer of die-cutter rules is, for example, Martin Miller firm (www.martin-miller.com). Die-cutter manufacturers buy the rules and process them in order to obtain the blades, creasing rules and accessories required to make each time the desired die-cutter. 
     In the paper processing industry, hybrid solutions are sometimes used, i.e. rules called cutting-creasing rules (or cut-crease rules), characterized by alternating cutting lengths, i.e. blades, and creasing lengths, i.e. creasing profiles. 
     For example, US 2018/178477 describes a cutting-creasing rule obtained by assembling sections of cutting rule and sections of creasing rule, and a method for obtaining such rule. In particular, this document teaches how to make the rule by fit coupling sections of the cutting rule and sections of the creasing rule in the desired sequence, by exploiting a dovetail coupling specifically designed for this ( FIGS. 3-6 ; claim  1 ). Each section of the rule, whether a cutting one or a creasing one, is provided with either a dovetail profile or a profile shaped as a puzzle piece at its bottom part—the one intended to be inserted into a corresponding seat obtained in the die-cutter support: this arrangement allows the sections to be assembled one to the other, in the desired sequence, until the cutting-creasing rule with the desired pattern of the cutting edge and creasing profile is obtained. The sections of the rules, including the respective dovetail profile or similar profile, are obtained by cutting to size, with shaped tools, continuous cutting rules and continuous creasing rules. 
     The solution described in US 2018/178477 has been ignored for some time by the paper processing industry, because it involves some difficulties. 
     In general, the individual sections of the cutting rule and creasing rule must be made very accurately, with tight dimensional tolerances. In fact, all the rule sections must be able to be aligned with extreme precision during the assembly on the die-cutter: the rule sections must not be vertically misaligned with respect to each other, because this would result in an inaccurate die-cutter, or even in an unusable cutting-creasing rule. 
     In addition, the sections of the cutting rule must have a perfectly straight cutting edge, which means that, when shearing the rules from which the sections are obtained, the corners of the cutting edge of each section of rule must not be bent or damaged at their ends. 
     Finally, it must be possible that, on request, on the initial and final edges of the creasing profile, the sections of creasing rule have indentations or chamfers, whose dimensions can be set each time. 
     Generally, the cutting-creasing rules described above are made by using two different shearing tools that produce shaped cuts, one for each type of rule section: the first tool has the function of shearing sections of a cutting rule and the second tool has the function of shearing sections of a creasing rule. 
     The reason why the manufacturers of apparatuses for processing the rules have been led to use two different shearing tools is that cutting rules and creasing rules usually have different heights. 
     However, precisely because the rule sections to be assembled are obtained with two different shearing tools, the assembled cutting-creasing rules can probably be imperfect, the rule sections that make it up being not perfectly aligned vertically, due to different mechanical tolerances of the two different shearing tools used to shear the sections. 
     Another limitation of the current method of making cutting-creasing rules is the fact that the first shearing tool used for the cutting rule can shear sections of the rule having only one specific height: if sections of the cutting rule with different heights are desired, the tool has to be changed. 
     In addition, in modern molding systems for boxes, a counter plate made of milled steel is used in the crease areas; in these cases, sections of cutting-creasing rule in which the height of the creasing profile is sometimes even greater than that of the cutting blade have to be created. The admissible geometrical tolerances of the sections of cutting-creasing rule must be within values of about 0.03 mm, a value that is difficult to obtain by using two different shearing tools to machine the rule sections to be assembled with one another. US 2016/121507 describes a solution according to the known art. 
     US 2018/0178477 describes a method for making a cutting-creasing rule for cutting-dies. First, sections are separated from a cutting rule for die-cutters having height H, the sections being provided with a cutting edge and with coupling means to obtain a shape coupling with sections of a creasing rule. Then, sections are separated from a creasing rule for die-cutters having height H′, the sections being provided with a creasing profile and with coupling means to obtain a shape coupling with sections of a cutting rule. Finally, the sections of cutting rule are coupled in succession to the sections of creasing rule until the cutting-creasing rule is obtained. 
     SUMMARY OF THE INVENTION 
     Object of the present invention is therefore to provide a method and an apparatus that allow to overcome the limits of the solutions available today, in particular allow to manufacture cutting-creasing rules having excellent quality, characterized by high dimensional and constructional accuracy. 
