DE2031351A1 - Polyurethane foam pallet - with tongue and groove union of plate and skids - Google Patents

Abstract

Polyurethane foam pallet with plate having grooves underneath to take tongues made on the skids fitted to the underneath side in assembly. The grooves are fitted with notching holes to accept notching wedges mounted on the spines of the skid tongues thus locking the skids and plate together. The skids have fork entries and the polyurethane should be solid at the rims but porous inside thus making for light weight, cheapness, stability and easy stackability.

Description

Plastic pallet The invention relates to a plastic pallet consisting of a plate and at least two runners as well as tools for manufacturing these parts.

So far, the main materials have been wood, light metal and steel Served for the manufacture of the pallets, which usually consist of a closed one Plate with runners or feet underneath. The runners or feet are required to achieve a certain ground clearance for transport with lifting devices. There the plates and runners in the known constructions made of wood, light metal and Steel are usually rigidly connected to one another and are created when they are stacked and transported The empty pallet left a considerable amount of unused space. Another disadvantage of the previously mentioned pallets consists in the relatively high dead weight, which for a conventional wooden pallet, for example, is approx. 30kg. This relatively high dead weight has a significant impact on freight costs Stackability of loaded pallets and the load assumptions for structures for storage. Finally, the prime costs for wooden pallets are around 15.00 to 20.00 DM / piece and for pallets made of light metal or steel with approx. 30.00 to 60.00 DM / piece relatively high.

To the above disadvantages of the known pallets made of wood, light metal and to eliminate steel, it has also become known to plastic pallets to manufacture. The well-known pallets made of high-density thermoplastic material but are even more expensive than, for example, wooden pallets and also have regarding their own weight have the same disadvantages as these.

The invention is based on the object of a pallet made of plastic to create that is light, has sufficient static stability, their Individual parts (plate and runners) stacked to save space and used as intended Use can be assembled in a few simple steps and their production costs if possible, lie so low that they can also be used as a one-way pallet can. Another object of the invention is a suitable tool for Manufacture of the individual parts to create this pallet. After all, it is the invention also based on the task of eliminating the disadvantages of the prior art.

Based on the known plastic pallets consisting of a plate and at least two runners is the object of the invention solved in that the plate on its underside with connecting grooves and each Skid are provided with connecting springs on their upper side, which are on their flanks several spaced apart, longitudinally overlapping ones and have wedges tapered in opposite directions so that the plate and runner are in engagement located tongue and groove connection connected to each other by relative displacement and can be solved by one another. Not only about the plate and the runners but also about strength to be able to connect positively to each other is proposed on the back the connecting springs of the runners locking wedges and in the connecting grooves of the plate Provide locking openings so that the plate and runner clamp after the mutual Ver of the plate and runner wedges not only in the vertical direction but also in the horizontal direction are locked against each other to the parting line.

The connecting grooves in the underside of the plate and the connecting springs on the top of the runners have a double technical effect. On the one hand they serve as connecting elements, on the other hand they enlarge the total area the underside of the plate and thus its static stability. To the static It has proven expedient to increase the stability of the pallet proven additional stabilization grooves between the connecting grooves and the connecting springs and to arrange stabilization springs.

The pallet designed according to the invention has in particular then Sufficient static stability that meets all requirements, if plate and skid made of a plastic with a sandwich-like structure (massive edge zone and microporous interior) are made, for example from polyurethane. Suitable Polypropylene, foam glass or other plastics are also used as materials similar physical properties.

The pallet designed according to the invention has compared to the conventional Pallets made of wood, light metal or steel initially have the outstanding advantage that their weight with the internationally standardized loading area 800x1200mm is only approx. 2.5 up to 3.0kg / per piece. This corresponds to about 10% of the weight of a pallet wooden. When dismantled, the pallet can be stacked in the smallest of spaces. For example, ten pallets with three runners per pallet result in a plastic package at a height of 60cm stacked on an assembled basic pallet. Corresponding a space saving of 50% compared to previously known pallets. According to the invention trained range is also very low in price. The pure raw material price is to be set with Dz3 | 25, so that the final price depending on the requirements with regard to Load capacity and format between DM 5.00 to DM 10.00 per piece the calculation basis will form. This price per pallet is so low that it can be used as a one-way pallet becomes economically justifiable.

The elements consisting of wedges for a non-positive connection the plate with its runners are created by backsliding on the flanks of the Connecting grooves and connecting springs.

Tools for making such undercuts on large areas Elements made of plastic are not yet known. The most popular tools are designed in two parts and consist of a lower part of the tool and an upper tool part, in the parting plane of which parts of the mold are arranged. Based on this state of the art in tool making, a further refinement The invention proposed the upper tool part for foaming the undercuts split into a main part and a slide on the plate and runner wedges.

