Pallet with stiffening elements

#The present invention is directed to a pallet having a frame whose upper part, at least sides thereof, is provided with edges projecting from the pallet, a frame structure being arranged inside the frame, the pallet further including a loading surface onto which a load is to be arranged.

#In a known pallet, the frame which forms the framing or framework of the pallet is implemented such that the sides and ends of the pallet are provided with edges projecting from the pallet. Such a structure is achieved e.g. by using interconnected L-shaped bars turned upside down or appropriately profiled rails. In order to strengthen the structure of the pallet, a frame structure is arranged inside the frame of the pallet, comprising bars running across the pallet. Excluding the corners of the pallet, the upper part of the pallet is provided with a loading surface made of plywood, onto which a load is to be arranged. On top of the loading surface, in turn, there is a friction surface made of rubber sheet arranged to prevent the load from moving on the pallet and to suppress vibrations and impacts the load is subjected to. The pallet is designed to be moved by a particular road transport means which comprises an open bottom cargo space and which is capable of receiving and carrying a pallet and a load arranged thereon without being assisted by a forklift truck or a loader. The corners of the pallet are provided with corner elements through which locking holes are formed. The pallet can be locked to the above transport means using locking elements to be arranged into the locking holes such that the pallet forms the bottom of the cargo space of the transport means, stiffening the structure of the transport means. The aim is to make the structure of the pallet as low and as light as possible. The low structure of the pallet enables rather tall loads to be transported in the cargo space of the transport means. The lightness of the pallet enables the proportion of effective load from the total weight of the transport means to be raised as high as possible. Despite the frame and the frame structure inside the frame, due to the above reasons the pallet is very flexible, however, which is why in practice the pallet, particularly while carrying a load, can only be lifted almost exclusively by lifting means which support the pallet by the edges on the sides of the pallet substantially over the entire length of the pallet. This restricts the usability of the pallet in railroad traffic and sea transport since the pallet cannot be lifted and moved by loaders arranged to lift e.g. containers by their ends that are typically used in terminals and ports.

#An object of the present invention is to provide an improved pallet which is easy to use also in railroad traffic and sea transport.

#The invention will be described in closer detail in the accompanying drawings, in which

#FIG. 1 is a schematic top view showing a prior art pallet,

#FIG. 2 is a schematic cross-sectional end view showing the pallet of FIG. 1,

#FIG. 1 is a schematic top view showing a prior art pallet 1, and FIG. 2 is a schematic cross-sectional end view showing the pallet of FIG. 1 along line A—A in FIG. 1. The pallet 1 of FIGS. 1 and 2 comprises a frame 2, which constitutes the framing or framework of the pallet 1. The frame 2 is formed by interconnected, appropriately profiled rails 3 such that both sides and ends of the pallet 1 are provided with edges 4 projecting from the pallet 1. The frame 2 can also be formed e.g. using L-shaped bars turned upside down such that the sides and ends of the pallet 1 are provided with edges 4. Longitudinally and laterally, the size of the pallet 1 corresponds to that of the bottom of a twenty-feet container typically used in sea transport; however, the size of the pallet 1 may vary. Inside the frame 2 of the pallet 1, a frame structure is provided which comprises frame bars 20 running across the pallet 1; the frame bars 20 are shown in FIG. 1 by broken lines. For the sake of clarity, FIG. 1 only shows a couple of frame bars 20 at one end of the pallet 1, but it is obvious that there are frame bars 20 arranged in a similar manner over the entire length of the pallet 1. The pallet 1 further comprises a loading surface 5 made of plywood, onto which a load is to be arranged. On top of the loading surface 5 there is provided a friction surface 6 made of rubber sheet to prevent the load from moving along the loading surface 5 and to suppress vibrations and impacts the load is subjected to. For the sake of clarity, FIG. 2 shows the loading surface 5 and the friction surface 6 thicker than they actually are in comparison to the rest of the structure of the pallet 1. The corners of the pallet 1 are provided with corner elements 7 through which locking holes 8 are formed. The pallet 1 further comprises clamps 21, to which the load is attached by means of belts and clamping devices or the like. The pallet 1 is designed to be conveyed by a particular road transport means which comprises an open bottom cargo space and which is capable of receiving and carrying the pallet 1 and a load arranged thereon to be rested on the edges 4 of the pallet 1 without being assisted by a forklift truck or a loader. When the pallet 1 is interlocked with a particular transport means by means of locking elements to be arranged into the locking holes 8, the pallet 1 constitutes the bottom of the cargo space of the transport means, the bottom stiffening the structure of the transport means. Despite the structure of the frame 2 and the frame structure inside the frame 2, the pallet 1 is still flexible enough to be lifted, particularly when carrying a load, only by lifting means which support the pallet 1 at least by the edges 4 located on its sides substantially over the entire length of the pallet 1. The fact that the pallet 1 cannot be lifted e.g. by its ends without the pallet considerably bending in the longitudinal direction restricts the usability of the pallet 1 in railroad traffic and sea transport because the pallet 1 cannot be lifted and moved by loaders lifting e.g. containers by their ends that are typically used in terminals and ports.

