NL2010999C2

NL2010999C2 - Airfreight pallet, method for manufacturing an airfreight pallet.

Info

Publication number: NL2010999C2
Application number: NL2010999A
Authority: NL
Inventors: Reinier Justin Kleis; Robert Willem Verkuijlen; Cornelis Petrus Maria Portegies
Original assignee: Driessen Air Cargo Equipment B V
Priority date: 2013-06-18
Filing date: 2013-06-18
Publication date: 2014-12-22

Description

Title: Airfreight pallet, method for manufacturing an airfreight pallet

The invention relates to an airfreight pallet.

Airfreight pallets are commonly known and widely used for transporting freight in airplanes. Airfreight pallets are usually manufactured from aluminium having a solid aluminium panel and aluminium edge profiles.

The conventional aluminium airfreight panels typically have a solid aluminium panel of about 4 mm thickness and hollow edge rail extrusions as edge profiles. The edge profiles typically are riveted to the panel to form an airfreight pallet.

Prompted by weight reduction, numerous alternatives for the aluminium airfreight panel have been developed. However, some of these alternatives do not reach sufficient weight reduction, or are too expensive to manufacture, or do not fulfil all requirements set by regulatory authorities, such as the IATA and SAE, or are otherwise disappointing in performance. Therefore, there remains a need for a lighter airfreight pallet that does meet these requirements.

An object of the invention is to provide an airfreight pallet that obviates at least one of the above mentioned drawbacks, in particular, to provide a pallet having a reduced weight as compared to a conventional aluminium airfreight pallet.

Thereto, the invention provides for an airfreight pallet comprising an aluminium panel having an upper side, a lower side and four panel edges; edge profiles connectable to each of the four panel edges; wherein the panel is a composite panel comprising at least an aluminium solid top sheet; an aluminium perforated core sheet and an aluminium sohd bottom sheet.

By providing a sandwich panel comprising at least three aluminium sheets, of which the core sheet is perforated, a significant weight reduction can be obtained as compared to conventional aluminium pallets having a sohd aluminium panel.

The core sheet is a perforated sheet, which is different from a honeycomb layer. To manufacture a perforated sheet, a solid aluminium sheet is provided and out of this aluminium sheet the perforations are punched. To the contrary, for a honeycomb layer typically thin aluminium foil is provided and from this aluminium foil the honeycomb structure is constructed. The perforated core sheet is approximately 1,5 mm to approximately 5 mm thick, whereas the honeycomb layer typically has a thickness of 10 mm or more

Preferably, a perforated area of at least 80% is provided to achieve sufficient weight reduction. It has been experimentally determined that a perforated area of approximately 84%, preferably approximately 84,6% provides for an optimal weight reduction as well as sufficient strength and stiffness of the panel.

The perforations can have any geometrical form, such as circular, octagonal, rectangular, etc. but are preferably hexagonal. By providing hexagonal perforations, the perforations can be configured optimally, while providing for sufficient perforated area and allowing sufficient material in between the perforations for strength and stiffness purposes.

A perforation preferably has an internal diameter between approximately 5 mm and approximately 9 mm, preferably approximately 8 mm. Airfreight pallets may be subject to relatively high point forces. This is in particular the case when the pallets are transported on so-called roller ball transport systems. On such systems, approximately the entire force of the freight load on the pallet is translated to the balls via point forces. In view of these roller ball systems, the perforations are preferably not larger than approximately 9 mm. Advantageously, the internal diameter of the perforations is approximately 8 mm. With an internal diameter of approximately 8 mm of a perforation, it can be obviated that the roller ball can indent the bottom sheet too much, e.g. more than the 0,5 mm maximum indentation requirement set by e.g. SAE AS1491A.

Advantageously, the centre to centre spacing between adjacent perforations is between approximately 5,5 mm and approximately 10 mm. By perforating the core sheet, there remains sufficient material between the perforations to provide for sufficient strength and stiffness.

