The invention concerns an apparatus for removing broken-out pieces, in particular waste potions, from a sheet of material containing blanks or the like flat portions, as set forth in the classifying portion of the independent claim.
EP 0 446 702 B1 to the present applicant discloses that automatic stamping machines for the production of blanks from sheets of card in the folding box industry have been provided for more than 30 years with breaking-out devices which are preferably arranged in a setting-up table outside the stamping machine. Such a breaking-out station is of particular importance in terms of manufacture as in the event of incorrect use it involves the highest proportion of the total setting-up time and a poorly set breaking-out station results in continual disturbances in the production procedure.
In the breaking-out station the stamped cardboard sheet, after reaching a predetermined detent position, on the breaking-out surface which is usually provided by a breaking-out board or a female die, is freed of the waste by means of breaking-out pins or cutting edges which press from above.
Development in the breaking-out procedures involved firstly entailed the top tool pin which presses downwardly from above and which passes the waste portion through the opening in the breaking-out board. There was then added an additional bottom tool with bottom pins, which are aligned with the top tool pins and which clampingly hold the waste portion. As a breaking-out tool can reliably break out a waste portion only when there is a certain force-locking engagement between the tool and the waste portion, the above-mentioned bottom pins have proven to be an advantageous resistance at the moment when the breaking-out tool or breaking-out member comes to bear against the waste portion.
If there is a wish to avoid using a clamping tool, the breaking-out opening in the breaking-out surface must be smaller at various locations, than the waste portion which is associated therewith, so that the waste portion rests with a relatively high friction, in small surface areas, on the breaking-out surface or female die. When the breaking-out pin comes into contact with the waste portion, the above-mentioned resistance occurs by virtue of the friction which is then produced. When the breaking-out pin and the waste portion pass through the opening, friction occurs at the relatively close walls of the hole, whereby a certain force-locking action is achieved.
DE-A-25 35 452 discloses the so-called DYN-pin, namely a breaking-out pin having a tip or point whose substantially conical side walls are of contours which are concave in cross-section, with a smooth surface. In the breaking-out procedure, that tip bears against the waste portion which, by virtue of being supported on the edges of the opening, opposes the tip with such a level of resistance that the tip can penetrate slightly into the material of the waste portion. That prevents unwanted lateral deflection movement of the waste portion. As it passes through the opening, the waste portion bends, and the stressing force between it and the wall of the opening is intended to afford the DYN-pin sufficient friction for the desired force-locking engagement with the waste portion; that could then possibly make a bottom tool in itself unnecessary, when using the DYN-pin.
As a simplification for breaking-out tools, above-mentioned EP 0 446 702 B1 proposes a support means which is a surface which is movable and/or resilient within the opening—at least in part in an inclined position —at a spacing relative to the breaking-out surface and which, in its rest position, engages substantially parallel beneath the waste portion in the sheet of material and which, upon movement—that is to say primarily upon downward movement—of the waste portion, is transferred, by the breaking-out member, into an angle of inclination with respect to the sheet of material. The resilient surface can be in the form of a tongue-like spring which is fixed at one end to the breaking-out surface—substantially aligned therewith in the rest position—while the free end of the tongue-like spring is arranged in the opening. Also described are angle portions having one limb aligned with the breaking-out surface while the other limb thereof is pivotably mounted beneath the breaking-out surface and is subjected to a spring loading. The resilient surface can also be afforded by rubber profile members or by bristles.
Finally, DE-C-41 24 089 provides a cuboidal breaking-out tool of rectangular cross-section, from the pressing end of which two pressing tips or points project, in line with the two narrow sides thereof.
In consideration of that state of the art relating to the breaking-out procedure, the inventor set himself the aim of substantially improving the removal of waste portions from sheets of material and simplifying the tools required for that purpose. In particular the invention seeks to provide that those tools can be used for the treatment of very small waste pieces.
