The invention relates to pallets and to methods for manufacture and use thereof.
Pallets are used when transporting packages such as boxes, crates and the like. Such pallets can be taken up and transported together with the packages stacked thereon and are usually manufactured from wood. It has already been proposed to manufacture such pallets through injection molding. However, this is relatively expensive since, due to the size, heavy and expensive apparatuses are required and, moreover, relatively much plastic is to be used, with complicated designs, in order to provide the pallet with sufficient load bearing capacity and stability. A further drawback of the known plastic pallets is that they are subject to deformations, in particular creep in the plastic, thereby causing the pallets to become instable and unusable relatively quickly.
The invention contemplates providing an alternative plastic pallet as well as methods for the manufacture and use thereof A pallet according to the invention is characterized by the features of claim 1.
By building up a pallet according to the invention from a top deck and a bearing construction, which can be manufactured independently of each other and subsequently be assembled, the advantage is achieved that the different parts can be manufactured on relatively simple apparatuses and that, moreover, a relatively large freedom of design is obtained for forming the parts and hence, the pallet as a whole. By using bearing constructions which can be included in or between these parts, the load bearing capacity, the rigidity and/or the creep can, for instance, be advantageously influenced, while the pallet as a whole can be of relatively light design. In particular, such a pallet can be manufactured from relatively little material. A further advantage of such a pallet is that the different parts can be manufactured from different materials, if this is desired. Naturally, also the same material can be used for top deck and bearing construction.
With a pallet according to the invention the top deck and bearing construction can be fixedly interconnected such that they cannot be separated from each other without damage. However, it is also possible to couple the top deck to the bearing construction with the aid of detachable connections, such as snap fingers or the like, so that a top deck and/or a bearing construction can be replaced or, for instance, support means can be exchanged, replaced or removed or moved, when, for instance, a pallet is to be made suitable for a different use.
Preferably, the support means are designed to prevent, at least reduce creep and/or shrinkage of the bearing construction and/of the top deck, so that deformations of the pallet are prevented. Moreover, thus, the top deck and bearing construction are even better prevented from detaching from each other as a result of, for instance, relaxation.
It is preferred that the material of the support means has a higher elasticity modulus than that of the top deck and/or the bearing construction. As a result, with relatively slim support means of simple design, rigidity improvements can be obtained, while the support means can be of relatively light design.
With a pallet according to the invention, the support means can have an at least top deck supporting, rigidity-enhancing function and can be manufactured from metal or from plastic, in particular fiber- or glass-reinforced or otherwise reinforced plastic.
In a further advantageous embodiment, a pallet according to the invention is characterized in that the bearing construction comprises at least two stringers extending substantially parallel to each other, provided with bearing elements on which the top deck rests. The stringers have a longitudinal direction, while at least a part of the support means extend in a direction that includes an angle with this longitudinal direction, i.e. an angle deviating from 0 or 180°. Preferably, this angle is between 5° and 175° relative to the longitudinal direction and is, preferably, approximately 90°.
Thus, a pallet is obtained having a relatively great rigidity both in the longitudinal direction of the stringers and in the direction transverse thereto, while the construction can be of relatively light design.
With a pallet according to the invention, further, a part of the support means can extend in a direction approximately parallel to the longitudinal direction of the stringers of the bearing construction, preferably wholly or partly in the bearing construction, so that the rigidity of the stringers and the load bearing capacity thereof can be increased in a simple manner.
Preferably, the support means are substantially confined in plastic of the top deck, the bearing construction or both. As a result, the support means are screened off from the surroundings in a suitable manner, so that they are well protected against, for instance, corrosion, pollution and the like. This is particularly advantageous when pallets are used in chemically aggressive surroundings or when used in combination with, for instance, foodstuffs, medical uses and the like. Preferably, the outside surfaces of the pallets are well cleanable, for instance of relatively smooth and closed design.
The invention further relates to a pallet, characterized by the features of claim 13. Preferably, such a pallet is designed as described hereinabove.
With such a pallet according to the invention, drive-on elements are provided, connected to channel elements such that via the inclined drive-on elements, a rolling container can be rolled by its wheels into these channel elements. In each channel element, at least one recess is provided in which, each time, a wheel of the rolling container can be received for fixing the rolling container onto the pallet. Thus, in a simple manner, it becomes possible to position rolling containers on pallets and to take them up, transport and or otherwise manipulate them together with the pallet.
