EP0446702B1 - Apparatus to remove pieces cut from a bent material or similar - Google Patents

Abstract

In an apparatus to remove pieces, especially waste pieces (12), cut from bent materials (10) containing blanks or the like and resting on a cutting-out surface (15) so that the piece to be cut out spans an opening (16) in the cutting-out surface (15) and is pushed down through this opening under the pressure of at least one cutting-out member, in particular a cutting-out pin (20), the cutting-out member is assigned, underneath the piece to be cut out, an abutment, guided in the direction of movement of the cutting-out member, in the form of a surface which is resilient and/or movable at least partially inside the opening (16) at a distance from the cutting-out surface (15) and, in its rest position, engages, approximately parallel, on the underside of the waste piece (12) situated in the bent material (10), and which can be conveyed into an angle of inclination with respect to the bent material (10) upon movement of the waste piece (12) by the cutting-out pin (20), in particular upon lowering of said waste piece (12). <IMAGE>

Description

The invention relates to a device for removing stripped parts, especially waste pieces, from a blank or the like. containing sheet of material, according to the preamble of claim 1.

For more than 30 years, punching presses for producing blanks from cardboard sheets in the folding box industry have been provided with stripping devices, which are preferably provided in a set-up table outside the punching machine. Such a stripping station is of particular importance for production, since if it is used incorrectly, it takes the largest part of the overall set-up time and a poorly set stripping station leads to ongoing disruptions to the production process.

In the stripping station, the punched cardboard sheet is freed of waste after reaching a predetermined latching position on the stripping surface usually offered by a stripping board or a die by means of stripping pins or cutting edges which press from above.

The first step in the development of the stripping technique was the top tool pin, which pushes the waste piece through the opening of the stripping board. Then there was an additional lower tool with lower pins, which are aligned with the upper tool pins and hold the waste piece in place.

Since a stripping tool can only safely break out a piece of waste if there is a certain amount of friction between the tool and the piece of waste, the lower pins mentioned have proven to be a favorable resistance at the moment the stripping tool or stripping member hits the piece of waste.

If you want to avoid a clamping tool, the break-out opening in the break-out area must be kept smaller at various points than the waste piece assigned to it, so that it rests in small areas on the break-out area or die with higher friction. The resistance now arises when the stripping pin hits the waste thanks to the friction generated. When driving through the breakthrough by means of the stripping pin and the waste part, friction occurs on the narrower hole walls, as a result of which a certain amount of force is achieved.

Also known is the so-called DYN pin, a stripping pin with a tip, the i.w. conical side walls have concave contours in cross section. During the stripping process, this tip hits the piece of waste, which, when placed on the breakthrough edges, opposes the tip with so much resistance that this tip can penetrate slightly into the material of the waste piece. This prevents undesired lateral evasion of the piece of waste.

A device according to the preamble of claim 1 has become known from DE-B-1 206 715. This document shows a stripping device for a press for punching shaped pieces of paper or the like. According to this document, shaped pieces of paper are thus created, rather than broken pieces of waste from a sheet of material containing blanks, as is the case according to the invention.

In this known device, a support frame made of rubber rests on the die. This support frame has an opening that is smaller than the die opening. Both openings lie vertically one above the other.

The patrix (i.e. the stripping element) hits the fitting with the stripping device and cuts the connecting webs in the further downward movement, the elastic edge of the rubber support frame, as shown in FIG. 3 of this document, being bent downwards.

The elastic edge of the support frame according to this DE-B is therefore an abutment, which can be converted into a deflection angle to the material sheet when the molded part is moved by the stripping member there when the molded part is lowered into a deflection angle.

The abutment according to this DE-B-1 206 715 is therefore part of a rubber pad, wherein rubber has the usual signs of aging. It must be assumed that the elastic edge of the support frame 19, which is bent downward when the shaped piece 12 broken out according to FIG. 3 breaks off, only snaps back into its old position to a limited extent in order to hold a new shaped piece 12 for the next breaking-out process . The rubber bearing frame 19 must often be replaced with certainty.

Knowing this prior art, the inventor set himself the task of avoiding the disadvantages mentioned and of creating a more reliable device for removing stripped parts.

To achieve this object, the features of the characterizing part of claim 1 lead to a device of the type mentioned at the outset.

Thanks to this requirement, a resilient abutment is created within the breakthrough, which first lies against the piece of waste to be broken out from below, then is guided downwards through the stripping element until its deflection angle is sufficient for the piece of waste now broken out due to the inclination during the downward stroke - based on the free edge - is pushed off to the side. Experiments have shown that this pushing off takes place at a surprising speed when the piece of waste flies away.