That object is attained by the teaching of the independent claim; the appendant claims set forth advantageous developments. In addition the scope of the invention embraces all combinations of at least two of the features disclosed in the description, the drawings and/or the claims.
In accordance with the invention, the support means is formed by a support tool which is rigidly connected in positively locking relationship to the breaking-out surface or female die in the edge region of the opening, and is provided with a contact or support surface which can be inclined with respect to that connection pairing.
In a preferred embodiment this connection pairing comprises a vertical receiving groove—extending in the breaking-out direction—in the female die at the edge of the opening thereof on the one hand and a coupling bar or rib which can be fitted thereinto, on the other hand. In a further preferred embodiment the support tool has an undercut groove for receiving a corresponding coupling bar of the female die.
The respective cross-sections of the coupling bar and the receiving groove should advantageously be of a dovetail-shaped configuration and thus define an operative position which is easy to bring about. It is perhaps possible to provide a plurality of such connecting pairings.
In accordance with a further feature of the invention the support tool is an angle portion with at least one coupling rib of dovetail-shaped cross-section which is formed out of the one limb—being vertical in the position of installation—, and another flexible limb which forms the support surface—being horizontal in the position of installation. In that respect, it has proven to be desirable for the angle portion generally to be formed from a material of limited flexibility, which ensures a long service life.
In a preferred embodiment the connection pairing comprises at least one vertical receiving groove—extending in the breaking-out direction—in the female die at the edge of the opening thereof on the one hand, and a portion—which can be fitted thereinto—of a vertical limb of the support tool on the other hand. The respective cross-sections of the coupling bar and the opening are advantageously to be of a rectangular configuration and thus define an operative position which is easy to bring about. A plurality of such connection pairings can possibly be provided.
It has proven to be desirable if the flexible limb forming the support surface has an edge opening which is delimited at both sides by cantilever portions, and, at a spacing relative to the edge opening, at least one inner opening. That configuration affords a particularly desirable support surface which is stable in respect of shape and nonetheless flexible.
It is also in accordance with the invention that formed on the vertical limb is at least one pin-like plug-in element which extends or extend at a spacing relative to the vertical limb and which is respectively adapted to be inserted into an opening provided in the female die at a spacing relative to the receiving groove. Like also the opening which receives the plug-in element, the plug-in element is to be of a rectangular cross-section, while the plug-in element projects either at a spacing relative to the back surface of the vertical limb or at a spacing relative to the flank surface of the vertical limb, from a respective transverse web portion. In the structure involving association with the flank surfaces, a pair of plug-in elements is preferred.
In a particular embodiment the flank surfaces of the vertical groove are stepped, wherein the vertical limb is supported in the back region, which is narrower in cross-section, of that stepped vertical groove, and therefore the horizontal limb projects beyond the wider front region of the vertical groove.
In another embodiment the vertical limb is to be connected with a coupling pairing to a limb, which extends in the vertical groove, of an angle bracket whose other limb is connected to the female die, preferably by means of force-locking engagement. It is however also possible to provide a pocket at the underside of the female die, for the limb of the angle bracket, whereby that limb projects in positively locking engagement into same.
So that the broken-out piece is possibly held after the releasing procedure, at least one catch finger can be arranged downstream, in the breaking-out direction, of the limb forming the support surface; a pair of catch fingers which are in flanking relationship on both sides is however preferred. The catch fingers increase in width from their free end towards the limb formed thereon, in terms of longitudinal section, for the purposes of increasing the degree of flexibility thereof. In another embodiment the horizontal limb is flanked by side portions which are formed on the other limb, and therefore extend vertically.
Another embodiment provides a support tool with a partial frame which is approximately U-shaped in cross-section and which comprises a back portion having the coupling rib and having two parallel side walls; a support plate for the broken-out portion is arranged between said side walls, pivotably about an axis which is generally horizontal in the position of use.
