Transport unit made of plastic for transporting goods on a roller conveyor, use of such a transport unit, and method for producing same

Abstract

The invention relates to a plastic transport unit (1) for storing and transporting goods, wherein the transport unit (1) is a plastic container (1'), a plastic tray, or a plastic pallet (1''), and the transport unit (1) has a coating-free lower face (11) with a running surface (2) and / or a rolling surface (2'). The surface of the running surface (2) and / or of the rolling surface (2') has a surface roughness with a mean roughness value Ra of 3 to 100 µm for a conveying process on a roller conveyor.

Description

[0001] Plastic transport unit with a roughened running surface for transporting goods on a roller conveyor

[0002] Technical field

[0003] The invention relates to transport units such as plastic containers, plastic trays, and plastic pallets for transporting and conveying goods on a roller conveyor. The invention also relates to the use of these transport units for transporting and conveying goods on a roller conveyor.

[0004] State of the art

[0005] Plastic containers and pallets for transporting goods via roller conveyors are known. Typically, these plastic containers or pallets have a base or skids with a running surface. The running surface is defined as the area of ​​the container on which it rests, at least partially, on a floor surface, or on which the container runs along the rollers of a roller conveyor and then comes into contact with them. The running surface is also referred to as the contact surface. The running surface can, for example, extend over the entire base of the plastic container or the underside of the pallet skids, or it can be designed as a running ring or walkway.

[0006] Such plastic containers with a running ring or flat bottom designs are described, for example, in EP3992096A1 or in EP4332010A1.

[0007] Plastic containers and pallets with smooth surfaces are prone to slipping during transport on roller conveyors, which can lead to accidents, traffic jams, or lost goods. To prevent slipping, plastic containers and pallets can have a coating on their running surface to increase grip and minimize the risk of slipping. Common examples include polymer coatings, such as rubber coatings, which are specially formulated to create a non-slip surface and ensure optimal slip resistance.

[0008] P248970 The disadvantage of such additional coatings on the running surface is that they wear down over time, and their anti-slip properties diminish with regular heavy use, requiring recoating. The additional material and increased time required to manufacture coated running surfaces also result in additional costs due to the need for an extra production step. Furthermore, an additional coating can increase the weight and thickness of the running surfaces and alter the appearance of the container or pallets, which is undesirable in certain applications. Some coatings can even slow down or prevent transport on a roller conveyor if the material is not sufficiently slippery.

[0009] Object of the invention

[0010] The present invention is based on the objective of creating a transport unit, in particular a plastic container or a plastic pallet with a running or rolling surface without additional coating, which can be manufactured simply and cost-effectively, transported and conveyed simply, stably and quickly on a roller conveyor and in which the goods can be transported safely via a roller conveyor.

[0011] Description of the invention

[0012] This task is accomplished by a plastic transport unit for moving and conveying goods on a roller conveyor. The transport unit is a plastic container, tray, or pallet with an uncoated underside featuring a running surface and / or roller surface with a surface roughness (average roughness Ra) of 3 to 100 µm. A minimum average roughness Ra of 3 µm ensures that the transport unit can be moved and conveyed easily and quickly on a roller conveyor. The surface of the running surface and / or roller surface is roughened directly during the manufacturing process of the plastic container or pallet, thus increasing the surface roughness.This eliminates the need for additional coatings and materials, making production faster and more cost-effective, and resulting in a lighter and more aesthetically pleasing container.

[0013] P248970 A plastic transport unit is a logistical or loading unit made of plastic that can be transported without disassembly or unpacking, enables the efficient and safe transport of goods, and represents a standardized unit in logistics. This includes plastic containers, plastic trays, and plastic pallets. All these transport units have a base with a running surface that allows the transport unit to rest, at least partially, on a surface, such as a support, floor, roller conveyor, or belt. The running surface is also referred to as the standing surface.

[0014] The underside refers to the side of the transport unit that faces away from the receiving area for goods and towards the surface when the transport unit is placed on a surface. For a plastic container or tray, the underside is located on the underside of the base plate. For a plastic pallet, the underside is located on the underside of the skids.

[0015] In a preferred embodiment, the transport unit is a plastic container, wherein the container has a base plate with four lateral edges, and two short side walls and two long side walls, each with a lower edge and an upper edge, wherein the short and long side walls extend vertically upwards from the lateral edges of the base plate, and wherein the base plate has an uncoated underside with a running surface and / or rolling surface having a surface roughness with a mean roughness value Ra of at least 3 pm. The base plate and the side walls define a receiving area of ​​the container in which goods can be stored and transported.The four side walls are joined together via four corner radii to form a rectangular shape and extend vertically upwards from the side edges of the base plate, starting at the lower edges at the bottom of the side walls, to the upper edges at the top of the side walls. The base plate can consist of a single layer with a top facing the receiving area and a bottom facing away from the receiving area. Alternatively, the base plate can consist of a double layer with a first layer facing the receiving area and a top layer, and a second layer facing away from the receiving area and a bottom layer. The second layer is preferably connected to the first layer via a plurality of ribs, the ribs of the second layer being integrally attached to the first.

