EP1588952B1 - Carton pallet - Google Patents

Abstract

The cardboard pallet has a base (10) and comprises a cardboard tube of rectangular cross section. It has open sections (20) to allow for passage through the bases, and closed load-bearing sections (30). The load-bearing sections are divided into compartments by a reinforcement walls formed by the inwardly folded side walls of the cardboard tube.

Description

The present invention relates to a pallet foot for a pallet according to the preamble of claim 1.

Such a pallet base is previously known from US-A-3,602,158 which consists of cut cardboard provided with notches. In US-A-5,365,857, predominantly corrugated board or multilayer paper is used, the pallet being folded from a single ply of such material.

Various approaches are known in the art to replace standard pallets of wood with pallets of cardboard material. Pallets made of cardboard material have the advantage that they can be supplied by the recipient of the goods the paper recycling cycle. But also for reasons of weight find such pallets more and more use, since they are lighter than pallets made of wood and therefore lower transport costs.

From DE 201 03 902 U1 a cardboard or corrugated cardboard existing pallet is known, which has feet, which consist of several, parallel and spaced apart and together with the upper deck integrally formed runners. In the folded arrangement, the skids have a triangular or square cross-section.

From DE 195 23 492 A1 a pallet is known which uses roll cores of paper, carpet and similar material rolls as support elements, wherein the roll cores are arranged in two layers one above the other and perpendicular to one another.

Finally, from WO 95/25672 a pallet system is known, which consists of a flat upper deck, which is provided with tubular runners. The runners are folded from a flat cardboard box. To reinforce the runners, separate cuboid reinforcing elements are introduced into the skids, which consist for example of wound or honeycomb cardboard material.

The carton pallets of the prior art disclose various disadvantages in terms of their low strength or stability, costly production, material consumption and large transport volume for shipping the pallet itself. Furthermore, the known carton pallets are prone to water and moisture due to the capillary action of the paperboard material.

There is therefore a need for a pallet that is easier to manufacture, has greater stability, uses less or less expensive material, is better protected against moisture and water, and is itself easier to transport. Furthermore, there is a need for a method of manufacturing such a pallet as well as a plant for producing such pallets.

The above problems and requirements are solved by a pallet foot for a pallet according to claim 1, and by a pallet according to claim 11.

In particular, the above-mentioned problems are solved by a pallet foot for a pallet, which is characterized in that the cardboard tube consists of wound (recycled) paper layers.

By winding the paper layers, a particularly high strength is achieved, even when using recycled paper. The use of recycled paper reduces material costs.

Such a pallet foot can be quickly and easily made from a square cardboard tube. Since the starting material is a pipe that is merely machined, no additional board elements need to be made and assembled. The stiffeners of the load-bearing areas are formed purely by the cardboard material present in the cardboard tube. This enables an absolutely waste-free production of the pallet feet. The tubular starting material is also particularly stable, since there are no splices, pronounced seams or similar. but preferably is wound in one piece. Furthermore, by the infill of the load-bearing areas by the stiffening walls on the one hand stable and on the other hand very light structure is created, which also resists high loads.

Furthermore, cardboard and paper mills have fixed working widths of their machines, so that in the production of certain paper or board widths constantly secondary tracks incurred. When weight changes also transition tracks that also occur as waste. These secondary or transitional tracks are usually returned to the waste paper cycle. This is associated with high costs for the paper mill as the rolls of the minor and transitional webs are too compact to recycle directly. They are therefore handled with great effort or sawn.

Since only narrow paper or cardboard strips of a width of about 70mm - 140mm are needed for winding the cardboard tubes according to the invention, the secondary and transition paths that are used in paper production as waste incurred, used without problems and thus supplied to a meaningful use. Wider sideways or transitional webs need only be cut to the required strip width, which is easily possible in the paper mill. Otherwise, the side panels are almost not to be sold, so they are available at very low cost, if not in vain, which significantly reduces material costs for the pallet feet.

Preferably, the cardboard tube has a quadrangular or octagonal cross-sectional shape. Through these forms of Palettenfuß forms a flat support surface for a cover plate of the pallet and a flat bearing surface on the floor, which can distribute occurring loads over a large area.

In a further preferred embodiment, the cardboard tube consists of a cardboard material which has been hardened by means of water glass. The hardening of the cardboard tube with water glass gives the pallet base produced therefrom a particularly high strength. Furthermore, water glass is very inexpensive as a hardening and adhesive material, since it costs only about 1/3 of the adhesives commonly used. In addition, water glass releases no toxic fumes when cured in air. In addition, the cardboard tube is protected from water and moisture after curing, so that the pallet can also be used outdoors.

Preferably, the closed portions of the plate feet have side walls which are provided with indentations that are substantially parallel to the load direction. The indentations or corrugations reinforce the sidewalls of the load-bearing areas and increase the buckling resistance compared to a flat surface. The impressions can also merge into each other, so that a waveform is created.

Preferably, the closed areas are divided into three or four chambers. Furthermore, the individual chambers of the closed regions preferably have the same shape. The shape and number of chambers determined significantly the stability of the pallet. The preferred closed chambers can also absorb particularly good lateral forces in addition to the compressive forces by the weight of the cargo, which often occur during transport and loading of the pallet.

In a further preferred embodiment, the stiffening walls are folded at folding grooves, which run parallel to the load direction. The folding grooves facilitate accurate folding of the stiffening walls. Since the folding grooves run in the load direction, the stiffening walls are perpendicular within the load-bearing areas and therefore transmit the pressure forces occurring in the main load direction in the bottom surface.

