DE20003120U1 - Punching device - Google Patents

Description

GRÜNECKER, KIN^EJiDETf, «sSrCfiCKlJlAlk |c*S(|hWANHÄUSSER

LAW FIRM

LAW FIRM MAXIMIUANSTRASSE 58 0-80538 MUNICH GERMANY

Applicant:

HANS KOLB CORRUGATED PAPER GMBH & CO.

PO BOX 1554
87685 MEMMINGEN

LAWYERS

MUNICH

DR. HELMUT EICHMANN

GERHARD BARTH

DR. ULRICH BLUMENRÖDER, LL. M.

CHRISTA NIKLAS-FALTER

OR. MAXIMILIAN KINKELDEY, LL. M.

SONJA SCHAEFFLER

DR. KARSTEN BRANDT

OF COUNSEL

PATENT ATTORNEYS

AUGUST GRÜNEECKER
DR. GUNTER BEZOLD
DR. WALTER LANGHOFF

DR. WILFRIED STOCKMAIR (-1996)

PATENT ATTORNEYS EUROPEAN PATENT ATTORNEYS

MUNICH

DR. HERMANN KINKELOEY

DR. KLAUS SCHUMANN

PETER H. JAKOB

WOLFHARD MEISTER

HANS HILGERS

DR. HENNING MEYER-PLATH

ANNELIE EHNOLD

THOMAS SCHUSTER

DR. KLARA GOLDBACH

MARTIN AUFENANGER

GOTTFRIED KLITSCH

DR. HEIKE VOGELSANG-WENKE

REINHARD KNAUER

DIETMAR KUHL

DR. FRANZ-JOSEF ZIMMER

BETTINA K. REICHELT

DR. ANTON K. PFAU

OR. UDO WEIGELT

RAINER BERTRAM

JENS KOCH, M.S. (U of PA) M.S. (ENSPM)

COLOGNE

DR. MARTIN DROPMANN

CHEMNITZ
MANFRED SCHNEIDER

YOUR REF.

OUR REF.

G 4262-25/Sü

DATE

21.02.00

Punching device

MAXIMILIANSTRASSE 58 D-805J8 (JUf^HEN ''. II '. JCAI^R-tylLHEtM-Rlfofc 13 015(2672C KOLfJ '. "I)EUTSCHE SANK MUNICH NO. 17 51734 TEL 089/21 23 50 FAX (Gr. 3 ) 089 / 22 02 8f, (f>.4) 089 / 21 8#92f 3 J JTEl;022J / 9J 9.7 2J 0 FAj (Gr.?) 0j21 /φ4 97^2 Z ' 700 10 SWIFT: DEUT OE MM http://www.grunecker.de - e-mail: postm«ster®^»ureckerfde· ·· ·· ii-nail^cgrafftfteJtlSki^ **

Punching device

The invention relates to a punching device of the type specified in the preamble of claim 1.

If sheets of corrugated cardboard or solid cardboard are punched with punching tools, dust and lint are created on the cut edges. This is particularly disadvantageous when the punched sheets are used for packaging or transport purposes, for example, and a high level of cleanliness is important, e.g. under clean room conditions or with certain foods. This problem is well known. This is countered by cleaning the punched sheets, e.g. by vacuuming them, which takes time, and if necessary, by installing suction devices for dust and lint in the punching devices. This is a considerable amount of labor-intensive and/or equipment-intensive work, which nevertheless does not offer satisfactory security against unwanted contamination occurring during the processing of the cardboard cut-outs.

The invention is based on the object of providing a punching device for cardboard sheets with which the problem of dust and lint is solved in a different, simple way.

The stated problem is solved with the features of claim 1.

The feed device is used to apply a binding agent to at least one surface of the punching tool that faces the edge or edges or brushes against them during the punching process. The binding agent is applied to the edge using the punching tool to seal it. This prevents dust and fluff from escaping or coming loose. The binding agent can be a varnish or another liquid binding agent that has favorable adhesive properties and produces the desired sealing effect. Since the punching tool is moved relative to the sheet anyway to form the edge (when punching through or when forming a fold), the essence of the invention lies in wetting the punching tool with a liquid binding agent at at least one point and using it as a transfer element to seal the edge or edges.

It is advisable not to apply the binding agent to the cutting edge, because the stripping effect of the cardboard is too strong there, but to a surface that is able to distribute the binding agent on the respective edge and ensure sufficient penetration depth in the punching direction and perpendicular to it.