[0016] P248970 The base is molded onto the base or welded to the first base. In all cases, the base plate has an uncoated underside on the side facing away from the receiving area, with a tread and / or roller surface. The plastic container can be, for example, a stacking container, a rotating stacking container, a box container, a collapsible container (also called a collapsible box), or a foldable container (also called a collapsible box).

[0017] In another embodiment, the transport unit is a plastic tray or a plastic pallet. Like the plastic container, the plastic tray has a base plate with four edges, a bottom and a top, and optionally two short side walls and two long side walls. Workpiece carriers are also considered plastic trays. The plastic pallet has a top section and several runners with a running surface on the underside of the runners.

[0018] Coating-free means that the running surface and / or roller surface on the underside of the transport unit has no additional coating and is formed directly from the plastic material of the transport unit, and that the underside of the transport unit is integral with the running surface and / or roller surface, with a surface roughness having a mean roughness value Ra of at least 3 pm.

[0019] The running surface is understood to be the area on the underside of the transport unit that allows the unit to rest, at least partially, on a surface when placed on it. This surface can be, for example, a support surface, a floor, a roller conveyor, or a belt conveyor. The running surface is also referred to as the standing surface. In the case of a plastic container, the running surface preferably has the form of a rectangular rim with four longitudinal sides and a central indentation, or, for example, the form of at least two parallel longitudinal or transverse skids with an indentation between the two skids. The indentation is located in the central area of ​​the base plate and provides a clearance that can accommodate deflection of the central area of ​​the base without the central area resting on the surface on which the container stands.This prevents the container from tilting. For example, on a plastic tray, the running surface extends across the entire underside of the tray, or, as with a plastic container, it forms a running ring. On a plastic pallet, the running surface is located on the underside of the runners, forming a so-called runner running surface.

[0020] P248970 or is only located below or in the area of ​​the foot parts which connect the upper part to the runners.

[0021] A rolling surface is understood to be an elongated surface on the underside of the transport unit, in particular on the underside of the base plate of a plastic container or plastic tray, or on the underside of the skids of a plastic pallet. This surface, when rolling along a roller track with lateral or central roller rails, runs onto the rollers and comes into contact with them. The rolling surface preferably extends along the side edges of the base plate, along the circumference of the underside of the rectangular base plate, or along the longitudinal edges of the skids. At least two rolling surfaces run parallel to each other and, in their elongated orientation, are arranged either parallel to the lower edges of the short side walls, parallel to the lower edges of the long side walls of the container, or parallel to the longitudinal edges of the skids of the plastic pallet.The roller surfaces are preferably arranged at a height between the height of the running surface and the height of the lower edge of the side walls. The roller surface can also have the form of a running ring and completely surround the running surface. If the underside of the base plate has both at least one running surface and at least one roller surface, the roller surface preferably extends along the outside of the running surface, more preferably along the outside of the running ring of the running surface. Between the outer sides of the running surface and the roller surface, a step is arranged as part of an elongated guide rib with a guide roller surface for positioning and guiding the plastic container on rollers of a roller conveyor with roller strips. The guide ribs preferably extend over the entire length at the transition between the roller surface and the outer sides of the running surface. All transport units according to the invention have a running surface.In addition to the running surface, the transport unit can also have a rolling surface, in which case either the running surface or the rolling surface or both have a rough surface.

[0022] A roller conveyor is a transport device in material handling technology, consisting of a series of fixed rollers, typically made of steel or plastic, over which goods can be transported. The roller conveyor comprises rollers arranged one behind the other, which are attached to roller supports, such as side rails. Depending on the width of the rollers, they are arranged in narrow roller tracks or as wide roller mats.

[0023] P248970 Preferably, the underside of the base plate of the plastic container or plastic tray, or the underside of the skids in the area of ​​the feet of the plastic pallet, has a closed surface. This means that preferably all parts of the underside, such as the running surface, the indentation in the central area of ​​the base plate, and the rolling surface, have a closed surface. A closed surface is understood to be a substantially continuous surface without openings, in which the individual parts are flat or planar. Particularly preferably, the running surface and / or the rolling surface has a closed surface with a rough texture.

[0024] In another embodiment, the underside of the base plate or the skids can be at least partially ribbed.

[0025] The surface of the running surface and / or the roller surface has a surface roughness with a mean roughness value (Ra) of at least 3 µm, preferably at least 4 µm, more preferably at least 9 µm and at most 100 µm, more preferably at most 20 µm, and even more preferably at most 13 µm. The rough structure improves grip and transport on rollers, preventing the container from slipping on the rollers or the rollers from spinning freely. The higher the mean roughness value (Ra), the better the grip of the running or roller surface on the rollers of the roller conveyor. The optimal roughness is selected depending on the roller properties. However, the surface roughness must not be too high, otherwise the transport unit will run too unevenly over the rollers and the goods will be subjected to undesirable vibrations. Preferably, the mean roughness value (Ra) is between 3 and 100 µm, more preferably between 4 and 20 µm, and even more preferably between 6 and 13 µm.A transport unit with a running surface and / or a rolling surface with a surface roughness with a mean roughness value Ra of 6 - 13 pm is particularly preferred because this surface roughness has the optimal rough structure for safe and slip-resistant transport on a roller conveyor and yet is not too heavily structured, which would lead to unclean transport.