Preferably, the stiffening walls of a closed area are glued together flat. Gluing the stiffening walls substantially increases the load capacity of the load-bearing areas because the splices can transfer shear forces between the stiffening walls.

Preferably, the cardboard tube has a continuous upper wall and a continuous lower wall, wherein the inwardly folded side walls are bonded to the upper wall and the lower wall. The continuous upper and lower walls of the pallet foot serve as spacers and reinforcements of the load bearing areas.

Furthermore, it is preferred that the closed areas furthermore each have at least one lateral window in order to connect the pallet foot to a transverse strut.

In particular, the above-mentioned problems are also solved by a pallet having a substantially flat, flat cover plate and at least two pallet feet according to one of claims 1-11. By adding a suitable cover plate, for example made of wood, plastic, metal or cardboard is formed with the palency feet a full range, which is adaptable to the particular application.

Preferably, the cover plate is also made of cardboard or recycled cardboard. This provides a completely recyclable cardboard pallet.

In a further preferred embodiment, the pallet feet are glued parallel to each other on the cover plate.

Preferably, the pallet further comprises at least one transverse strut, which is connected to the pallet feet and which extends perpendicular to them. By such a cross strut, the stability of the pallet can be extremely increased, so that the material thickness of the cover plate can be reduced. For example, the thickness of the comparatively expensive cover plate could be reduced to about 50% with the same load. As a result, a cost reduction of up to 20% can be achieved.

Furthermore, the cross member can be used as needed or omitted, so that an individually configurable pallet system is provided.

Preferably, the cross member is made of the same cardboard tube as the pallet feet. Thus, the same pipe winding machine can be used.

• 1. Stanzen von Schnittlinien in die Mantelfläche eines Kartonrohrs, um Versteifungswände auszuschneiden;
• 2. Einprägen von Faltrillen in die Mantelfläche des Kartonrohrs, um Faltrillen zum Falten der versteifungswände zu bilden; und
• 3. Falten der Versteifungswände, um die lasttragenden Bereiche des Palettenfußes in Kammern zu unterteilen.

Furthermore, the above problems are also solved by a method for producing a pallet foot for a pallet, which comprises the following steps; however, is not the subject of the present patent.

• 1. Cutting cutting lines in the outer surface of a cardboard tube to cut stiffening walls;
• 2. Impressing folding grooves in the lateral surface of the cardboard tube to form folding grooves for folding the stiffening walls; and
• 3. Folding the stiffening walls to divide the load bearing areas of the pallet base into chambers.

The inventive method also achieves the advantages described above with respect to the pallet feet according to the invention.

• 1. Wickeln eines Endlos-Kartonrohres aus Papier- oder Kartonlagen; und
• 2. Abschneiden des Endlos-Kartonrohres auf eine gewünschte Länge, um ein einzelnes Kartonrohr zu bilden.

In a preferred embodiment, the method further comprises the following steps, which are performed before the other steps:

• 1. winding an endless cardboard tube from paper or cardboard layers; and
• 2. Cutting the endless cardboard tube to a desired length to form a single cardboard tube.

Thus, in a process based on paper stock, a pallet foot of a certain length and of a certain strength and load is manufactured. The step of winding can be varied so that different wall thicknesses of the cardboard tube are obtained and thereby also a different load of the pallet base.

Preferably, the method further comprises the step of introducing indentations in the lateral surface of the cardboard tube, wherein the indentations extend substantially parallel to the desired load direction. The depressions or corrugations reinforce the lateral surface of the cardboard tube.

Preferably, the steps of punching cut lines, impressing folding grooves, and inserting indentations are performed simultaneously. This reduces the production time of the pallet foot.

In a further preferred embodiment, the method further comprises the step of introducing the cardboard tube with water glass. Preferably, the paper strip from which the cardboard tube is wound is pulled through a gluing aggregate, one side of the paper strip being coated on the full surface with waterglass. The use of water glass as an adhesive and hardening agent is only possible because immediately after the winding process of the "Press-stamping-punching process" is performed. By pressing the tube an absolute bond is achieved, which can be achieved in a conventional winding only by a costly post-treatment using high quality adhesives. In particular, the winding of the cardboard tube can be done at a much higher winding speed than in conventional methods, since any air bubbles between the paper webs to be bonded are pressed by the pressing of the tube.

In a further preferred embodiment, the method comprises the step of pressing and heating the cardboard tube to cure the cardboard tube bubble-free. Preferably, the step of pressing and heating is performed simultaneously with the stamping-stamping step. During pressing, the paperboard fibers are retained and the board surface is smoothed, whereby the pallet base shows a lower moisture absorption. Furthermore, by heating the drying time of the pallet feet is reduced so much that an immediate further processing can take place. In the case of ordinary drying, drying times of up to 2 weeks would otherwise have to be observed.

Preferably, the method further comprises the step of applying adhesives to portions of the stiffening walls to bond the stiffening walls together.

Furthermore, the above-mentioned problems are also solved by a plant for producing pallet feet, comprising a pipe-processing machine for punching cutting lines and introducing folding grooves in a lateral surface of a square Cardboard tube and a folding machine for folding stiffening walls along the folding grooves, for forming load-bearing areas of a pallet base.

By such a system Palettenfiiße can be made quickly and inexpensively from cardboard tubes. The system can operate fully automatically, so that a high number of pallet feet can be produced at low unit costs.

Preferably, the system further comprises a tube winding machine for. Producing an endless cardboard tube and a cutter for cutting the endless cardboard tube to obtain a cardboard tube of a desired length;

In a further preferred embodiment, the tube processing machine has an inner tool that can be inserted into the cardboard tube and wherein the inner tool can be radially spread to abut the inner wall of the cardboard tube.

