EP1970318B1 - Closed palette with milling line - Google Patents

Abstract

A multi-part plastic pallet comprises an upper cover (4) part (2), a lower part (3) comprising runner (6) and foot (5) and a surrounding sidewall. The upper and lower parts are joined together and comprise a seam along the joint line and the pallet has a milling line along the sidewall. Either the upper or lower part is essentially free from a milling line.

Description

The invention relates to a pallet according to the preamble of claim 1 and a method for their preparation.

Such pallets are known from practice, as well as from the DE 25 07 275 C2 . EP 0 997 383 B1 or EP 1 422 152 A1 , If the deck is designed as a closed surface, such pallets are also referred to as "closed pallets", which can be used where increased demands are placed on the hygienic conditions. For economic reasons, the pallets often have cavities.

In the production of upper and lower part, the materials and colors used cause shrinkage and / or distortion of the manufactured parts. As a result, the upper and lower parts often do not congruently join together along their seam. To avoid interfering edges and heels, along the seam on the sidewalls a milling line is created which causes a flush transition from the top to the bottom on the outside surface of the sidewall. Although so disturbing edges are eliminated, but then the wall thickness of the side wall is reduced and the side wall thus mechanically weakened.

In practice, there is the problem that when handling the pallet using industrial trucks, the forks or their individual prongs may not be properly aligned with the entry openings of the pallet, so that there is a risk that the tines pushed against the seam of the pallet can be. In this area, however, the pallet is relatively sensitive due to the material weakening caused by the milling line, so that in such contacts undesirably large damage to the pallet can result. In particular, when a hole has been pushed into the side wall, the pallet becomes unusable through the opening of the pallet cavity from a hygienic point of view

The invention has for its object to improve a generic range to the effect that this is possible inexpensively produced and thereby as stable as possible and protected against damage by the tines of a material handling vehicle as well as possible.

This object is achieved by a pallet having the features of claim 1. This pallet is produced in a process according to claim 16.

In other words, the invention proposes to leave either the upper part or the lower part substantially free of the milling line. "Substantially" means in the context of the present proposal that the seam itself, if they z. B. is configured as an adhesive or weld and forms an outwardly projecting bead on the side wall of the pallet, can lie in the milling line, so that the proportion of the seam, which is attributable to the free of the milling line upper or lower part, can be removed by milling, without departing from the present proposal.

According to the proposal, therefore, the other, namely to be milled component of the pallet can be deliberately over-dimensioned in its manufacture, so that a supernatant Edge results when both components, ie the upper part and the lower part, are joined together. The subsequent milling operation removes the excess, overhanging edge area of the oversized component and, if desired, optionally the weld or adhesive bead of the seam. The material thickness of the other, ungrastened component thus remains as designed, so that a material weakening in the side wall of the pallet and in particular in the region of the seam is avoided.

According to the proposal, it is also provided that the seam at the outer peripheral edge of the pallet runs approximately at the level of the upper side, that is approximately at the level of the deck. Thus, economically advantageous, the upper part only in the region of a comparatively thin plate which forms the deck of the pallet, be dimensioned larger than the lower part. Accordingly, less material must be removed during milling and recycled as if a larger proportion of the side wall would be oversized correspondingly thick and then would have to be milled away.

Advantageously, the seam can be offset from the outer peripheral edge of the pallet toward the center thereof, in particular from the top to the bottom to the middle. As a result, the stability of the pallet is improved, because the aforementioned impact forces that can act on the pallet by tines or an entire fork of a material handling vehicle in a lateral impact, do not burden the range and in particular the seam between the upper and lower part to shear. Rather, the interior supports where z. As ribs, fillers or reinforcing elements can be provided, the side edge at a horizontally directed towards the center of the pallet shock downright, so that the seam load is significantly reduced.

