Method for subsequent reinforcement of injection moulded transport means

[0001] The invention relates to a method for the subsequent strengthening of injection molded transport means, such as plastic pallets or the bottom of plastic containers.

[0002] Since such means of transport are mass articles that are produced in large quantities, smaller simplifications in production already bring great economic benefits.

[0003] In addition to cheap production, however, sufficient stability of the transport means must still be ensured.

[0004] With unreinforced transport means during shelf storage, the deflection is particularly high at higher temperatures. However, it is precisely for this purpose that applications must be available to keep this deflection as low as possible.

[0005] For normal use on a forklift or for floor storage, however, the unreinforced design of the transport means is sufficient.

[0006] The injection molded transport means and the method of its subsequent reinforcement are known from DE 10 2004 049 201 A1. According to this publication, a reinforcing strip is first attached to the consoles of two diagonally opposite feet, which are then attached in the corner areas of the bottom of the container by screwing. This method cannot therefore be used for the feet formed together with the bottom of the container in one piece.

[0007] The object of the invention is therefore to shape the transport means in such a way that they can also be reinforced later to prevent sagging, without having to dismantle and then re-assemble the elements of the ready-formed transport means. [0008] The invention solves this task according to claim 1 in such a way that at the bottom of the plastic pallet or the bottom of the container are placed at least at the corners of the foot and between the two feet facing diagonally opposite each other a groove is provided for inserting a reinforcing profile and both ends of the groove are formed by one pocket each formed according to the profile cross-section in the area each foot assigned to the end of the groove, however, after making the pallet or the bottom of the container, the elastic deformation increases the distance between both pockets, then the reinforcement profile is inserted into the groove and one end of the profile in one of the pockets, then the deformation is lifted and the pallet or the bottom of the container returns to the relaxed the original state and also the other end of the reinforcing profile goes into the appropriate pocket.

[0009] The material properties of the transport means make it possible to deform the pallet or the bottom of the container to some extent so that the profile can be inserted and after the force is exerted on the pallet or the bottom of the container, he / she may, due to its flexibility, return to the initial position .

It is preferably provided in accordance with claim 2 that the pallet or bottom of the container extends in the longitudinal direction of the groove.

[0011] A few centimeters of elongation is enough for the free end of the profile, i.e. the one opposite the end already inserted into the pocket, to be placed in front of the pocket. After unloading, the pocket slides over this free end of the profile. So the profile is held firmly on the bottom (possibly also on top) and is secured against falling out.

[0012] Other deformations are possible to increase the distance between the two pockets, for example bending the groove with respect to the axis which lies perpendicular to the longitudinal direction of the groove.

[0013] The pockets may be injection molded separately next to the feet. However, it is also possible according to claim 4 that the pockets be integrated in the side walls of the feet.

[0014] As material for the reinforcing strips, for example, metal (steel, aluminum, etc.) is provided. [0015] As the metal and plastic have different coefficients of thermal expansion, it is important to ensure that the reinforcing strip is received in the loose pockets, so that the greater thermal expansion of the metal profile does not damage the plastic environment of the pallet or the bottom of the container.

[0016] For this reason it is also technically impossible to place the metal profile during the injection process in the pallet or in the bottom of the container.

[0017] The invention is illustrated and explained below based on the drawings, with the plastic pallet being exemplified. [0018] The individual figures show:

Fig. 1 the bottom of the injection-molded plastic pallet, in perspective view Fig. 2 the pallet according to Fig. 1 in the stretched state (in cross-section) Fig. 3 enlarged fragment of figure 2 Fig. 4 enlarged fragment according to figure 3, but in the unloaded state .

[0019] The figures show a plastic pallet and it is generally provided with reference number 1. It consists of a loading surface 2 which on its bottom is formed in the shape of a honeycomb and therefore has greater stability. Feet 3 are formed in the four corners of the loading surface 2. A groove 4 is formed between two diagonally facing feet 3 diagonally in the honeycomb shaped bottom of the loading surface 2, which groove is limited at its ends 5, which are located in the immediate vicinity of the respective foot 3, by pockets 6. The pocket openings are facing each other in the longitudinal direction of the groove.

[0020] A reinforcing strip 7 is inserted in the groove 4 and in the pocket 6. This figure shows the final state of the reinforced pallet.

[0021] The method of inserting the reinforcing strip 7 results from figures 2 to 4.

[0022] In Figure 2, the pallet 1 shown in cross-section in Figure 1 is stretched in the longitudinal direction of the groove. The reinforcement strip 7 is already stuck in the right pocket

6. The free end 8 of the reinforcement strip 7 is above the pocket 6 on the opposite side. As is more apparent from Figure 3, this free end 8 is in front of the opening of the pocket 6.

[0023] In figure 4 the final state is again represented (figure 1). The force necessary for

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pocket 6. This clearance x is necessary due to the different coefficients of thermal expansion of the material of the reinforcing strip and the plastic of the pallet.

Georg Utz Holding AG

Proxy:

EP 1 985 546 B1