Apparatus for cutting a die rule according to predetermined user's requirements and method for using the apparatus

Abstract

Apparatus for cutting an uncut die rule according to predetermined user's requirements, comprising a feeder block (23) for moving the die rule along a linear guided path in a first direction (x) and a cutting unit (40) arranged in a cutting zone at a section of said path, wherein the cutting unit (40) comprises a laser unit (50) arranged at the cutting zone at a first side of the guided die rule (10) and a beam receiving unit (70) arranged at the other opposite side of the die rule (10), wherein the laser unit (50) comprises an optical head (51) connected to a laser source (124) to emit laser beams towards points of said predetermined cut on said die rule (10) and being moved along a second direction (y) normal to the first direction, and the apparatus comprises means for the coordinated and controlled movement both of the optical head (51) and of the die rule (10) along their respective linear paths, wherein the guiding of the guided path is broken in the narrow cutting zone defined around the line of movement of the optical head (51). A die rule cutting method with the apparatus is also included.

Description

[0001] Apparatus for cutting a die rule according to predetermined User's requirements and method for using the apparatus.

[0002] Field of the Invention

[0003] The invention relates to an apparatus for cutting an uncut die rule according to predetermined user's requirements, comprising a feeder block for moving the die rule along a linear guided path in a first direction and a cutting unit arranged in a cutting zone at a section of the guided path.

[0004] The invention also relates to a method for cutting the die rule by means of the apparatus.

[0005] Background of the invention

[0006] US 10,427,248 B2 relates to the technology of making different packages from cardboard. The patent uses the term "package" in broad sense, it covers paperboard or carton boxes, parcels, cardboard boxes, brochures, flyers, plastic boxes, etc. Also, the term "cardboard" is used in broad sense, and it covers materials used to construct a package, pre-treated cardboard and / or plastic and / or paper-based materials. The term "cardboard" has also been used in broad sense covering cardstock, display board, corrugated fiberboard, paperboards of different paper-based material, folding boxboard, carton, blanks, blister cards, plastics board with enhancement or lamination.

[0007] To make the present specification concise, such broad interpretations will also be used therein. It is explained that the technology of making such cardboard boxes requires a pre-treatment including creasing, cutting, embossing, piercing or a combination of these operations.

[0008] A preferred way of performing such operation is the use of a steel rule die which, following an appropriate processing and forming, is inserted and embedded in a plywood die holder so that in the die holder the pre-designed contours of the product are cut in advance by laser, then the steel die rule formed previously to the same contour is inserted and held in these slots.

[0009] The present invention deals with the way how a steel band of die material with a pre-formed edge can be processed for insertion into the prefabricated slots of such a die holder plate.

[0010] The line of cuts made by laser in the plywood base plate cannot be continuous, since then the inner portions of the plate would fall out, therefore at certain distances the laser cuts are terminated, and narrow bridges are produced thereby that interconnect the two sides of the slots and render the plate a single rigid body. In places of such bridges the die rule must be cut so that the die rule can be inserted in the remaining slots. The depth of the cuts must allow that that cutting edge of the die rule swell out in the required height from the surface of the plywood plate. This height depends on the thickness of the cardboard to be cut and processed, and on properties of the pressing tool using the plywood plate with the die-rule inserted thereon. A typical height of the tip of the cutting edge above the surface of the plate is about 6 to 15 mm. DE 10 2007 011 516 Al relates to the processing of a die rule, wherein Fig. 1 illustrates in enlarged view how a narrow die rule with a sharp upper edge is embedded in a slot, and Fig. 2 shows a narrow cut made in the edge at a location where during use of the die the cardboard must not be cut. This publication uses form-milling for making the cuts. Because different types of cuts may be required, the publication suggests the using of a tool with four milling discs.

[0011] State of the art die rule processing machines use computer control and comprise a controlled feeding assembly that moves the steel band obtained in coils along a linear path where the prefabricated and hardened edge is at the top, and along the path there is a first processing site where the milling or grinding operations in the edge region are performed and at a second processing site the required cuts are made at the bottom and / or in the body of the band by die cutting tools, then there is a bending site where the previously processed and cut band is bent to the required shape, then the final tool cuts the band and removes the prefabricated die rules.

[0012] Such machines are commercially available e.g. by ELCEDE GmbH, Kirchheim / Teck Germany product name: COILMATE PRO, available at: https: / / elcede.de / produkte / tooling. One can find a similar machine available at a different manufacturer: Proform s.r.l. Caravaggio, Italy, product name: die making machines, visible at https: / / www.serviform.com / machines?id=2.