Thanks to the spring force, this discharge process takes place in the same way for all types of stripping bodies, but it is best if the known DYN pin with a strongly tapering tip is used.

After the piece of waste has snapped off, the spring swings back into its rest position in order to be available for a new stripping process.

It has proven to be advantageous to fold the free end of the tongue-like spring to a step or to fold it by at least two fold lines; this deformation creates an additional spring force to the spring constant of the material.

The opening in the stripping board is usually shaped in accordance with the piece of waste to be removed therein; according to the invention, the opening arm, which is preferably directed transversely to its longitudinal axis, for receiving the spring, which is fixed at one end therein, for example on a support profile running in the opening arm, and with it the angle of inclination already mentioned certainly. This support profile or its support section can either in turn be aligned with the surface of the stripping board or can run at a distance from it, which can result in a correspondingly different shape of the spring tongue, which then also, if appropriate can carry a vibrating pin that is coaxial with the stripping pin coming from above in the rest position.

There are a variety of configurations of the spring tongue and its attachment within the scope of the invention. With regard to further features, reference is made to the subclaims.

The principle according to the invention is also realized by a rigid bearing surface, which can be lowered at a distance from the break-out surface and can be adjusted in the described angle of inclination.

An angle piece, which can be rotated about an axis and is under the action of the restoring force of an energy store, has proven to be particularly suitable for this purpose, which preferably bears in a bearing block of the stripping board and offers a leg as an abutment.

According to the invention, however, one or the like - in addition to the path of movement of the stripping pin (s) or the like. - Provided axis rotatable roller-like body may be provided, the periphery of which has a plurality of surfaces which are inclined to radii of the axis. A roller is particularly suitable for this purpose, the cross-section of which, structurally, consists, for example, of a plurality of interlocking circles and which offers a circumferential groove through which the path of movement of the stripping pin is laid tangentially. It is also possible, instead of one roller with a circumferential groove, to place two disc-shaped rollers on the axis, which have circumferential contours which are aligned with one another and between which the path of movement of the stripping pin lies.

According to a further feature of the invention, at least one edge recess should extend from the free edge of the abutment, in particular the spring, as a lateral limitation of the movement path of the stripping element or stripping pin. Instead of this mostly part-circular edge recess or - in the case of several stripping elements - in addition to it, a hole can be provided within the abutment surface, the width of which is greater than the cross section of the stripping pin or the like, so that this - as in the described edge recess - cannot come into direct contact with the spring surface on its way down. This requirement also significantly improves the discharge effect.

Further features can be found in the other subclaims.

Fig. 1:

die Draufsicht auf einen Teil eines Ausbrechbrettes für das Entfernen von Abfallstücken aus Kartonbogen in der Faltschachtel-Industrie;

Fig. 2:

den Schnitt durch Fig. 1 nach deren Linie II-II;

Fig. 3:

einen Teil der Fig. 2 zu einem weiteren Ausführungsbeispiel;

Fig. 4:

die Draufsicht auf ein ausgebrochenes Abfallstück;

Fig. 5:

die Draufsicht auf einen Teil eines anderen Ausbrechbrettes mit in einem Durchbruch angeordneter Federzunge;

Fig. 6:

den Schnitt durch Fig. 5 in Ruhelage der Federzunge;

Fig. 7, 8:

der Fig. 6 entsprechende Wiedergaben unterschiedlicher Betriebsstellungen der Federzunge;

Fig. 9:

ein vergrößertes Detail aus Fig. 6 bis 8;

Fig. 10,11:

Teilschnitte durch andere Ausführungen der Vorrichtung;

Fig. 12 bis Fig. 14:

Schrägsichten zu unterschiedlichen Federzungen;

Fig. 16:

einen Teilquerschnitt durch ein Ausbrechbrett mit einem drehbaren Widerlager für Abfallstücke;

Fig. 17:

eine Schrägsicht auf das Widerlager der Fig. 16;

Fig. 18:

die Frontansicht einer anderen Ausführungsform des Widerlagers;

Fig. 19:

eine Seitenansicht eines Teils einer anderen Vorrichtung;

Fig. 20:

eine der Fig. 5 entsprechende Darstellung einer weiteren Ausführung;

Fig. 21:

den Schnitt durch Fig. 20 nach deren Linie XXI - XXI;

Fig. 22:

eine Schrägsicht zu einem Detail der Fig. 20, 21;

Fig. 23:

einen Querschnitt durch ein Ausbrechbrett mit einem Paar von einander zugeordneten Federzungen;

Fig. 24:

eine Schrägsicht zu einem Teil der Fig. 23;

Fig. 25,26:

Teilschnitte durch andere Ausführungsformen des Ausbrechbrettes.