To hem the plate it is proposed that. the main part the cross-section of the connecting grooves on at least one of the length of the plate wedges corresponding section filling pegs into corresponding openings of the slide intervene. Furthermore, the slide should wedge the volume of the plate have corresponding recesses and correspond to one of the length of the plate wedges Slidable section relative to the main part in the direction of the inclination of the plate wedges For the tool for foaming the runners it is proposed that the main part the cross-section between two stabilizing springs at least on one of the length the section that fills the section corresponding to the runner wedges has the corresponding Engage the openings of the slide.

Further details and advantages of the subject matter of the invention result from the following description of the associated drawings in which preferred embodiments of a plate, a runner and the tools for the manufacture of these parts are shown in views and sections. In the The drawings show: FIG. 1 an assembled pallet in a perspective view position; Fig. 2 disassembled the same pallet into its individual parts (plate and three runners) in perspective view; 3 shows a plate in a view from below; Fig. 4 the same plate sectioned along the line IV-IV in FIG. 3; 5 the same Plate sectioned along the line V-V in Fig. 9; 6 shows a view of a runner from above; FIG. 7 shows the same runner in section along the line VII-VII in FIG. 6; FIG. 8 shows the same runner in section along the line VIII-VIII in FIG. 7; 9 the same Skid cut along the line IX-IX in Fig. 7; Fig. 10 an upper part of the tool of the tool for foaming the plate in a view from below; Fig.11 the whole Tool along the line XI-XI in Fig.

10 cut; Fig. 12 the same tool along the line XII-XII in Fig.

10 cut; Fig. 13 a tool top part of the tool for heming out the runner in view from below; 14 shows the entire tool along the line XIV -XIV sectioned in Fig. 13; Fig. 15 the same tool along the line XV-XV in Fig. 14 in section; Fig. 16 the same tool along the line XVI-XVI sectioned in Fig. 14.

The pallet shown in Figures 1 and 2 consists of a Plate 1 and a total of three runners 2. The runners 2 are required to have a certain To achieve ground clearance so that the pallet was picked up by the forks of a lifting device can be. The forks of the lifting device can either directly between the runners 2 grab under the plate 1, or engage in recesses 3 of the runners 2 and with these pick up the pallet.

The plate shown in detail in FIGS. 9 to 5 1 has a smooth support base 11 on its upper side and i, t on its lower side with connecting grooves 12 and Stabili sierungsnuten 13 profiled, the one to the other edge are arranged alternately next to one another and parallel to one another get lost. The connecting grooves 12 and also the stabilizing grooves 13 have a approximately the same trapezoidal cross-section. While the stabilization grooves 13 are open at the bottom of the plate 1 over their entire length the connecting grooves 12 at their lower end inwardly reaching plate wedges 14. These plate wedges are spaced apart in the longitudinal direction of the connecting studs 12 arranged from each other and leave a narrow gap 15 free between them.

in the three outer and middle connecting grooves open from the support base 11 outgoing locking openings 16.

The runners 2 shown in detail in Figures 6 to 9 be seated a lower chord 22 provided with a smooth standing surface 21 on the outside and an upper chord 23 profiled on its upper side. Of these lower and upper chords as well as three webs 24 made of solid crinkles, the recesses 3 are enclosed Of the Upper belt 24 is arranged at a distance from one another on its free upper side and connecting springs 25 and stabilizing springs extending parallel to one another 26 provided. While the stabilizing springs 26 have a smooth trapezoidal cross-section own and run through the entire width of the runner 2 are the connecting springs 25 undercut at the base of their flanks and form runner wedges 27 there the connecting springs 25 are only on the longitudinal sides of the runner 2 in full cross-section formed, while they only consist of narrow connecting webs in the central area 27 stand.

The connecting springs 25 lying on a longitudinal side of the runner 2 wear locking wedges 28 on their presses.

For further stabilization of runner 2 and to reduce weight can be embedded in the webs 24 grooves 29.

The plate 1 is completed with three runners 2 to form a pallet. Included the runners 2 with their connecting springs 25 are inserted into the connecting grooves 12, namely at the points where the connecting grooves 12 on their full cross-section are open. The connecting webs 27 engage in the column 15 between the Plate wedges 14 a. By shifting the runner 2 to the plate 1 laterally the plate wedges 14 and the runner wedges 27 are stirred over one another and against one another tense. This creates a forceful connection between the runners 2 and the plate 1 to stand. At the same time, however, the runners 2 snap into the end position also the locking wedges 28 in the locking openings 16 of the plate 1, so that a positive connection between the Ku. -fen 2 and plate 1 comes about.

The plate 1 and the runners 2 are made of a foamable plastic produced, which has a sandwich-like structure (massive edge zone and microporous Inner) owns. For foaming such a plastic, for example polyurethane, The tools shown in detail in FIGS. 10 to 16 can be used will.