#FIG. 3 is a schematic top view showing a pallet 1′ of the invention, and FIG. 4 is a schematic cross-sectional end view showing the pallet 1′ of FIG. 3 along line B—B in FIG. 3. Excluding the point where the corner elements 7 are located, both sides and ends of the pallet 1′ of FIG. 3 are provided with recesses or reductions 9. The reductions 9 are preferably about 20 mm wide; however, the width of the reductions 9 may vary. At the bottom of FIG. 3, the reduction 9 in a side of the pallet 1′ is designated by a broken line. Both sides of the pallet 1′ are provided with stiffening elements 10. For the sake of clarity, FIG. 3 only shows a stiffening element 10 in the side of the pallet 1′ located at the bottom of FIG. 3 in order to make the reductions 9 in the sides and at the ends of the pallet 1′ easier to illustrate. The stiffening element 10 has the same length as the pallet 1′ and it can be locked into the locking holes 8 in the corner elements 7 by employing an ordinary procedure for locking containers in a manner known per se. In addition to or instead of this locking procedure, the stiffening elements 10 can be arranged in connection with the pallet 1′ such that the stiffening elements 10 are attached to each other by means of supporting elements running across the pallet 1′. The stiffening elements 10 can be fastened to the pallet 1′ also in many other ways; preferably, however, such that the stiffening elements 10 can be detached from the pallet 1′. The ends of the pallet 1′ may also be provided with stiffening elements e.g. when a fixed protective housing is arranged in connection with the pallet 1′. The stiffening element 10 further comprises fastening points 11, to which e.g. the fixed protective housing to be arranged in connection with the pallet 1′ can be fastened. The fastening points 11 may be e.g. openings provided in the stiffening element 10, the shape of the openings being allowed to vary in many ways. The stiffening elements 10 arranged in the sides of the pallet 1′ stiffen the structure of the pallet 1′ in the longitudinal direction, enabling the pallet 1′, also while carrying a load, to be lifted and moved by loaders gripping the pallet 1′ by its ends without the pallet substantially bending in the longitudinal direction. When the pallet 1′ is provided with stiffening elements 10, the width of the stiffened pallet 1′ corresponds to the width of the prior art, unstiffened pallet 1 shown in FIG. 1. Similarly, if both ends of the pallet 1′ are provided with stiffening elements, the length of the pallet 1′ corresponds to the length of the prior art pallet 1. The stiffening element 10 comprises a stiffening part 12 to be arranged on top of the pallet 1′ which, in the embodiment of FIG. 4, resembles a hollow. However, the cross section of the stiffening element 10 may vary in many ways. The stiffening element 10 further comprises a gripping part 13 comprising a horizontal flange 14 to be arranged below the edge 4 of the pallet 1′, and a vertical flange 15 connecting the stiffening part 12 and the horizontal flange 14. The height of the stiffening part 12 may vary, preferably being about 150-300 mm. The width of the stiffening part 12 may also vary, preferably being chosen such that about a 2250-mm-wide space is left for the load between the stiffening elements 10 if the size of the pallet 1′ corresponds to that of the bottom of a twenty-feet container typically used in sea transport. The size of the gripping part 13 is designed to enable the stiffening element 10 to be firmly arranged in connection with the pallet 1′. The shape of the joint between the pallet 1′ and the stiffening element 10 makes the joint a close one, preventing water from ascending on top of the pallet 1′ from between the pallet 1′ and the stiffening element 10. Furthermore, the friction surface 6 made of rubber sheet tightens the joint between the pallet 1′ and the stiffening part 12. If the pallet 1′ is not provided with a friction surface 6 or the friction surface 6 cannot be used for tightening purposes or the joint between the pallet 1′ and the stiffening element 10 is otherwise to be made even tighter, a separate sealing element can be arranged between the pallet 1′ and the stiffening element 10. For the sake of clarity, FIG. 4 shows the profiled rail 3, the loading surface 5 and the friction surface 6 clearly thicker than they typically are in comparison to the structure of the stiffening element 10.

#A stiff pallet 1′ can also be implemented by providing the pallet 1 with no reductions 9 but arranging the stiffening elements 10 directly in the pallet 1. After the pallet 1 has been provided with the stiffening elements 10, the total width and/or total length of the stiffened pallet 1′ does not then, however, any longer correspond to the total width and/or total length of the pallet 1.