Advantageously, the top sheet and/or the bottom sheet has a thickness of between approximately 0,3 mm and approximately 3 mm, or between approximately 2 mm. The core sheet may have a thickness of between approximately 1,5 mm and approximately 5 mm, preferably between approximately 2 mm and approximately 4 mm. For example, the top sheet can have approximately 0,8 mm thickness, the core sheet approximately 2,5 mm thickness and the bottom sheet approximately 1,2 mm thickness. The top sheet and the bottom sheet do not necessarily have the same thickness.

The invention further relates to a method for manufacturing an aluminium airfreight pallet.

The invention further relates to an airfreight container comprising such a sandwich panel.

The invention will further be elucidated on the basis of exemplary embodiments which are represented in the drawings. The exemplary embodiments are given by way of non-hmitative illustration of the invention.

In the drawings:

Fig. 1 shows a schematic top view of a part of a pallet with a transparent panel top sheet;

Fig. 2 shows a schematic perspective view of the top sheet, core sheet and bottom sheet of the panel;

Fig. 3 shows a schematic cross-section of the panel according to the invention;

Fig. 4 shows a schematic top view of a perforations configuration according to the invention; and

Fig. 5 shows a schematic perspective cross-sectional view of the panel with an edge profile.

It is noted that the figures are only schematic representations of embodiments of the invention that are given by way of non-limiting example. In the figures, the same or corresponding parts are designated with the same reference numerals.

Fig. 1 shows a schematic top view of a part of an airfreight pallet 1 according to the invention. The airfreight pallet 1 comprises a panel 2. The panel 2 has an upper side and a lower side. The upper side is arranged for carrying the freight. The lower side is arranged for transferring the load to a floor structure, the floor structure can be a cargo deck floor, or a conveying structure for moving the pallet 1 from one location to another, or a floor in a logistic centre, etc.

The panel 2 typically has four panel edges 3. On each panel edge 3, an edge profile 4 is connected. At each corner of the pallet 1, the edge profiles 4 are connected to each other via a corner piece 5.

The edge profile 4 can be a conventional aluminium extrusion profile 4 that can be connected to the panel 2 via rivets 6. The edge profile 4 is provided with a guide rail 7 for freight fastening elements. In Fig. 5 it can be seen that the edge profile 4 is a substantially hollow extrusion profile 4 provided with chambers 8. Instead of an aluminium extrusion profile, a profile from other materials or manufactured via other methods may be provided.

The panel 2 is a sandwich panel 2 according to the invention. The sandwich panel 2 is an aluminium sandwich panel and comprises at least three aluminium sheets, as shown in Fig. 2 and Fig. 3: an aluminium solid top sheet 9, an aluminium perforated core sheet 10 and an aluminium sohd bottom sheet 11. In Fig. 1 the top sheet is made transparent such that a direct view is given on the perforated core sheet 10.

The top sheet 9, the core sheet 10 and the bottom sheet 11 can be joined together to form the panel 2 by means of adhesives. This is shown in Fig. 3, between the top sheet 9 and the core sheet 10 a first adhesive layer 12 is provided and between the core sheet 10 and the bottom sheet 11a second adhesive layer 13 is provided. Instead of an adhesive layer, other joining means may be provided, e.g. welding.

The core sheet 10 is perforated, meaning that starting from a solid blank sheet, holes or perforations 14 are punched out of the sheet to provide for a perforated sheet. Between adjacent perforations 14, material remains that forms a bridge 15. By providing a perforated core sheet 10, a significant weight reduction of more than 35% can be achieved as compared to a conventional sohd panel aluminium airfreight pallet, while obtaining sufficient strength and stiffness. A perforated aluminium sheet is contrary to an aluminium honey comb layer for which aluminium foil is folded to construct the honeycomb structure.