[0013] In such machines the die rules should be processed with a high accuracy, wherein the tolerance should be less than 100 microns, and in case the task changes (change of pattern and / or the width or edge profile of the band), the tool set used therein must be changed, which is a time-consuming operation, and the new tools are expensive to make. On the other hand, the tool sets, especially the cutting tools used in such machines get abraded after extended use and require replacement, which takes costs and labor. Because of the mechanical technology used for cutting and making the slots gaps narrower than about 0.2 mm cannot be made, however in certain fields the making of such narrow gaps is required, especially when making the edge region of the die rule.

[0014] In other field of technology laser cutting is a known technology which is used for cutting materials, and metal sheets. When a cut should be made with a predetermined profile, the optical head emitting the laser beams is moved along to the profile of the intended cut (in a plane spaced from the sheet material) so that the focal point of the laser beams remain always on the sheet, material to be cut. It is also a general practice that a pressurized gas is blown parallel to the laser beams which help removal of the molten particles. The pressure of the gas and of the beams exerts a force on the sheet material, norma to its plane, in front of the optical head, and the rear side of the sheet material needs to be supported by a support plate to prevent bending or deformation of the sheet material. Since the laser beams can be harmful to the supporting rear plate, openings corresponding to the shape of the intended cuts must be made in such support plates. As the task of the cutting often changes, the replacement of the support plate is often required, which step relates to extra workload and cost. The cutting is carried out mostly so that the laser beams are vertical and directed in downward direction, since a laser beam proceeding towards the floor cannot cause dangerous accidents.

[0015] Object of the invention

[0016] It is an object of the present invention to provide an apparatus and a method for processing a die rule, which is accurate, does not require replacement after extended use and in case the task of the technology is changed, this can be carried out by a new programming of the control process, but the components used do not require change and finally that can provide special forms and sizes of cuts and engravings which have been impossible or difficult to make with mechanical processing technology.

[0017] Summary of the invention

[0018] According to the invention the object of the invention is solved by an apparatus and a method as defined in the attached claims.

[0019] Description of the drawings

[0020] Fig. 1 shows the perspective view of a pair of die rules ready for use;

[0021] Fig. 2 is the perspective view of a die plate in which the die rules are inserted;

[0022] Fig. 3a and 3b show examples of different cuts and creasing depressions made in the die rule;

[0023] Figs. 4 a to d show different edge profiles of a die rule;

[0024] Fig. 5 shows the axonometric simplified view of an embodiment of the apparatus according to the invention;

[0025] Fig. 6 is the top view of the apparatus shown in Fig. 5;

[0026] Fig. 7 is the side view of the apparatus shown n Fig., 5 taken from a first side;

[0027] Fig. 8 is the side view of the apparatus shown in Fig., 5 taken from the opposite side;

[0028] Fig. 9 is the axonometric view of the laser unit and the beam receiving unit, partially in section;

[0029] Fig. 10 is the sectional view of the units shown in Fig. 9;

[0030] Fig. 11 is an enlarged top view of a detail of the beam screening structure;

[0031] Fig. 12 is an explanatory sketch showing the beam path with reflections and the path of the gas stream;

[0032] Fig. 13 is an enlarged section view of the cutting zone;

[0033] Fig. 14 is the general functional lock diagram of the apparatus; and Fig. 15 shows the diagrams of the laser power and the cutting speed during the laser treatment of a rectangular cut in the die rule.

[0034] Description of the preferred embodiments

[0035] For the better understanding of the task and field of use of the present invention Figs. 1 to 4 show certain prior art tools and their details how cardboard boxes are made. Fig. 1 shows a double part die rule 10a, 10b which is inserted in use in conforming nests of a die plate 11 made preferably of plywood and shown in Fig. 2. The die plate 11 has a long nest or slot that has a shape conforming to that of the die rules 10a, 10b, and to make the die plate 11 to have an integral body, along the nest at discrete intervals respective narrow bridges are formed that interconnect outer plate portion 12 and inner plate portion 13. Between the bridges the nest is made as throughgoing slots preferably by a CO2 laser which is a fast and accurate technology. The die rules 10a, 10b are made by a steel band which are hardened at their upper edge 15 region. The die rules 10a, 10b can be inserted into the conforming nest only in case appropriate cuts 14 are made at discrete locations conforming to the position and size of the bridges. The remaining height in the die rule above the cuts 14 determines the effective cutting height of the tool so obtained.