The tool shown in Figures 10 to 12 for foaming the plate 1 consists of a lower tool part 31 and a divided upper tool part 32. The divided upper tool part 32 is made up of a main part 32a and a slide 32b formed The main part 32a has pegs) D, which in corresponding openings 34 of the slide 32b protrude. In the inner flanks of the slide 32b keyways 35 for the plate wedges 14 are embedded.

That shown in Figures 11 and 12 in the closed state The mold for foaming the panel 1 is opened by first opening the main part 32a with its pin 33 is pulled out of the slide 32b. Then he can Slide 32b, can be moved parallel to the main part 32a until its keyways 35 come free from the molded plate parts 27. Then the entire upper part of the tool, Main part 32a and slide 32b, from which the lower tool part 31 is lifted The foamed sheet 1 is then ejected without any difficulty.

The tool shown in Figures 13 to 16 for foaming the runner 2 consists of a lower tool part 41 and a divided upper tool part 42. The upper tool part 42 is formed from a main part 42a and a parallel one to this displaceable slide 42b. The slider 42b has on its underside Pins 43 which engage in corresponding openings 44 of the slide 42b. At the slide 42b are wedges 45 with which the runner wedges 27 in the runner 2 are molded.

That shown in Figures 14 to 16 in the closed state After foaming the skid 2, the tool is opened by first removing the main part 42a with its pin 43 is lifted out of the slide 42b Slide 42b initially parallel to the main part 42a by the length of the wedges 45 from the lower tool part 41 is pulled off and then lifted off the lower tool part 41 together with the main part 42a will. The molding can then be easily repelled from the lower tool part 41.

The assembly of the outer runners 2 on the plate 1 is made easier, if the runners 2 can be pushed open from the outside. For this purpose it is necessary that the inclination of the plate wedges 14 extends outwards so that the runner wedges 27 can be inserted in the correct position. To do this, the slide 32b of the work tool for the plate 1 along the line x-x shown in FIG. 10 will. The two parts of the slide 32b are then used for demolding the plate 1 initially parallel to the main.

part 32a moved outwards and then together with the main part 32a withdrawn from the lower tool part 31.

All mentioned in the description and shown in the drawing New features are essential to the invention, also insofar as they are in the following claims are not expressly claimed.

Claims (10)

Expectations : 1. Pallet made of plastic consisting of a plate and at least two runners, that is, that the plate (1) is on its Underside with connecting grooves (12) and each runner (2) on its upper side with connecting springs (25) are provided, which on their flanks several spaced apart, Longitudinal, overlapping and oppositely tapered wedges (Plate wedge 14; runner wedge 27), so that plate (1) and runner (2) at in Engagement of the tongue-and-groove connection by relative displacement with one another can be connected and detached from each other. 2. Pallet according to claim 1, characterized in that on the back the connecting springs (25) locking wedges (28) and locking in the connecting grooves (12) Openings (16) are provided so that plate (1) and runner (2) after the mutual Bracing of the plate and Kufan wedges (14, 27) can be locked against each other. Pallet according to claims 1 and 2, characterized in that between the connecting grooves (12) additional Stabilislerungsnuten (13) and between the connecting springs (25) additional stabilizing springs (26) are arranged 4. Pallet according to claims 1 to 3, characterized in that the runners (2) continuous recesses (3) for the arms of forklifts in their long sides or the like. 5. Pallet according to claims 1 to 4, characterized in that the plate (1) and the runners (2) made of a plastic with a sandwich-like structure (massive edge zone and microporous interior) are made, for example from Polyurethane. 6. Tool for foaming the plate and skid for a pallet according to claims 1 to 5, consisting of a lower tool part and an upper tool part, characterized in that the upper tool part for foaming the undercuts on the plate and runner wedges (14, 27) consisting of a main part (32a) (42a) and a Slide 32bm 42b). 7. Tool according to claim 6 for foaming the plate, characterized in that that the main part (32a) at least the cross section of the connecting grooves (12) one of the constraints of the plat tenkeile (14) corresponding section filling pin (33) which engage in corresponding openings (34) of the slide (32b). 8, tool according to claims 6 and 7, characterized in that the slide (32b) has keyways (35) corresponding to the volume of the plate wedges (14) and dm has a parallel section corresponding to the length of the plate wedges to the main part (32a) is displaceable. 9. Tool according to claim 6 for foaming the runner, characterized in that that the main part (42a) has the cross-section between two stabilizing springs (26) at least on one section corresponding to the length of the runner wedges (27) Has pins (43) which are inserted into corresponding openings (44) of the slide (42b) intervention. 10. Tool according to claims 6 and 9, characterized in that that on the pin (43) wedges (45) are provided for molding the runner wedges (27).