Method of making a counter-die cutter, adapting unit for a milling machine and milling machine comprising this unit

Abstract

A method of making a counter-die cutter for a die cutting machine having a die cutter and respective counter-die cutter includes: acquiring a digital drawing of a die cutter to be made, which is provided with comparing means; acquiring a digital drawing of a respective counter-die cutter to be made; providing a wooden support of the die cutter; making a plurality of comparing means on the support of the die cutter; making the die cutter; detecting the position and/or orientation of the comparing means of the finished die cutter; comparing the detected position and/or orientation with corresponding position and/or orientation of the comparing means being in the digital drawing of the die cutter; modifying the digital drawing of the counter-die cutter based on the detected differences to adapt the digital drawing to the finished die cutter; and making the counter-die cutter based on the modified digital drawing.

Claims

1. A method of making a counter-die cutter (2) for a die cutting machine comprising a die cutter (1) and a respective counter-die cutter (2), the method comprising the steps of: a. acquiring a digital drawing of a die cutter (1) to be made, said die cutter (1) being provided with comparing means; b. acquiring a digital drawing of a respective counter-die cutter (2) to be made; c. providing a wooden support (3) of the die cutter (1); d. making a plurality of comparing means on the support (3) of the die cutter (1); e. making the die cutter (1); f. detecting the position and/or orientation of the comparing means of the finished die cutter (1); g. comparing the detected position and/or orientation with corresponding position and/or orientation of the comparing means being in the digital drawing of the die cutter (1); h. modifying the digital drawing of the counter-die cutter (2) on the basis of the detected differences to adapt the digital drawing to the finished die cutter (1); and i. making the counter-die cutter (2) on the basis of the modified digital drawing.

2. The method of making a counter-die cutter (2) according to claim 1, wherein the step (d) of making a plurality of comparing means on the support (3) of the die cutter (1), comprises making a plurality of comparison holes (4).

3. The method of making a counter-die cutter (2) according to claim 2, wherein the step (d) of making a plurality of comparing means on the support (3) of the die cutter (1), comprises making said plurality of comparing means generally in peripheral areas of the wooden support (3).

4. The method of making a counter-die cutter (2) according to claim 1, wherein the step (d) of making a plurality of comparing means on the support (3) of the die cutter (1), comprises making said plurality of comparing means generally in peripheral areas of the wooden support (3).

5. The method of making a counter-die cutter (2) according to one of claims 1, wherein the step (e) of making the die cutter (1) comprises the following two sub-steps: making a plurality of cuts on a surface of the wooden support (3); inserting cutting rules (5) and creasing rules (6) inside said cuts.

6. The method of making a counter-die cutter (2) according to claim 1, wherein the step (f) of detecting the position and/or orientation of the comparing means of the finished die cutter (1) comprises detecting at least two coordinates, orthogonal to one another, of these means, with respect to a Cartesian reference system.

7. The method of making a counter-die cutter (2) according to claim 1, wherein the step (f) of detecting the position and/or orientation of the comparing means of the finished die cutter (1) is carried out by image capturing means or space scanning means.

8. The method of making a counter-die cutter (2) according to claim 1, wherein the step (g) of comparing the detected position and/or orientation with corresponding position and/or orientation of the comparing means being in the digital drawing of the die cutter (1) and/or the step of modifying the digital drawing of the counter-die cutter (2) on the basis of the detected differences to adapt the digital drawing to the finished die cutter (1) is/are carried out by conveniently-programmed programmable means (14).

9. The method of making a counter-die cutter (2) according to claim 8, wherein said programmable means (14) comprise a linear scaling algorithm.

10. The method of making a counter-die cutter (2) according to claim 1, wherein the step (i) of making the counter-die cutter (2) on the basis of the modified digital drawing, is carried out by a milling cutter (15) driven by an electronic control unit (10).