     Therefore, a first aspect of the present invention concerns a method according to claim  1 . 
     In particular, the method comprises: 
     (a) from a cutting rule for die-cutters having height H, separating sections provided with a cutting edge and provided with coupling means to obtain an interlocked shape-coupling with other sections of a creasing rule; 
     (b) from a creasing rule for die-cutters having height H′, separating sections provided with a creasing profile and provided with coupling means to obtain an interlocked shape-coupling with other sections of a cutting rule; 
     (c) coupling in succession the sections of cutting rule to the sections of creasing rule until the cutting-creasing rule is obtained. 
     Advantageously, steps (a) and (b) are not carried out by tools different from each other for the cutting rule and the creasing rule, but by the same shearing tool, by shearing the rules so as to intercept the upper edges thereof, i.e. by intercepting the cutting edge of the cutting rules and the creasing profile of the creasing rules which are sheared each time. Since the cutting rules and the creasing rules can have same or different heights, this condition can be achieved in two ways. 
     In a first, complete-shearing mode, the shearing tool intercepts the rules throughout their height, i.e. it protrudes beyond the upper and lower edges of the rules which are each time sheared. Therefore, each time the shearing tool is activated, it separates a section from the respective rule. For example, the shearing tool defines an impression, i.e. the shape of the shaped cut it makes on the rules, whose height H″ is greater than the height H of the cutting rule and greater than the height H′ of the creasing rule, or at least is equal to the greater one between H and H′. 
     In a second, partial-shearing mode, which is independent of the height H″ of the impression of the shearing tool (which could even be less than the height H of the cutting rule and less than the height H′ of the creasing rule, or at least is equal to the smaller one of the heights H and H′), during the shearing the relative position of the rules with respect to the shearing tool is such that the impression of the shearing tool intercepts the cutting edge of the cutting rule and the cutting edge of the creasing rule, i.e. the impression of the shearing tool protrudes beyond the upper edge of the sheared rules, but does not intercept the lower edge of the rules. In this case, the rule each time subject to shearing is only partially cut, remaining intact at its lower edge, which is not intercepted by the shearing tool and where a connecting portion remains. The separation of the rule sections is completed at a later time, downstream of the shearing tool, for example with shears. 
     Herein, the expression “height H” of the impression of the shearing tool means the pattern of the impression on a plane, in particular the plane where the rules lie during shearing, along the height of the rules themselves. 
     The two ways described above allow both cutting rules and the creasing rules to be sheared with the same tool, even when the rules have different heights; since the shearing is performed with the same tool, the precision of execution is the same for the sections of cutting rules and for the sections of creasing rules, i.e. the sections have the same dimensional tolerances even if obtained from different rules. As direct result, by coupling the sections obtained with this method to each other, a cutting-creasing rule of excellent quality is assembled, characterized by precise alignment of the lower edges of all the sections that make it up, and without undesirable vertical misalignments between the sections; the assembly is not only precise, but also requires less time than the solutions used so far, and there is no waste. 
     Among other things, the proposed solution allows the simplification of the layout of the equipment normally used to shear the sections of the rule, right because it intends to share the same shearing tool for the cutting rules and the creasing rules. 
     Preferably, steps (a) and (b) are carried out by using the same shearing unit provided with:
         a plane for feeding or sliding the cutting rules and the creasing rules,   a shearing tool which can be orthogonally moved with respect to the feed plane, and   a corresponding shearing die into which the shearing tool is inserted.       

     The shearing tool together with the shearing die define the above-mentioned impression. The impression includes the side edges of the sheared sections, i.e. the side edges of both the sections of the cutting rules and the sections of the creasing rules as well as the respective coupling means. 
     Preferably, the coupling means include shaped projections and respective accommodating seats. 
     In the preferred embodiment the shaped projections and the respective accommodating seats have complementary shapes, e.g. they are dovetail shaped. Alternatively, they can be circular, half-moon-shaped, mushroom-shaped, etc., as long as they allow to obtain a shape coupling as puzzle pieces, with a rule section side by side with the consecutive rule section. 
     Preferably, the method also comprises prior to step (a), the optional step of: 
     (a′) obtaining notches or recesses at the cutting edge of the cutting rule and/or at the creasing profile of the creasing rule. 