In a simple embodiment, at least one depression is formed in a side surface of the body, which serves as an intermediate storage for the binding agent. The adhesive tendency of the binding agent, which is also needed for the sealing effect, is used to temporarily store the binding agent on the punching tool. The punching tool can be attached and operated as before; it is only necessary to ensure that a certain amount of binding agent is present on the punching tool during the punching stroke.

Alternatively, the punching tool could have a cavity in the body from which the binding agent is introduced into the edge via outlet openings. A permanent or intermittent or metered supply of the binding agent takes place from a reservoir.

Conveniently, the binding agent is brought through the carrier element for the punching tool to or into the punching tool.

Alternatively, it would be sufficient to dip the punching tool in the binding agent before each punching stroke or at regular intervals.

Alternatively, the binding agent could be applied to the outside of the punching tool or introduced into its cavity using a type of drip oiler or through a spray nozzle.

If necessary, a conveying and/or dosing pump is provided in the feed device in order to be able to provide at least the required amount of binding agent.

Since such punching tools are usually enclosed by elastically deformable separating bodies that push the sheets away from the punching tool, a further alternative would be to design the separating bodies with cavities and spray openings directed towards the punching tool and, for example, to use the push-off deformation movement of the separating bodies to wet the punching tool with the binding agent.

It is advisable to design the transitions from the punching tool to the carrier element or to provide them with a deflector in order to avoid a gradual accumulation of a mixture of binding agent and contaminants.

Embodiments of the subject matter of the invention are explained with reference to the drawing. They show:

Fig. 1 shows a schematic vertical section of a sheet punching device,

Fig. 2 shows a part of a section of another embodiment,

Fig. 3 shows a part of a section of another embodiment,

Fig. 4 shows part of another embodiment, and

Fig. 5 shows part of another embodiment.

When producing punching material, e.g. for folding boxes or the like, sheets B are punched in a punching device S in order to form, for example, the outline and/or folding flaps and/or fold lines and/or openings or the like. The punching device S consists of a carrier element 1, usually a plate to which at least one knife-like punching tool W is anchored, along which elastically deformable separating elements 6, e.g. made of rubber or elastomer, run at intervals. The sheets B made of corrugated cardboard or solid cardboard lie (individually or stacked) on a counter plate 2 and are punched by relative movements between the carrier element 1 and the counter plate 2.

The punching tool W has a body 3 and at least one cutting edge 4 formed at the end thereof. During punching, an edge K is formed in the cardboard, whereby dust and fluff can be released, which are undesirable or even very disadvantageous for certain applications, e.g. of this punching material or container. For these reasons, the punching tool W is assigned a feed device Z for a liquid binding agent M, which is applied to the edges K formed during punching and seals them (if necessary, only the edge formed on the blank of the packaging is sealed).

In Fig. 1, recesses 5, e.g. longitudinal grooves, rows of dents or vertical grooves, are formed on the body 3 of the punching tool W. With the feed device Z, binding agent M is either only brought into the recesses 5 or onto the sides of the body 3, so that the punching tool W is wetted with the binding agent or the binding agent is even concentrated in the recesses 5. During the punching process, the binding agent M is stripped off at the edge K, which is thus sealed. Adhesive or varnish or a similar substance can be used as a binding agent, which has a tendency to adhere to the edge and/or penetrate it and create a sealing effect. If necessary, the same varnish is used as is used to impregnate the outside of the sheet, particularly when it comes to packaging material for electronic components, where packaging and containers later have, for example, shielding and/or dissipative effects.

In Fig. 1, the punching tool W is dipped into a reservoir R with binding agent M, for example, before each punching stroke or at regular intervals, whereby a sufficient dose remains on the punching tool due to the surface tension of the liquid binding agent M. Instead of the depressions S, a clearance angle (receding upwards) of a flat free surface of the punching tool W and the adhesion tendency of the binding agent M could also be sufficient to produce a sufficient locking.

In Fig. 2, the binding agent M comes, for example, from drip-oiler or spray nozzle-like feed elements 7 of the feed device penetrating the carrier element 1.

•••a ··· ··

Z. If necessary, a supply line 8 is provided in the carrier element 1 (or above it). The application elements 7 are used to apply the binding agent at a predetermined dosage, temporarily store it in the recesses 5 if necessary and apply it during punching.

In Fig. 3, the punching tool W is designed with an inner cavity 9 which is connected to the feed line 8 for binding agent M. If necessary, a feed or metering pump P is provided. The body 3 has outlet openings 10 connected to the cavity 9, which are separated from the cutting edge 4 and are located at points on the body 3 with which the latter brushes over the edges during punching.