In an advantageous further embodiment, a pallet according to the invention is characterized in that in a bottom of the or each recess, an opening is provided through which, from an underside of the pallet, an ejector element can be inserted. With this ejector element, during use, a wheel of the rolling container can be pushed from a recess so that the rolling container can be rolled from the pallet in a relatively simple manner. This can, for that matter, also be done by slightly tilting the rolling container such that the wheel is pulled from the respective recess.
The invention further relates to an assembly of a pallet and at least one rolling container, characterized by the features of claim 16.
Such an assembly is particularly advantageous because the rolling container and the pallet are geared to each other. Preferably, at least two rolling containers can be received side by side on the pallet, with the wheels in the recesses, on the drive-on elements or on a surface contiguous thereto, respectively.
In a further advantageous embodiment, further, a push-out device with ejector elements is provided on which the pallet can be laid such that the wheels of a rolling container are slightly pushed upwards on the pallet, so that rolling the rolling container from the pallet is further simplified.
The invention further relates to a method for manufacturing a pallet, characterized by the features of claim 19.
With such a method, in a particularly simple manner, a pallet can be manufactured from relatively little material with good properties of use.
The invention further relates to a method for transporting a rolling container, characterized by the features of claim 21.
By using pallets according to the invention, at least assemblies according to the invention, the advantage is achieved that rolling containers can be manipulated in a particularly simple manner by fixedly arranging them on a pallet, for instance in pairs, while, detached from the pallet, the rolling containers can be used individually and can be, for instance, moved by rolling. The pallets with rolling containers can be easily manipulated with, for instance, pallet carts, forklifts and the like and can be stacked at wish.
Preferably, pallets and rolling containers according to the invention have standard sizes, for instance fitting within Euro-pallet systems.
In the further subclaims, further advantageous embodiments of pallets and methods according to the invention are described.
In clarification of the invention, pallets, assemblies and methods according to the invention will be further elucidated with reference to the drawing. In the drawing:
FIGS. 11A-C show, in cross sectional side view, schematically, the principle for a mold for manufacturing a top deck or a bearing construction for a pallet according to the invention.
In this description, identical or corresponding parts have identical or corresponding reference numerals. Combinations of separate parts of devices according to the invention or associated methods are expressly understood to fall within the framework of the invention as outlined by the claims and are expressly incorporated in this application.
In
As is visible in
In
Further, in
In the embodiment shown in
In
It will be clear that the supporting elements 21 can include any desired angle with the longitudinal direction L of the stringers 6, in particular deviating from 0°, for instance between 5° and 175°.
If the top deck 2 is attached to the bearing construction 3 with the aid of only the clamping projections 24 or comparable means, it can, with some skill, be taken from the bearing construction 3 without damage, for instance with a tool suitable to that end which can be inserted through openings 26 in the top deck 2 for pushing the clamping projections 24 back. Thus, the possibility can be offered, for instance, to replace a top deck, or exchange a bearing construction, while, moreover, the supporting elements 21 can be replaced, taken away or, conversely, placed, depending on the use of the pallet, or for repairs. For instance, if a less rigid pallet can suffice, the number of supporting elements 21 can be reduced, so as to reduce the weight, or they can be replaced by supporting elements 21 of different material, for instance if a pallet according to the invention is to be used in a food setting, a clean room or the like in which metal is less suitable.
In
In this embodiment, the pallet 1 has top deck 2 with an upper side 29, three stringers 6 which extend parallel to each other and define openings 10 for, for instance, tines of a pallet cart or forklift. The pallet 1 can be manufactured in a way as described hereinabove with reference to
In this embodiment, on two longitudinal sides 30, the pallet has channels 31 extending in the longitudinal direction L of the stringers 6. The mutual distance D of the channels substantially corresponds to the mutual distance between the wheels 27 of each pair of one rolling container which is to be borne on the pallet 1. Therefore, the rolling container 25 can be rolled by the pairs of wheels into the channels 31, being guided, then, by the sidewalls 32 of the channels 31. In
Each channel 31 comprises a running surface 33 extending substantially horizontally, parallel to the upper side 29, which running surface, on the side facing the small side 34 of the pallet 1, connects to an inclined drive-on element 35 which merges into a positioning surface 36 on which a wheel 27 of the rolling container 25 can stand. At the opposite side, via a curved surface 37, the running surface 33 connects to a recess 38 in the channel 31, in which a wheel 27 of the same rolling-container 25 can be received. The bottom 39 of the recess 38 can be provided with a hole 40, for reasons to be mentioned hereinafter. Insertion openings 9 for tines of a forklift or pallet cart are provided below the running surface 33.