Preferably, the inner tool has interchangeable working surfaces for grooving, embossing and punching or cutting. The working surfaces of the inner tool can thus be easily replaced when worn.

Preferably, the inner tool further comprises at least one electric heating element. By the heating element, the inner tool can be heated to promote the curing of soaked with water glass and thus moist cardboard tube. The cardboard tube is thus quasi "baked" or pressed in the mold.

In a further preferred embodiment, the processing machine has outer tools, which interchangeable punching tools for punching cutting lines in the lateral surface of the cardboard tube and interchangeable embossing tools for introducing Faltrillen in the lateral surface of the cardboard tube include. Due to the interaction of the outer and inner tools, the cardboard tube is still pressed together so far that air is pressed out between the paper layers of the cardboard tube and an optimal bonding of the paper webs is achieved.

Preferably, the outer tool further comprises interchangeable embossing tools for the introduction of indentations.

It is further preferred that the system further comprises edge cutter for punching longitudinal cutting lines in the lateral surface of the cardboard tube.

Preferably, the folding machine on vacuum suction to bend the stiffening walls of the lateral surface of the cardboard tube to the outside. The vacuum cups are placed on the cut-out side wall portions of the cardboard tube and the vacuum applied to grip the stiffening walls and simply bend them outward.

The folding machine preferably has motor-driven screwing-in claws in order to fold the reinforcing walls into the load-bearing areas of the cardboard tube. After bending the stiffening walls by means of the vacuum cups, screw-in claws can be used to fold the stiffening walls into their desired shape.

Preferably, the Einrehkrallen can be rotated by stepper motors and pneumatically driven up and down.

• 1. Formen von Preformen aus einem eckigen Kartonrohr;
• 2. Versand der Preformen zum Endanwender;
• 3. Befestigen der Preformen an eine geeignete Deckplatte beim Endanwender.
  Da der letzte Verfahrensschritt erst beim Endanwender durchgeführt wird, entsteht die vergleichsweise sperrige Palette erst zu diesem Zeitpunkt. Die Preformen nehmen beim Versand an den Endanwender nur einen geringen Raum ein, so dass die Versandkosten niedrig sind. Ein LKW kann üblicherweise 800 Leerpaletten der Europalettengröße laden. Beim Versand von Preformen können ca. 8000 Einzelsysteme pro LKW transportiert werden, die dann beim Endanwender montiert werden.
  Bevorzugt sind die Preformen Palettenfüße oder Querstreben, dann bleibt dem Endanwender überlassen, welche Deckplatte, etwa aus Holz, Kunststoff oder Karton, er verwenden möchte. Weiterhin ist er je nach zu transportierender Traglast flexibel bezüglich der Anzahl der benötigten Preformen. Beispielsweise könnten statt drei bei leichten Lasten nur zwei Palettenfüße pro Palette eingesetzt werden, was eine Materialersparnis von ca. 30% pro Palette bedeuten würde. Der Endanwender kann weiterhin je nach Traglast wählen, ob Querstreben eingesetzt werden sollen oder nicht.
  In einer weiteren bevorzugten Ausführungsform weist das Verfahren weiterhin den Schritt des Lieferns der Deckplatte an den Endanwender auf Somit erhält der Endanwender einen kompletten Bausatz einer Palette.
  Bevorzugt weist eine erfindungsgemäße Palette bei gleichen Abmessungen nur ein Eigengewicht von ca. 3,5 kg auf, verglichen mit einer Europalette aus Holz die ca. 11 kg aufweist. Somit lassen sich diese Paletten auch von weiblichen Mitarbeitern handhaben. Weiterhin kann eine Gasbehandlung, wie sie für Exporteinsätze vorgeschrieben ist, entfallen, was zu einer weiteren Senkung der Herstellkosten führt.
• 4. Kurze Beschreibung der Zeichnungen
  Im Folgenden werden die Zeichnungen beschrieben, welche bevorzugte Ausführungsformen der vorliegenden Erfindung darstellen. Darin zeigt:

  Fig. 1

  eine erfindungsgemäße Palette in einer dreidimensionalen Ansicht gemäß einer ersten bevorzugten Ausführungsform der vorliegenden Erfindung, mit erfindungsgemäßen Palettenfüßen;

  Fig. 2

  zwei Seitenansichten einer bevorzugten Ausführungsform eines erfindungsgemäßen Palattenfußes, wobei die obere Seitenansicht Faltlinien und die untere Seitenansicht Schnittlinien zeigt;

  Fig. 3A bis 3E

  horizontale Schnittansichten durch lasttragende Bereiche bevorzugter Palettenfüße, wobei verschiedene Faltvarianten der Versteifungswänden dargestellt sind;

  Fig. 4

  eine horizontale Querschnittsansicht durch eine Rohr-Bearbeitungsmaschine zum Bearbeiten von Kartonrohren; die jedoch nicht Gegenstand des vorliegenden Patentes ist;

  Fig. 5

  eine Querschnittsansicht durch ein Außenwerkzeug einer bevorzugten Rohrbearbeirungsmaschine;

  Fig. 6

  eine dreidimensionale Ansicht eines Außenwerkzeuges;

  fig. 7

  eine longitudinale Querschnittsansicht durch einen Innenwerkzeug einer bevorzugten Rohr-Bearbeirungsmaschine;

  Fig. 8

  eine axiale Querschnittsansicht durch ein bevorzugtes Kartonrohr sowie ein Innenwerkzeug einer bevorzugten Rohr-Bearbeitungsmaschine;