[0036] Depending on the task of the user, the required cuts 14 may have differing shapes. Fig 3a shows a few examples how the cuts 14 can look like. When the die plate 11 with the die rules 10 therein are placed in a press, and a sheet of cardboard and a negative die plate are placed underneath, the cardboard gets completely cut where the edges 15 of the die rule extend out in their full height. However, in making boxes, the cardboard does not have to be fully cut everywhere, because at later folding lines the cardboard requires only a creasing or thinning. At such locations the edges of the die rule must be shortened according to different profiles and extent. Fig. 3b shows a few examples how the edge 15 of a die rule can be formed by tooling therein shallow depressions 16 which can also have differing profiles and sizes.

[0037] Finally, Figs. 4a to d show examples of the different profiles of the edges 15 of the die rule 10. The user selects the appropriate shape depending on the material, thickness and intended properties of the box to be made.

[0038] The present invention has the main task to provide an apparatus and a method how the die rules 10 can be made to have the required cuts 14 and depressions 16. The starting basis for these works is a steel band with the required hardened edge 15.

[0039] The apparatus must be able to guide and forward the band along a linear path, pass it in front of an operation zone where the required cuts and depressions are made therein, and preferably it can also have a bending station where the previously cut die rule is bent to the required shape, (if one or more bending is required) and finally the apparatus can have a cutting unit where the ready pieces are separated and forwarded to their destinations.

[0040] The apparatus must function with high speed in an automated way with a high accuracy, wherein the tolerance range can be under 100 microns.

[0041] Reference is made now to Figs. 5 to 8 which show the simplified view of apparatus 1 made according to the invention mounted on base plate 20 supported on a stander not shown. The task of the apparatus 1 is to make the die rule 10 to take its final shape as shown in Fig. 2 when in can be inserted in the die plate 11. The initial uncut die rule band is not shown, from it the unprocessed die rule is fed in the apparatus 1 between a pair of linear guiding bars 21, 22. The distance between the guiding bars 21, 22 can be adjusted to fit to the actual thickness of the die rule 10 but the guiding bars 21, 22 do not squeeze the die rule 10 between them and they do not prevent the linear movement thereof. The height of the guiding bars 21, 22 is smaller than that of the die rule 10 placed between them so that the edge 15 is at the top, and the upper portion of the die rule 10 extends out between the guiding bars 21, 22 to a predetermined extent. The guiding bars 21, 22 guide the die rule 10 until it reaches the bending block, and their length is broken only at the cutting zone.

[0042] The first functional block of the apparatus 1 has the task of guiding and feeding the die rule 10 in longitudinal direction which will be referred to as direction x. Feeder block 23 has precision threaded shaft 24 rotated by feeder motor 25 according to strict control of a processor, and this moves a sliding gate 26 guided precisely by a pair of slots 27, 28 tooled in the base plate 20 (see the top view of Fig. 6). At the upper section where the die rule 10 extends out from the guiding bars 21, 22, a pair of electronically controlled clamping jaws 29, 30 are mounted on the sliding gate 26, and when the clamping jaws 29, 30 are energized, they squeeze the upper section of the die rule 10 between them, and when the motor 25 is precisely driven, the die rule 10 will slide along with the movement of the sliding gate 26 in the direction x in either forward or backward direction between the two guiding bars 21, 22.

[0043] The next block following the feeder block 23 is a cutting unit 40 that comprises two main parts, arranged at the two sides of the die rule 10, namely laser unit 50 and beam receiving unit 70, of which laser unit 50 moves the laser beam precisely according to a control program along the plane y-z, wherein the direction z is a horizontal movement normal to the longitudinal direction x as shown by the double arrow z in the top view of Fig. 6, and the direction y is the vertical direction as shown in the side view of Fig. 7. The beam receiving unit 70 has the task of receiving the laser beam following the cutting operation and to prevent the environment from any harmful effect of the high-power laser beam and to prevent that reflected laser beams can act on the die rule 10. It should be noted that laser cutting operations are mostly performed so that the direction of the laser beams is vertical which decreases the danger of accidents. In the present cutting task, however, the direction of the laser beams is horizontal, thus increased safety measures are required. At the place where the laser head can move, an operation window is provided in the guiding bars 21, 22. The structure of the laser unit 51 and of the beam receiving unit 70 will be explained in detail at a later part of the description.

[0044] Following the path of the die rule 10 along the direction x, at a distance from the cutting unit 40 bending block 90 is arranged which has the task of bending the die rule 10 at the corner regions of the cardboard to be made according to the user's needs and plans. The required geometric data are fed and stored in advance in the central processor of the apparatus 1. The design of the bending block 90 is per se known and comprises a column 91 which is an upright cylinder mounted on a support 92 including a step motor. The previously cut die rule 10 is led trough the body of the column 91 which is turned to the required angle and bending thereby the die rule 10 to the required degree.