     In practice, it is advantageous to cut notches at the cutting edge of the cutting rules and/or at the creasing profile of the creasing rules, before the rules are sheared. The function of the notches is to ensure that the cutting edge of each sheared section of cutting rule and/or the creasing profile of each sheared section of creasing rule are not damaged right during shearing. 
     By taking care that shearing is performed so that the impression of the shearing tool intercepts the notches, rule sections having perfect cutting edges, with sharp corners without defects can be obtained and, similarly, rule sections having creasing profiles without defects can be obtained. This can be achieved by obtaining the notches at a distance of L on at least one between the cutting rule and the creasing rule, and by carrying out steps (a) and (b) by separating sections of cutting rule and sections of creasing rule which are between two consecutive notches. 
     Clearly, the notches can also be made with regular pitch, i.e. with constant distance L, but more frequently the notches have to be made with a pitch (and therefore a distance) that is not constant, because the cutting-creasing rule to be made is customized. The method can be carried out in both cases. 
     Step (a′) can be carried out by aligning the shearing tool each time with an edge of the notch at which either a section of the cutting rule is separated or a section of the creasing rule is separated. If the alignment is not set, along the upper profile of the cutting-creasing rule there will be chamfers, i.e. interruptions between the consecutive cutting edges and creasing profiles. 
     For example, step (a′) can be implemented with punching techniques, i.e. by using a punch or punching unit provided with several punches (and corresponding dies). 
     Preferably, step (a′) is implemented by using a punching tool positioned upstream of the shearing tool with respect to the feed direction of the cutting rules and the creasing rules in the same processing apparatus. This way, the shearing is subsequent to the formation of the notches. 
     Therefore, a second aspect of the present invention concerns an apparatus according to claim  13  for processing cutting-creasing rules for die-cutters. 
     In particular, the apparatus comprises at least one shearing tool and feeding means to feed cutting rules and creasing rules to the shearing tool. Advantageously, the impression or shearing shape defined by the shearing tool intercepts the cutting edge of the cutting rules and the creasing profile of the creasing rules each time they are subject to shearing, regardless of their height, i.e. the shearing tool is positioned with respect to the rule-feeding means so as to intercept anyway the upper edge of the rule each time brought under the shearing tool. 
     Other advantageous characteristics of the apparatus are described in claims  14 - 19 . 
    
    
     
       BRIEF LIST OF THE FIGURES 
       Further characteristics and advantages of the invention will be better highlighted by the review of the following detailed description of a preferred, but not exclusive, embodiment illustrated by way of example and without limitations, with the aid of the accompanying drawings, in which: 
         FIG. 1  is an elevation view of a cutting-creasing rule made with the method according to the present invention; 
         FIG. 2  is a perspective view of the cutting-creasing rule shown in  FIG. 1 ; 
         FIG. 3  is an enlargement of  FIG. 1 ; 
         FIG. 4  is a perspective view of a cutting rule processed according to the method of the present invention for making sections of cutting rule in order to assemble a cutting-creasing rule; 
         FIGS. 5-8  are elevation views of the cutting rule shown in  FIG. 4 , in which each of  FIGS. 5-8  sequentially shows a further corresponding step of the method according to the present invention; 
         FIG. 9  is a perspective view of a punching unit of the apparatus according to the present invention, having the function to make notches according to a first step of the method of the present invention and to obtain the rule shown in  FIG. 4 ; 
         FIG. 10  is an enlarged perspective view of a detail of the punching unit shown in  FIG. 9 ; 
         FIG. 11  is a perspective and enlarged view of a detail of the punching unit shown in  FIG. 9  during the processing of a cutting rule; 
         FIG. 12  is also a perspective and enlarged view of a detail of the punching unit shown in  FIG. 9  during the processing of a cutting rule; 
         FIG. 13  is a perspective view of a shearing unit of the apparatus according to the present invention, intended to shear sections of cutting rule and sections of creasing rule; 
         FIG. 14  is a perspective and enlarged view of a detail of the shearing unit shown in  FIG. 13 ; 
         FIG. 15  is a perspective and enlarged view of a detail of the shearing unit shown in  FIG. 13  during the processing of a cutting rule; 
         FIG. 16  is a perspective and enlarged view of a detail of the shearing unit shown in  FIG. 13  during the processing of a creasing rule. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a cutting-creasing rule  1  obtained by the method according to the present invention, intended to be mounted on a die-cutter. The rule  1  is finished and ready for use, i.e. it is ready to be received in a corresponding seat obtained by laser cutting in the die-cutter supporting plate. 
