EP2216255B1 - Plastic pallet with reinforced runner - Google Patents

Abstract

The plastic pallet (1) has a pallet provided with separate runners (6) made of rigid material, where the runners have a single piece squirted hollow chamber profile with inner reinforcement ribs. The runners are connected with pallet foot within the range of retaining bars in a form-fit and detachable manner. The runners have a rear section in the range of retaining bars. The runners are made of glass-fiber reinforced plastic and polymer. The pallet has retaining devices in cover range for reinforcing elements made of steel.

Description

The invention relates to a plastic pallet for reusable use in in-house and inter-company goods transport. Such pallets consist essentially of a cargo area having pallet deck and the pallet deck located, downwardly directed feet and are made by injection molding of a polymer or less stringent requirements of a regenerated plastic or a plastic mixture. In addition, the undersides of the feet can be connected by plastic runners with each other, so that entry openings are formed for the tines of industrial trucks. A generic pallet is for example in the EP 121 9543 B1 and in the EP 1076011 B1 described.

For in-house transport provided with skids plastic pallets are transported by trucks and / or Rollenund chain conveyors, the pallet is made in a very common form in one piece with directly molded runners.

For the production of corresponding one-piece plastic pallets, relatively "soft" plastics or plastic mixtures are generally used in order to achieve a high impact resistance of the entire range. This naturally reduces the stability of the runner. When transporting loaded pallets on roller and chain conveyors, the conveyor lines can be dimensioned so that the rollers or chains are not below the massive and relatively stable feet, but in the area of relatively thin runners. By the weight of the cargo the pallet runner is bent upwards at this point, as a result of which the load can slip off the pallet and the pallet can no longer be conveyed due to the deformation and thus becomes unusable.

It is very advantageous if the pallet, in particular in the area of pallet decks and pallet feet, has a high impact resistance. As a result, the pallet is less susceptible to damage by forklifts of industrial trucks and falling objects or in case of a fall from the high bay on a pallet corner. When transporting the pallets with industrial trucks, it may happen that the tines do not enter the designated entry openings properly, but hit the pallet in the area of the pallet foot or the pallet deck. The high impact strength of the material ensures that the pallet base or pallet deck is not damaged and the pallet can still be used.

To improve stability, the skids of plastic pallets are reinforced by steel inserts. However, steel inserts are very detrimental to the recycling of plastic pallets, as they must be removed beforehand.

In order to increase the stability of the pallet skid, all or part of the pallets are made of materials that have high flexural strength and are partially reinforced with fibers. For example, a pallet is known which has a deck made of an impact-resistant material and feet and runners made of a rigid material, wherein the feet are releasably or non-detachably connected to the deck. However, as the flexural rigidity increases, the impact resistance of the plastic material decreases, so that the pallet is not resistant to lateral shock loads in the area of the feet, and thus has a short life in "rough" labor input.

Furthermore, it is off DE 10063281 A1 a plastic pallet known, which has at least partially releasable runners. As a result, a quick and cost-effective replacement of the skids should be made possible when the skids wear. If this pallet is moved with an industrial truck, it may happen that the rollers of the trucks stand on the pallet skids and the pallet is pushed apart during the lifting process. When reaching a certain lifting height, the catches between the pallet base and the pallet runner are deformed or even destroyed. The pallet skid can no longer be used. In this embodiment, it is assumed from the outset that the runner of the plastic pallet becomes unusable after a certain period of use. This is very disadvantageous for the user of the plastic pallet, since he either has to stockpile a certain number of spare skids, or in case of failure of a skid can no longer use the pallets until the corresponding Ersatzkufe arrives. In addition, the user incurs permanent costs for the purchase of replacement skids. When loosening the defective pallet skids, a great deal of effort is required to ensure that the runners do not release themselves from the pallet feet.

The invention has for its object to make a recycle-enabled and durable plastic pallet of the type described in more detail so that the pallet deck and the pallet feet made of a "soft", impact resistant material and the runners have the highest possible rigidity. In addition, the runners should be releasably connected to the pallet body and can be easily solved without tools and without much effort from the pallet body, as soon as a vertical compressive force acts on the pallet skid.