In the embodiment of Fig. 4, spray nozzles 11 connected to the supply lines 8 are arranged on the underside of the carrier element 1, from which the punching tool W is wetted with the binding agent. The reservoir R is designed, for example, in the manner of a bellows 12, which is actuated in cycles by pressure in the direction of an arrow 13 in order to apply a certain dose to the punching tool W.

In Fig. 5, the separating elements 6, which serve to push the sheets off the punching tool W, are simultaneously designed as a feed device Z for binding agent M. The separating elements 6 have internal cavities 14 and spray openings 15 that point towards the punching tool W. The cavities 14 are connected to supply lines 8. The separating elements 6 are deformed by pressure in the direction of the arrows 16, whereby a predetermined dose of the binding agent is applied to the punching tool W. The pressure pulses 16 can be generated, for example, by the punching cycle itself, so that the punching tool W is wetted with binding agent during one punching cycle for the subsequent punching cycle.

At 17, deflectors are indicated which fill the gaps between the body 3 and the carrier element 1 and prevent the accumulation of a slurry formed from binding agent M and impurities. Lip-like elements or the like could also be used as deflectors. If necessary, this area is

freed from deposits, e.g. by spraying with the existing binding agent or by compressed air.

According to the invention, in order to prevent the release of dust and lint and other contaminants through the punching process, at least the edges formed on the cardboard blank are sealed with a liquid binding agent, e.g. varnish. In order to be able to carry out this sealing with as little additional effort as possible during the production of the blank, the punching tool is used to transfer the binding agent to the punching edge, whereby either the surface adhesion of the binding agent to the body of the punching tool or in depressions or dents provided thereon is used, or the binding agent is metered through the punching tool. Several options are useful for wetting the surface of the punching tool that brushes over the edge with the binding agent. The punching tool is particularly easily formed with intermediate storage depressions for the binding agent, with which the binding agent is applied to at least one edge of the sheet, lagging behind the cutting edge of the punching tool. A relatively small dose of binding agent per unit area of the edge is sufficient, provided that the binding agent has a good adhesive and impregnating effect. Contamination of the area around the punched edge is irrelevant because the cardboard material absorbs the binding agent anyway. In addition, a suction effect of the punched edge of the cardboard is used to effectively penetrate the binding agent, as the sheet, which is temporarily compressed at least at the edge during the punching process, absorbs the applied binding agent and distributes it effectively when it is relaxed.

Claims (10)

1. Punching device for sheets of cardboard, in particular corrugated cardboard or solid cardboard, with a knife-like punching tool (W) which can be driven into or through the sheet or sheets (B) transversely to the plane of the sheet by means of a body ( 3 ) carrying at least one cutting edge ( 4 ), characterized in that a feed device (Z) for a liquid binding agent (M) is provided to the outside of the body ( 3 ) of the punching tool (W) in order to seal at least one punched edge (K) with binding agent (M) by means of the punching tool (W) penetrating into the sheet (B) and taking binding agent (M) with it. 2. Punching device according to claim 1, characterized in that the feeding device (Z) is aligned with at least one location ( 5 , 10 ) on the outside of the body ( 3 ) of the punching tool (W), which faces the edge (K) formed during punching and is locally distant from the cutting edge ( 4 ). 3. Punching device according to claim 1, characterized in that the feed device (Z) has at least one recess ( 5 ) provided in the side surface of the body ( 3 ) as an intermediate storage for binding agent (M). 4. Punching device according to claim 1, characterized in that the body ( 3 ) is hollow and has at least one outlet opening for the binding agent (M) at the location ( 10 ), and that the cavity ( 9 ) in the body ( 3 ) is connected to a reservoir (R) for the binding agent. 5. Punching device according to claim 1, characterized in that the punching tool (W) is fixed in a carrier element ( 1 ), and that the feed device (Z) extends through the carrier element to the punching tool (W). 6. Punching device according to at least one of the preceding claims, characterized in that at least one binding agent reservoir (R) is provided, from which the binding agent (M) can be brought to the location ( 5 , 10 ) of the body ( 3 ) by flowing in under gravity or by immersing the punching tool (W). 7. Punching device according to claim 1, characterized in that the feeding device (Z) has a drip oiler or a spray nozzle ( 7 , 11 ). 8. Punching device according to at least one of the preceding claims, characterized in that a feed and/or metering pump (P) is provided in the feed device (Z). 9. Punching device according to claim 1, characterized in that elastically deformable separating elements ( 6 ) adjacent to the punching tool (W) are provided with cavities ( 14 ) containing binding agent (M) and spray openings ( 15 ) facing the body ( 3 ) of the punching tool (W) and are incorporated into the feed device (Z). 10. Punching device according to claim 1, characterized in that deflectors ( 17 ) are assigned to the punching tool (W).