  Fig. 9

  eine Quersichtsansicht eines Teilbereichs einer Rohr-Bearbeitungsrnaschine, welche Kartonrohr, Außenwerkzeuge, Innenwerkzeug und Kantenschneider zeigt;

  Fig. 10

  eine dreidimensionale Ansicht eines Kartonrohrs mit Innenwerkzeug, sowie einen bevorzugten Kantenschneider;

  Fig. 11

  oben eine Aufsicht auf ein Faltwerkzeug einer Faltmaschine und unten eine Seitenansicht des Faltwerkzeuges, sowie eine angedeutete Versteifungswand des Kartonrohrs;

  Fig. 12

  eine Eindrehkralle im Eingriff mit einer Versteifungswand;

  Fig. 13

  eine Seitenansicht, sowie acht Aufsichten auf eine bevorzugte Ausführungsform eines Palettenfußes zur Verdeutlichung des Einfaltsvorganges der Versteifungswände;

  Fig. 14

  eine Aufsicht auf eine bevorzugte Ausführungsfonn einer Anlage zur Herstellung von Palettenfüßen;

  Fig. 15

  eine Seitenansicht der Anlage aus Figur 14;

  Fig. 16

  eine zweite Ausführungsform einer Palette in der Seitenansicht, wobei zusätzlich zu den Palettenfüßen auch Querstreben verwendet werden;

  Fig. 17

  ein Zusammenbauschema in der Draufsicht für eine Palette, die drei Palettenfüße und sechs Querstreben verwendet;

  Fig. 18

  eine Seitenansicht auf ein mit Faltrillen und Schnittlinien versehenes Kartonrohr;

  Fig. 19

  den Endbereich einer Querstrebe in einer dreidimensionalen Ansicht; und

  Fig. 20

  eine Querschnittsansicht einer Querstrebe.

• 5. Detaillierte Beschreibung der bevorzugten Ausführungsformen
  Im Folgenden werden unter Bezugnahme auf die Figuren bevorzugte Ausführungsformen der vorliegenden Erfindung im Detail beschrieben.

The problem of space-consuming transport of the finished pallet is solved by a method for producing a pallet, the method comprising the following steps in this order:

• 1. molding preforms from a square cardboard tube;
• 2. shipping the preforms to the end user;
• 3. Attach the preforms to a suitable cover plate at the end user.
  Since the last process step is only carried out by the end user, the comparatively bulky pallet arises only at this time. The preforms take only a small space when shipping to the end user, so that the shipping costs are low. A truck can usually load 800 euro pallet empty pallets. When shipping preforms, approx. 8,000 individual systems can be transported per truck, which are then assembled by the end user.
  Preferably, the preforms are pallet feet or cross struts, then it is up to the end user to decide which cover plate, for example made of wood, plastic or cardboard, he would like to use. Furthermore, it is flexible depending on the transport load to be transported in terms of the number of preforms required. For example, instead of three at light loads only two pallet feet per pallet could be used, which would mean a material saving of about 30% per pallet. The end user can also choose depending on the load, whether cross struts should be used or not.
  In a further preferred embodiment, the method further comprises the step of providing the cover plate to the end user. Thus, the end user obtains a complete kit of a pallet.
  Preferably, a pallet according to the invention with the same dimensions only a weight of about 3.5 kg, compared with a Euro pallet made of wood which has about 11 kg. Thus, these pallets can also be used by female employees handle. Furthermore, a gas treatment, as prescribed for export operations, omitted, resulting in a further reduction in manufacturing costs.
• 4. Brief description of the drawings
  The drawings which illustrate preferred embodiments of the present invention will now be described. It shows:

  Fig. 1

  a pallet according to the invention in a three-dimensional view according to a first preferred embodiment of the present invention, with pallet feet according to the invention;

  Fig. 2

  two side views of a preferred embodiment of a Palattefußes invention, the upper side view shows fold lines and the lower side view section lines;

  Fig. 3A to 3E

  horizontal sectional views through load-bearing areas of preferred pallet feet, wherein different folding variants of the stiffening walls are shown;

  Fig. 4

  a horizontal cross-sectional view through a pipe processing machine for processing cardboard tubes; which, however, is not the subject of the present patent;

  Fig. 5

  a cross-sectional view through an outer tool of a preferred Rohrbearbeirungsmaschine;

  Fig. 6

  a three-dimensional view of an outer tool;

  fig. 7

  a longitudinal cross-sectional view through an inner tool of a preferred Rohr-Bearbeirungsmaschine;

  Fig. 8

  an axial cross-sectional view through a preferred cardboard tube and an inner tool of a preferred pipe processing machine;

  Fig. 9

  a cross-sectional view of a portion of a pipe processing machine, which shows cardboard tube, outer tools, inner tool and edge cutter;

  Fig. 10

  a three-dimensional view of a cardboard tube with an internal tool, and a preferred edge cutter;

  Fig. 11

  above a plan view of a folding tool a folding machine and below a side view of the folding tool, and an indicated stiffening wall of the cardboard tube;

  Fig. 12

  a screw-in claw engaged with a stiffening wall;

  Fig. 13

  a side view, as well as eight views of a preferred embodiment of a Palettenfußes to illustrate the folding operation of the stiffening walls;

  Fig. 14

  a plan view of a preferred Ausführungsfonn a plant for the production of pallet feet;

  Fig. 15

  a side view of the system of Figure 14;

  Fig. 16

  a second embodiment of a pallet in the side view, wherein in addition to the pallet feet and transverse struts are used;

  Fig. 17

  an assembly plan view of a pallet using three pallet feet and six cross braces;

  Fig. 18

  a side view of a provided with folding grooves and cut lines cardboard tube;

  Fig. 19

  the end region of a transverse strut in a three-dimensional view; and

  Fig. 20

  a cross-sectional view of a crossbar.