This object is achieved by a trained according to claim 1 range.

The subclaims contain advantageous and expedient developments of the invention.

The object is achieved by a plastic pallet, consisting of a deck, protruding from the deck and down facing feet of an impact resistant material, and located at the bottom of the feet, the feet interconnecting runners, and which the features of claim 1.

The pallet body made of an impact-resistant plastic material, z..B. PE or PP, has from the deck protruding and downwardly directed feet, which have a cavity inside and at the bottom receiving openings. The pallet has, for example, nine feet which are arranged, for example, in three rows at equal distances from each other. In the example pallet, three pallet feet are connected by a skid. The invention can also be applied to pallets with a different number of feet. In certain applications, only certain feet, preferably the outer feet, connected by runners. The feet can expediently have at least a partial ribbing inside. The feet have an approximately square cross-section. The outer feet may have a smaller thickness compared to the middle feet. At the bottom, at least the outer feet on at least one of its broad sides, preferably the outer broad side, on the inner surface specially shaped projections which are dimensioned so that at least one corresponding surface of the upwardly directed foot receiving webs of skids locked with them and a positive connection between pallet feet and pallet skids arises. This corresponding surface can advantageously be designed as an undercut.

The runners are made separately from a preferably rigid composite material, e.g. PP made with a certain glass fiber content, wherein the composite material consists of the same base polymer as the base material of the pallet body. This is particularly advantageous for the recycling of the complete range, since the runners do not have to be separated from the pallet body and disposed of separately.

The runner is designed as an integrally molded hollow chamber profile with stiffening ribs in the interior and a closed top and bottom. Due to the chosen geometry a maximum bending stiffness is possible with minimal use of material. The achievable runner stability is comparable to that which is achieved by a corresponding runner made of solid material.
The hollow chamber profile of the pallet runner is dimensioned so that it is intelligently and positively covered by the outer sides of the outer feet of the pallet body in the area of the openings, so that no dirt and no water can collect in the hollow chambers.
For the empty transport of the pallets, ie a stack of pallets is transported on top of each other without load, must be ensured be that the pallets do not slip off each other. This can be advantageously ensured by the fact that the deck of the plastic pallet at at least two points, on which the runners of the pallet above stand, with respect to the upper surfaces have not projecting profiles. In order to achieve a better locking of the overlying pallet, it may be advantageous that the skids are also equipped with respect to the lower surfaces not protruding profilings, so that the profiling interlock positively in the stacking of unladen plastic pallets. In other words, it may be advantageous for this purpose that the closed bottom of the pallet skid is at least partially equipped with profilings, which, however, do not protrude down beyond the closed, planar areas of the runner underside. The transport on rollers and chain conveyors is still given. These profilings also do not affect the readability of the buttons, which are installed on roller conveyors for scanning the pallets and are located in the area of the underside of the pallet skid. It can also be provided that the areas that are queried by a button, have no profiling. The profiling also increases the skid resistance of the pallet on roller and chain conveyors.

For some applications, the slip resistance that can be achieved by profiling may not be sufficient. To increase the slip resistance, the underside of the pallet skid may at least partially have a slip-resistant, so-called "anti-slip" coating. The anti-slip coating can be advantageously formed by a thermoplastic polyurethane (TPU). Another possibility for making an anti-slip coating on the skid base is a thermoplastic elastomer (TPE) or an olefin block copolymer, which is injected directly by means of a known 2K process in the manufacture of runners. To achieve a uniform anti-slip effect, it can be advantageous be that the pallet skid on the bottom has no profiles.

If a produced according to claim 1 pallet to be transported with a truck, and the wheels of the truck are exactly on the pallet skids, the pallet is not pressed apart during the lifting process by means of the lifting force, and can not be used due to the permanent deformation, but the Runners detach themselves from a specific vertical pressure load independently and without damage from the specially shaped protrusions of the pallet feet.

