EP0677448A2 - Pallet made of sheet metal - Google Patents

Abstract

The palette comprises pressed parts (2) for the feet each consisting of a conical wall section (4) next to the carrying surface (3), and a connected hemispherical head (5). The deep-drawn parts have a depth of more than 80 mm, which corresponds to a standardized foot height of palettes, for the purpose of handling by fork lift truck. The metal sheet (1) has a standard carrying surface of 800 mm width and 1200 mm length. It has nine pressed foot parts, positioned in three rows. Spaces for the insertion of lifting forks of a truck are located between the rows. The carrying surface has downward facing stiffening ribs (6), with ribs of neighbouring palettes engaging with each other. <IMAGE>

Description

The invention relates to a pallet made of a sheet metal, which forms a support surface for loads and has at least two cup-shaped shapes produced by deep-drawing and corresponding to each other along its edges as pallet feet.

In the metal sheet pallets known from W 93/13997, from which the invention is based, the pallet feet consist of truncated conical shapes of the metal sheet. The pallets are stackable, with the frustoconical shapes interlocking when stacked. However, there is still a considerable and annoying gap between the contact surfaces of the nested pallets. There is also the risk that the stacked pallets jam, particularly when stacking higher. Finally, it has been found that the frustoconical pallet feet can only be produced by deep drawing up to a maximum depth of 50 mm. The material breaks when producing deeper shapes with a frustoconical shape. The foot height achievable within the scope of the known measures is not sufficient for handling the pallet with conventional forklift vehicles.

From DE-U 73 13 405 a pallet is known which consists of two metal sheets with molded-in frustoconical spacers. The spacers of the two metal plates are welded together at their rear end, riveted or screwed. Material and manufacturing costs are considerable.

The invention has for its object to provide a pallet of the type described above, which can be handled with conventional forklift vehicles and can be stacked with a high packing density.

To achieve this object, the invention teaches that the expressions each consist of a conical wall section adjoining the bearing surface and a hemispherical head continuously adjoining it.

The hemispherical shapes, which are conical or conical in their upper area adjoining the support surface, allow the individual pallets to be placed one inside the other, so that, depending on the weight and the size of the loads to be transported, any number of pallets are arranged one above the other and next to one another can be, the hemispherical features fix the position of the individual pallets to each other exactly and do not allow displacement of the individual pallets. The substantially hemispherical shapes designed in accordance with the invention can be produced to such a depth that the height of the pallet corresponds to the standard height for forklift loading and thus the pallet is so far away from the ground that it can easily be picked up by floor vehicles. This is not possible with the known pallets because the material would tear if it were deformed in this way.

The favorable stacking option of the pallet according to the invention is particularly evident when it is transported back. The height of a stack is only slightly larger than the sum of the individual height of the first pallet and the wall thickness of all other pallets. A very large number of the pallets according to the invention can therefore be stacked with the smallest space requirement. Because of the special design of the features according to the invention, it is not possible to jam the individual pallets into one another, even with a stack of over 100 pallets. The pallet according to the invention can be used without any previous manual activity, such as nailing, screwing or the like of individual parts. It is also characterized by the fact that it consists of only a single material and the recycling of pallets that have become unusable can be carried out easily and inexpensively by any user.

A preferred embodiment of the teaching according to the invention provides that the metal sheet has a standard contact surface of 800 mm width and 1200 mm length and contains nine versions which are arranged in three rows of three versions, with insertion spaces for tines between the rows of forklift vehicles are available. The features designed according to the invention have a depth of more than 80 mm.

In a further embodiment, the invention teaches that the support surface has stiffening beads which are formed downwards and are arranged in a uniform pitch and are formed up to the edges of the metal sheet extend that the stiffening beads interlock in the overlap area of two pallets of the same type, stacked with partial overlap, and that the bearing surfaces lie one on top of the other in the overlap area. The stiffening beads are arranged symmetrically over the entire surface of the metal sheet and extend to the edge of the metal sheet. As a result, the torsional rigidity of the pallet according to the invention is significantly improved. The symmetrical distribution and the extent of the beads up to the edge of the metal sheet mean that when two or more pallets are placed next to or on top of one another to form a larger pallet, the beads of one pallet fit exactly into the beads of the other pallet. The stiffening beads are preferably arranged at equidistant intervals in parallel rows that overlap both in the longitudinal direction and in the transverse direction, all the beads being oriented at an angle of 45 ° to the edge of the pallet and the beads of adjacent rows being arranged at right angles to one another. The arrangement of the stiffening beads according to the invention leads to a high dimensional stability of the contact surface.