11. A counter-die cutter (2) made by the method according to claim 1.

12. A die cutter (1) comprising comparing means configured to carry out the method according claim 1.

13. A method of making a counter-die cutter (2) for a die cutting machine, comprising a die cutter (1) and a respective counter-die cutter (2), the die cutter (1) being provided with a wooden support (3) and comparing means, the method comprising the steps of: a. acquiring a digital drawing of the die cutter (1); b. acquiring a digital drawing of a respective counter-die cutter (2) to be made; f. detecting the position and/or orientation of the comparing means of the finished die cutter (1); g. comparing the detected position and/or orientation with corresponding position and/or orientation of the comparing means being in the digital drawing of the die cutter (1); h. modifying the digital drawing of the counter-die cutter (2) on the basis of the detected differences to adapt the digital drawing to the finished die cutter (1); and i. making the counter-die cutter (2) on the basis of the modified digital drawing.

Description

BRIEF LIST OF THE FIGURES

(1) Further characteristics and advantages of the invention will be better evident by the review of the following specification of some preferred, but not exclusive, embodiments illustrated for illustration purposes only and without limitation, with the aid of the attached drawings, wherein:

(2) FIG. 1 shows a schematic block diagram of the method of the present invention;

(3) FIG. 2 shows a sectional view of a detail of a die cutter during the step of creasing a die cut blank;

(4) FIG. 3 shows a plan view of a die cutter during a step of the method of the present invention;

(5) FIG. 4 shows a plan view of a counter-die cutter implemented by the method of the present invention;

(6) FIG. 5 shows a block scheme of an adapting unit according to the present invention; and

(7) FIG. 6 shows a block scheme of a milling machine according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(8) The following detailed description relates to a method of making a counter-die cutter, to an adapting unit for a milling machine intended for making counter-die cutters and to a milling machine comprising this unit.

(9) The method of the present invention relates in particular to counter-die cutters made by milling a metal or metal alloy plate, which are adapted to cooperate with die cutters provided with a flat wooden support.

(10) In FIG. 1 all the steps of the method of the present invention are outlined.

(11) Such a method, in accordance with the respective steps (a) and (b), provides the acquisition of digital drawings of a die cutter 1 and the corresponding counter-die cutter 2, both adapted to cooperate in a die-cutting machine. Such drawings are preferably CAD drawings.

(12) Thus, the method provides the step of providing a wooden flat-type support 3 of the die cutter 1 (step (c)) and for drilling on its surface a plurality of comparing means (step (d)), according to the digital drawing.

(13) In accordance with a preferred embodiment, the present invention provides for carrying out comparison holes 4 since they are simple to make, however equivalent comparing means can be provided, i.e. any concave, convex or flat reference with respect to the wooden support 3 that can serve to identify the point position of a small portion of the support 3. One could for example think of using small projecting elements or simply colored traces, for example drawn circles. Such comparing means are preferably punctiform.

(14) The comparison holes 4, or the equivalent comparing means, are preferably made in peripheral areas of the support 3, as visible in FIG. 3, so as to not interfere with the workings of the support 3.

(15) Then the die cutter 1 is made, according to step (e), preferably by making a plurality of cuts on a surface of the wooden support 3, in which the cutting rules 5 and the creasing rules 6 are then inserted, according to digital drawing. Preferably the cuts are carried out by means of a CO.sub.2 laser, as already known in the field.

(16) In FIG. 3, that shows a die cutter 1 after the step (e), only one cutting rule 5 and only one creasing rule 6 are denoted with the respective reference numbers for the sake of clarity of the drawing, however, substantially all the substantially horizontal lines and the substantially vertical lines represent cutting rules 5 or creasing rules 6.

(17) In FIG. 3 mounting holes 7 are then depicted, adapted for the mounting of the die cutter 1 on a die cutting machine, and further through holes of known type that could serve as air vents during the die cutting or as further mounting holes. These are usually made before making the cuts.

(18) Following the afore mentioned operations, it is likely that the so-made die cutter 1 has undergone deformations, i.e. that its real shape is different from the digital drawing. For this reason, the method of the invention provides a step (f) of detecting the position and/or orientation of the comparison holes 4 of the finished die cutter 1.