An assembly of a pallet 1 and a rolling container 25 can be used as follows.
A pallet 1 is laid with the underside on a floor. With one pair of wheels 27, the rolling container 25 is placed next to the positioning surfaces 36 of two channels 31 and then, by these wheels, rolled over the positioning surfaces 36 and the drive-on elements 35 onto the running surfaces 33 and, from there, into the recesses 38. The wheels of the other pair 27B are thereby pulled onto the positioning surfaces since the sizes of the rolling container 25 and the pallet 1 are thus geared to each other. The depth and profile of the channels 31 are selected such that the rolling container 25 can be rolled onto the pallet 1 in a simple manner, that the tines can be inserted into the insertion openings 9 or 10 and that, preferably, with the rolling container rolled onto the pallet, the floor element 26 of the rolling container rests on the top deck 2 of the pallet 1. As a result, the rolling containers 25 are well confined in a positionally fixed manner.
Naturally, in order to obtain an even better confinement, further measures can be taken, such as a fitting profile of the curved surfaces such that the wheels in the recesses are urged below these curved surfaces 37 to some extent and can only be rolled therefrom by, first, pushing the rolling container slightly further into the channel 31. Such a profile has been sketchily drawn at the bottom of
As appears from the Figures, in the embodiment shown, two rolling containers can be placed side by side on the pallet 1, so that a standard package is obtained. Also, three channels 31 could, for instance, be provided next to each other, while two are located directly side by side in or above the middle stringer, so that two times two rolling containers can be arranged on the pallet 1 side by side, for instance when smaller rolling containers such as dollies are used.
Pallets 1 with rolling containers 25 positioned thereon can simply be taken up in their entirety as an assembly and be transported to a destination or be stored. Upon arrival at a destination, the rolling containers are then rolled from the pallet 1 and used further. The assemblies of pallets and rolling containers can even be stacked on top of each other, for economical use of space.
In
In
The mold 50 according to
The mold according to
The mold is closed from the opened position, while the slide 55 is retracted to the lowest position, i.e. at a relatively large distance G from the opposite wall 59 of the mold cavity. The distance G is considerably greater than the wall thickness of the pallet (part) which is to be formed therebetween. As a result, particularly much space is available for injection of plastic, while the plastic in the mold cavity 53 will experience little resistance and therefore can be introduced into the mold cavity with low injection pressure. Moreover, the distance the plastic travels in the mold cavity after injection is relatively short. The projected surface of the total amount of plastic that is introduced into the mold cavity, with the mold in the position as shown in
After the desired amount of plastic has been introduced into the mold cavity 53, the slide 55 is moved to the position shown in
As a result of this combination of features, during injection, the mold 50 can be kept closed with relatively low closing pressure (approximately readable from standard tables for injection pressure with the respective plastic, projected surface and wall thickness with the mold in the position as shown in
Use of such a mold 50, at least the method described for pallets according to the invention, is particularly advantageous because the projected surfaces of the parts to be injection molded are particularly large, which, with conventional techniques, would require particularly large devices.
With a method according to the invention, for that matter, also pallets in one piece can be formed without supporting elements.
It will be clear that a mold according to the invention, at least for use in a method according to the invention, can be designed in many comparable manners. It is of importance in particular that the slide can be moved after closure of the mold. Parts of the pallet according to the invention, for that matter, could also be manufactured with conventional techniques, for instance also with compression molding techniques.
The slide 55 can be moved relatively slowly to the position shown in
The invention is not limited in any way to the exemplary embodiments represented in the description and the drawing.
For instance, several parts can be assembled to form a pallet according to the invention, for instance several loose stringers and a top deck. Also, differently shaped top decks can be used, for instance of wholly or partly openwork design or provided with specific elements such as means for attaching straps or the like. A pallet according to the invention can have any desired size. Walls of rolling containers within an assembly according to the invention can be foldable or detachable for reducing return volume and increasing the possibilities of use. Other numbers of stringers and bearing elements, supporting elements, openings and the like can be used, according to need. These and many comparable variations, among which all possible combinations of elements as shown and described, are understood to fall within the framework of the invention as outlined by the claims.
Number | Date | Country | Kind |
---|---|---|---|
1021546 | Sep 2002 | NL | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/NL03/00658 | 9/26/2003 | WO | 5/23/2005 |