Further advantages and details of the invention emerge from the following description of preferred exemplary embodiments and with reference to the drawing; this shows in

Fig. 1:

the top view of part of a stripping board for removing waste pieces from cardboard sheets in the folding box industry;

Fig. 2:

the section through Figure 1 along the line II-II.

Fig. 3:

part of Figure 2 for a further embodiment.

Fig. 4:

the top view of a broken piece of waste;

Fig. 5:

the top view of part of another stripping board with spring tongue arranged in an opening;

Fig. 6:

the section through Figure 5 in the rest position of the spring tongue.

7, 8:

6 corresponding reproductions of different operating positions of the spring tongue;

Fig. 9:

an enlarged detail of Figures 6 to 8;

Fig. 10,11:

Partial sections through other versions of the device;

12 to 14:

Oblique views to different spring tongues;

Fig. 16:

a partial cross section through a stripping board with a rotatable abutment for waste pieces;

Fig. 17:

an oblique view of the abutment of Fig. 16;

Fig. 18:

the front view of another embodiment of the abutment;

Fig. 19:

a side view of part of another device;

Fig. 20:

a representation of another embodiment corresponding to FIG. 5;

Fig. 21:

the section through Figure 20 along the line XXI - XXI.

Fig. 22:

an oblique view of a detail of FIGS. 20, 21;

Fig. 23:

a cross section through a stripping board with a pair of associated spring tongues;

Fig. 24:

an oblique view of part of Fig. 23;

Fig. 25, 26:

Partial sections through other embodiments of the stripping board.

Cardboard sheets 10 used in the folding box industry have punched blanks for folding boxes or the like. on, in the blanks or on them waste pieces 12, 12 _a arise.

The punched cardboard sheet 10 comes after the sake of clarity is not shown in the drawing, punching station to a stripping board and a template 14 on which / is freed of the cardboard sheet from its waste portions 12, 12 _a; these are located above - depending on their contour - openings 16 in which, in the cross section of FIG. 2, an upper frame part 17 with a vertical wall is followed by a cone part 18 that opens downwards.

The stripping board 14 has small edge zones of the waste pieces 12, 12 _a , while other areas of edges 12 'of the waste piece 12, 12 _{a run} at a distance within the contour of the opening 16 on the surface 15 of the stripping board 14. This results in support zones R shown in FIG. 2 with a relatively high frictional resistance and areas of lower friction designated with N.

Press on the pieces of waste 12, 12 _a from above, break-out elements 20 in the form of a pin, or - in Fig. 1, 2 on the right, for example - as pressure cutters 20 _{s in a} line-like manner, wherein differently designed break-out elements, not shown, can also be used.

The waste pieces 12, 12 _a are separated from the cardboard sheet 10 and guided away downward in the breaking-out direction x.

In Fig. 3, a stripping tool with a clamping or lower pin 22 is shown, the surface of which rests on the lower surface of the waste piece 12 coaxially with the upper stripping pin 20, holds the waste piece 12 in a clamped manner and thus also leads out of the opening 16. Figure 4 shows a typical multi-arm waste piece 12 _t , on which - in accordance with the marked pressure points 20 '- eight break-out pins 20 act, of which only two (in FIG. 4: black points) are each supported on a coaxially provided lower pin 22.

The exemplary section of a stripping board 14 according to the invention according to FIGS. 5 to 8 shows an approximately rectangular opening 16 for a waste strip 12 to be broken out, to which a breakthrough arm 24 connects transversely to its longitudinal axis M for receiving a stepped shaped support profile 26; this is with a short profile section 27 on the underside of the board 15 _{t at one} end by screws 25 or the like. so determined that a - compared to the profile section 27 - longer support section 28 extends near the board surface 15 and the end edge 29 runs at a small distance b from the parallel opening edge 16 '.