The very rigid pallet skids are very advantageous because they do not bend under the vertical pressure load. The connection between the pallet base and the pallet skid can only be solved simply and non-destructively if the foot receiving webs and the connection areas of the runner do not change their geometry and are dimensionally stable.

In order to increase the stability and in particular the load-bearing capacity of the entire pallet, the pallet body may additionally be provided in the deck area with receiving means for reinforcing elements, e.g. made of steel.

When transporting goods inside and outside it can be advantageous if the pallet is equipped with one or more transponders for tracking the goods or the pallet. Therefore, the pallet can be advantageously provided with at least one receiving device for receiving transponders.

The transponder can advantageously be fastened before connecting the runner to the pallet foot. As a result, he is due to the positive connection between the pallet base and pallet skid from environmental influences protected. In this case, the transponder permanently, eg by gluing, or only for a certain period, eg by clamping, remain in the receiving device. To replace the transponder, the runner is released from the pallet body and the transponder is changed. This can be advantageous, for example, if the transponder is defective or the range of customers with different transponder systems is used in pool use.

Fig. 1

eine isometrische Ansicht einer erfindungsgemäßen Kunststoff-Palette,

Fig. 2

eine perspektivische Unteransicht eines erfindungs- gemäßen Palettenmittelfußes ohne Kufe,

Fig.3

eine perspektivische Ansicht einer erfindungsgemä- β en Palettenkufe,

Fig. 4

eine Schnittdarstellung einer erfindungsgemäßen Pa- lettenkufe aus Fig. 3, und

Fig. 5

eine Schnittdarstellung des Verbindungsmechanismus der Palette aus Fig. 1, wobei zwei unterschiedliche Stellungen dargestellt sind, welche die zu verbinden- den Palettenteile während der Herstellung der Verbin- dung einnehmen.

In the following the invention will be explained by way of example with reference to the purely schematic drawings. It shows:

Fig. 1

an isometric view of a plastic pallet according to the invention,

Fig. 2

a perspective bottom view of a pallet center foot according to the invention without skid,

Figure 3

3 a perspective view of a pallet skid according to the invention,

Fig. 4

a sectional view of a lettenkufe invention Fig. 3 , and

Fig. 5

a sectional view of the connection mechanism of the pallet Fig. 1 showing two different positions which occupy the pallet parts to be joined during the manufacture of the connection.

In the Fig. 1 illustrated plastic pallet 1 consists of a trained as a horizontal surface Deck 2, nine projecting from the deck 2 and downwardly directed feet 3 and three runners 6. The deck 2 and the feet 3 form the pallet body are made in one piece and consist of a impact resistant material, eg PP.

According to Fig. 1 the arrangement of the deck 2, the feet 3 and the runners 6 together form the entry openings 7 for the tines of the trucks.

The outer feet 4 and middle feet 5 each have an approximately quadrangular cross-section. However, other cross-sectional shapes, e.g. circular, possible. The outer feet 4 have a reduced width compared to the middle feet 5. In other types of pallets, which may also have a different number of feet and / or runners, all feet may have the same width or there may be reverse width ratios.

A runner 6 is positively connected to three pallet feet 3.

The outer edges of the outer feet 4 extend to the footprint of the pallet runner 6, and thus are longer than the inner edges of the outer feet 4. When connecting runners 6 and outer feet 4 is a hollow-chamber web profile 17 (FIG. Fig. 3 ) thereby positively overlapped by the outer edges of the outer feet 4, so that no dirt and no water in the hollow chamber profile 17 can accumulate.

As in Fig. 1 shown, the deck 2 has on the top of Profilierungen 8 for better locking of generic pallets in the empty stack. The deck 2 and is designed substantially as a closed, planar surface. The deck can also have a different structure, for example a grid structure, and / or different locking ribs at the edges or in the middle.

Each four ribs of the profilings 8 are arranged in a comparatively wide reduction, which is lower than the closed, flat surface of the deck 2, and in each case above one of the runners 6 extends. From the bottom of the respective countersinking, the profiles 8 designed as ribs extend upwards, not higher than to the plane of the two flat surfaces of the deck 2. Thus, boxes or sacks be pushed or pulled over the surface of the pallet without being braked or damaged by obstructive, located on the pallet surface supernatants, or without in turn damage such supernatants of the pallet surface.