[0045] The final station of the apparatus is cutting unit 100 arranged in the line of the die rule 10 further away from the bending block 90, and when the bent die rule 10 is moved further forward in the direction x, as soon as the end of the processed (cut and bent) die rule 10 approaches the zone of the cutting unit 10, it moves upward from a previously sunken position, and the die rule 10 engages its upper zone that comprises a conventional cutting tool with positive and negative die parts and separates the previously formed die rule 10 which is removed and gets collected.

[0046] Following the cutting, the die rule 10 is moved back to the zone of the cutting unit 40 for processing the next piece of the die rule 10.

[0047] Reference is made now to Figs. 9 to 13 which show different parts of the laser cutting unit 40. In the sectional view of Fig. 10 the die rule 10 can be seen as a narrow vertical line, and the picture shows the cutting unit along the transversal direction z, wherein the parts right from the plane of the die rule 10 belong to the cutting unit 50 and left from this plane the parts belong to the beam receiving unit 70. The scale of the figures is slightly distorted for the sake of better illustration. The actual cutting operation is performed by an optical head 51 connected through a glass fiber cable 52 to a fiber laser source (not shown). These are commercially available units, and a preferred product for the fiber laser source can be the 2kW model of IPG Photonics Corporation, Santa Clara, CA, USA, and a preferred type for the optical head 51 is the one having the commercial name: Minicutter 2D Lasermatic of the same company. The optical head 51 has a narrow central frontal opening surrounded by the mouth of a ring-like channel 63 through which a gas is blown in the direction of the beams to assist the removal of the melt metal particles produced by the laser power. The optical head 51 is equipped with a duct 53 that can be releasably connected to a pressurized and controlled gas source, that can be nitrogen or even compressed air.

[0048] The remaining parts of the laser unit 50 serve for the controlled and precise movement of the optical head 51 along the directions y and z. The vertical movement is controlled by motor 54 and a vertical drive 55 connected thereto. The horizontal displacement in the direction z is controlled by motor 56, its threaded shaft 57 is coupled by a gearing to and moving a pair of spindles 58, 59. The spindles are connected to the body of the laser unit 50 to which the optical head 51 is fixed. The laser unit 50 is mounted on the base plate 20 of the apparatus 1. The optical head 50 is moved in the vertical direction y by the control of the motor 54 within the full height range of the die rule 10. The movement in the transversal direction z is required from safety point of view, and when the optical head 51 is not in operation, it is moved out of the operational zone, away from the plane of the die rule 10. The range of displacement in this transversal direction z is much less than in the vertical direction y.

[0049] In front of the optical head 51 a frame 60 is arranged around the path of the die rule 10 in which an operational window 61 is provided, that covers the area through which the die rule 10 can be cut. The structure in the region of the operational window 61 is illustrated in the enlarged top view of Fig. 3 and the sectional elevation view of Fig. 12. In a preferred embodiment the guiding bar 21 which is behind the die rule 10 in the direction of the laser beams serves as a rear support for the die rule 10 during the laser cutting steps. In this zone the rear guiding bar 21 gets higher and thicker to cover the whole vertical range of the path of the optical head 51 and the operational window 61 is provided as a narrow vertical gap through this portion of the rear guiding bar 21. A rear support is required to resist the forces acting on the die rule 10 because of the pushing forces of the high-pressure gas blown through the channel 63 in the optical head 51. This wider and higher portion of the rear guiding bar 21 can also be realized as a separate rectangular support plate which is fixed behind the path of the die rule 10 in the operational zone. The frontal guiding bar 22 is made of two separate parts 22a and 22b in the operational zone as shown in Fig. 13, and the distance between the respective inner ends of these inner guiding bars 22a and 22b is wider than the width of the operational window 61, since place should be provided for the removal of the previously cut portions, and the gap formed between the inner ends of the two parts of the inner guide bars 22a, 22b allows sufficient space for the discharge of the cut pieces.

[0050] Let us note that in the scale of Fig. 12 the here explained design of the guide bars 21 and 22 cannot be seen as they are so tiny in that scale. The width of the operational window 61 is in the range of a few millimeters, while the distance between the two parts of the inner guiding bars 22a and 22b can be 20 mm or higher.