[0026] Surface roughness refers to the roughness of a solid's surface, describing its unevenness. It is a measure of the surface's deviation from an ideal smooth shape and is characterized, for example, by the arithmetic mean roughness value Ra.

[0027] The average roughness value Ra (P248970) is standardized according to DIN EN ISO 21920-1:2021. To determine this measured value Ra according to DIN EN ISO 21920-1:2021, the surface is typically scanned over a defined measuring distance using stylus instruments. These instruments guide a stylus across the surface to detect and quantify irregularities, recording all surface height and depth variations. After calculating the definite integral of this roughness profile along the measuring distance, the result is divided by the length of the measuring distance. The range of roughness values ​​extends from approximately 1 µm with barely visible machining marks to over 25 µm for very rough surfaces with noticeable grooves. For injection-molded parts, the guidelines of the Association of German Engineers (VDI), in particular VDI 3400, also known as VDI Surface Finish, are used, which categorize Ra values ​​into specific VDI ​​values ​​or classes.VDI 3400 textures are produced, for example, by electro-erosive machining of the injection mold or by classic texturing processes. VDI values ​​of 30 to 45 are preferred, especially 33 to 45, which corresponds to a mean roughness value Ra of 3–20 pm or 4 to 20 pm, respectively. Particularly preferred for the transport unit according to the invention are VDI values ​​of 36 to 42 with a mean roughness value Ra of 6–13 pm; a VDI value of 39 with a mean roughness value Ra of 9 pm is especially preferred.

[0028] The surface with a surface roughness having a mean roughness value of at least 3 pm, preferably 3–100 pm, according to the present invention, is also referred to as a rough or structured surface. The higher surface roughness of the running or rolling surfaces of the transport units according to the invention leads to increased efficiency, stability, and safety when transporting units on roller conveyors compared to conventional transport units with smooth running or rolling surfaces, because the slippage of the transport units and the loaded goods, and thus the risk of accidents, is reduced. Handling and transport of goods on the roller conveyor are improved, and transport is more efficient. This results in cost savings.Surfaces with intentionally applied patterns or with alternating rough and smooth surfaces, which are usually produced in a classic manner, such as by larger steps in the injection mold, and which, for example, have flat ribs or regular repetitions or perceptible geometric structures, are not part of the invention. The running surface and / or rolling surface of the transport unit according to the invention is pattern-free and has a consistently rough surface.

[0029] P248970 Structure and an arbitrarily distributed surface roughness, which is achieved, for example, by electro-erosive machining or sandblasting.

[0030] A key feature of all transport units is that the underside, including the running surface and / or the rolling surface, is formed in one piece with a surface roughness having a mean roughness value Ra of at least 3 pm, and that the underside of the base plate of the inventive plastic container or plastic tray, or the underside of the skids of the plastic pallet, has a coating-free rough surface on the running and / or rolling surface. This is achieved by treating and roughening the plastic material directly on the underside in the area of ​​the running and / or rolling surface, or by creating this roughening directly during manufacturing. Preferably, the base plate of the plastic container or plastic tray, or the skid of the plastic pallet with the rough running and / or rolling surface on the underside, is manufactured as a one-piece injection-molded part using the injection molding process. Preferably, the entire transport unit, i.e.,The plastic container, plastic tray or plastic pallet is manufactured as a one-piece injection-molded part using the injection molding process.

[0031] The plastic used is preferably polypropylene (PP). Other plastics are also possible, such as polyethylene (PE) as HDPE, polyvinyl chloride (PVC), or polystyrene (PS). The plastic transport unit can also be manufactured using other methods, such as 3D printing, thermoforming, or by cutting.

[0032] The invention further relates to a method for manufacturing a plastic transport unit by injection molding using an injection mold with a roughened surface for the running surface and / or the rolling surface. During injection molding, the surface of the injection mold is preferably processed so that the transport unit is produced directly with the desired surface texture on the underside. If, for example, the underside, or the running surface and / or the rolling surface, is to have a rough surface, the inner surface of the injection mold is processed so that the transport unit can be produced directly with the desired rough surface on the underside. Preferably, the surface of the injection mold for the running surface and / or the rolling surface is modified by laser treatment, chemical etching, or sandblasting.This means that the surface for the running surface or rolling surface in the injection molding tool used for injection molding the transport unit is changed from smooth to rough, for example by...

[0033] P248970 Sandblasting before injection molding. The result is a rough surface on the running or rolling surface after injection molding.

[0034] The transport unit with a coating-free, rough surface on the roller and / or running surface can also be manufactured using methods other than injection molding. The surface roughness can be increased directly on the running or roller surface of the transport unit after the fact, for example by laser cutting, chemical etching or sandblasting, hot stamping, thermoforming, or milling.

[0035] Another aspect of the present invention relates to the use of the transport unit according to the invention with a rough running surface and / or roller surface for transporting and conveying goods via a roller conveyor.