The profilings 8 do not extend in their longitudinal direction as far as the edge of the pallet 1, so that they can be encompassed by the outer contour of the runners of a similar pallet to be stacked on top of the pallet 1.

In Fig. 2 the metatarsus 5 of the pallet 1 shown from below. The cavity of the metatarsal 5 forms the receiving area for the middle receiving web 14 of the pallet skid. The middle foot 5 has inside a cross rib 10. Advantageously, the rib 10 is designed so that it rests positively when connecting the skid 6 with the Palettenfuß 5 on the rib 15 of the skid 6, and thus increases the stability of the pallet 1 in the loaded state becomes. The cavity of the midfoot 5 and / or the outer feet 4 can also be designed without ribs or with another rib structure.

In addition, the metatarsus 5 on one broadside inside two projections 9 for releasably connecting the blade 6 with the metatarsus 5 on. The opposite inner broad side of the metatarsus 5 is not visible. For better locking of the runner 6 projections 9 can also be located there. The projections 9 are provided in the example with a radius, so that the connection between the skid 6 and midfoot 5 can be solved more easily, but there are other geometries of the projections 9, such as locking lugs, possible. Also, the projections 9 may extend over the entire length of the inner broad side of the middle Palettenfuβes 5 or consist of several interrupted sections. The projections 9 are analogously also on at least one inner broad side of at least one outer foot 4. It is also conceivable the projections 9 in the middle foot 5 or in the outer feet 4 have different geometries, since the geometries of the feet 3 are different.

Based Fig. 2 as well as in Fig. 1 , It is easy to see that the final contour of the metatarsus 5 is exactly adapted to the contour of the upper side 11 of the runner 6 in order to achieve the best possible form fit.

In Fig. 3 a pallet skid 6 according to the invention is shown. The skid 6 consists of a closed top 11 and a closed, straight resting bottom 12 and has approximately a trapezoidal geometry. The runner 6 may also have other geometries. Thus, the skid 6 is better overridden by trucks, it can be advantageously provided with so-called Anfahrschrägen. At the two end regions is in each case an upwardly directed outer receiving web 13, which is received by a corresponding outer leg 4 of a pallet body. In the middle of the runner is accordingly the middle receiving web 14, which is received by a corresponding metatarsus 5 of a pallet body. Again, like the one in Fig. 2 represented a cross rib 15 so that the cross rib of the blade 15 in the assembled pallet 1 exactly positive fit against the cross rib 10 of the metatarsus 5, whereby the carrying capacity of the pallet 1 is increased by the more stable middle feet 5.

At the front outer receiving web 13 and the central receiving web 14, the locking portions 16 are shown as undercuts in the upper region, which together with the corresponding projections 9 of the pallet feet 3 form the detachable connection between the pallet body and runners 6. In order to ensure the most easily releasable connection, the geometry of the undercut 16 must be matched to the geometry of the projections 9 in the pallet base 3.

The runner 6 has a continuous hollow-chamber web profile 17, whereby a maximum of bending stiffness is achieved in conjunction with the very rigid material. In the example, the hollow chamber profile 17 three webs 18. The number of webs 18 may be different. It is important that the webs 18 are made stable and not have too small a wall thickness. In order to increase the stability of the hollow chamber profile 17, additional transverse ribs may be introduced or the ribs 18 may be in a different geometry, e.g. as a bridge framework, be executed.

The outer receiving webs 13 have centrally a slot 19 for receiving a corresponding rib 20 of the outer feet 4 of the pallet body. This also increases the carrying capacity and the stability of the pallet 1.

Fig. 4 shows a section through a runner 6 according to the invention. In the front region, the hollow-chamber web profile 17 is shown with three webs 18. The webs 18 together with the upper part 11 and the lower part 12 approximately rectangular cavities, which, as shown here, may have rounded corner areas. In the area of the bottom 12 has the skid 6 profiling 8, for better locking on the same type pallets 1, wherein four such profiles are shown, which can cooperate with four ribs provided in the deck 2 Profilierungen 8.