(19) In other words, once the manufacturing process of the die cutter 1 is ended, detecting means 13 to detect the position and/or orientation are used to detect the exact position of the comparison holes 4. For this purpose, at least two coordinates are detected, orthogonal to one another, of each of such comparison holes 4, with respect to a Cartesian reference system having origin in one of the four corners of the support 3, for simplicity reasons.

(20) The detecting means 13 preferably comprise image capturing means, such as for example a camera, or space scanning means or photocells.

(21) The Applicant found that detecting the position of the holes 4 is enough in the most frequent instances. For particular cases not yet experimented on the field, the orientation of the comparison holes 4 could also be determined, in order to obtain higher precision, a third spatial coordinate would be necessarily detected. Alternatively, the deformation of the comparison holes 4 detected in the image provided by the camera, or by equivalent means, could be studied, in order to deduce the orientation of the same. This is preferably carried out by special programmable means.

(22) Then a step (g) is carried out that provides for comparing the camera detected position and/or orientation with corresponding position and/or orientation of the comparison holes 4 being in the digital drawing of the die cutter 1. Such a comparison is preferably carried out by programmable means 14, suitably programmed for this purpose.

(23) In case of differences between the real comparison holes 4, i.e. the detected ones, and the ideal comparison holes 4, i.e. those being in the respective digital drawing, the method provides a following step (h) of modifying the digital drawing of the counter-die cutter 2 on the basis of the differences found so as to adapt the counter-die cutter 2 to the finished die cutter 1, i.e. to the real one. Such a step is also preferably carried out by programmable means 14 programmed for this purpose.

(24) They are known programs exploiting equally known algorithms, such as for example the linear scaling algorithms.

(25) Substantially such algorithms compare the detected coordinates of the comparison holes 4 with the ideal coordinates of the corresponding comparison holes 4, to obtain an error on each reference axis. If for example two coordinates x, y for the detected holes and x, y for the ideal holes are detected, the algorithm will calculate an error x (=x-x) and an error y (=y-y) for each comparison hole 4. It will then calculate the arithmetic mean of all the errors in the x direction and the arithmetic mean of all the errors in the y direction, in order to obtain a corrective factor having two coordinates (.sub.x and .sub.y):
.sub.x=x.sub.i/n.sub.y=y.sub.i/n (i=1,n),

(26) wherein n is the number of the comparison holes 4.

(27) The Applicant found that nonlinear algorithms can also be used, but such algorithms, much more complex than the linear algorithms, do not bring particular advantages.

(28) Once the corrective factor has been obtained, the programmable means 14 are adapted to apply such corrective factor to the digital drawing of the counter-die cutter 2 so as to obtain a modified drawing, i.e. conforming to the real die cutter 1. In other words, the creasing channels 8 are modified by a factor .sub.x in the x direction and by a factor .sub.y in the y direction. The Applicant found that, by doing so, a modified drawing of the counter-die cutter 2 can be obtained through which a counter-die cutter 2 is made that well couples with its die cutter 1, i.e. it is possible to achieve a mutual accurate positioning of the creasing rules 6 with the creasing channels 8, as shown in FIG. 2.

(29) Such a figure shows a detail of a die cutting machine during a step of die cutting a material 9. From such a figure, it is noted how a good coupling between creasing rules 6 and creasing channels 8 is strictly needed in order to achieve an accurate and effective creasing line.

(30) Where differences are absent between the detected and drawn holes, the algorithm will calculate null x and y and thus the corrective factor will have coordinates (0,0), whereby the drawing will not be modified, i.e. the step (h) will not be carried out.

(31) The last step of the method of the present invention, i.e. the step (i), comprises making the counter-die cutter 2 on the basis of the modified digital drawing. It is carried out by a milling cutter 15 driven by an electronic control unit 10. In other words, an electronic control unit 10 receives the digital drawing modified by the programmable means 14 and translates it in a milling program that, once applied to a plate, achieves making a counter-die cutter 2. Such an electronic control unit 10 can be integrated in the programmable means 14.