[0036] The advantage of the transport unit according to the invention, with its uncoated rough running surface and / or roller surface, lies in the fact that the transport unit with the rough running surface and / or roller surface can be transported and moved easily, safely, and quickly on a roller conveyor, thus ensuring the safe transport of goods along the conveyor. Slippage of containers or pallets and the risk of accidents are minimized, thereby increasing transport safety.Since the rough surface of the tread and / or roller surface is applied directly to the surface of the transport unit during manufacturing, no additional coating steps or materials are required. This makes production faster and more cost-effective compared to conventional coated treads, where applying an additional coating to the tread adds time and expense. Furthermore, the direct rough surface, without a coating, results in a lighter and more aesthetically pleasing transport unit.

[0037] The invention comprises the aforementioned embodiments as well as any combinations thereof.

[0038] Further advantages of the invention will follow from the description below, in which the invention is explained in more detail with reference to the exemplary embodiments shown in the schematic drawings.

[0039] P248970 Brief description of the figures

[0040] They show:

[0041] Fig. 1a a perspective view from a low angle of a first base design of a plastic container,

[0042] Fig. 1b shows a side view of the short side wall of the plastic container with the first bottom design,

[0043] Fig. 1c shows a view from below of the first bottom version of the plastic container,

[0044] Fig. 2a shows a perspective view from a low angle of a second bottom version of a plastic container,

[0045] Fig. 2b shows a side view of the short side wall of the plastic container with the second bottom design,

[0046] Fig. 2c shows a view from below of the second bottom design of the plastic container,

[0047] Fig. 3a shows a perspective view from a low angle of a third bottom design of a plastic container,

[0048] Fig. 3b shows a side view of the short side wall of the plastic container with the third bottom design,

[0049] Fig. 3c shows a view from below of the third bottom design of the plastic container,

[0050] Fig. 4a shows a perspective view from a low angle of a fourth bottom design of a plastic container,

[0051] Fig. 4b shows a side view of the short side wall of the plastic container with the fourth bottom design,

[0052] Fig. 4c shows a view from below of the fourth bottom design of the plastic container,

[0053] Fig. 5a shows a perspective view from a low angle of a fifth bottom design of a plastic container,

[0054] Fig. 5b shows a side view of the short side wall of the plastic container with the fifth bottom design,

[0055] Fig. 5c shows a view from below of the fifth bottom design of the plastic container.

[0056] Fig. 6a shows a perspective view from a low angle of a plastic pallet with roller surfaces at the middle skid.

[0057] Fig. 6b shows a side view of the plastic pallet from Fig. 6a,

[0058] Fig. 7a shows a perspective view from a low angle of a plastic pallet without roller surfaces.

[0059] P248970 Fig. 7b a side view of the plastic pallet of Fig. 7a,

[0060] Fig. 8a shows a perspective view from a low angle of a plastic pallet with roller surfaces on the outer edges of the outer runner.

[0061] Fig. 8b shows a side view of the plastic pallet from Fig. 6a.

[0062] The same reference symbols are used for the same elements in the figures, and explanations for a particular reference symbol apply to all figures unless explicitly stated otherwise.

[0063] Exemplary embodiments of the invention

[0064] Figure 1a shows a perspective view of a first transport unit 1 according to the invention, a plastic container T, with a first base design for transporting and conveying goods on a roller conveyor. The container has a base plate 5 with a simple bottom and four side edges, two short side walls 3, and two long side walls 4. The short side walls 3 and the long side walls 4 extend vertically upwards from the side edge of the base plate 5, are joined to each other via four corner radii to form a rectangular shape, and define a receiving area of ​​the container in which goods can be stored and transported. The base plate 5 has an uncoated underside 11 with a running surface 2, the surface of which has a surface roughness with a mean roughness value Ra of at least 3 pm, preferably at least 9 pm, thus improving conveying on a roller conveyor.Preferably, the mean roughness value Ra is between 6 and 13 pm.

[0065] The running surface 2 has the form of a rectangular running ring with four longitudinal sides and a recess 6 in the middle. The outer sides of the four longitudinal sides of the running ring of the running surface 2 run along the side edges of the base plate 5. The recess 6 is located in the central region of the base plate 5 and provides a clearance that can accommodate deflection of the central region of the base plate 5 without the central region resting on the surface on which the container 1 stands. This prevents any potential tilting of the container 1. The individual parts of the underside of the base plate 5, in particular the running ring of the running surface 2 and the recess 6, have a closed surface.

[0066] P248970 Figure 1b shows a side view of the short side wall 3 of the plastic container 1' as described in Figure 1a.

[0067] Figure 1c shows a view from below of the underside 11 with a first bottom embodiment of the invention of the plastic container 1 ' as described in Figure 1a, with a base plate 5 having a coating-free underside 11, the running ring of the running surface 2 with a surface roughness with a mean roughness value Ra of at least 3 pm, preferably of at least 9 pm, and with the indentation 6 in the middle area of ​​the base plate 5.