[0051] The above descried design around the optical window 61 has been made possible by the fact that the optical head 51 moves only in the vertical direction y unlike the movement of the optical head in a conventional laser cutting device which moves along a much wider zone, as it must cover the whole area to be cut. In the present invention the movement in the direction x is done by the controlled pulling of the die rule 10 so that the optical head 51 can move only along a vertical line.

[0052] Further away from the plane of the die rule 10, the beam receiving unit 70 is arranged, which defines a substantially closed interior. The beam receiving unit 70 has a frontal frame71 abutting the frame 60 around the operational window 61, and behind it a further frame 72 is arranged and attached to the frontal frame 71 which has the task of holding a beam screening structure 73 (shown separately in Fig. 11) which is arranged across the operational window 61 and comprises e.g. a surface of honeycomb-like tunnels 74 made of a thin metal sheet material, preferably aluminum, which has the task of preventing the passage of reflected laser beams from reaching the operational area. The way of its function will be explained in connection with Fig. 12.

[0053] The beam receiving unit 70 is mounted on a base plate 75 and comprises a pair of parallel, interconnected closing plates 76, 77 with inclined plane. The angle of inclination closed with the base plate 75 can be between about 45°and 80°, its value is not critical, in the exemplary embodiment it is around 75°. The task of the closing plates 76, 77 is to absorb and lead out the heat generated by the laser beams impinging thereon, and to prevent the reflected beams from reaching the operational zone. The material of the closing plates 76, 77 is preferably also aluminum because of their excellent heat conducting properties. They are relatively thick with a width of 15 mm each or more, and in the interior surface of the outer closing plate 77 a continuous groove is provided that constitutes a cooling channel 78 communicating at its ends with respective ducts 79, 80 extending out from the outer plate 77 for connection to a water supply and drain pipe. The two sides of the beam receiving unit 70 are closed by respective plates (not shown in the drawing). It worth mentioning that the inclined inner surface of the inner closing plate 76 is roughened e.g., by sand blasting, whereby scattered reflected beams will leave the roughened surface.

[0054] In the interior of the beam receiving unit 70 in the space formed between the beam screening structure 73 and the operational window, an opening is formed in the base plate 75 and under it through the base plate 20, which opening is communicating with a duct 81 to which a vacuum pump and a filter (not shown) can be connected, that have the task of removing the gas stream from the interior of the beam receiving unit 70 with the small metal particles obtained during the laser cutting operation. Reference is made to Fig. 12 which shows the path of the laser beams (full lines) and of the gas (dotted lines) in distorted scale to visualize the important details. In the enlarged picture of the optical head 51 a lens 62 is arranged that focuses the laser beams just to fall on the plane of the target die rule 10, and the high energy concentrated to this focus point melts and cuts the material of the die plate 10 at the adjusted focal point. The laser beams propagating past the punching of the die rule 10 and past the focal point are diverted, and when they reach the frontal surface of the beam screening structure 73, they will have much lower energy density. The dominant portion of the beams will proceed through the interior passages of the hexagonal openings and only a reduced number of the beams will hit the thin frontal edges of these openings. The energy falling on such edges cannot cause much harm there because of the smaller energy density. Most of the beams will reach the inclined and roughened inner wall of the inner closing plate 76, and in Fig. 12 such a location is shown in enlarged scale, and the beams will be reflected in any direction, whereby the reflected beams cannot pass through the hexagonal tunnels and arrive at the die rule 10.

[0055] In operation the optical head 51 and the die rule 10 are moving simultaneously or alternatively according to the actual cutting task, therefore the situation illustrated in Fig. 12 exists only for a very short time. The energy of the beams will heat the wall of the inner closing plate 76 and owing to its good heat conductivity and the fluid flowing through the cooling channel 78 the heat will be lead away. The large surface of the closing plates 76, 77 will keep the temperature in the interior of the beam receiving unit 70 with tolerable limits.

[0056] The gas is introduced through the duct 53 from a pump (not shown) and will stream through the ring-like channel 63 (shown in the enlarged view of Fig. 12) to the direction of the die rule 10 and its pressure will remove the small, molten metal particles. The gas will flow under the sucking effect of the vacuum pump through the space formed behind the die rule 10 towards to duct 81 as sown in Fig. 12.

[0057] The design of the beam receiving unit 70 provides sufficient protection against any leakage of the laser beams, and the inclined design of the closing plates 76, 77 with the roughened inner surface and the honeycomb-like beam screening structure 73 prevents not only the leakage but both the protection of the die rule 10 and the optical head 51 from any harm that would be caused by the spurious reflected beams.