• 5. Detailed Description of the Preferred Embodiments
  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

Figure 1 shows a pallet 1 consisting of a substantially flat, flat cover plate 50 and three pallet feet 10, which are preferably mounted under the cover plate 50. Preferably, three pallet feet 10 are used, wherein the pallet feet 10 are arranged parallel to each other. Two pallet feet 10 are at the edge of the cover plate 50 and a pallet base 10 is fixed in the middle of the cover plate 50. The attachment can be made by various attachment methods, however, an adhesion of the pallet feet 10 to the cover plate 50 is preferred.

Depending on the application of the pallet 1 and depending on the maximum load, only two pallet feet or more than three pallet feet can be used.

The pallet feet 10 essentially consist of a one-piece cardboard tube 11 with a polygonal cross-section. FIG. 1 shows cardboard tubes 11 with a square cross-section, FIGS. 8 to 15 show cardboard tubes with an octagonal cross-section. Of course, hexagonal or rectangular sections are also conceivable, but the bearing surfaces of the pallet base 10 should be flat with respect to the cover plate 50 so that the pallet feet can be glued securely to the cover plate 50.

The pallet base 10 of Fig. 1 shows three closed load-bearing areas 30, which are preferably cuboid-shaped, and two open areas 20 between the load-bearing areas 30. The open areas represent a transverse, i.e., horizontal, load-bearing area 30. transverse passage through the pallet feet, so that the pallet can also be received in the transverse direction of the fork of a forklift.

The pallet leg 10 has a continuous top wall 16 which secures the pallet leg 10 to the top panel 50, and a continuous bottom wall 14 which interconnects and spaces the load-bearing sections 30 to provide improved stability of the pallet leg 10.

Each pallet base 10 is made of a cardboard tube 11 of angular cross-section, which may be a specially wound cardboard tube or a cardboard tube obtained as a waste product in the paper or board production. For wrapping the cardboard tube, recycled or waste paper from secondary webs or transitions is preferably used, which can preferably be soaked or coated with waterglass prior to winding in order to provide increased stability to the later pallet base 10.

Water glass is available as potassium water glass (potassium silicate K ₂ SiO ₃ ) or as sodium silicate (sodium silicate Na ₂ SiO ₃ ) and is a syrup-like solution of sodium silicate or potassium silicate in water. Water glass cures in the air and serves as an inorganic binder, which gives the cardboard tube 11 and the pallet base 10 increased strength and moisture resistance. Water glass is used as a component for bonding, hardening and moisture protection of the pallet feet. Moisture protection can be increased even more if the pallet feet are immersed 20 - 30 mm from the bottom or completely in water glass. Due to the accuracy of the punching no water glass can penetrate into the interior of the load-bearing areas 30.

FIG. 2 shows how a cardboard tube 11 is provided with folding grooves 36 and cutting lines 38 in order to produce a pallet base 10 therefrom. The upper view in Figure 2 shows a side wall of a square cardboard tube 11 with later load-bearing portions 30 and stiffening walls 32 which are folded from the side wall of the cardboard tube 11. Furthermore, the upper view of Figure 2 shows the folding grooves 36 shown in dashed lines, which are introduced into the cardboard tube 11 in order to facilitate a folding of the stiffening walls 32 at these folding grooves 36.

The bottom view of Figure 2 shows the cutting lines 38 which are needed to cut out the stiffening walls 32 from the side walls of the cardboard tube 11.

To stiffen the load-bearing areas 30 of each pallet leg 10 and to increase its carrying capacity, portions of the side walls of the cardboard tube 11 are folded into the load-bearing areas 30 as stiffening walls 32. As a result, in each case a plurality of chambers 34 arise within the tube in the region of the load-bearing regions 30.

Preferred examples of the shape of such chambers 34 and preferred folding patterns are shown in Figs. 3A to 3E. FIGS. 3A to 3E show horizontal cross sections through a respective load-bearing region 30. Preferably, regions of the reinforcing walls 32 which abut on one another in a planar manner are adhesively bonded to one another, whereby the stiffening effect is significantly increased. For gluing the stiffening walls 32 together and also for bonding with the deck 16, bottom 14 and side walls 17 of the pallet base, a conventional paper adhesive, hot melt adhesive, or the like. be used. Preferably, water glass is also used for this purpose.

The gap between the stiffening walls 32 shown in FIGS. 3A to 3E merely serves to clarify the corresponding folding pattern and is not or not so pronounced in reality.

3A shows a first folding variant in which the stiffeners 32 are folded inwardly at three folding grooves 36 to form a cross-shaped stiffening structure within the closed area 30, the stiffening walls extending on the lines of symmetry of the closed area 30. As a result, the closed region of FIG. 3A is subdivided into four essentially equal chambers 34.

Figure 3B also shows a cross-shaped arrangement of the stiffening walls 32, wherein, however, a stiffening wall is not duplicated.

Figure 3C shows a variant in which two elongated chambers are formed, with a chamber in the middle partially divided by stiffening walls.

FIG. 3D shows an embodiment in which the stiffening walls 32 form three closed chambers 34, which are arranged in the longitudinal direction of the pallet foot 10. This embodiment provides a very good stiffening effect through the large overlapping portions of the individual stiffening walls 32.