[0068] The container in Figures 1a, 1b and 1c has low side walls and is suitable for transporting goods of all kinds.

[0069] Figure 2a shows a perspective view of a second transport unit 1, a plastic container T with a second bottom design for transporting and conveying goods on a roller conveyor. The container has a base plate 5 with a double bottom and four side edges, two short side walls 3, and two long side walls 4, each with a lower edge 7 and a top edge. The short side walls 3 and the long side walls 4 extend vertically upwards from the side edge of the base plate 5, are joined to each other via four corner radii to form a rectangular shape, and define a receiving area of ​​the container in which goods can be stored and transported. The base plate 5 has a double bottom with a first bottom facing the receiving area, which has a top surface, and a second bottom facing away from the receiving area, which has an uncoated underside 11.The second floor with the uncoated underside is connected to the first floor via a plurality of ribs 10, the ribs of the second floor being welded to the first floor.

[0070] The underside 11 of the base plate 5 has a running surface 2, the surface of which has a surface roughness with a mean roughness value Ra of at least 3 pm, preferably at least 9 pm, thus improving conveying on a roller conveyor. The running surface 2 has the shape of a rectangular running ring with four longitudinal sides and a recess 6 in the middle. The outer sides of the four longitudinal sides of the running ring of the running surface 2 run along the side edges of the base plate 5 and along the lower edges 7 of the side walls 3, 4. The recess 6 is

[0071] P248970 is arranged in the central area of ​​the base plate 5 and provides a clearance that can accommodate deflection of the central area of ​​the base plate 5 without the central area resting on the surface on which the container T stands. This prevents any potential tilting of the container T. The running ring of the running surface 2 forms the second layer of the base plate 5 and has a substantially closed surface without a ribbed structure, while the indentation 6 in the central area of ​​the base plate 5 has a ribbed structure in the form of a honeycomb-like grid where the second layer is not continuous. Along the short side walls 3, the base plate 5 can have recesses 8 on its underside for gripping by a gripper or hand. The recesses 8 can also be slots for the drainage of liquid through the base plate 5 and, in the case of slots, can also be distributed across the running surface 2.

[0072] Figure 2b shows a side view of the short side wall 3 of the plastic container 1 ' as described in Figure 2a.

[0073] Figure 2c shows a bottom view of the underside of the second bottom embodiment of the invention of the plastic container 1 ' as described in Figure 2a, with the lower edge 7 at the lower end of the short side walls 3 and the long side walls 4, with a base plate 5 having a coating-free underside 11 with elongated recesses 8 along the lower edge 7 of the short side walls 3 of the container 1, the running ring of the running surface 2 with a surface roughness with a mean roughness value Ra of at least 3 pm, preferably of at least 9 pm, and with the indentation 6 with rib structure in the middle area of ​​the base plate 5.

[0074] The container in figures 2a, 2b and 2c has high side walls 3, 4 with lower edges 7 and upper edges and is suitable for transporting goods of all kinds and in particular as a stacking container for stacking several containers on top of each other.

[0075] Figure 3a shows a perspective view of a third transport unit 1, a plastic container 1 with a third bottom design for transporting and conveying goods on a roller conveyor. The container has a base plate 5 with a double-welded bottom and four side edges, two short side walls 3, and two long side walls 4, each with a lower edge 7 and an upper edge. The short side walls 3 and the long side walls 4 extend vertically upwards from the side edge of the base plate 5 and are joined by four corner radii to form a

[0076] P248970 rectangular shape connected to each other, and define a receiving area of ​​the container in which goods can be stored and transported. The base plate 5 has a double bottom with a coating-free underside 11 with a running surface 2 and a rolling surface 2', wherein the surface of the running surface 2 and the rolling surface 2' has a surface roughness with a mean roughness value Ra of at least 3 pm, preferably at least 9 pm, and thus improves transport on a roller conveyor.

[0077] The running surface 2 has the shape of a rectangular running ring with four longitudinal sides and a recess 6 in the middle. The outer sides of the four longitudinal sides of the running ring of the running surface 2 run within the rolling surface 2' and parallel to, and at a distance from, the side edges of the base plate 5 and parallel to, and at a distance from, the lower edges 7 of the side walls 3, 4. The rolling surface 2' also has the shape of a running ring and completely surrounds the running ring of the running surface 2. The rolling surface 2' is arranged along the short and long side edges of the base plate 5 and parallel to the lower edges 7 of the short 3 and long side walls 4, and extends along the short and long outer sides of the running ring of the running surface 2. The rolling surface 2' is arranged at a height between the height of the running surface 2 and the height of the lower edges 7 of the short side walls 3 and the long side walls 4.Between the outer sides of the running surface 2 and the roller surface 2', a step is arranged as part of an elongated guide rib 9 with a guide roller surface for positioning and guiding the plastic container T on rollers of a roller conveyor with roller strips. The guide ribs 9 preferably extend over the entire length of the transition between the roller surface 2' and the outer sides of the running surface 2.

