DE4128883A1 - Lightweight plastic pallet prodn. - by injection moulding in one piece and comprises flat load bearing surface, hollow projecting feet and hollow stiffening ribs - Google Patents

Abstract

A lightweight pallet includes a flat load carrying surface and feet projecting from one side along two parallel edges and also symmetrically in lines parallel to the edges. The feet in each line are connected by a flat strip along the feet bases. The complete pallet including the load carrying surface, feet and connecting strips are mfd. in one injection moulding operation. Hollow chambers are formed inside the rectangular profiled feet which are completely enclosed on all sides. Hollow chambers are produced during moulding by moving wall areas of the tool during the holding pressure phase to increase cavity volume and injecting high pressure gas. USE/ADVANTAGE - The pallet replaces a conventional wooden type, is very light, extremely robust and can be mfd. in a single operation.

Description

The invention relates to a flat pallet with a essential flat shelf, one-sided of this protruding feet, mainly in the area of two parallel edges, if necessary also symmetrical between them in further parallel alignment, whereby the feet of a row of feet on their free, the shelf opposite end by a substantially flat bar are connected.

Such flat pallets are a lot in the prior art well known. So far it has been common to use such flat pallets made of wood. The storage area is covered by several wooden strips formed parallel to each other. In the area of the longitudinal edges of the shelf further wooden strips running transversely to these strips provided on those in the corner area and where appropriate  wooden feet can also be attached in the middle of the pallet, which in turn by rows of nailed strips are connected.

Flat pallets of this type are already known, where the feet are made of U-shaped angled steel parts are formed, but with the remaining components after consist of wood as before. Such pallets are called so-called four-way pallet used, whereby by means of Forks of a stacker stack the rectangular pallet Drive under and raised from all four sides can be.

Based on this state of the art Invention based on the task of a very light, extremely robust and inexpensive to manufacture pallet to accomplish.

To achieve this object, the invention proposes that the flat pallet with storage space including feet and Moldings molded in one piece from plastic (injection molded  water) and that at least the feet are closed Side walls forming cavities and top and bottom have walls.

The one-piece design is made of plastic the production is very simplified, the required Stability and stability of the feet achieved is that the feet are formed as closed cavities are. This measure also leads to an increase saving weight and shortening the Cycle times due to solid plastic feet significantly higher material requirements and significantly longer Would need cooling times.

A preferred further development is seen in the fact that the feet are approximately flat rectangular in cross section if they are designed with rounded edges.

Despite the small space requirement, one will be sufficient en Stiffness and resilience achieved.  

It is preferably provided that the head wall of the feet lies in the level of the storage surface of the pallet.

Furthermore, it is provided that a long and a short side wall in the alignment of the marginal edges Storage space in each corner area of the rectangular Storage area.

This training is an excellent connection of the feet on the counter surface, resulting in a further stiffening and increased usability of the pallet leads.

Furthermore, it is preferably provided that the bar, that connects the feet belonging to a row of feet, is designed as a ribbed profile, the sides wall and / or the bottom wall of the feet integral comprises, the rib profiles to that of the storage surface facing away from the bar side are open.

This measure serves to provide additional stiffening.  It is preferably provided that the bar in Cross section forms a flat triangular profile.

This ensures that the bar when Inserting the forks of a stacking device is not on Form obstacle, but by the flat rising triangle sides guide the forks at Insertion is effected.

For the purpose of further stiffening, that the bar near or at the top of the triangle has a closed hollow channel that connects to the bar molded feet near their bottom connects, the Hollow channel through the side wall areas of the feet at the end closed is.

As a result of this measure, the bar can also small wall thickness, which leads to a Ge weight savings and cost savings (material costs and cooling times).

Furthermore, it is provided for stiffening purposes that  the hollow profiles between each facing Sides of the feet run with the side walls of the feet form the top surfaces of the hollow profiles.

For the same purpose it is provided that additional hollow profiles parallel to the hollow connecting the feet profiles and shaped symmetrically between them are.

For this purpose, it can also be provided that the hollow profiles with a side surface in the shelf surface of the pallet.

The invention further relates to a method for the manufacture position of a flat pallet according to one of the claims 1 to 11 made of thermoplastic material, wherein in one consisting of at least two mold halves, ge closed mold liquid thermoplastic under high Pressure is injected to fill the mold and during the Solidification phase of meltable thermoplastic to end equalized the shrinkage caused by solidification  is fed (holding pressure phase) as an addition to P 40 34 663.3.