Different connection possibilities between the upper and lower part are conceivable, so that these two parts, for example can be welded or glued together or clipped, so can be locked. In particular, two types of connection can be used simultaneously, for example, first a latching and secondly a bonding or welding, so that a particularly reliable connection between the upper and lower part is guaranteed. The not only lying in a plane course of the seam requires the welding or gluing of the two upper and lower parts of the pallet increased attention or more complex manufacturing facilities. Surprisingly, however, it has been found that by the proposed achievable stability of the range, the production of the pallet can otherwise be done more economically, for example, by lower material thicknesses, so that the improved stability of the proposed range is also achievable in an economically manufacturable range.

Advantageously, the connection of the individual parts of the pallet is permanently carried out with one another, ie as a non-detachable connection. This improves the stability of the pallet. In particular, when the non-releasable connection is made tight, for example by gluing or welding the pallet parts together, the hygiene of the pallet is also favorably influenced, since the penetration of liquids into cavities of the pallet, or even the escape of gases from the cavities can be avoided ,

Advantageously, cavities can be provided on the deck or in the feet of the pallet so that a particularly lightweight and material-saving, in turn, a particularly economically producible range can be created. The cavities mentioned are provided with stiffening elements, which are formed by foaming of the cavities or by uniform material formed by the pallet parts ribs or by separate stiffening profiles, such as metal profiles. The proposed pallets can be advantageous Have upper and lower parts, which are made by injection molding. Thus, the pallets can be produced inexpensively in large quantities.

Advantageously, the pallet on its upper side, ie on the deck or on the underside, ie below at least one runner, be provided with a slip-resistant covering, so that in terms of improved load securing the range against unwanted sliding movements and the load on the pallet against unwanted Slipping motions can be secured.

Advantageously, an automated detection of the pallets or of the goods transported therewith can take place in that the pallet can be detected electronically. For this purpose, for example, the known per se transponder or RFID tags can be used. These can be optimally integrated into the pallet, protected from the effects of the weather and protected against mechanical influences. D. H. So be provided either in a cavity of the pallet, there for example glued, or they can be injected into the pallet material.

On the deck can advantageously be mounted locks for the goods to be transported. For example, upstands in the form of angles or points can be provided, which support the stable arrangement of the goods to be transported on the pallet. Thus, for example, on the outside of the rim of the pallet, a corresponding upstand or a correspondingly molded circumferential collar can be provided, which both secures the load on the pallet and supports the stacking of several similar pallets by creating a stable bond between these stacked pallets ,

Fig. 1 bis 3

Querschnitte durch eine vorschlagsgemäße Pa- lette während der Fertigung, wobei die Ober- und Unterteile in drei fertigungstechnisch be- dingt unterschiedlichen Anordnungen zueinan- der befinden,

Fig. 4 bis 6

den Fig. 1 bis 3 gegenübergestellt die jeweilige Palette nach Erzeugung der Fräslinie,

Fig. 7 und 8

eine Palette nach dem Stand der Technik, in zwei idealisierten Ansichten während der Ferti- gung und nach Fertigstellung, und

Fig. 9 und 10

eine Palette nach dem Stand der Technik, in zwei der Praxis entsprechenden Ansichten wäh- rend der Fertigung und nach Fertigstellung.

An embodiment of a proposed range will be based on the purely schematic representations below explained in more detail. It shows

Fig. 1 to 3

Cross-sections through a proposed pallet during production, wherein the upper and lower parts are located in three different production-related arrangements,

4 to 6

the Fig. 1 to 3 compared the respective pallet after generation of the milling line,

FIGS. 7 and 8

a pallet according to the state of the art, in two idealized views during production and after completion, and

FIGS. 9 and 10

a pallet according to the prior art, in two practical views during manufacture and after completion.

In the drawings, a total of 1 denotes a pallet having an upper part 2 designated as an injection molded part and a lower part 3 designated as an injection molded part. The upper part 2 forms a closed deck 4 of the pallet 1, so that a hygienically closed pallet surface is achieved. By way of example only, an upwardly directed, circumferential upstand 11 is provided at the edge of the deck 4. Feet 5 are arranged in a known per se and therefore not shown manner in three parallel rows, each three feet 5 are connected by longitudinally extending skids 6 together.