[0078] The indentation 6 is located in the central area of ​​the base plate 5 and provides a clearance that can accommodate deflection of the central area of ​​the base plate 5 without the central area resting on the surface on which the container 1 stands. This prevents any potential tilting of the container 1. The individual parts of the underside of the base plate 5, in particular the running ring of the running surface 2, the running ring of the rolling surface 2', and the indentation 6, have a closed surface without ribs or openings.

[0079] P248970 The rough running surface 2 is designed for safe rolling on a roller conveyor with continuous transverse rollers between the side rails of the roller conveyor, and the rough rolling surface 2' is designed for safe rolling on a roller conveyor with side roller rails. This makes this container versatile for use on various roller conveyors.

[0080] Figure 3b shows a side view of the short side wall 3 of the plastic container 1 ' as described in Figure 3a.

[0081] Figure 3c shows a bottom view of the third bottom embodiment of the invention of the plastic container T as described in Figure 3a, with the lower edge 7 at the lower end of the short side walls 3 and the long side walls 4, with a bottom plate 5 having a coating-free underside 11, with the tread of the roller surface 2' and the tread of the running surface 2 each having a surface roughness with a mean roughness value Ra of at least 3 pm, preferably of at least 9 pm, and with the indentation 6 in the middle area of ​​the bottom plate 5.

[0082] The container in Figures 3a, 3b and 3c has high side walls 3, 4 and is also suitable for transporting goods of all kinds and in particular as a stacking container for stacking several containers on top of each other.

[0083] Figure 4a shows a perspective view of a fourth transport unit, a plastic container T with a fourth bottom design for transporting and conveying goods on a roller conveyor. The container has a base plate 5 with a double bottom and four side edges, two short side walls 3, and two long side walls 4, each with a lower edge 7 and a top edge. The short side walls 3 and the long side walls 4 extend vertically upwards from the side edge of the base plate 5, are joined to each other via four corner radii to form a rectangular shape, and define a receiving area of ​​the container in which goods can be stored and transported. The base plate 5 has a double bottom with a first bottom facing the receiving area, which has a top surface, and a second bottom facing away from the receiving area, which has an uncoated underside 11.The second floor with its underside is connected to the first floor via a plurality of ribs 10 (shown in Fig. 4b), the ribs of the second floor being welded to the first floor.

[0084] P248970 The underside 11 of the base plate 5 has a running surface 2, wherein the surface of the running surface 2 has a surface roughness with a mean roughness value Ra of at least 3 pm, preferably of at least 9 pm, thus improving conveying on a roller conveyor.

[0085] The running surface 2 has the form of a rectangular running ring with four longitudinal sides and a recess 6 in the middle. The outer sides of the four longitudinal sides of the running ring of the running surface 2 can be chamfered and run along the side edges of the base plate 5 and parallel to the lower edges 7 of the side walls 3, 4. The recess 6 is located in the central region of the base plate 5 and provides a clearance that can accommodate deflection of the central region of the base plate 5 without the central region bearing on the surface on which the container 1 stands. This prevents any potential tilting of the container 1. The running ring of the running surface 2 and the recess 6 form the second base of the base plate 5 and have a substantially closed surface without a ribbed structure.

[0086] Figure 4b shows a side view of the short side wall 3 of the plastic container 1 ' as described in Figure 4a.

[0087] Figure 4c shows a bottom view of the fourth bottom embodiment of the invention of the plastic container T as described in Figure 4a, with the lower edge 7 at the lower end of the short side walls 3 and the long side walls 4, with a bottom plate 5 having a coating-free underside 11, the running ring of the running surface 2 with a surface roughness with a mean roughness value Ra of at least 3 pm, preferably of at least 9 pm, and with the indentation 6 in the middle area of ​​the bottom plate 5.

[0088] The container in Figures 4a, 4b and 4c has high side walls 3, 4 and is suitable for transporting goods of all kinds and in particular as a stacking container for stacking several containers on top of each other.

[0089] Figure 5a shows a perspective view of a fifth transport unit, a nestable plastic container T with a fifth bottom configuration for transporting and conveying goods on a roller conveyor. The container has a base plate 5 with a double bottom and four side edges, two short side walls 3, and two long side walls 4, each with a lower edge 7 and an upper edge. The short side walls 3 and the long side walls 4 extend perpendicularly from the

[0090] The side edges of the base plate 5, extending upwards, are connected to each other via four corner radii to form a rectangular shape, defining a receiving area of ​​the container in which goods can be stored and transported. The base plate 5 has a double bottom with a first bottom facing the receiving area, having a top surface, and a second bottom facing away from the receiving area, having an uncoated underside 11. The underside of the second bottom is connected to the first bottom via a plurality of ribs 10 (shown in Fig. 5b), the ribs of the second bottom being welded to the first bottom.