On the lower surface of the support section 28 nestles a spring tongue 30, or the like riveted to it with its rear end region. attached and otherwise resiliently pivoted downward from this. In the spring tongue 30, a cranked upward-facing bearing step 32 is formed at its free end, which is arranged in front of the end edge 29 of the support section 28 and which, in the rest position shown in FIG. 6, is in the opening 16 and the upper side of which is approximately flush with the surface 15 of the stripping board 14 flees. The free length i of the spring tongue 30 of approximately 35 mm corresponds in the selected exemplary embodiment to almost three times the thickness q of the stripping board 14 or the height of its opening 16. The cone angle t from the cone part 18 of the opening 16 is more than 50 °.

When pressure is applied to the stripping pin 20, which is equipped with a pressure tip 21, which offers a circumferential shape which is concave in accordance with FIG , until the bearing stage 32 with the horizontal support section 28 forms a deflection angle w of approximately 45 ° and the broken-out waste strip 12 can snap away laterally (arrow z); this detachment process is favored by the shape of the pressure tip 21 of the stripping pin 20, but can also be carried out in the case of stripping pins 20 with a flat pin end (FIGS. 10, 11).

As can be seen in FIG. 5, the bearing step 32 of the spring tongue 30 has a part-circular recess 34 in the region of its free edge 33, within which the movement path of the stripping pin 20 determined by the pin axis A runs.

The spring tongue 30 in the embodiment of FIG. 10 is curved in cross-section like a loop between the bearing stage 32 and the fastening end and is fixed under the support section 28 of a U-shaped support profile 26 _a , the transverse wall of which has a cut-out 36 penetrated by the spring tongue 30; the edges of this cutout 36 limit the spring deflection of the spring tongue 30.

11, 12, instead of that support profile 26 in the breakthrough arm 24, a spring bolt 30 _{a which} crosses and holds at its bearing end 31 in a spiral manner and which holds axles 38 can be fixed. Instead of the edge recess 34 described here - as is also possible in other examples - there is an elongated hole 34 _n at a distance from the free edge 33 through which the movement path of the stripping pin 20 leads.

According to FIG. 13, a spring tongue 30 fixed at one end at a distance from the surface 15 of the stripping board 14 is bent upwards with its free part and folded into a double-layered bearing step 32 _d ; this training increases the elasticity of the device considerably. Correspondingly folded free ends are also possible with approximately vertical lines projecting into the opening 16 spring tongues 30 _v according to FIG. 14.

In the embodiment according to FIG. 15, a spring pin 30 resiliently mounted in this way protrudes from a spring tongue 30 _h provided at a distance from the surface 15 of the stripping board 14 and ends slightly below the surface 15.

Instead of a flexible spring tongue 30 _, a roller 40 can be rotatably supported in a stepwise manner in the opening arm 24 on a horizontal axis 38a, the cloverleaf-like or cruciform cross-sectional contour of which - here four - is composed of partial circles; the outer surface 41 of the roller 40 from bead strips thus formed form abutments which can be moved downward against the force of a spring 42 for the stripping pin 20 or the intermediate waste piece 12. The roller 40 is otherwise provided with a central circumferential groove 44 for the passage of the pin axis A. . Instead of the roller 40 with its circumferential groove 44, two roller disks 40 _a can also be fixed at a distance e from one another on the axis 38 _a (FIG. 18).

19, the axis B of a clamping pin or lower pin 22 _{a is} inclined at an angle f of approximately 20 ° in a bushing 46 and the clamping pin 22 _a is held in the gripping position shown by the force of a spring 48. This clamping pin 22 _a is equipped with a stop head 50, the surface 51 of which encloses the angle f with a radial to the axis B and extends approximately parallel to a fastening collar 52 of the sleeve 46.

The embodiment according to FIGS. 20 to 22 offers in the opening 16 an angle piece 58, which can be tilted to a limited extent against an axis bolt 54 running parallel to the stripping board 14 against the force of an expansion spring 56 and whose one leg 59 runs on the surface 15 of the stripping board 14; the other (bearing) leg 60 - possibly also a wing 61 - is penetrated by that axle 54. The latter is mounted in flank walls 62 of a bearing block 64, which in turn is fixed by means of wing-like flanges 65 which engage under the stripping board 14. The flank walls 62 are connected by a front transverse web 63 of the bearing block 64, in which a free end 55 of that spreading spring 56 is fixed; whose other radial end 57 sits below the axle pin 54 in the bearing arm 60.

23 shows two approximately vertical leaf springs 30 _v on both sides of the opening 16. These leaf springs 30 _v flank a passage gap 66 (FIG. 24), which determines the path of movement of a stripping pin 20 _s with a flat end edge or cutting edge. Such a passage gap 66 can be limited according to FIG. 25 by resilient rubber noses 68 or brush-like inserts 70 (FIG. 26). Bristles 72 of the brushes 70 extend transversely to the pin axis A and are of decreasing length in the printing direction, so that they are able to serve as an abutment on the one hand and on the other hand allow the waste piece 12 to be guided downwards.