The pallets according to the invention can be stacked with partial overlap to form a transport surface which is adapted to the dimensions of the load to be transported. The transport surface formed in this way has only slight unevenness due to the good stackability of the individual pallets. It is suitable for the transport of stacks of sensitive thin sheets of high surface quality.

In a further embodiment, the invention teaches that the cup-shaped features have an opening on their underside for connecting sheet metal strips, the width of which is slightly greater than the diameter of the features and the length of which corresponds to the entire length or the entire width of the pallet, the sheet metal strips are releasably attachable to the pallet and form a belt that prevents the pallet from bending. In order to achieve a perfect connection of the sheet metal strips with the metal sheet forming the pallet, projections are provided on the top of the sheet metal strips, the spacing from one another of which corresponds to the distance of the hemispherical shapes of the metal sheet and which are dimensioned such that they fit into the underside of the shapes engage the openings provided. The projections provided on the top of the sheet metal strips are also expediently produced by deep drawing.

A particularly tight fit of the projections provided on the top of the sheet metal strips in the openings of the hemispherical shapes on the metal sheet forming the pallet is achieved in that the external dimension of the projections corresponds to the internal dimensions of the openings in the hemispherical shapes. This creates a clamping effect, so that the sheet metal strip can be removed from the pallet with little effort. The fastening of the sheet metal strip to the pallet can be further improved in that the outer dimension of the projections is slightly larger than the inner dimension of the openings in the hemispherical shapes and in that the projections are slightly curved outwards, are. This results in a kind of push button system.

St W 22:

C 0,020 - 0,090; Si max 0,050;
MN 0,12 - 0,38; P max 0,030; S max 0,030;
Al 0,020 - 0,090; N 0,0020 - 0,0100;
Cu max 0,20; Cr max 0,10; Ni max 0,150;
Mo max 0,020;

St W 24:

C 0,028 - 0,060, Si max 0,040;
MN 0,18 - 0,28, P max 0,020; S max 0,018;
Al 0,020 - 0,050; N 0,0030 - 0,0075;
Cu max 0,12; Cr max 0,08; Ni max 0,12;
Mo max 0,015
(alle Angaben in Gew.-%).

In a preferred embodiment of the invention, the metal sheet forming the pallet is made of steel. On the one hand, steel has the required deep-drawing quality with regard to the hemispherical characteristics, on the other hand, steel is easily fully recyclable. The steel qualities St W 22 and ST W 24, which have the following alloy compositions, have proven to be particularly suitable:

St W 22:

C 0.020 - 0.090; Si max 0.050;
MN 0.12 - 0.38; P max 0.030; S max 0.030;
Al 0.020-0.090; N 0.0020 - 0.0100;
Cu max 0.20; Cr max 0.10; Ni max 0.150;
Mo max 0.020;

St W 24:

C 0.028 - 0.060, Si max 0.040;
MN 0.18-0.28, P max 0.020; S max 0.018;
Al 0.020-0.050; N 0.0030 - 0.0075;
Cu max 0.12; Cr max 0.08; Ni max 0.12;
Mo max 0.015
(all figures in% by weight).

Cold-rolled thin sheets of steel qualities St W 22 and St W 24 are preferably used. A material thickness in a narrow range of 2.0 to 2.4 mm has proven to be particularly favorable for deep drawing.