     The rule  1  is obtained by coupling in succession a plurality of sections  2 ′- 2 ″″ sheared from a cutting rule  13 , i.e. a rule  13  with a cutting edge  4 , and a plurality of sections  3 ′- 3 ″″ sheared from a creasing rule  14 , i.e. a rule provided with an upper creasing edge  5 , also called creasing profile  5 . The sections  2 ′- 2 ″″ of cutting rule are generally denoted by the reference number  2  and the sections  3 ′- 3 ″″ of creasing rule are generally denoted by the reference number  3 . 
       FIG. 2  shows the rule  1  perspectively. In this figure we can best appreciate the difference in the shape of the cutting edge  4  of the sections  2  of cutting rule, substantially wedge or knife shaped, and the shape of the upper edge  5  (also called upper profile) of the sections  3  of creasing rule, substantially rounded. All sections of cutting rule  2 ′- 2 ″″ and all sections  3 ′- 3 ″″ of creasing rule have height extending between a lower edge  2   i ,  3   i  and either the cutting edge  4  or the upper edge  5 , respectively. In order for the rule  1  to be usable and to allow sheets of paper or cardboard to be die-cut with the desired dimensional accuracy, the height H, H′ of the rule sections  2  and  3  have to be precise and the lower edges  2   i  and  3   i  of all sections  2 ′- 2 ″″ of cutting rule and all sections  3 ′- 3 ″″ of creasing rule have to be perfectly aligned. 
     In the example shown in  FIGS. 1 and 2 , the cutting-creasing rule  1  consists of sections  2  of cutting rule alternated in succession with sections  3  of creasing rule, so that in the upper edge of the rule  1  there are cutting edges  4  alternated with upper creasing edges  5 . The height H′ of the sections  3  of creasing rule is greater than the height H of the sections  2  of cutting rule, i.e. H′&gt;H; this is only an example, since in general the rule  1  can be assembled by coupling sections  2  and  3  in which H′&lt;H or H′ is substantially equal to H. 
     In the example shown in figures, the thickness of the rule sections  2  and  3 , and therefore also the thickness of the finished rule  1 , is equal to 0.71 mm, H=22 mm and H′=24 mm. The rule sections  2  and  3  are made of carbon steel. 
       FIG. 3  is an enlargement of  FIG. 1  that allows the following constructive details, however visible also in the  FIGS. 1 and 2 , to be best appreciated. 
     Between the cutting edge  4  of the sections  2  of cutting rule and the upper creasing edge  5  of the sections  3  of creasing rule, there are preferably chamfers  6 , which can also be defined as indentations. In the example shown in figures, the chamfers  6  are obtained on the sections  3  of creasing rule, but in general they can also be obtained on the sections  2  of cutting rule or else on both types of rule sections  2  and  3 . In practice, the chamfers  6  create a small gap between the cutting edges  4  and the upper creasing edges  5 . 
     Another optional characteristic is the so-called bridge-like notch  7 , which is obtained indifferently in the sections  2  or  3  of rule. The bridge-like notch  7  is designed to allow the insertion of the creasing-cutting rule  1  in the dedicated seat obtained in the die-cutter support, thereby preventing the rule  1  from interfering with the support of the die-cutter where the respective material has not been cut, i.e. where the accommodating seat of the rule  1  is locally interrupted. For example, if the die-cutter support is made of wood, thanks to the bridge-like notch  7  the length of the accommodating seat of the rule  1 , where the wood has not been removed by laser, can be by-passed. 
     The reference number  8 , on the other hand, generally denotes an essential construction detail, i.e. a shape coupling between the sections  2 ′- 2 ″″ of cutting rule and the sections  3 ′- 3 ″″ of creasing rule. In the example shown in the figures, the coupling  8  is obtained by making dovetail projections  9 ,  11  on the side edge of a rule section  2 ,  3  and, on the opposite side of the same rule sections  2 ,  3 , a corresponding accommodating seat  10 ,  12  complementary shaped, to accommodate the projections  9 ,  11 . This arrangement allows the sections  2  to be coupled to the sections  3  as pieces of a puzzle. 