Claims (10)

1. Apparatus for the removal of knock-out portions, above all waste pieces (12), from a sheet of material (10) containing blanks or the like which rests on a knock-out surface of a die (14) in such a way that the knock-out portion spans an aperture (16) of the die (14) and is pushed out through this aperture (16) under the pressure of at least one knock-out member (20), in particular a knock-out pin, wherein associated with the knock-out member (20) beneath the knock-out portion (12) is a support which is guided in the direction of movement of the knock-out member (20) and which within the aperture (16) is at least partially movable to a distance from the knock-out surface of the die (14) and/or resilient, and which in its rest position engages under the waste piece (12) which is in the sheet of material and, on movement of the waste piece (12) by the knock-out member (20), particularly on lowering of the waste piece (12), can be changed to an angle of deflection (w) from the sheet of material (10), characterised by a tongue-like spring (30) as the support, which at one end is fixed to the die (14) providing the knock-out surface (15) and of which the free end (32) is more or less aligned with the knock-out surface (15) in the rest position in the aperture (16).
2. Apparatus according to claim 1, characterised in that the tongue-like spring (30) is fixed by its bearing end to a supporting section (28) of a supporting profile (26) within the aperture (16) and extends transversely to the longitudinal axis (M) thereof.
3. Apparatus according to claim 2, characterised in that the free end (32) of the tongue-like spring (30) is bent out of the plane thereof to form a step, or the strip of material forming the spring (30) is folded at its free end at least about two fold lines, wherein if occasion arises the spring (30) is fixed at one end to a supporting profile (26) which is provided in the arm (24) of the aperture and which extends close to the knock-out surface (15).
4. Apparatus according to any of claims 1 to 3, characterised in that the spring (30) is fixed at one end at a distance from the knock-out surface (15) and the free end of the spring is bent up towards the latter, and/or in that the spring (30_h) extends at a distance from the knock-out surface (15) and carries at least one extension (22) which extends up towards the latter and which can be inclined with the spring.
5. Apparatus according to one or more of claims 1 to 4, characterised in that the spring (30_v) is fixed with a bearing end (31) which is rolled in spiral fashion cross-sectionally at a distance from the knock-out surface (15), wherein if occasion arises the rolled bearing end (31) of the spring (30_v) is fixed to a shaft (38) or the like bolt.
6. Apparatus according to claim 1, characterised in that the support (41, 59) forms part of an element (40_a; 58) which is rotatable about a shaft (38_a; 54) against an energy storing device (46; 56) to an angle (w) from the knock-out surface (15) of a knock-out board (14) or the like, wherein the energy storing device produces a return force, wherein if occasion arises there is provided as the pivot element an angle piece (58) of which one arm (59) forms the support and of which the other arm (60) is mounted on the shaft (54).
7. Apparatus according to claim 6, characterised in that the angle piece (58) is mounted within the aperture (16) in a bearing block (64) fixed to the knock-out board (14) or the like, and/or in that the shaft (54) rests at both ends in flank walls (62) of the bearing block (64) and these extend in the aperture (16).
8. Apparatus according to claim 6 or 7, characterised in that the energy storing device (56) is an expanding spring which is fixed on the one hand to the free end of the bearing arm (60) and also at the other end to the face of the bearing block (64) which is adjacent to the path of movement of the knock-out pin (20).
9. Apparatus according to one or more of claims 1 to 8, characterised in that the surface which can be moved at a distance from the knock-out surface (15) or downwards and changed to an angle of inclination (w) is formed by sections (41) of at least one roller-like body (40_a) rotatable about a shaft (38_a) provided adjacent to the path of movement of the knock-out pin(s) (20) or the like, wherein the body (40_a) if occasion arises is a roller (40) which comprises several partial circles in cross-section and of which the circumference (41) provides parallel-axis surfaces at an angle to the shaft radius, and/or the roller (40) comprises if occasion arises a circumferential groove (44) through which the path of movement of the knock-out pin (20) or the like is placed more or less tangentially.
10. Apparatus according to claim 9, characterised in that two disc-like roller elements (40_a) with aligned circumferential contours are fixed at a distance (e) from each other on the shaft (38_a) and between them extends the path of movement of the knock-out pin (20) or the like.

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