The same applies to the embodiment of FIG. 3E, wherein the bending of two ends of the stiffening walls 32 towards the side wall results in a more uniform stiffening of the load-bearing regions 30.

Of course, other folding patterns are conceivable as the punched side walls 32 of the cardboard tube 11 can be folded into the load-bearing areas 30 to form a plurality of chambers 34.

Figure 4 shows a horizontal cross-sectional view through a tube processing machine 110. In the illustrated embodiment, the tube processing machine 110 consists of two inner tools - 111 and two Aßenwerkzeuge 114 which can be pressed by hydraulic cylinder 130 towards the inner tools 111 to press the cardboard tube 11 to press, embossing to grooves and to cut. The inner tools 111 are introduced laterally into the tube 11 and spread open by means of two pressure cylinders 140. After spreading, the inner wall 18 of the cardboard tube 11 bears against the outside of the inner tool 111.

FIG. 5 shows a detail of an outer tool 114 and two impression cylinders 130. A three-dimensional representation of the outer tool 114 can be seen in FIG. Figures 5 and 6 show that the actual tools 115, 116, 117 of the outer tool 114 are constructed of elongated profile-shaped elements which are screwed to a continuous support plate. Thus, the tools 115, 116, 117 of the outer tool 114 are interchangeable if necessary.

An outer tool 114 includes cutting tools 115, for cutting cutting lines 38 in the lateral surface of the cardboard tube 11, embossing tools 116 for introducing Faltrillen 36 in the lateral surface of the cardboard tube 111 and embossing tools 117 for introducing indentations 39 for reinforcing the lateral surface of the cardboard tube 11. The embossing tools 117 are preferably rounded at their working surface, so that a slight curls of the side surface of the cardboard tube 11 is formed, but no sharp edges are introduced, which could promote kinking.

FIG. 7 shows a longitudinal section of the inner tool 111 and illustrates how radially it can be spread in the tool 111. For this purpose, the inner tool 111 comprises a pressure cylinder 140, which moves a wedge-shaped element 141, which is pushed between two likewise wedge-shaped outer elements 142 can be. In this Einschiebevorgang move the wedge-shaped outer elements 142 parallel to each other away. The spreading of the inner tool 111 is limited by two stops 143, so that the cardboard tube 11 is clamped only firmly on the inner tool but not torn.

FIG. 8 shows a cross section through the inner tool 111 and through a cardboard tube 11. In particular, FIG. 8 shows electrical heating elements 113, which make it possible to heat the inner tool. Thus, the external hardening process of the impregnated with water glass cardboard tube 11 can be accelerated or even completed. The cardboard tube 11 is then "baked" quasi at a temperature of about 80 ° C to 120 ° C in the pipe processing machine. In this case ev. Is trapped between the paper layers trapped air. Furthermore, FIG. 8 shows interchangeable machining surfaces 112 which correspond to the machining tools 115, 116, 117 of the external tool 114. The processing surfaces 112 can also be replaced if necessary.

FIG. 9 shows a cross-section through a tube processing machine 110, in which case four outer tools 114 are used in order to be able to process all four sides of the cardboard tube 111. In order to cut the longitudinal cuts for the stiffening walls, the pipe processing machine is equipped with cutting tools 118, which introduce the longitudinal sections of the stiffening walls 32 into the cardboard tube 11.

FIG. 10 shows an exemplary cutting tool 118 in a three-dimensional view, wherein the cutting tool 118 can be moved by two pressure cylinders 130 in the direction of the inner tool 111. Furthermore, Figure 10 shows a further embodiment of the indentations 39 in the S-shape. A cutting line 38 created by the cutting tool 118 is also shown symbolically.

In the embossing process, the continuous upper 16 and lower walls 14 also receive an embossing (not shown) which increases the stability of the two walls, in particular against deflection. By embossing the stiffening walls 32 are fixed inside and may not need to be glued together. Furthermore, the bearing surface of the pallet base 10 is reduced to the cover plate 50, whereby a better bonding due to a higher contact pressure can be achieved. In this case, the adhesive insert can be reduced.

In addition, such an embossing reduces the bearing surface running the soil, so that the moisture absorption is additionally reduced. Furthermore, damage to the pallet is avoided by retracting pallet trucks, as the wheels of the pallet truck are guided through the curvature of the cardboard wall into the free spaces provided. Such a design also allows the use of the pallet on automatic transport lines, as well as the storage and removal of automatic storage warehouses.

FIG. 11 shows the plan view at the top and a side view of a folding device 127 of a folding machine 120 for folding the stiffening walls 32. A folding machine 120 has as many folding devices as there are stiffening walls 32. In the embodiment described herein, these are 12 unfolding devices 127.

The illustrated folding-in device 127 consists of two screw-in claws 122, 123, which are also shown in detail in FIG. The screw-in claws 122, 123 can be placed on the edge of a stiffening wall 32 to fold the stiffening wall 32 along its folding grooves 36. For this purpose, the driving-in claws 122, 123 are pneumatically movable up and down in order to grip the edge of the stiffening wall 32.

The folding-in device 127 further comprises two stepping motors 124 and 125 which turn the driving-in claws 122, 123 in a PLC-controlled manner. The left stepper motor 124 rotates the entire fold-in device 127, and the right stepper motor 125 rotates a turntable 126 that has a drive-in claw 123 and associated pneumatic up and down travel.

With the help of such Einfaltvorrichtungen 127 and vacuum cups 121 of the Einfaltvorgang runs for all stiffening walls 32 of the pallet base 10 automatically and simultaneously. The folding process is exemplified in steps 2 to 9 of FIG.

