DE69813613T2 - PALETTE - Google Patents

Description

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

State of the art

Currently, pallets, which are available in many different models, are almost exclusively joined together using nail joints, which provide a strong connection. For certain types of pallets, such as the so-called office pallet, standards are set in terms of materials, dimensions and strength. Consequently, it is important that the joint is strong and resistant to stress so that the pallet meets the applicable standard for the respective pallet type. This is one of the reasons why nail joints are common.

Nowadays, damaged pallets are repaired to some extent, but it is difficult and uneconomical to remove the nail joints without causing further damage to the various parts of the pallet. Furthermore, if the pallet is made of several materials, such as spacers or blocks, sometimes made of plastic, it is desirable to separate the different materials before reusing and/or reprocessing them. Discarded pallets can be cut up for later use as fuel or, for example, as raw material for the manufacture of chipboard or chip blocks. One of the disadvantages of nail joints is the movement of the nails when the wood moves due to humidity fluctuations. In this context, the nails can, for example, protrude from the pallet's loading plate and damage the pallet's load. Another disadvantage of nail joints is that, in connection with the cutting up of pallets, the nails considerably increase the wear of the mechanical equipment, which results in increased costs. Furthermore, problems arise in the treatment of ash related to incineration residue. However, due to the increased Producer responsibility requirements must somehow address pallets.

US 4,128,253 discloses the invention of a pallet having an upper and a lower platform, the platforms being connected to one another by the insertion of a plurality of connecting devices arranged between the platforms. Each connecting device comprises a spacer which is attached to the platform by means of a riveting device which comprises a rivet insertion part and a rivet receiving part. It is intended that these rivet parts are inserted into the upper platform from above and into the lower platform from below, or through aligned opposite holes in the platforms into a through hole in the spacer, and are thus fitted into one another. The connecting device can also comprise a hollow, cylindrical part, a roller which is freely rotatable above the spacer and is intended to "guide" the forks of the stacker by rotating when in contact with the forks. In addition, the roller protects the other parts of the connector by absorbing shocks or other forces to which the connector is exposed.

US 4,267,781 discloses the invention of a pallet variant corresponding to US 4,128,253. In this pallet, the roller and the outer frame of the spacer have the shape of a truncated cone.

These two pallets described above have the mutual limitation and disadvantage that one of the platforms must be a plate in order for the pallet to be able to absorb diagonal forces, which may occur, for example, when a pallet is inserted into a narrow space. Consequently, none of these pallets would be able to absorb diagonal forces if, for example, the pallet were a so-called Euro pallet, i.e. if the platforms consisted of several boards instead of an integral plate. Furthermore, these pallets have the disadvantage that the connecting device contains many different individual parts, which complicate the assembly of the pallet and increase the manufacturing costs and the storage costs of the individual parts. In addition, the connecting device is dependent on the special design of the spacer. This requires, for example, a stock list of spare parts. In addition, the pallets according to the patent specifications listed above do not seem to meet the special requirements regarding strength imposed on certain types of pallets, e.g. a Euro pallet.

There are also pallets assembled by adhesives, e.g. FR 7,1112,656. However, gluing is time-consuming and expensive, and it can be difficult to separate the glued joints in an effective manner. Furthermore, glue can be hazardous both from an employee health and environmental point of view.

For information on the background of the invention, reference is also made to the patent specifications US 4,604,014, US 4,019,634 and DE 19 519 969.

Description of the invention

It is an object of the present invention to prevent the above-mentioned disadvantages by providing a pallet which can be quickly and easily assembled and disassembled without deviating from established standards for the respective pallet type, thus allowing suitable reuse of individual parts or reuse of the pallet material by inexpensive disassembly for use as fuel or as raw material for new products. Furthermore, it is an object of the invention to provide a pallet which is capable of absorbing diagonal forces acting on the pallet. It is also an object of the invention to provide a pallet which allows damaged pallets to be repaired by quickly and easily replacing the damaged parts. Furthermore, it is an object of this invention to provide a continuous integrated connection which is easy and inexpensive to manufacture, which is easy to attach to the pallet and which is made of a material which, if necessary, can be bonded together with the wooden material without difficulty such as by welding. B. considerable wear and tear on machines and equipment. It must also be possible to incinerate the connecting material together with the separated wood material without producing waste products that are hazardous to the environment. Another aim of the invention is that the connection can be reused and recycled after it has been returned. Finally, all of these goals are achieved with a pallet according to claim 1.

According to the invention, the pallet is assembled at the joints by means of a connecting or fastening device, preferably made of plastic, which comprises a receiving part with an inner bore and a pin-like flange portion at one end thereof. The connecting device also comprises an insertion part which has a shaft and a pin-like flange portion at one end thereof. With its The insertion part can be inserted into a shaft and brought into engagement with the bore of the receiving part, the parts being pressed together by a force emanating from the connecting device. The parts can be separated from one another by exerting a force in the opposite direction. The receiving part is inserted into a through hole in the corresponding spacer and in the loading plate. The flange sections of the receiving and insertion parts project on opposite sides of the pallet. Thus, the flange sections have the task of applying the force necessary to hold the various parts of the pallet together on the opposite sides of the pallet. Compared to a pallet assembled by means of nail connections, where the nails are hammered in on opposite sides, the pallet according to the invention has the advantage of being held together by a continuous, integrated connection. In the pallet according to the invention, the receiving part is provided with one or more longitudinal webs on the outside, with the aim of preventing the spacer from rotating and making it possible to absorb diagonal forces, e.g. B. when a forklift hits the pallet. US patents 4,128,253 and US 4,267,781 propose to use them together with a specially designed spacer that defines a hole and any ribs on the outside of the receiving part would have no anti-rotation effect.