     The specific shape of the coupling  8  shown in figures is not the only one possible, i.e. the figures show a non-restrictive embodiment, but in general the coupling  8  can also be obtained by making the projections  9 ,  11  and the corresponding accommodating seats  10 ,  12  having shapes different from the dovetail one, such as circular shapes, mushroom shapes, etc. The only precaution is that the projections  9 ,  11  and the corresponding accommodating seats  12 ,  10  have to be made so as to be complementary for the coupling: they have to allow the sections  2  and  3  to be effectively interlocked with each other in order to assemble the rule  1  without interruptions and with the sections  2  and  3  precisely aligned at the respective lower edges  2   i ,  3   i.    
     The number of the projections  9 ,  11  and the corresponding accommodating seats  12 ,  10  can also be different from two for each side of the sections  2  and  3 , as shown in the figures. For example, the coupling  8  can be obtained with a single projection  9  and a corresponding accommodating seat  12  having dovetail or mushroom or other suitable shape. 
     The method according to the invention that allows the cutting-creasing rule  1  to be obtained will be described hereafter. 
     The method provides for separating the sections  2 ′- 2 ″″ from a cutting rule  13 , for example of a commercially available type, and the sections  3 ′- 3 ″″ from a creasing rule  14  ( FIG. 16 ), for example of a commercially available type. 
     Optionally, before initiating this operation, the rules  13  and/or  14  are first processed in order to obtain the notches or recesses  15  shown in  FIG. 4 . The distance between the notches  15  corresponds to the length L of the sections  2 ′- 2 ″″ of cutting rule and of the sections  3 ′- 3 ″″ of creasing rule to be obtained. As will be described later, the notches  15  are preferably obtained with a punching unit  16 , and more preferably with the cartridge unit  16  visible in  FIGS. 9-12  which can be installed on an apparatus for processing rules  13 ,  14  for die-cutters according to the present invention. 
       FIG. 4  relates to this optional step: processing notches  15  on a cutting rule and/or on a creasing rule  14 . In particular,  FIG. 4  shows a cutting rule  13  on which 15 cuts have been made at a distance L from each other. If necessary, the same processing can be carried out on a creasing rule  14 . 
     As described below, after creating the notches  15 , an intermediate section between two notches  15  can be separated from the rule  13  or  14 . The notches  15  are designed so that, during the separation of the sections  2 ′- 2 ″″ of cutting rule and the sections  3 ′- 3 ″″ of creasing rule, which provides that the rules  13 ,  14  are sheared, the cutting edges  4  of the sections  2 ′- 2 ″″ of cutting rule and/or the upper creasing edges (profiles)  5  of the sections  3 ′- 3 ″″ of creasing rule are prevented from being damaged, for example by being bent, weakened or broken at the corners. In addition, if when separating the sections  2 ′- 2 ″″ and the sections  3 ′- 3 ″″ from the respective rules  13 ,  14 , a clearance is left between the cutting tool used and the edge of the notches, then the notches  15  can also be made to obtain the chamfers  6 . 
       FIG. 5  shows a first step of the method according to the present invention: the cutting rule  13 , which in the example described above was previously processed to obtain the optional notches  15 , is subjected to further machining. The reference number  17  denotes the impression of a shearing tool  22  that, moving orthogonally to the rule  13 , removes a portion  13 ′ thereof and creates at the same time the accommodating seats  10  to accommodate corresponding projections  11  of one of the sections  3 ′- 3 ″″ of creasing rule. As described below, the shearing tool  27  is shown in  FIGS. 14-16 . 
     In particular,  FIG. 5  shows a first (complete shearing) mode in which the impression  17  of the shearing tool  27  has height greater than the height of the cutting rule  13  and the creasing rule  14 , or at least equal to the greater of the two. The shearing tool  27  is positioned with respect to the rules  13  and  14  which are each time sheared, so that the impression  17  encloses the height of the rules  13  and  14 , i.e. so as to intercept the cutting edge  4  and the lower edge  2   i  of the cutting rule  13  and the creasing profile  5  and the lower edge  3   i  of the creasing rule. 