The feature whereby the breaking-out tools extend between surfaces of the support means, said surfaces being movable in the breaking-out direction, results in a higher level of operational reliability as the arrangement affords a kind of tongs or pincer engagement; that cannot be achieved in the state of the art as the breaking-out tools are usually within the contour which is defined by the free edges of the surfaces.
Engagement of the breaking-out tools can also become more efficient when an edge opening is disposed in opposite relationship to the free end of the tools, the edge opening extending from the free edge of the support surface.
It has proven to be desirable to associate with the support surface, as a breaking-out tool, a pressure pin having a rounded free end or a fork member with one or more finger-like fork prongs, preferably of flat cross-section.
In particular small waste pieces also take part in the bending movement of the breaking-out tool, in such a way that they assume a perpendicular position. When dealing with smooth cardboard surfaces, that results in slipping movement of the pressure pins on the surface of the cardboard and thus results in the waste portions being unsatisfactorily broken away. Therefore, for the sake of better engagement, the free end of the pressure pin or the fork prongs is in the form of a rough surface. That rough surface can be formed by a coating which for example is formed with oxides, carbides, corundum or the like and is possibly applied by means of thermal spraying. Another embodiment according to the invention provides a rough surface with irregularities such as teeth or steps in the surface of the pressure pin or the fork prong or prongs. The irregularities can be produced by a mechanical, chemical or electrical treatment.
By virtue of the rough surface described—for which protection is claimed separately—the arrangement affords the desired firm engagement and the piece which is to be broken away is effectively prevented from sliding away. For that purpose, it has been found sufficient for the axial height of the rough surface to correspond at most to the diameter of the pressure pin or the width of the fork prong, preferably making it less than 5 mm.
Each fork member is to project from a plate-shaped male die and in accordance with the invention it is connected thereto by a portion of the fork member which has clamping noses and which can also have abutments which are guided against the underneath surface of the male die.
Other insert portions for the female die are shaped support portions which are arranged in the opening of the female die at the edge thereof and which are fitted to plug-in profile members and which are disposed in mutually opposite relationship and which are provided with mutually directed radial support lips of elastic material. Preferably that shaped support portion is an angle portion of which one limb is the support lip, while the other limb formed thereon is formed by a hollow profile member; the latter preferably corresponds to a cylindrical cup and is pressed on to a plug-in profile member by a simple assembly procedure in the breaking-out direction.
The scope of the invention also embraces clip-like tools which are fixed at the opening in the female die and which each include a respective frame portion from which resilient support tongues project inwardly or on which are arranged inwardly disposed support plates which can be guided about a pivot axis; that arrangement therefore affords simple additional tools in the form of spring clips or mechanically moved clips which would even permit standardisation of the tools.
Further advantages, features and details of the invention will be apparent from the description hereinafter of preferred embodiments and with reference to the drawings in which:
Cardboard sheets 10 which are used in the folding box industry have stamped blanks for folding boxes or the like, with waste portions 12 being produced in or on the blanks. Downstream of a stamping station which is not shown in the drawing for reasons of enhanced clarity thereof, the stamped cardboard sheet 10 passes on to a breaking-out board or a female die 14 of a thickness b for example of 12 mm, on which the sheet 10 is freed of its waste portions 12; the waste portions 12 are disposed over openings 16 which are of a configuration designed in dependence on the contour of the waste portions 12 and at which, in the cross-sectional view in
Fixed in the opening 16 is a support tool 20 for the waste portion 12, which as shown in
The resilient horizontal limb 24 of the support tool 20, of a thickness a, has an inner opening 30 and at its free edge 25 an edge opening or recess 32; two prong-like cantilever portions 34 of the horizontal limb 24, which flank the edge opening 32, are curved in longitudinal section and each form a kind of bowl or cup.