The task of the procedure is to provide an opportunity create with which it is particularly simple and with simple design effort is possible using flat pallets form closed internal cavities.

The solution to this problem is in the procedural claims Designated 12 to 19.

The advantages and beneficial effects of use this procedure are in the main filing P 40 34 663.3.

An embodiment of the invention is in the Drawing shown and described in more detail below.

It shows

See Figure 1 is a flat pallet of dimensions 800 × 600 × 140 in plan view, partly in section along the line AA of Fig. 3.

Fig. 2 also seen in section CC of Fig. 1;

Fig. 3 also seen in section BB of FIG. 1.

The flat pallet has a substantially flat, provided with openings storage surface 1 , from the one side, in the use position down, feet 2 protrude from.

The feet are each in the area of two parallel edges edges and also symmetrical between these in further Parallel alignment arranged.

The feet 2 of a row of feet are connected at their free end facing away from the storage surface 1 by an essentially flat strip 3 .

The flat pallet is injection molded with its storage surface 1 , the feet 2 and the strips 3 in one piece from plastic. The feet 2 form closed cavities 4 with side walls 5 head walls 6 and bottom walls 7 .

The feet 2 are approximately rectangular in cross section with rounded edges, the long right corner side of all feet being parallel to one another and parallel to a side wall alignment of the flat pallet. The top wall 6 of the feet 2 lies in the plane of the storage surface 1 . A long and a short side wall 5 of the feet 2 lies in the alignment of the edge edges of the storage surface 1 in each corner area of the rectangular storage surface 1 , additional feet 2 being additionally arranged in the center of the corner pairs of feet relative to the pallet.

The strip 3 , which connects the feet 2 belonging to a row of feet, is designed as a ribbed profile strip, as can be seen particularly clearly from FIG. 3. This rib profile strip comprises the bottom wall 7 of the feet 2 as an integral part, the rib profiles being open on the strip side facing away from the storage surface 1 . The bar 3 is formed in cross section as a flat triangular profile, so that insertion aids for inserting forks of a stacking device are formed. The bar 3 additionally has a closed hollow channel 8 at the triangle tip, which connects the feet 2 formed on the bar 3 near the bottom 7 thereof. The hollow channel 8 is closed at the end by side wall areas of the feet.

Furthermore, the storage surface 1 of the pallet is stiffened by parallel hollow edge profiles 9 that run parallel to the edge edges. The hollow profiles 9 each extend between the mutually facing side walls 5 of the feet 2 , the side walls 5 of the feet 2 forming the cover surfaces for the conclusion of the hollow profiles 9 .

Furthermore, additional hollow profiles 9 are formed parallel to the hollow profiles 9 connecting the feet 2 and symmetrically between them. These hollow profiles 9 each have a side surface in the storage surface 1 of the pallet. Due to the training shown in the drawing, a material-saving production with high rigidity and resilience of the pallet, it is sufficient, due to the stiffening provided by closed hollow profiles, a total material saving can also be achieved with respect to the wall thicknesses of the pallet, which saves weight, material and Manufacturing cost savings leads.

The invention is not limited to the exemplary embodiments limited, but often within the scope of the disclosure variable.

All new, in the description and / or drawing disclosed individual and combination features regarded as essential to the invention.

Claims (19)