[0058] Reference is made now to Fig. 14 which shows the general functional block diagram of the apparatus 1. The operation of the apparatus is fully automated and controlled by a computer 110 having a controller 111 or processor programmed according to the actual cutting task. Optionally, a remote control or programing is possible through user interface 112. The general task is to make the die rule 10 as required by the actual cutting task. This is symbolized in Fig. 14 as rule processing operation 113. As explained earlier, this function can be fulfilled by four coordinated tasks, namely rule feeding 114, laser processing 115, rule bending 116 and final cutting 117.

[0059] Rule feeding 114 includes feeding unit 118, movement control in the direction x 119, and x drive 120. The laser processing 115 has the task of cutting the die rule 10 according to the required design and to carry out that task, the optical head 51 must be moved, the laser beam must be controlled by switching on and off and by controlling the intensity. These are separate tasks jointly solved by optical head control 121 and this can be subdivided to a control of y-movement 122, z movement 123, control of the on-off state of the laser source 124, control of the processing gas 125 and the power control 126 of the laser beam. The control also includes the elements executing such controls, like y-drive 130 and z-drive 131.

[0060] The rule bending 116 has a bending unit 127 including turning operation 128 driven by a bending control 128. The position and angle of the require bending is included in the actual program.

[0061] The final cutting 117 uses edge cutting 132 and pneumatic ejection control 133, which ejects the cut final die rules to a collecting location, not shown.

[0062] As described earlier, the operation of the previously explained apparatus 1, namely the method according to the invention requires the simultaneous control of the listed parts and blocks. The actual work starts with the preparation of the control program in the knowledge of the final shape of the required die rule 10. The apparatus 1 can receive uncut die rules in the height range between about 20 mm to 100 mm, and in the thickness range between about 0,2 to 1 mm. The outer and inner guiding bars 21, 22 can fulfill their guiding function in the whole size range of the die rule 10, since the distance between them is adjustable to correspond to the actual thickness of the chosen die rule.

[0063] The movement of the fed die rule 10 in the direction x is controlled together with the control of the movement in the direction y of the optical head 51 in harmony with the required cutting plan. In this way in contrast to the movement control of conventional laser cutting machines the movements are divided between x control acting on the movement of the die rule, and the y control, and the optical head 51 must be moved only along the direction y. The movement of the optical head 51 in the direction z occurs when the laser beams are in off state for a period longer than any technology-determined momentary stop. Then the optical head 51 is moved backwards, away from the zone of the die rule 10, and in this remote position the on state of the laser source is prevented. During the cutting operation the optical head 51 should be moved to the starting position where the required cutting should be made, and the die rule 10 must be moved to the corresponding position so that the starting position of that cut will be opposite to the adjusted position of the optical head 51.

[0064] When the cutting operation is started, the momentary power of the laser source should be adjusted so that the cut line made in the die rule 10 must be as uniform as possible, and this requires the coordinated adjustment of the speed of the relative movement between the die rule 10 and the optical head 51, and the power of the laser source. Different powers are required for creasing the upper edge of the rule and for the cutting of recesses therein, which have predominantly the shape as illustrated in Fig. 15. There a rectangular cut 14 is shown in enlarged view drawn twice beside each other. In the first illustration the three main phases of the movement of the optical head 51 and the die rule 10 is illustrated. In section A only the optical head 51 moves in upward direction and the die rule 10 remains in its momentary position. Then in section B the optical head 51 retains its position and the die rule 10 is moved in the direction x till the end of the horizontal section B is reached and then it is stopped. Now in section C the optical head 51 is moved in downward direction with the stationary position of the die rule 51, and when the bottom edge of the die rule 10 is reached, the cut has been made and the apparatus can be brought to the next cutting site and task.

[0065] The adjacent illustration of the cut 14 includes letters from a to p which identify different parts along the circumference of the cut 14. The identification is required, because the diagrams above the illustration of the cut 14 shows the relative speed between the optical head 51 and the numbered points of the die rule 10, wherein the full line shows the percentual value of the momentary laser power, and the dashed line shows the relative speed.