In a preferred embodiment, the flange section is designed so that it extends over the entire circumference of the respective receiving and insertion part. But in an alternative embodiment, the flange section can only extend over certain parts of the circumference of the respective insertion and receiving part, i.e. in the form of two exactly oppositely arranged locking devices with hooks in the respective loading and base plate.

In a preferred embodiment, a portion of the shaft of the insertion part is designed with a knurled section, in which each knurl extends around the circumference of the shaft in the shape of a truncated cone. Similarly, in the preferred embodiment, the receiving part has a knurl, in which each knurl extends around the circumference of the bore and has the shape of the envelope surface of a truncated cone. The conical knurls of the respective insertion and receiving parts are adapted to one another in such a way that they engage with one another to form a connection. In a preferred embodiment, the cross-sectional dimension in the region of the knurling of the insertion part is slightly larger than the dimension of the bore in the region of the edges. of the receiving part, since the material is preferably somewhat elastic, and in terms of strength, a better connection of the insertion and receiving parts is achieved when the wall of the receiving part is subject to a certain degree of stretching.

However, it is not necessary that both the male and female parts have a knurled section in the shape of a truncated cone. One of the parts can be essentially flat and join the other part by means of friction. In essence, both parts can be flat and in a conical shape and join by means of friction, i.e. the shaft of the male part can abut the flange section with its largest diameter and the bore of the female part can conically abut the flange section with the smallest diameter of the bore so that the two parts fit together. However, it is the requirements related to the specificity of the pallet that determine which combination of male and female parts is suitable.

In a preferred embodiment, the flange portion of the respective introducing and receiving part is arranged in recesses of the respective top and bottom of the pallet in order to facilitate stacking of the pallet, to ensure that the connecting device does not interfere with loading of the pallet, to avoid damage to the flange portion in relation to handling of the pallet or by the load of the pallet. But these recesses can be dispensed with.

In a preferred embodiment, the inner bore of the receiving part is continuous. This simplifies, for example, the disassembly of the pallet. In this case, the insertion part can easily be pushed out of the receiving part from the underside. However, a through-bore of the receiving part is not fundamentally necessary. It would be possible, for example, to hold the insertion part at the flange section and pull it out of the receiving part.

In a preferred embodiment, the pallet also comprises a lower base plate. In this embodiment, the receiving part is inserted into a through hole in the base plate, the base plate being connected to the spacer and the loading plate by means of the insertion part which is inserted into the receiving part from the opposite direction.

Lead-in and lead-in parts can be made in different lengths, depending on which parts of the pallet belong to the respective joint type. For example, in the corner joints of the pallet, the different parts can consist of the loading plate, the spacer, a lower base plate and a crossbar or longitudinal bar, while in other joints, only the loading plate and a crossbar are included. Some pallet models can only be connected at the corners, and in this case, no shorter forms of lead-in and lead-in part are needed. The length of the respective lead-in and lead-in part can therefore be varied depending on the type of pallet to be assembled.

Brief description of the attached drawings

The following refers to the drawings, where Figs. 1, 3 and 5 are drawn on a larger scale in the horizontal direction than in the vertical direction:

Fig. 1 is a perspective view of a preferred embodiment of an assembled pallet according to the invention, in which the hidden parts of the connecting device in six of the connecting locations are indicated by dashed lines;

Fig. 2 is a side view of a preferred embodiment of the insertion part;

Fig. 3 is a cross-section of a preferred embodiment of the receiving part;

Fig. 4 is a bottom view of a preferred embodiment of the receiving part;

Fig. 5 is a cross-section of a preferred embodiment of a pallet joint according to the invention; and

Fig. 6 is a cross-section of an alternative embodiment of the connection.

Detailed description of preferred embodiments of the invention

Fig. 1 shows a pallet, generally designated 1, with a loading plate 2 comprising loading plate boards, spacers 3, a bottom plate 4 and crossbars 5 which are mounted between the loading plate boards and the spacers and which run parallel to the shorter side of the pallet. In this embodiment, the pallet has fifteen connection points. At the connection points 6, the loading plate 2, the crossbars 5 and the spacers are connected. slat 5, the spacer 3 and the base plate 4 are connected to each other. The loading plate 2 and the crossbar 5 are connected to each other at the connection points 7.

Fig. 2 shows the preferred embodiment of an insertion part 8, with a pin-like flange section 9 and a shaft 10. In one section, the shaft 10 is provided with barbs in the form of knurls 11, which are shaped like a truncated cone.