The invention further relates to a method for producing a pallet from a metal sheet, with cup-shaped shapes being formed on a metal sheet forming the support surface of the pallet with deep-drawing tools, each of which consists of a conical wall section adjoining the support surface and a hemispherical head continuously adjoining it Form pallet feet. According to the invention, the forms are first drawn out and then shaped to the final dimension, hemispherical deep-drawing tools with different diameters being used for the drawing and during the subsequent finishing. It goes without saying that all cup-shaped versions of the pallet are produced at the same time. According to a preferred embodiment of the invention, hemispheres are used as deep-drawing tools for flattening, which are flattened on their front side assigned to the metal sheet and have a smaller diameter than the deep-drawing tools used for finishing. When finishing the cup-shaped shapes, downward-facing stiffening beads can be molded into the support surface at the same time. St W 22 or St W 24 non-alloy steel sheets are preferably used as metal sheets.

Fig. 1

eine Palette in Vorderansicht,

Fig. 2

die Palette gemäß Fig. 1 in der Draufsicht,

Fig. 3

eine andere Ausführung der Palette in Vorderansicht,

Fig. 4

einen Abschnitt einer Palette im Querschnitt, in größerem Maßstab,

Fig. 5

einen Abschnitt einer anderen Palette im Querschnitt, ebenfalls in größerem Maßstab,

Fig. 6 - 9

Anordnungen aus zwei mit Teilüberdeckung versetzt ineinandergestapelter Paletten gleicher Bauart,

Fig. 10.

einen Querschnitt durch einen Abschnitt eines Stapels von Paletten im Bereich der erfindungsgemäßen Ausprägungen.

In the following, the invention is explained on the basis of a drawing which represents only one exemplary embodiment. Show it:

Fig. 1

a pallet in front view,

Fig. 2

1 in top view,

Fig. 3

another version of the pallet in front view,

Fig. 4

a section of a pallet in cross section, on a larger scale,

Fig. 5

a section of another pallet in cross section, also on a larger scale,

6 - 9

Arrangements of two pallets of the same type stacked inside one another with partial overlap,

Fig. 10.

a cross section through a portion of a stack of pallets in the area of the features of the invention.

The pallet shown in FIGS. 1 and 2 consists of a metal sheet 1 which has cup-shaped features 2 directed downwards. The features 2 are produced by deep-drawing and each consist of a conical wall section adjoining the contact surface 4 and a hemispherical head 5 continuously adjoining them. In the following, they are also referred to briefly as hemispherical features. The metal sheet 1 is further provided with downward stiffening beads 6 which have an elongated shape and are symmetrical extend over the entire surface of the metal sheet 1, up to the edge.

The hemispherical shapes 2 form pallet feet. They have a depth of more than 80 mm. In the exemplary embodiment, the depth of the features 2 corresponds to the standard base height of pallets specified for forklift loading. In the exemplary embodiment, the metal sheet 1 has a support surface that is standardized in practice and is 800 mm wide and 1200 mm long, and contains nine features 2, which are arranged in three rows of three features each (see FIG. 2). Between the rows there are sufficient slots for tines for forklift vehicles. The stiffening beads 6 are arranged in a uniform pitch and extend to the edges of the metal sheet 1 in such a way that the stiffening beads 6 in the overlap area 7 of two pallets of the same type, stacked with partial overlap, interlock with one another and the contact surfaces 3 lie in the overlap area 7 (cf. 6 - 9). The stiffening beads 6 are arranged with equidistant spacings a in rows 8, 8 ', 9, 9' which overlap both in the longitudinal direction and in the transverse direction, all stiffening beads 6 being oriented at an angle of 45 ° to the edge of the pallet and the stiffening beads of adjacent rows 8, 8 'and 9, 9' are arranged at right angles to each other.

It can be seen from the exemplary embodiments shown in FIGS. 6-9 that the formation of a larger pallet is possible by joining several pallets according to the invention, the transport surface 10 of which is adapted to the dimensions of the load to be transported. The arrangements shown in Figs. 6 - 9 from two or more pallets of the same size, which are stacked together with partial overlap 7 to form a transport surface 10 adapted to the dimensions of the load, are also particularly suitable for transporting stacks of sensitive thin sheets of high surface quality .

From Fig. 10 it can be seen that a stack of pallets according to the invention has only a relatively low height.