The profiles 8 on the underside of the runners 6 do not extend in their longitudinal direction to the edge of the respective runner 6, so that the runner forms a peripheral edge which comprises the four ribs of the upper, provided on the deck 2 Profilierungen 8, if two similar pallets 1 are stacked.

In the rear area, an outer receiving web 13 is shown. In the middle of the web 13 is a slot 19 for receiving a corresponding rib 20 of an outer foot 4 of the pallet body. For better introduction of the web 13 in the foot 4 of the web can be provided at the upper end with radii or chamfers.

Fig. 5 illustrates the latching mechanism between Palettenfüβen 3 and pallet skid 6 in detail.

In the upper part of the picture skid 6 is pushed from below into the pallet feet 3. The receiving webs 13, 14 of the runner 6 are introduced into the corresponding receiving areas of the feet 3.

On the second part of the picture form-fit connection between pallet feet 3 and 6 skid is already completed. In the sectional view can be clearly seen that the undercuts 16 of the receiving webs 13, 14 fit positively against the projections 9 of the feet 3. In the area of the metatarsus 5 it can also be clearly seen that the rib 10 of the foot 5 rests exactly on the rib 15 of the runner 6. The outer edge of the outer foot 4 protrudes to the bottom 12 of the runner 6 and forms part of the footprint.

The invention is not limited to the illustrated embodiment. Thus, for example, the latching between pallet base and runner can be designed so that the receiving webs of the runner have projections and the insides of the feet have corresponding undercuts.

Claims (7)

1. Plastic pallet (1) consisting of a deck (2),
   with feet (3) made of impact-resistant material projecting downwards from the deck (2) and skids (6) located on the underside of the feet (3) connecting the feet (3) with one-another, where the pallet (1) has skids (6) which are manufactured separately of a different material, where the skids (6) have retaining webs (13, 14) and are fitted positively and detachably to the pallet feet (3) in the area of the retaining webs (13, 14) and have at least one corresponding undercut in this area,
   and the undercuts of the skids (6) are shaped in such a way that the skids (6) are detached from the specially shaped projections of the pallet feet (3) when pressure is exerted on the skids vertically from above without damaging the undercuts of the skids (6) and/or the projections of the pallet feet (3), characterised in that

   - the skids (6) consist of a more rigid material than the rest of the pallet,

   - the skids (6) consist of the same polymer as the basic material of the pallet (1), and where they consist of a glass-fibre reinforced plastic,

   - the skids (6) have a hollow-chamber profile (17) injection-moulded in one piece with internal stiffening fins.
2. Plastic pallet according to claim 1, characterised in that the skids (6) have a closed upper side, a closed underside and at least partial profiling (8) on the underside,
   where the profiling (8) extends downward at the furthest to the level of the closed flat area of the lower side of the skid.
3. Plastic pallet according to claim 1, characterised in that the skids (6) have a closed upper side, and, an anti-skid coating of a thermoplastic polyurethane on at least part of the underside.
4. Plastic pallet according to claim 1, characterised in that the skids (6) have a closed upper side, and, an anti-skid coating on at least part of the underside,
   where the anti-skid coating consists of a thermoplastic elastomer or an olefin block copolymer, and is sprayed into place during the manufacturing process of the skids (6) by means of a 2K process.
5. Plastic pallet according to one or more of the preceding claims, characterised in that
   the pallet (1) has profiling (8) on at least part of the upper side to lock a second pallet (1) of the same design into position which is stacked on top of the first pallet,
   where the profiling (8) extends upwards at the furthest to the level of the closed flat area of the upper side.
6. Plastic pallet according to one or more of the preceding claims, characterised in that
   the pallet (1) has retaining devices for reinforcing elements, e.g. of steel, in area of the deck.
7. Plastic pallet according to one or more of the preceding claims, characterised in that the pallet (1) has at least one retaining device for a transponder.

Images