1. Flat pallet with a substantially flat storage surface from these unilaterally projecting feet, especially in the area of two parallel edge edges, optionally also symmetrically between these in a further parallel orientation, the feet of a row of feet at their free end facing away from the storage surface by an essentially Flat bar are connected ver, characterized in that the flat pallet with storage area ( 1 ) together with feet ( 2 ) and bars ( 3 ) is formed in one piece from plastic (injection molded), and that at least the feet ( 2 ) ge closed cavities ( 4 ) forming side walls ( 5 ) and head ( 6 ) and bottom walls ( 7 ). 2. Flat pallet according to claim 1, characterized in that the feet ( 2 ) are approximately flat rectangular in cross section, optionally with rounded edges. 3. Flat pallet according to claim 1 or 2, characterized in that the head wall ( 6 ) of the feet ( 2 ) lies in the plane of the storage surface ( 1 ) of the pallet. 4. Flat pallet according to one of claims 1 to 3, characterized in that a long and a short side wall ( 5 ) in the alignment of the marginal edges of the storage surface ( 1 ) are each in a corner region of the rectangular storage surface ( 1 ). 5. Flat pallet according to one of claims 1 to 4, characterized in that the bar ( 3 ), which connects the feet belonging to a row of feet ( 2 ), is designed as a ribbed profile strip, which may be the side wall ( 5 ) and / or the bottom wall ( 7 ) of the feet ( 2 ) integrally comprises, the rib profiles being open on the strip side facing away from the storage area ( 1 ). 6. Flat pallet according to one of claims 1 to 5, characterized in that the bar ( 3 ) in cross section forms a flat triangular profile. 7. Flat pallet according to claim 5 or 6, characterized in that the bar ( 3 ) near or at the triangular tip has a closed hollow channel ( 8 ) which the molded on the bar ( 3 ) feet ( 2 ) near the bottom ( 7 ) connects, the hollow channel ( 8 ) being closed at the end by side wall regions ( 5 ) of the feet ( 2 ). 8. Flat pallet according to one of claims 1 to 7, characterized in that the storage surface ( 1 ) of the pallet is stiffened by edgewise closed hollow profiles ( 9 ) running parallel to the edge edges. 9. Flat pallet according to claim 8, characterized in that the hollow profiles ( 9 ) each run between the mutually facing sides ( 5 ) of the feet ( 2 ), the side walls ( 5 ) of the feet ( 2 ) the cover surfaces of the hollow profiles ( 9 ) form. 10. Flat pallet according to claim 8 or 9, characterized in that additional hollow profiles ( 9 ) are formed parallel to the feet ( 1 ) connecting hollow profiles ( 9 ) and symmetrically between them. 11. Flat pallet according to one of claims 8 to 10, characterized in that the hollow profiles ( 9 ) lie with a side surface in the storage surface ( 1 ) of the pallet. 12. Process for producing a flat pallet one of claims 1 to 11, made of thermoplastic Plastic, being in one of at least two molds halves existing, closed mold more liquid Thermoplastic filled in under high pressure is injected and during the solidification phase melted thermoplastic to compensate for it Rigid shrinkage is replenished (Holding pressure phase), characterized in that for Forming the hollow profiles in an area of the flat pallet through the mold surrounding this area  Displacement of a wall area of the mold is enlarged during the reprinting phase there, at least still melt in the core liquid or pasty thermoplastic material under gas high pressure turned on during the holding phase is pressed, so that the shifted wall area of the already frozen skin of the thermo plastmaterials the shifted wall area following, on these with simultaneous education a cavity is pressed and the still liquid or pasty core mass of this area the separation join between the molded plastic part in this Area and the shifted wall area displaced thermoplastic part area material conclusively connects. 13. The method according to claim 12, characterized in that that the mold in the area of the cavity to be molded has a displaceable mandrel that the shifted wall area with its insertion forms the front end face, whereby  with a molded core, a pot-like web part is formed, from the bottom of which after withdrawal of the mold core and after supplying the compressed gas in the still liquid or doughy core of the soil one to the bottom and the face of the mandrel parallel layer is lifted off with its already solidified outer surface against the end face the mold core is pressed, the parting lines between the side walls of the web part and the lifted layer through the residual melt the ver between floor and lifted layer permanent thermoplastic compound is sealed, the by means of the compressed gas on the walls of the ge formed cavity is pressed. 14. The method according to claim 12 or 13, characterized records that the compressed gas through a hole in the tool shape or that in the tool sword (form core) is led to the cavity. 15. The method according to any one of claims 12 to 14, characterized  characterized in that the compressed gas under higher pressure as the thermoplastic molding compound is supplied. 16. The method according to claim 15, characterized in that the compressed gas at about 200 bar and the thermo plastic molding compound with slightly lower Pressure is supplied. 17. The method according to any one of claims 12 to 16, characterized characterized that the bottom of the pot-like cavity before pulling back the mandrel with about double the target wall thickness is injected, using compressed gas feed lifted off about half the wall thickness and this Space element against the face of the withdrawn Mold core is pressed. 18. The method according to any one of claims 12 to 17, characterized characterized in that the duration of the night printing phase including the printing task of printing gases for the demolding of the thermoplastic Product does not exceed the permitted time.   19. The method according to any one of claims 12 to 18, characterized characterized in that the compressed gas via one of separate duct fed to the thermoplastic feed becomes.