[0066] To have a uniform cut profile, both the power of the beams and the speed of the optical head 51 should be adjusted and controlled. At lower speeds, namely at the beginning of the cutting operation when the operation starts, or at the corner regions where the speed and the direction changes, the focused laser beam spends longer time at a section compared to the travel with higher speed. Therefore, a longer illumination requires less laser power to provide a cut, and conversely at higher speeds higher power is required. The diagram of Fig. 15 illustrates this effect. In the section A a vertical head movement takes place in the direction y, while when the section B starts, the vertical movement is stopped and the die rule 10 will be moved in the direction x. At the end of the section B the die rule 10 is stopped and the optical 51 starts moving downward along the direction y. When the cut 14 has been made, the optical head 51 is moved away from the plane of the die rule 10 along the axis z. In case a creasing operation is required above the cut 14 in the edge region, the optical head 51 is moved upward until it reaches the edge zone, and if the die rule 10 was previously moved forward from the cutting zone, the feeder block 23 will reverse the sense of the movement in the direction x and the die rule 10 is returned to the section where the new cutting is required.

[0067] While the apparatus in the exemplary embodiment has been shown to have a bending unit and a final cutting unit, these units are not always required since die rules without any bending can also be required and in such case the final cutting can be solved also by laser cutting.

[0068] By the apparatus 1 according to the invention when the thickness, edge-profile and / or the height of the uncut die rule must be changed, there will be no need of changing the built-in tools, including using separate tools for the creasing the edge region and cutting the lower side of the die rule as it was required at the technology used earlier. Also, the replacement of the different tools after extended use can be spared. The spatial adjustment range of the optical head 51 covers all sizes of the uncut die rule. The distance between the guiding bars 21, 22 can be adjusted to receive any thickness of the uncut die rule. These properties render the subject apparatus faster and easier for use. The movement of the optical head 51 along a vertical line only has spared the use of specific inner support plate, as explained earlier. With the special control of laser cutting and using laser technology narrow slots referred to as nicks narrower than about 0.2 mm can also be made, which was not possible by using mechanical tools. The laser technology obtains the advantage that any shape of cut can be made without the need of using special tools.

[0069] So far, the cutting of the die rule 10 at the required positions has been explained. A further possibility of using the controlled laser unit 50 lies in that in addition to the precisely defined cutting operations, the labelling of the side surface of the die rule 10 can also be made with it like an engraving. In this case the optical head 51 must be adjusted to a smaller laser power, and the coordinated movement of the x and y coordinates of the optical head 51 and of the die rule 10 must correspond to the required label.

[0070] The present invention cannot be limited to the exemplary embodiments described but modifications can be made within the scope of the attached claims. List of the reference numbers and symbols

[0071] I apparatus

[0072] 10 (10a, 10b) die rule

[0073] II die plate

[0074] 12, 13 outer plate / inner plate

[0075] 14 cut

[0076] 15 edge

[0077] 16 depression

[0078] 20 base plate

[0079] 21, 22 guiding bar

[0080] 23 feeder block

[0081] 24 shaft

[0082] 25 motor

[0083] 26 sliding gate

[0084] 27, 28 slot

[0085] 29, 30 clamping jaw

[0086] 40 cutting unit

[0087] 50 laser unit

[0088] 51 optical head

[0089] 52 fiber cable

[0090] 53 duct

[0091] 54 motor

[0092] 55 vertical drive

[0093] 56 motor

[0094] 57 shaft

[0095] 58, 59 spindle

[0096] 60 frame

[0097] 61 operational window

[0098] 62 lens

[0099] 63 gas channel

[0100] 70 beam receiving unit

[0101] 71 frontal frame

[0102] 72 further frame

[0103] 73 beam screening structure 74 tunnel

[0104] 75 base plate

[0105] 76, 77 closing plate

[0106] 78 cooling channel

[0107] 79, 80 duct

[0108] 81 duct

[0109] 90 bending block

[0110] 91 column

[0111] 92 support

[0112] 100 cutting unit

[0113] 110 computer

[0114] 11 controller (processor)

[0115] 112 user interface

[0116] 113 rule processing

[0117] 114 rule feeding

[0118] 115 laser processing

[0119] 116 rule bending

[0120] 117 final cutting

[0121] 118 feeding unit

[0122] 119 x-control

[0123] 120 x-drive

[0124] 121 optical head control

[0125] 122 y-movement

[0126] 123 z-movement

[0127] 124 laser source control

[0128] 125 gas source

[0129] 126 power control

[0130] 127 bending unit

[0131] 128 turning operation

[0132] 129 bending control

[0133] 130 y-drive

[0134] 131 z-drive

[0135] 132 edge cutting

[0136] 133 pneumatic cutting & ejection

Claims

Claims:

1. Apparatus for cutting an uncut die rule according to predetermined user's requirements, comprising a feeder block (23) for moving the die rule along a linear guided path in a first direction (x) and a cutting unit (40) arranged in a cutting zone at a section of said path, characterized in that said cutting unit (40) comprises a laser unit (50) arranged at the cutting zone at a first side of the guided die rule (10) and a beam receiving unit (70) arranged at the other opposite side of the die rule (10), wherein the laser unit (50) comprises an optical head (51) connected to a laser source (124) to emit laser beams towards selected point(s) on said die rule (10) where the focus point thereof lies in an operational position, and means for the controlled moving of the optical head (51) along a second line in said operational position that has a direction normal to said first direction, wherein said guided path is broken in said cutting zone being an operational window (61) around said line of movement of said optical head (51), wherein the relative movement between the die rule (10) and the optical head (51) is defined by the combined control of said movements provided by said feeder block (23) along the first line and of said optical head (51) along said second line, and said optical head (51) can be moved away from said operational position along a third direction being normal to both the first and second directions when the optical head (51) is not emitting laser beams.

2. The apparatus as claimed in claim 1, wherein the plane of said die rule (10) is vertical, the first direction (x) is horizontal, the second direction (y) is vertical, and the third direction (z) is in the horizontal plane.

3. The apparatus as claimed in claims 1 or 2, wherein said guided path is defined by a pair of guiding bars (21, 22) arranged at both sides of said die rule (10) and the distance between the guiding bars (21) can be adjusted to fit to the thickness of the die rule (10), and the guiding bars (21, 22) are ended before and started after said operational window (61).

4. The apparatus as claimed in any of claims 1 to 3, wherein a rear support plate is arranged in the operational zone behind the die rule (10), and a narrow operational window (61) is cut through the support plate along said second line.

5. The apparatus as claimed in any of claims 1 to 4, comprising a pressurized gas source (125) coupled to a duct (123) on said optical head (51) to blow pressurized gas surrounding said emitted laser beams, and the beam receiving unit (70) comprises a gas flow path through said operational window (61) towards a duct (81) provided therein and leading to a vacuum pump, and the interior of the beam receiving unit (70) is closed at parts other than along said gas flow path.

6. The apparatus as claimed in any of claims 1 to 5, wherein in said beam receiving unit (70) comprises a closing plate (76) arranged to receive said laser beams, that has an inner surface which is inclined relative to the direction of said laser beams and being roughened to divert and scatter the impinging laser beams predominantly in directions other than towards said die rule (10) and to absorb and lead away heat generated by the incident laser beams.

7. The apparatus as claimed in claim 6, wherein a further closing plate (77) is arranged behind and attached to said closing plate (76), and a cooling channel (78) is defined between said closing plates (76, 77) through which a cooling fluid can be circulated, and said cooling plates (76, 77) are made of a heat conductive material.

8. The apparatus as claimed in any of claims 1 to 7, wherein a beam screening structure (73) is arranged opposite to the operational window (61) and spaced from the plane of said die rule (10) the beam screening structure comprises a plurality of adjacent tunnels (74) with axes extending beside each other parallel to the path of the laser beams.

9. The apparatus as claimed in any of claims 1 to 8, further comprising a bending block (90) arranged past the cutting unit (40) for bending the previously cut die rule (10) and a cutting unit (100) arranged past the bending block (90) for separating the previously cut and bent die rule (10).

10. A method of cutting a die rule (10) according to predetermined user's requirements using the apparatus as claimed in any of claims 1 to 9, wherein said optical head (51) is moved along said second line opposite to a starting point (q) of the planned cut on the die rule (10) and moving said optical head (51) to a position in which the focal point thereof falls on the plane of the die rule (10) and energizing said optical head (51) with laser beams so that a movement of the die rule (10) is made along said first line between the optical head (51) and coordinating the control of the movements along said first and second line so that the optical beam follows said predetermined cutting line.

11. The method as claimed in claim 10, wherein controlling the speed of said movement along said first and / or second lines and the power of said laser beams so that they increase and decrease together when the speed and / or the direction of the movement is changed.

12. The method as claimed in claims 10 or 11, wherein, and causing the laser beams to diverge past said focus point, and simultaneously with the emission of the laser beams passing gas through the cutting zone to remove molten metal particles therewith.

13. The method as claimed in any of claims 10 to 12, wherein directing said laser beams past said die rule (10) to get partially absorbed by cooling said closing plates (66, 67) and to get reflected predominantly to locations other than said die rule (10).

14. The method as claimed in any of claims 10 to 13, wherein following the cutting step moving said optical head (51) away from the cutting zone in the direction (z) normal to the plane of the die rule (10).

15. The method as claimed in any of claims 10 to 14, wherein the cutting includes creasing the edge of the die rule (10).

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