In the embodiment shown in
The waste portion 12 which rests on the surface 25 of the horizontal limb 24 is subjected to a pressure from above by a breaking-out member or tool in the form of a pressure pin 40 with a roughened part-spherical pressure end which is similar to a fingertip, with the contact between the pressure end and the waste portion being in point form or—for example in FIGS. 8 and 12—as a fork member 41, in substantially linear configuration; the flat fork prongs 42 of the fork member 41 are aligned with each other. Both the part-spherical pressure end of the pressure pin 40 and also the flat ends of the above-mentioned fork prongs 42 are provided with a coating 44, affording the roughness thereof, of an axial height h of between about 4 and 10 mm. The coating was produced for example by thermal spraying from aluminum oxide, corundum, carbide grains or the like.
The preferred height h is at most equal to the diameter d of the pressure pin 40 and the roughness depth is less than 0.5 mm. That coating can also be replaced by roughening of the surface of the pressure pin or the flat prong 41, which is effected chemically, electrically or—for example by means of sand blasting—mechanically.
In the downward movement of the breaking-out tool or tools 40, 41, the waste portion 12 is separated by pressure from the cardboard sheet 10 and carried away downwardly in the breaking-out direction x.
In the embodiment shown in
In the support tool 20a shown in
The support plate 46a in
In
The ridge-like clamping nose 60 or the abutment 54 respectively can also be seen in the fork member 41a shown in
In addition
In that respect,
The described system affords advantages not only in relation to internal waste portions 12, but also in relation to so-called edge waste; the procedure for breaking away edge waste is effected only with the above-described combination of the breaking-out tool 41a and the support tool 20; wooden die or support members are unnecessary. The risk which arises due to wooden die or support members which are necessarily disposed close to the breaking-out female die 14 no longer arises. A spacing of 4 mm between the breaking-out tool 41a and the outside contour of the breaking-out female die 14 affords sufficient tolerance and security. A movement in the severing operation, which corresponds to the pitching action, carries the edge waste positively away from the breaking-out female die 14. As in the case of internal waste, in this case also the edge waste is disposed perpendicularly and is reliably guided downwardly by the thrust teeth 61, 61a, 61b, 61c.
The fork member 41a in
The breaking-out tool 41b in FIG. 31—corresponding to that shown in FIG. 23—is provided with a flat prong 42a which is here disposed laterally and which has a shoulder 61c at its end.
Referring to
The waste portion 12 which lies on the mutually facing support lips 64 is urged in the breaking-out direction against the support lips 64 by pin-like breaking-out tools 40 which are provided above the support lips 64. In that case, the support lips 64 are elastically deformed and, when relieved of load, move quickly back into the initial position. In this case also, the breaking-out tools 40 are arranged in the region of the edge openings 32.
The drawing shows in plan hereinafter some diagrammatic views of special tools, more specifically
These special tools 66, 66a, 68, 70, 72, 72a —which are suitable as a basis for standardisation—each have a frame portion 76 from which project spring tongues 34a which are directed inwardly in
The parallel strip 80 engages from below into a stamped-out opening 84, which is of a cross-section corresponding to the parallel strip 80, in the breaking-out board 14. The stamped-out opening 84 is separated from the opening 16 of rectangular cross-section, by a board web portion 86 which is disposed in the above-mentioned channel. A vertical groove 28a—also of rectangular cross-section—extends from the opening 16, with stepped flank surfaces 88. The vertical limb 22 of the support tool 20f in
A support arrangement 96 in the breaking-away board 14 in
Number | Date | Country | Kind |
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198 14 736 | Apr 1998 | DE | national |
198 20 557 | May 1998 | DE | national |
198 37 316 | Aug 1998 | DE | national |
298 15 042 U | Aug 1998 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP99/02266 | 4/1/1999 | WO | 00 | 9/29/2000 |
Publishing Document | Publishing Date | Country | Kind |
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WO99/51405 | 10/14/1999 | WO | A |
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41 03 339 | Sep 1992 | DE |
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