The uppermost view of FIG. 13 again shows by way of example a punched cardboard tube 11 provided with folding grooves 38. Steps 1 to 8 are shown in plan view.

Before the folding process, adhesive is applied to regions of the stiffening walls 32 to be bonded.

In step 1, the vacuum cups 121 are placed on the punched side walls 32 of the cardboard tube 11 and applied a vacuum to suck the side walls 32. In operation 2, the vacuum cups 121 are pivoted outwardly and the stiffening walls 32 are turned outward, i. folded away from the cardboard tube 11. In step 3, the Einrehkrallen 122, 123 are placed on the edges of the stiffening walls 32 by the Einrehkrallen 122, 123 are pneumatically moved down. The Einrehkrallen are symbolized in Fig. 13 by black or circles. At the same time, the vacuum cups 121 are removed by releasing the vacuum.

In step 4, the outer Einrehkrallen 122 are screwed, whereby the first folding takes place at a first Faltrille 26. In step 5, the removed external driving claws, ie moved up and screwed the middle Einrehkrallen to make a second folding, if desired.

In step 6, all screw-in claws are removed by lifting them pneumatically. In step 7, the stiffening walls 32 are automatically folded into the load-bearing areas 30 by a pressure from the outside by means of the folding device, as symbolized by the illustrated arrows.

In step 8, finally, the remaining end tabs 37 are folded down and up and glued to the stiffening walls 32.

FIG. 14 shows a plan view of a system 100 for producing pallet feet 10. The system 100 comprises a tube winding machine 150, which winds the wrapping paper 13 into an endless cardboard tube 12 with an angular cross-section. Preferably, the endless cardboard tube 12 and thus also the cardboard tube 11 5 to 20 layers of paper, depending on the required load of the Palettenfußes 10. Thus, a wall thickness of about 3mm - 5mm obtained, which may be thinner due to the special manufacturing process, than in conventionally produced cardboard tubes, which have the same strength a wall thickness of 12mm - 15mm. The winding paper of the endless cardboard tube is coated on one side with water glass before winding by means of a Beleimungsaggregats in the tube winding machine 150.

The endless carton tube 12 is discharged from the tube winding machine 150 and cut by a cutter 160 into cardboard tubes 11 of a desired length. A length of 1.40 meters is preferred for the cardboard tube 11.

After cutting the cardboard tube 11 falls on a first conveyor belt 170. From there it is conveyed to a second conveyor belt 180, as through the Arrows symbolizes. The second conveyor belt conveys the cardboard tube 11 to the respective processing lines. In FIG. 14, only a first processing line is completely shown and a second line is indicated, but further processing lines could follow upwards.

At the height of the first processing line, the cardboard tube 11 is conveyed by means of an ejector 185 from the second conveyor belt 180 onto a tube depot 200. Should a tube overcapacity be present, the cardboard tubes 11 are collected at the end of the conveyor belt 180 in a magazine (not shown). If necessary, the cardboard tubes 11 can be returned to the second conveyor belt 180 via a further tube depot 190.

From the pipe depot 200, the cardboard tubes 11 are gripped by means of a first transport cross 210 through a vacuum suction and conveyed to the tube processing machine 110. For this purpose, the transport cross 210 moves upwards and rotates through 180 °. The vacuum is then removed and the cardboard tube 11 falls into the pipe processing machine 110. Thereafter, the transport cross 210 moves back to its original position.

The machining process of the cardboard tube 11 now begins in the tube processing machine 110. The six pressure cylinders 130 move to the right and to the left on "fixation", wherein the cardboard tube 11 is only held light but not pressed. Then the inner tools 111 are rapidly retracted by means of gear transporters 145 in the cardboard tube 11. At the same time, the upper pressure cylinder 135 (see FIG. 15) on a further gear transporter 146 drops rapidly downward. The gear transporters 145 and 146 are locked to apply enough counterforce to the respective impression cylinders 140, 135. The pressure cylinders 130, 135 and 140 are now hydraulically or pneumatically pressurized and go into "working position". In this position, all folding grooves 36, cutting lines 38 and indentations 39 are simultaneously introduced into the lateral surface of the cardboard tube 11. At the same time, the material of the cardboard tube 11 pressed together so much that air between the paper webs is pressed out. Then, or even before, the electric heating elements 113 of the inner tool 111 are activated, whereby the inner tool 111 heats up, and the cardboard tube 11 is dried and cured.

After curing of the cardboard tube 11, or even after a partial curing, the pressure cylinders 130, 135, 140 and the gear transporters 145 and 146 are returned to their original position.

The finished cut and provided with folding grooves 36 and indentations 39 cardboard tube 11 is then conveyed by means of a second transport cross 220 of the tube processing machine 110 to the folding machine 120. There, the required folding operations, as described above in detail.

The pallet feet 10 are now finished and are required by means of a third conveyor belt, which connects all existing processing lines to a depot (not shown).

Subsequently, the pallet feet 10 can be glued to a pallet 1 with a suitable cover plate 50. Preferably, however, this last assembly step is not performed directly after the production of the pallet feet 10, but only at the end user. For this purpose, the finished pallet feet 10 are separated from the cover plates 50 to be shipped to the end user. The end user can then perform the final assembly (gluing, pinning, stapling, etc.). Thus, the transport volume is reduced to a minimum and minimizes the transport costs for shipping the pallet.

Of course, the pallets can also be mounted directly at the manufacturer of the pallet feet 10, if the end user does not want to make any assembly.

FIG. 16 shows a further preferred embodiment of a pallet 1. In this embodiment, transverse struts 300 are used between the pallet feet 10, which further increase the stability of the pallet 1.