A seam 7 results from the separation points at which the upper part 2 adjoins the lower part 3. As in Fig. 7 shown, the seam 7 extends in a manufactured according to the prior art pallet 1 on the outer periphery of the Palette1, at about half the height of the side walls. The connection of the upper and lower parts 2 and 3 is carried out by welding, resulting in a bead along the seam 7 both on the inside and on the outside of the side wall. In order to remove this disturbing bead, it becomes according to Fig. 8 through a milling process removed, so that there is a Fräslinie, which reduces the wall thickness of the side wall slightly and does not represent a problematic mechanical weakening of the side wall.

The FIGS. 7 and 8 show an ideal state of a pallet according to the prior art. In practice, however, often results in a misalignment between the upper part 2 and the lower part 3 due to different shrinkage or distortion processes in the production of the respective parts. It can therefore happen that, as in the FIGS. 9 and 10 shown, the side wall portions of the upper part 2 and the lower part 3 are not flush with each other. By the in Fig. 9 recognizable offset leads to the introduction of the milling line to the fact that in the lower part 3 a particularly strong projection is created, which in itself must not be problematic. For example, the lower part 2 may have the standardized dimensions, so that the lower part 3 does not have impermissible dimensions with this clearly visible projection. The problem, however, is that the side wall is considerably weakened in the milling line, since it has a significantly smaller wall thickness than intended there. For the regular treatment of the pallet 1, this does not necessarily mean a disadvantage. However, the pallet 1 is handled in a non-intended manner, for example by falling from a certain height with a corner of the pallet 1 on a hard floor, or if an industrial truck accidentally not in the entrance pockets of the pallet 1, but against the side wall of the pallet. 1 is guided, in the area in which this material weakening, so the side wall can be damaged so that an opening to the pallet interior, ie in the cavity of the pallet 1 is created.

According to the proposal, the seam is displaced upwards from the central region of the side wall towards the deck 4 of the upper part 2, like the latter FIGS. 1 to 6 demonstrate: Fig. 1 also shows one here idealized representation in which the upstand 11 is exactly aligned with the side wall of the lower part 3. Fig. 4 shows the corresponding finished pallet: By creating a cutting line of the protruding edge portion 10 as well as the outer bead of the seam 7 is removed. The lower part 3 has thus remained free of a milling line, except for the minor portion, namely where the bead of the seam 7 was present on the outside of the lower part 2. Based on the entire cross-sectional area of the side wall, as far as the side wall is formed by the lower part 3, this amount of material which has been removed at the lower part 3 by the Fräslinie, negligible. In particular, is off Fig. 4 recognizable that the wall thickness of the side wall on the lower part 3 has not been noticeably reduced and, accordingly, the structurally provided stability of the pallet 1 is not impaired by a reduction in the side wall thickness.

Fig. 2 shows the basically same pallet 1 as Fig. 1 , but in a practice typical first variant: By appropriate shrinkage, the upper part 2 is smaller than in the idealized representation of Fig. 1 failed, so that the upstand 11 is arranged offset from the side wall of the lower part 3 inwards. The laterally projecting edge region 10 of the upper part 2 therefore coincides Fig. 1 correspondingly smaller.

Again, however, results after the milling an undiminished stability of the pallet 1, as based on Fig. 5 becomes clear: Although now the upstand 11 is located somewhat further from the outer edge region of the pallet 1 further inside, the mechanical stability in the region of the seam 7 and in particular the wall thickness of the side wall is as undisturbed as it is in the ideal conditions of Fig. 1 and 4 the case is.

Fig. 3 shows the same palette of Fig. 1 and 2 but in a typical practice typical variant: The upper part 2 is in this Case larger than the lower part 3, so that the upstand 11 is offset relative to the side wall of the lower part 3 to the outside and the edge portion 10 of the upper part protrudes particularly far beyond the side wall of the lower part 3.