Fig. 3 shows a preferred embodiment of the receiving part 12, with a pin-like flange section 13 and an internal bore 14 into which the shaft 8 of the insertion part 10 in Fig. 2 is intended for insertion. The receiving part has a section with barbs in the form of knurls 15 on the bore wall 14, which have the shape of the envelope surface of the truncated cone. The knurls 15 point in the opposite direction to the knurls 11 in Fig. 2 to ensure that the insertion part 8 and the receiving part 12 can engage.

Accordingly, the knurls are shaped so that the cross section of the shaft 10 of the insertion part 8 and the bore 14 of the receiving part tapers. In the receiving part 12, the cross section tapers towards the flange section 13. The cross section of the insertion part 8 (Fig. 2) tapers away from the flange section 9. In the areas where the knurls 11, 15 on the insertion part 8 and the receiving part 12 meet, the knurls 11, 15 are horizontally stepped, perpendicular to the corresponding longitudinal axis of the insertion part 8 and the receiving part 12, so that they catch on the protruding steps of the corresponding part 8, 12. On its outside, the receiving part has a number of webs 16 which are intended to prevent the rotation of the spacers and the connecting device, e.g. B. when diagonal side forces act on the pallet.

To provide a clearer illustration of the arrangement of the webs 16, Fig. 4 shows a view from below of a preferred embodiment of the receiving part 12 with the bore 14 in the middle, the flange section 13 and the arrangement of the webs equidistant from each other around the circumference of the receiving part 12.

Fig. 5 shows a cross-section of the connection of the pallet according to the invention. In the connection shown, the loading plate 2, the crossbar 5, the spacer 3 and the bottom plate 5 are connected to each other by the insertion part 8 and the receiving part 12. The knurled portion 11 of the insertion part 8 is in engagement with the knurled portion 15 of the receiving part 12. Webs 16 are arranged around the circumference of the receiving part 12 to prevent rotation of the pallet components. The flange section 9 of the insertion part 8 and the flange section 13 of the receiving part 12 are arranged in recesses 17 on the opposite sides of the pallet 1, see also Fig. 1.

Fig. 6 shows an alternative embodiment of the connecting device in which the shaft 10 of the male part 8 is conical and has knurls 11 in the shape of a truncated cone 11, while the female part has a simple conical bore 14. The conical shape of the parts ensures that the male part 8 and the female part 12 are pressed together and a secure connection is achieved. Furthermore, in this embodiment, the knurls 11 in the shape of a truncated cone on the shaft 10 of the male part 8 contribute to the mutual engagement of the parts and hold the parts of the pallet together, since the knurls 11 of the male part 8 in the shape of a truncated cone have wider dimensions than the female part 12 and elastically "stretch" the female part 12.

When the pallet is assembled according to the invention, firstly the various parts of the pallet are pre-drilled at the points of the joints. Then the parts are positioned and the male part 8 and the female part 12 are inserted into the pre-drilled holes from opposite sides of the pallet. Preferably, the male part 8 and the female part 12 are pressed together using a pressure tool rather than hammered together. When the pallet is disassembled, an external force preferably acts from below on the male part 8 to push the male part out of the female part 12 and for this reason the bore of the female part is preferably continuous, as shown in the examples. Subsequently, the parts of the pallet can be sorted, after which undamaged parts can be reused as pallet parts. Damaged parts are replaced and discarded and can be for example shredded and used in chipboard or as fuel.

Claims (6)

1. A pallet comprising at least one upper loading plate (2) and spacers (3) connected to the loading plate (2), the loading plate (2) and each of the spacers (3) being connected to one another by means of a connecting device comprising a receiving part (12) having an inner bore (14) and a flange portion (13) at one end thereof, and an insertion part (8) having a shaft (10) and a flange portion (9) at one end thereof and which can be inserted with its shaft (10) into and engaged with the bore (14) of the receiving part (12) by exerting a force pressing the insertion part (8) and the receiving part (12) towards one another, and can be released by exerting a force in the opposite direction, the receiving part (12) being inserted into a through hole in the pallet and the Flange sections (9, 13) rest on the surfaces of the pallet located on opposite sides, characterized in that the receiving part (12) is provided on its outside with at least one longitudinal web (16). 2. Pallet according to claim 1, characterized in that the shaft (10) of the introduction part (8) has at least one knurled section in which each knurl (11) has the shape of a truncated cone. 3. Pallet according to claim 1 or 2, characterized in that the bore of the receiving part (12) has a knurled section in which each knurl (15) has the shape of the envelope surface of the truncated cone. 4. Pallet according to one of the preceding claims, characterized in that the inner bore (14) of the receiving part (12) is continuous. 5. Pallet according to one of the preceding claims, characterized in that the shaft (10) of the insertion part (8) is conically shaped and the diameter in Direction of the flange portion (9), and that the bore (14) of the receiving part (12) is oppositely conical and the diameter decreases in the direction of the flange portion (13). 6. Pallet according to one of the preceding claims, characterized in that the pallet further comprises a lower base plate (4), and that the receiving part (12) is inserted into a through hole in the base plate (4).