3 - 5, a sheet metal strip 11 is attached to the underside of the hemispherical features 2. The length of the sheet metal strip 11 corresponds to the entire length or the entire width of the pallet. The sheet metal strip can be detachably attached to the pallet and forms a belt that prevents the pallet from bending when carrying large loads. Fastening options for the belt are shown in FIGS. 4 and 5. 4 shows a pallet in which the hemispherical features provided on the metal sheet 1 have openings 12 and in which 11 projections 13 are provided on the top of the sheet metal strips, which engage in the openings 12 of the hemispherical features 2. In the embodiment shown in Fig. 5 that is The outer dimension of the projections 13 is slightly larger than the inner dimension of the openings 12 in the hemispherical features 2. Furthermore, the projections 13 - which cannot be seen in the drawing - are slightly curved outwards.

Claims (13)

Pallet made of a sheet metal, which forms a support surface for loads and has at least two cup-shaped features of the same shape and size along its edges as pallet feet, characterized by deep-drawing, characterized in that the features (2) each consist of one on the support surface (3 ) adjoining conical wall section (4) and a continuously adjoining hemispherical head (5). Pallet according to claim 1, characterized in that the deep-drawn features (2) have a depth of more than 80 mm. Pallet according to Claim 1 or 2, characterized in that the depth of the cup-shaped features (2) corresponds to the standard base height for pallets specified for forklift loading. Pallet according to one of claims 1 to 3, characterized in that the metal sheet (1) has a support surface of 800 mm width and 1200 mm length, which is standardized in practice, and contains nine cup-shaped shapes (2), each in three rows of three Expressions (2) are arranged, with insertion spaces for tines of forklift vehicles being present between the rows. Pallet according to one of claims 1 to 4, characterized in that the bearing surface (3) has stiffening beads (6) molded downwards, which are arranged in a uniform pitch and extend to the edges of the metal sheet (1) in such a way that the Stiffening beads (6) in the overlap area (7) of two pallets of the same type, stacked inside one another with partial overlap, interlock positively and the support surfaces (3) lie on top of one another in the overlap area (7). Pallet according to Claim 5, characterized in that the stiffening beads (6) are arranged at equidistant intervals (a) in parallel rows (8, 8 'and 9, 9') which overlap both in the longitudinal direction and in the transverse direction, all stiffening beads (6) aligned at an angle of 45 ° to the edge of the pallet and the stiffening beads (6) of adjacent rows (8, 8 'and 9, 9') are arranged at right angles to each other. Pallet according to one of claims 1 to 6, characterized in that the metal sheet (1) is a 2.0 to 2.4 mm thick steel sheet. Pallet according to one of claims 1 to 7, characterized in that the embossments (2) have on their underside an opening for connecting sheet metal strips (11), the width of which is slightly larger than the diameter of the embossments (2) and their length corresponds to the entire length or the entire width of the pallet, the metal strips (11) are releasably attachable to the pallet and form a belt that prevents the pallet from bending. Pallet according to Claim 8, characterized in that projections (13) are provided on the top of the sheet metal strips (11), the spacing of which from one another corresponds to the spacing of the cup-shaped features (2) of the metal sheet (1) and are dimensioned such that they are in engage the openings (12) provided on the underside of the stampings (2). A method for producing a pallet from a metal sheet according to one of claims 1 to 9, wherein cup-shaped shapes are formed on a metal sheet forming the support surface of the pallet with deep-drawing tools, each of which consists of a conical wall section adjoining the support surface and a hemispherical head continuously adjoining it and form pallet feet, characterized in that the stampings are first drawn out and then shaped to the final dimension, hemispherical deep-drawing tools with different diameters being used for the drawing and during the subsequent finishing. Method according to Claim 10, characterized in that hemispheres are used as deep-drawing tools for pulling forward, the front of which is assigned to the metal sheet are flattened and have a smaller diameter than the deep-drawing tools used for finishing. A method according to claim 10 or 11, characterized in that during the finishing of the cup-shaped features, downwardly directed stiffening beads are simultaneously molded into the bearing surface. Method according to one of claims 10 to 12, characterized in that steel sheets of the quality ST W 22 or St W 24 are used as the metal sheet.

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