The transverse struts 300 are like the pallet feet 10 of a wound cardboard tube 11. The required cardboard tube can be produced on the same tube winding machine 150, as the tubes 11 for the pallet feet 10. From a cardboard tube 11 of the required length can punching, creasing and Embossing each two transverse struts 300 are made.

18 shows a side view of a cardboard tube 11 with embossed longitudinal folding grooves 304 and stamped cut lines 302. The cutting lines 302 separate the cardboard tube 11 into an upper half 305 and a lower half 306, which respectively form a transverse strut 300. When punching the cutting lines 302 at the same time the ends of the cardboard tube are cropped (not shown) to later form pin 310 can, as shown in Fig. 19.

As shown in FIG. 20 in a cross-sectional view, the side surfaces of the cardboard tube halves 305, 306 are folded inwardly along the folding grooves 304 to double the sidewall thickness of the U-shaped cross member 300. Thereafter, at the ends of the transverse struts 300, trunnions 310 are formed by turning the double side walls outwardly at the end, as shown in FIG.

To connect the pallet feet 10 to the transverse struts 300, the pallet feet 10 in their load-bearing areas 30 are provided with side windows 22 which are also punched as shown in FIG. When assembling the pallet 1 with cross struts 300, the pins 310 are inserted into the side window 22 of the pallet feet 10 and glued as needed with water glass. In this case, the open side of the U-shaped transverse strut 300 preferably points upward, in the direction of the cover plate 50, and abuts against this with its upper edge.

The production of the transverse struts 300 is analogous to the production of the pallet feet 10, by means of a corresponding system. The transverse struts 300 are also pressed, punched, grooved and indented by means of a tube processing machine 110 in one operation, if desired. Thereafter, the folds of the side walls and the pin 310 are performed with a folding machine 120.

LIST OF REFERENCE NUMBERS

1

palette

10

pallet

11

cardboard tube

12

Continuous cardboard tube

13

paper documents

14

bottom wall

16

upper wall

17

Side wall

18

inner wall

20

open areas in the cardboard tube

22

sidewindow

30

closed load-bearing areas in the cardboard tube

32

stiffening walls

34

chambers

36

folding grooves

37

end flaps

38

cut lines

39

indentations

50

cover plate

100

investment

110

Pipe processing machine

111

internal tool

112

working surfaces

113

electric heating element

114

External tools

115

Cutting Tools

116

Embossing tools for folding grooves

117

Embossing tools for indentations

118

Edger

120

folding machine

121

vacuum cups

122

turning claws

127

folding in device

130

pressure cylinder

135

pressure cylinder

140

pressure cylinder

141

wedge-shaped inner element

142

wedge-shaped outer element

143

attack

145

gear Transportation

146

gear Transportation

150

Pipe-winder

160

cutter

170

first conveyor belt

180

second conveyor belt

185

ejector

190

second pipe depot

200

first pipe depot

210

first transport cross

220

second transport cross

230

third conveyor belt

300

crossmember

302

intersection

304

folding grooves

305

upper half

306

bottom half

310

spigot

Claims (14)

1. Pallet foot (10) for a pallet (1) having:

   a) a cardboard tube (11) having an angular cross-section, in which

   b) the cardboard tube (11) has open areas (20) providing a transverse passage through the pallet feet (10) and having closed load-bearing areas (30), in which

   c) each of the closed, load-bearing areas (30) is subdivided by stiffening walls (32) into a plurality of chambers and in which

   d) the stiffening walls (32) are formed from inwardly folded side walls of the cardboard tube (11),

   
   characterized in that the cardboard tube (11) is made from wound paper layers (13) or wound recycled paper layers.
2. Pallet foot according to claim 1, wherein the cardboard tube (11) has a quadrangular or octagonal cross-sectional shape.
3. Pallet foot according to one of the claims 1 or 2, wherein the cardboard tube (11) is made from a cardboard material hardened by means of water glass.
4. Pallet foot according to one of the claims 1 to 3, wherein the closed areas of the pallet feet (30) have side walls provided with impressions (39) essentially running parallel to the load direction.
5. Pallet foot according to one of the claims 1 to 4, wherein the closed areas (30) are subdivided into in each case three or four chambers (34).
6. Pallet foot according to claim 5, wherein the individual chambers (34) of the closed areas (30) have the same shape.
7. Pallet foot according to one of the claims 1 to 6, wherein the stiffening walls (32) are folded at folding grooves (36) running parallel to the load direction.
8. Pallet foot according to one of the claims 1 to 7, wherein the stiffening walls (32) of a closed area (30) are bonded together flat.
9. Pallet foot according to one of the claims 1 to 8, wherein the cardboard tube (11) has a through upper wall (16) and a through lower wall (14), the stiffening walls (32) being bonded to the upper wall (16) and the lower wall (14).
10. Pallet foot according to one of the claims 1 to 9, wherein the closed areas (30) have in each case at least one side window (22) in order to connect the pallet foot (10) to a crossbar (300).
11. Pallet (1) having:

    a) a substantially flat, planar cover plate (50),

    b) at least two pallet feet (10) according to one of the claims 1 to 9.
12. Pallet according to claim 11, wherein the cover plate (50) is made from cardboard or recycled cardboard.
13. Pallet according to one of the claims 11 or 12, wherein the pallet feet (10) are bonded parallel to one another to the cover plate (50).
14. Pallet according to one of the claims 11 to 13 having at least one crossbar (300), which is connected to the pallet feet (10) and runs perpendicular thereto.

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