[0091] The uncoated underside 11 of the base plate 5 has a running surface 2, also referred to as the standing surface, and a rolling surface 2', wherein the surface of the running surface 2 and the rolling surface 2' has a surface roughness with a mean roughness value Ra of at least 3 pm, preferably at least 9 pm, thus improving conveyance on a roller conveyor. The running surface 2 has the shape of a rectangular tread with four longitudinal sides and a recess 6 in the middle. The long outer sides of the tread of the running surface 2 run along the long side edges of the base plate 5 and parallel to the lower edges 7 of the long side walls 4. The short outer sides of the tread of the running surface 2 run within the rolling surface 2' and parallel to and at a distance from the short side edges of the base plate 5 and parallel to and at a distance from the lower edges 7 of the short side walls.The rolling surface 2' runs along the short side edges of the base plate 5 and is arranged parallel to the lower edges 7 of the short side walls 3. The rolling surface 2' is positioned at a height between the height of the running surface 2 and the height of the lower edge 7 of the short side walls 3. On the outer sides of the running surface 2', in particular between the short outer sides of the running surface 2' and the rolling surface 2', a step is arranged as part of an elongated guide rib 9 with a guide roller surface for positioning and guiding the plastic container T on rollers of a roller conveyor with roller strips. The guide ribs 9 preferably extend over the entire length at the transition between the rolling surface 2' and the outer sides of the running surface 2', or along the long outer sides of the running surface 2'.

[0092] The indentation 6 is located in the central area of ​​the base plate 5 and provides a clearance that can accommodate deflection of the central area of ​​the base plate 5 without the central area resting on the surface on which the container 1 stands. This ensures

[0093] P248970 avoided a possible tilting of the container T. The individual parts of the underside 11 of the base plate 5, in particular the running ring of the running surface 2, the running ring of the rolling surface 2', and the indentation 6, have a closed surface without rib structure or openings.

[0094] The rough running surface 2 is designed for safe rolling on a roller conveyor with a wide roller mat and continuous transverse rollers between the side rails of the roller conveyor, and the rough rolling surface 2' is designed for safe rolling on a roller conveyor with narrow side roller rails. This makes the container versatile for use on various roller conveyors with roller widths ranging from narrow roller rails to wide roller mats.

[0095] Figure 5b shows a side view of the short side wall 3 of the plastic container 1 ' as described in Figure 5a.

[0096] Figure 5c shows a bottom view of the fifth base embodiment of the invention of the plastic container T as described in Figure 2a, with the lower edge 7 at the lower end of the short side walls 3 and the long side walls 4, with a base plate 5 having a coating-free underside 11, the running ring of the running surface 2 or the standing surface with a surface roughness with a mean roughness value Ra of at least 3 pm, preferably of at least 9 pm, and with the indentation 6 with rib structure in the middle area of ​​the base plate 5.

[0097] The container in Figures 5a, 5b, and 5c has high side walls 3, 4, which are slightly conical towards the bottom, so that a second, uniform container can be placed inside the rectangular opening of the first container. Such containers are suitable for transporting goods of all kinds and are particularly suitable as nestable containers or stackable containers, which can be nested when empty, thus enabling a significant reduction in volume.

[0098] Figure 6a shows a perspective view from a low angle of another transport unit 1 according to the invention, a plastic pallet 1” with a top part 13 and two outer runners 12 and a middle runner 12'. The runners 12, 12' have an uncoated underside 11 with a running surface 2 in the area of ​​the foot parts 14, which connect the runners 12, 12' to the top part 13. In addition, the middle runner 12' has two parallel grooves along both longitudinal edges on the underside 11 of the runner.

[0099] P248970 Roller surfaces 2' extend along the longitudinal sides of the central longitudinal runner. The roller surfaces 2' are arranged at a height between the height of the running surface 2 and the height of the lower edge of the side walls of the foot sections 14. That is, the roller surfaces 2' are higher than the running surfaces 2 when the plastic pallet 1" is on the floor. Along the running surface 2 of the central runner's underside 11, a step is arranged on both sides as part of an elongated guide rib 9' with a guide roller surface for positioning and guiding the plastic pallet 1" on rollers of a roller conveyor with central roller rails (not shown). This guide rib 9' is arranged between the running surface 2 of the central runner's underside 11 and the roller surfaces 2'. The guide rib 9' preferably extends over the entire length of the underside 11 of the central runner 12' at the transition between the roller surfaces 2' and the running surface 2 of the central longitudinal runner 12'.Preferably, the ends of the elongated guide rib 9' are chamfered or rounded at the narrow end edge, in each case in the region of the narrow end of the longitudinal runner 12'. The underside 11 of the runners 12, 12' has a closed surface in the region of the foot sections 19, and a ribbed structure between the foot sections 14.

[0100] The surface of the running surface 2 in the area of ​​the foot sections 14 and the surface of the rolling surface 2' have a surface roughness with a mean roughness value Ra of at least 3 pm, preferably at least 9 pm, thus improving conveying on a roller conveyor. It is also possible, depending on the application, that only the running surface 2 or only the rolling surface 2 has a surface roughness with a mean roughness value Ra of at least 3 pm, and that the other running surface or rolling surface has a smooth surface if it is not used for rolling on a roller conveyor.

[0101] Figure 6b shows a side view of the plastic pallet 1 “ as described in Figure 6a, with a top part 13 and three runners 12, 12' with a bottom surface 11 with running surfaces 2, and with two roller surfaces 2' which are each arranged along the longitudinal edges of the middle runner bottom surface 11.