Fig. 6 shows this variant of the pallet 1 after the milling process: The milling line has not only removed the protruding edge portion 10, but also reduces the wall thickness of the upstand 11. As a result, the stability of the pallet 1 is not impaired and in particular the pallet 1 has not become more sensitive to the unwanted generation of openings to the inner cavity of the pallet by this reduced wall thickness of the upstand 11.

From a hygienic point of view, therefore, the pallet 1 is also in practice typical dimensional variations, as they FIGS. 2 and 5 as well as 3 and 6 show just as advantageous as the ideal palette of Fig. 1 and 4 ,

On the outer sides of the pallet 1, the seam 7 extends at the lower edge of the deck 4. Inside the pallet 1, however, the seam 7 extends deeper, namely where two ribs 8 and 9 abut each other and abut each other, so that the seam 7 from outer circumference of the pallet 1 runs down towards the center of the pallet 1. The ribs 8 are formed by the upper part 2 and the ribs 9 of the lower part 3.

Claims (17)

1. Multipart pallet (1) made of plastic, having an upper portion (2) forming an upper side also termed the deck (4),
   and a bottom portion forming runners (6) and feet (5),
   and having a side wall running all the way round, where the upper portion (2) and lower portion (3) are joined together and incorporate along their joining line a seam (7),
   and where the pallet (1) incorporates along the side wall a milling line which extends over the seam (7),
   characterised in that
   the lower portion (3) is essentially free of the milling line and in that the seam (7) runs along the outer peripheral edge of the pallet (1) at approximately the same height as the deck (4).
2. Pallet in accordance with claim 1,
   characterised in that,
   the seam (7) is set higher on the outer peripheral edge of the pallet (1) than at its middle.
3. Pallet in accordance with any one of the foregoing claims,
   characterised in that
   the upper portion (2) is welded to the lower portion (3).
4. Pallet in accordance with any one of the foregoing claims,
   characterised in that
   the upper portion (2) is bonded to the lower portion (3).
5. Pallet in accordance with any one of the foregoing claims,
   characterised in that
   the upper portion (2) is locked to the lower portion (3).
6. Pallet in accordance with any one of the foregoing claims,
   characterised in that
   the deck (4) incorporates one or more cavities, and bracing elements are provided for in the deck (4).
7. Pallet in accordance with any one of the foregoing claims,
   characterised in that
   bracing elements are provided for in the cavities formed by the feet (5).
8. Pallet in accordance with claim 6 or 7,
   characterised in that
   the cavities are filled with foam.
9. Pallet in accordance with any one of claims 6 to 8,
   characterised in that
   the upper portion (2) and/or the lower portion (3) incorporates or incorporate projecting members (8,9) which extend into the cavities.
10. Pallet in accordance with any one of claims 6 to 9,
    characterised in that
    metal profile sections are fitted into the cavities.
11. Pallet in accordance with any one of the foregoing claims,
    characterised in that
    the upper portion (2) and/or the lower portion (3) is or are constructed as an injection-moulded part or parts.
12. Pallet in accordance with any one of the foregoing claims,
    characterised in that
    the deck (4) is provided with a slip-retardant lining.
13. Pallet in accordance with any one of the foregoing claims,
    characterised in that
    the underside of one or more runners (6) is provided with a slip-retardant lining.
14. Pallet in accordance with any one of the foregoing claims,
    characterised in that
    one or more transponders, also referred to as RFID tags, is or are integrated into the pallet (1).
15. Pallet in accordance with any one of the foregoing claims,
    characterised in that
    the deck (4) is constructed as a continuous surface.
16. Method of manufacturing a pallet in accordance with any one of the foregoing claims,
    where the upper portion (2) is overdimensioned during manufacture so that a projecting rim is produced when these two component parts are joined together,
    and so that the projecting rim portion of the overdimensioned component part is removed by means of a subsequent milling operation.
17. Method in accordance with claim 16,
    where also a welding or adhesive bead of the seam (7) is removed by means of the milling operation.

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