     As described in the summary, this is not the only possible mode. In a second (partial shearing) mode, the impression  17 ′ of the shearing tool  27  intercepts the cutting edge  4  of the cutting rule  13  and the creasing profile  5  of the creasing rule, but does not intercept the lower edge  2   i  of the cutting rule  13  and the lower edge  3   i  of the creasing rule. Therefore, regardless of the height H″ of the impression  17 ,  17 ′, the cutting tool  27  partially separates the sections  2 ′- 2 ″″ of cutting rule and the sections  3 ′- 3 ″″ of creasing rule. In  FIG. 7  the reference number  29  denotes the portion of rule  13  not sheared when using this second mode. The rules  13  and  14  remain intact at the respective lower edges  2   i  and  3   i : the sections  2 ′- 2 ″″ of cutting rule and the sections  3 ′- 3 ″″ of creasing rule are definitely separated at a later time, for example by means of shears, downstream of the shearing tool  27  with respect to the feed direction of the rules  13 ,  14 . This second mode, which does not depend on the height of the impression  17 , is useful when the rules  13  and  14  have to be further machined between the partial shearing and the final cutting with the shears. 
     It should be noted that the shearing tool  27  is positioned with respect to the cutting rule  13  so that the impression  17  is aligned with the edge  15 ′ of the notch  15  further to the right, if any. If this does not happen, i.e. if the impression  17  is not aligned with the edge of the notch  15 , the previously described chamfers  6  are obtained (which can be obtained on the sections  2 ′- 2 ″″ of cutting rule and/or on the sections  3 ′- 3 ″″ of creasing rule;  FIG. 3  shows the case in which chamfers  6  are obtained on the sections  3 ′- 3 ″″ of creasing rule). 
       FIG. 6  shows the result obtained after shearing the portion  13 ′, which is the first portion at the beginning of a new cutting rule  13 : on the right edge, two dovetail seats  10  have been created to accommodate corresponding projections  11 . Cutting edges  4  with the perfect sharp corner  4 ′, i.e. not damaged by the shearing, for example not bent, can be obtained thanks to the shearing of the portion  13 ′ carried out at the notch  15 . In other words, the notches  15  allow the geometry of the cutting edges  4  to be preserved regardless of the depth and length of the notches  15 . 
       FIG. 7  shows a second step subsequent to the first one: a section  2 ″ is separated from the cutting rule  13  by shearing again orthogonally to the rule  13  itself. As can be noted by observing the relative position of the impression  17  of the shearing tool  27  with respect to the rule  13 , the shearing tool  27  is aligned with the edge  15 ″ of the only notch  15  left. As described above, this arrangement allows perfect corners  4 ′ of the cutting edge  4  to be obtained. 
       FIG. 7  shows the shearing of the section  2 ″ of cutting rule  4  according to the first mode, in which the height of the impression  17  of the shearing tool extends beyond both cutting edge  4  and the lower edge  2   i . As mentioned above, if the second mode is preferred, in which the impression  17 ′ of the shearing tool  27  does not intercept the lower edge  2   i  of the rule  13 , the section  2 ″ would be partially sheared, as the section  2 ″ would remain attached to the remaining part of the cutting rule  13  through the unsheared portion  29 . The portion  29  would then be cut by shears at a later time. 
       FIG. 8  shows the result obtained after shearing the section  2 ″ from the cutting rule  13  by using the first mode, i.e. by completely shearing the section  2 ″: on the right edge there are two previously created dovetail seats  10  and on the left edge there are two dovetail projections  9  that can be interlockingly inserted into the corresponding accommodating seats  12  of one of the sections  3 ′- 3 ″″ of creasing rule. In addition, the perfect corner  4 ″, i.e. not damaged by the shearing, for example not bent, can be obtained thanks to the shearing of the portion  2 ′ carried out at the notch  15 . 
     The steps described are also carried out on a creasing rule  14 , with the exception of the step of making the notches  15 , which is preferential but optional, and can be performed on only one of the rules  13 ,  14 , or both, depending on the need. 