[0102] Figure 7a shows a perspective view from a low angle of another transport unit 1 according to the invention, a plastic pallet 1” with a top part 13 and two outer runners 12 and a middle runner 12', as described in Figure 6a, with the difference that none of the runners 12, 12' have lateral rolling surfaces 2'. The runners 12, 12' have an uncoated underside 11 with a running surface 2 in each area

[0103] P248970 of the foot sections 14, which connect the skids 12, 12' to the upper section 13. The surface of the running surface 2 in the area of ​​the foot sections 14 and the surface of the rolling surface 2' has a surface roughness with a mean roughness value Ra of at least 3 pm, preferably at least 9 pm, thus improving conveying on a roller conveyor. It is also possible, depending on the application, that only the running surface 2 or only the rolling surface 2 has a surface roughness with a mean roughness value Ra of at least 3 pm, and that the other running surface or rolling surface has a smooth surface if it is not used for rolling on a roller conveyor.

[0104] Figure 7b shows a side view of the plastic pallet 1 “ as described in Figure 8a, with a top part 13 and three runners 12, 12' with a bottom 11 with running surfaces 2.

[0105] Figure 8a shows a perspective view from a low angle of another transport unit 1 according to the invention, a plastic pallet 1” with a top part 13 and two outer runners 12 and a middle runner 12', as described in Figure 6a, with the difference that the middle runner 12' does not have lateral rolling surfaces 2', but rather the outer runners 12 have them along their outer longitudinal edge. The runners 12, 12' have an uncoated underside 11 with a running surface 2 in the area of ​​the foot parts 14, which connect the runners 12, 12' to the top part 13. The two outer runners each have two parallel rolling surfaces 2' along their outer longitudinal edge on the underside 11, which extend along the long outer sides of the longitudinal runners.The surface of the running surface 2 in the area of ​​the foot sections 14 and the surface of the rolling surface 2' have a surface roughness with a mean roughness value Ra of at least 3 pm, preferably at least 9 pm, thus improving conveying on a roller conveyor. It is also possible, depending on the application, that only the running surface 2 or only the rolling surface 2 has a surface roughness with a mean roughness value Ra of at least 3 pm, and that the other running surface or rolling surface has a smooth surface if it is not used for rolling on a roller conveyor.

[0106] Figure 8b shows a side view of the plastic pallet 1 “ as described in Figure 8a, with a top part 13 and three skids 112, 12' with a bottom surface 11 with running surfaces 2, and with two mutually parallel rolling surfaces 2' which are each arranged along the outer longitudinal edges of the outer skid underside 11.

[0107] P248970 Reference numeral list

[0108] 1 transport unit

[0109] T plastic container

[0110] 1" plastic pallet

[0111] 2 Running surface

[0112] 2' rolling surface

[0113] 3 short side walls

[0114] 4 long side wall

[0115] 5 Base plate

[0116] 6 indentation

[0117] 7 Bottom edge of the side wall

[0118] 8 In-depth study

[0119] 9 guide rail container

[0120] 9' Guide gangway skid

[0121] 10 ribs

[0122] 11. Bottom

[0123] 12 outer runner

[0124] 12' middle runner

[0125] 13 Top

[0126] 14 Foot section

[0127] P248970

Claims

Patent claims 1. Transport unit (1) made of plastic for transporting and conveying goods on a roller conveyor, wherein the transport unit is a plastic container (T), a plastic tray or a plastic pallet (1"), characterized in that the transport unit (1 , T, 1") has a coating-free underside (11) with a running surface (2) and / or a rolling surface (2'), wherein the surface of the running surface (2) and / or the rolling surface (2') has a surface roughness with a mean roughness value Ra of 3 to 100 pm for conveying on a roller conveyor.

2. Transport unit (1) according to claim 1, characterized in that the transport unit (1) is a plastic container (T) with a base plate (5), two short side walls (3) and two long side walls (4), wherein the short (3) and long (4) side walls extend vertically upwards from the side edge of the base plate (5), and wherein the base plate (5) has a coating-free underside (11) with a running surface (2) and / or a rolling surface (2') with a surface roughness with a mean roughness value Ra of 3 to 100 pm.

3. Transport unit (1) according to claim 1 or 2, characterized in that the surface of the running surface (2) and / or the rolling surface (2') has a surface roughness with a mean roughness value Ra of 4 to 20 pm.

4. Transport unit (1) according to claim 1 or 2, characterized in that the surface of the running surface (2) and / or the rolling surface (2') has a surface roughness with a mean roughness value Ra of 6 to 13 pm.

5. Transport unit (1) according to one of the preceding claims, characterized in that the transport unit (1) and the surface roughness of the running surface (2) and / or the rolling surface (2') are produced by injection molding.

6. Use of a transport unit (1) according to one of the preceding claims for transporting and conveying goods via a roller conveyor. P248970 7. Method for manufacturing a transport unit (1) according to one of claims 1 to 4, characterized in that the transport unit (1) is manufactured by injection molding using an injection molding tool with a roughened surface for the running surface (2) and / or the rolling surface (2'). P248970

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