(32) The present invention also relates to a counter-die cutter 2 made by the described method and a die cutter 1 provided with comparison means adapted to carry out this method.

(33) In presence of an already finished die cutter 1 provided with comparing means, the method reduces to:

(34) a. acquiring the digital drawing of the die cutter 1;

(35) b. acquiring a digital drawing of a respective counter-die cutter 2 to be made;

(36) f. detecting the position and/or orientation of the comparing means of the finished die cutter 1;

(37) g. comparing the detected position and/or orientation with corresponding position and/or orientation of the comparing means being in the digital drawing of the die cutter 1;

(38) h. modifying the digital drawing of the counter-die cutter 2 on the basis of the detected differences to adapt the digital drawing to the finished die cutter 1;

(39) i. making the counter-die cutter 2 on the basis of the modified digital drawing.

(40) In practice steps (c), (d) and (e) are omitted.

(41) The steps of the method are not necessarily all consecutive. In fact, step (a) and step (b) can have a reversed order, i.e. it does not matter which digital drawing is acquired first. Furthermore, the succession of consecutive steps (c), (d) and (e), when present, can be carried out before steps (a) and (b), or between step (a) and step (b), without modifying the result. In other words, the die cutter 1 can be made and then the digital drawings can be acquired, otherwise a first digital drawing can be acquired, the die cutter 1 can be made and then the second digital drawing can be acquired.

(42) The finished counter-die cutter 2 can be seen in FIG. 4 where, for the sake of clarity of the image, only one reference number has been inserted related to a creasing channel 8, however, all the substantially horizontal and substantially vertical lines inside the counter-die cutter 2 represent creasing channels 8.

(43) The present invention, in a second aspect thereof, relates to an adapting unit 11 for a milling machine 12 adapted to make a counter-die cutter 2 by programmable means 14 programmed to mill a plate, based on a digital drawing of the counter-die cutter 2. Said adapting unit 11 comprises: detecting means 13 to detect the position and/or orientation of comparing means being on a finished die cutter 1 adapted to cooperate with the counter-die cutter 2 to be made; programmable means 14 adapted to compare the detected position and/or orientation with corresponding position and/or orientation of comparing means being in a digital drawing of the die cutter 1 and to modify the digital drawing of the counter-die cutter 2 on the basis of the detected differences to adapt the digital drawing to the finished die cutter 1.

(44) Preferably, the comparing means are comparison holes 4.

(45) Preferably, the detecting means 13 to detect the position and/or orientation of the comparing means comprise image capturing means, such as a camera for example, or space scanning means or photocells.

(46) The invention, in a further aspect thereof, relates to a milling machine 12 comprising at least one adapting unit as described above. The milling machine 12 further comprises at least one milling cutter 15 and an electronic control unit 10. The milling cutter 15, driven by the electronic control unit 10, removes material from a plate according to a milling program, so as to make a counter-die cutter 2 having the desired drawing. The electronic control unit 10 communicates with the programmable means 14 of the adapting unit 11, so that a counter-die cutter 2 precisely couplable with its corresponding die cutter 1 is obtained, for what explained above. The electronic control unit 10 can be integrated in the programmable means 14.

(47) The milling machine 12 also comprises a working table accommodating the finished die cutter 1 in order to detect the position and/or orientation of the comparing means. Following the detecting operation, the die cutter 1 is removed from the working table that will therefore accommodate the plate during the working thereof.

(48) In order to meet contingent and specific needs, the field technician could make further changes and variations to the method for implementing a counter-die cutter, to the adapting unit and the milling machine, as they have been described and claimed, without departing from the protection scope of the present invention.

(49) For example, although the present invention is based on flat type supports of die cutters and counter-die cutters, one could consider using the same method for cylindrical type supports, by adding a spatial coordinate to detect the reference means position and making the obvious changes as needed. Therefore, the adapting unit and the milling machine could also be used for cylindrical supports, by making the obvious changes as needed, without departing from the protection scope of the present invention.