     Having obtained the required sections  2 ′- 2 ″″ of cutting rule and the required sections  3 ′- 3 ″″ of creasing rule, the cutting-creasing rule  1  can be assembled by interlocking the sections with each other, for example manually, according to the desired sequence. Clearly, the method can be carried out to obtain sections  2 ′- 2 ″″ of cutting rule and sections  3 ′- 3 ″″ of creasing rule each having a given length, i.e. the length L of each section  2 ′- 2 ″″ and  3 ′- 3 ″″ can be selectively set, if necessary, in order to obtain sections of different length. 
       FIGS. 9-12  help to understand how the optional notches  15  can be obtained in practice. For simplicity, the figures show the case in which the notches  15  are obtained on a continuous cutting rule  13  but, alternatively or in addition, the same technique can be used, if necessary, to obtain the notches on a creasing rule  14  as mentioned above. In the example shown in the figures, the notches  15  are obtained with a cartridge unit  16  that punches the rules  13  and/or  14 , i.e. a unit that can indifferently punch a cutting rule  13  and a creasing rule  14 . 
     The cartridge unit  16  is an interchangeable unit of an apparatus for processing metal rules for die-cutters; an example of a cartridge unit, even if intended for other types of machining (for processing the so-called nicks which are different from the notches  15 ), is described in the European Patent EP 2851169 in the name of the Applicant. 
     The cartridge unit  16  is provided with a feed plane  18  for feeding the rules  13 ,  14 . On the feed plane  18  a cutting rule  13  or a creasing rule  14  is fed each time, with intermittent movement, along a longitudinal direction (identified by the arrow in  FIG. 12 ) corresponding to the lengthwise extent of the rule  13 ,  14 . The intermittent motion is given by a special actuator (not shown), for example a pair of counter-rotating motorized rollers having the rule  13 ,  14  inserted in between and positioned upstream of the cartridge unit  16 . The intermittent movement allows the rule  13 ,  14  to be fed so as to cover a distance corresponding to the length L shown in  FIG. 4 , then the rule is stopped and a notch  15  is made. For this purpose the cartridge unit  16  is provided with at least one punch  20  and a corresponding punching die  19 . The punch  20  can be alternately moved along a direction orthogonal to the feed plane  18  of the rules  13 ,  14 , while the punching die  19  is stationary and defines part of the plane  18 . The combined action of the punch  20  and the corresponding punching die  19  allows a portion corresponding to a notch  15  to be cleanly cut from the rules  13 ,  14 . When the unit  16  is activated, at a time when the rule  13 ,  14  is stationary, the punch  20  lowers on the rule  13  or  14  and passes through it, intercepting the die  19  on the opposite side of the rule  13 ,  14  with respect to the initial position of punch  20  itself. 
     As best shown in  FIG. 10 , preferably the cartridge unit  16  is provided with several die-punch pairs  21 - 22  and  23 - 24  to be able to make on the rules  13 ,  14  notches  15  of different sizes, for example more or less high or more or less long. 
     The actuator of the punches  20 ,  22  and  24  is not shown in the figures, for simplicity; for example it can be an actuator of the type described in EP 2851169. 
     In particular,  FIGS. 11 and 12  show the punch  22  having just made a notch  15  on a cutting rule  13  at a distance L from another notch  15  previously made, in order to obtain the rule  13  having the characteristics shown in  FIGS. 4 and 5 . The distance L is adjustable to selectively obtain sections  2 ′- 2 ″″ of cutting rule each of the desired length. 
     As an alternative to punching, the notches  15  can also be performed with milling or grinding techniques. In this case, the cartridge unit  16  is replaced by a unit provided with one or more millers or grinding wheels that can be activated to remove material from the rules  13  or  14 . 
     The technique described above can also be used to obtain the bridge-like notch  7  shown in  FIG. 3 . 
       FIG. 13  shows a shearing unit  25  as a whole having the function of shearing the sections  2 ′- 2 ″″ of cutting rule and the sections  3 ′- 3 ″″ of creasing rule from the respective starting rules  13  and  14 . As shown, also the unit  25  is preferably of the interchangeable-cartridge type. 
       FIG. 14  shows the inside of the unit  25 , which is provided with a feed plane  26  for feeding the rules  13 ,  14 : similarly to what described above as regards to unit  16 , the rules slide on the plane  26  pushed with intermittent movement by a special actuator between a punching tool  27  and a corresponding punching die  28  of complementary shape. In the example shown in figures, the shearing tool  27  together with the die  28  define the impression  17  or  17 ′ shown in  FIGS. 5 and 7 : when the shearing tool  27  is at least partially inserted into the die  28 , the complete separation (first mode) or partial separation (second mode) of the sections  2 ′- 2 ″″ of cutting rule and sections  3 ′- 3 ″″ of creasing rule is obtained. 
       FIG. 15  shows the unit  25  when shearing a cutting rule  13  and  FIG. 16  shows the same unit  25  when shearing a creasing rule  14 , both in the first complete-shearing mode. The shearing tool  27  obtains the projections  9  and the dovetail seats  10  on the sections  2 ′- 2 ″″ of cutting rule, and obtains the projections  11  and the dovetail seats  12  on the sections  3 ′- 3 ″″ of creasing rule. 
     As described above, the method according to the present invention provides that the cutting rules  13  and the creasing rules  14  are sheared in the same unit  25  and not in different shearing units, as in traditional solutions. This provision allows an important result to be achieved: the perfect alignment of the sections  2 ′- 2 ″″ of cutting rule with the sections  3 ′- 3 ″″ of creasing rule. Using two different shearing units, one for the cutting rule  13  and the other for the creasing rule  14 , it is assumed that the two rules  13 ,  14  are processed with different dimensional tolerances, precisely because the shearing tools would be different for the two rules  13 ,  14 . On the other hand, using the same shearing unit  25  for both rules allows sections  2 ′- 2 ″″ of cutting rule and sections  3 ′- 3 ″″ of creasing rule with exactly the same dimensional tolerances to be obtained, which therefore can be perfectly assembled without inaccuracies of reciprocal positioning. This way, cutting-creasing rules  1  of excellent quality can be obtained, consisting of sections  2 ′- 2 ″″ of cutting rule and sections  3 ′- 3 ″″ of creasing rule which are able to be perfectly aligned and having cutting edges  4  and upper creasing edge  5  without defects. 
     In the preferred embodiment at least one between the cutting rule  13  and the creasing rule  14  is processed to obtain the notches  15 . In this case, the punching unit  16  is positioned on the apparatus according to the present invention upstream of the punching unit  25 , so that the rules  13 ,  14  first pass through the punching unit  16  and then through the shearing unit  25  without having to adapt the punching unit  25  to work on rules of different heights H, H′, exactly as usually happens with cutting rules  13  compared to creasing rules  14  to make a cutting-creasing rules  1 . In other words, first the notches  15  are punched and then the sections  2 ′- 2 ″″ of cutting rule and the sections  3 ′- 3 ″″ of creasing rule are sheared. 
     Since the punching of the rules  13 ,  14  at the respective upper edge (cutting edge  4  and creasing profile  5 ) takes place in the apparatus before the rules  13 ,  14  enter the shearing unit  25 , the latter can actually perform the shearing, i.e. the shaped cut, of both the cutting rules  13  and the creasing rules  14  regardless of their respective heights. 
     In fact, in the first mode, the impression  17  defined by the shearing tool  27  and the respective die  28  has higher height than both the rules  13 ,  14  and extends beyond the upper edges  4 ,  5  and the lower edges  2   i ,  3   i  of the rules  13 ,  14 . Referring to  FIG. 7 , the height H″ of the impression  17  is greater than H and H′ (H″&gt;H; H″&gt;H′), or at least is equal to the greater of the two heights, which in the example shown in the figures is H′ (H″=H′). This characteristic allows the same shearing tool  27  to be used on both rules  13 ,  14  without having to replace the tool each time you switch from processing a cutting rule  13  to processing a creasing rule  14 , or vice versa. 
     Alternatively, in the second mode, the impression  17 ′ of the shearing tool intercepts the upper edges  4 ,  5  of the rules  13 ,  14  but not the lower edges  2   i ,  3   i , thereby leaving connecting portions  29  that are cut by shears downstream of the shearing (not shown). 
     As mentioned above, since always the same cutting tool  27  is used to process both the rules  13  and  14 , it can be guaranteed that the sections  2 ′- 2 ″″ of cutting rule and the sections  3 ′- 3 ″″ obtained of creasing rule are straight and meet the required dimensional tolerances.