The perforations 14 can have any shape, but are, in the embodiments shown, hexagonal. By providing a hexagonal shape, a relatively large open area can be provided while maintaining sufficient bridge material 15 between the perforations 14. Preferably at least 80% of the area of the core sheet 10 is perforated to achieve sufficient weight reduction.

The sheet thickness of the core sheet 10 is preferably between approximately 1,5 mm and approximately 5 mm, more preferably between approximately 2 mm and approximately 4 mm.

The sheet thickness of the top and/or bottom sheet 9, 11 is between approximately 0,3 mm and approximately 3 mm, preferably between approximately 2 mm. By way of example, some example values are given. In the example, the aluminium alloy is provided, but this is just an example so other aluminium alloys may be used as well.

Example sheet thickness

Top sheet 9 having a thickness of 0,8 mm

Core sheet 10 having a thickness of 2,5 mm

Bottom sheet 11 having a thickness of 1,2 mm

The total thickness of the panel 2 may be between approximately 3 mm and approximately 8 mm, and will depend on the actual sandwich configuration.

Fig. 4 shows an embodiment of a configuration of perforations 14 with a bridge 15 of material in between the perforations 14. The hexagonal perforations 14 allow close packing of the perforations 14 in the core sheet 10, while providing for sufficient bridge material 15 to obtain the required strength and stiffness.

The perforations 14 advantageously have an internal diameter D between approximately 5 mm and approximately 9 mm. For example, the internal diameter D can be approximately 8 mm.

The centre to centre spacing S between adjacent perforations is advantageously between approximately 5,5 mm and approximately 10 mm. For example, the spacing S can be approximately 9 mm, more specifically 8,7 mm

As an example, with an internal diameter D of about 8 mm and a spacing S of about 9 mm, an open area of 80% or more can be obtained, which is sufficient to achieve sufficient weight reduction. The bridge 15 is in this example approximately 1 mm wide, which is sufficient to fulfill rules and/or regulations requirements. An internal diameter D of about 8 mm also allows to restrict the indentations that may be the result of transporting the pallet 1 over a roller ball system.

As can be seen in Fig. 2 or in Fig. 5 a zone 3a of the edge 3 of the panel 2 is not perforated. The zone 3a is to remain solid and non-perforated to connect the edge profile 4 to the panel 2. The non-perforated zone 3a may be one part with the perforated sheet by not perforating this zone.

Alternatively, the non-perforated zone may be a separate strip of material, positioned adjacent to a perforated part of the core sheet and between the top and bottom sheet. A width W of the edge zone 3a clear of perforations is between approximately 2,5 cm to 5 cm, preferably approximately 3 cm to approximately 4 cm, such that there is sufficient width to fixate the edge profile 4 to the panel 2, which can be done by using rivets 6.

Many variants will be apparent to the person skilled in the art. All variants are understood to be comprised within the scope of the invention as defined in the following claims.

Claims

An air freight pallet comprising - an aluminum panel with a top side, a bottom side and four panel edges; - edge profiles connectable to each of the four panel edges; wherein the panel is a sandwich panel that has at least one aluminum solid top plate; comprises an aluminum perforated core plate and an aluminum solid bottom plate.

Air cargo pallet according to claim 1, wherein the thickness of the core plate is between approximately 1.5 mm and approximately 5 mm, preferably between approximately 2 mm and approximately 4 mm.

Air cargo pallet according to claim 1 or 2, wherein the thickness of the top plate and / or the bottom plate is between approximately 0.3 mm - approximately 3 mm.

Air cargo pallet according to any of the preceding claims, wherein at least 80% of the surface of the core plate is perforated.

Air freight pallet according to one of the preceding claims, wherein the perforations are hexagonal.

Air cargo pallet according to one of the preceding claims, wherein the inner diameter of the perforations is between approximately 5 mm and approximately 9 mm, preferably approximately 8 mm.

Air cargo pallet according to any of the preceding claims, wherein the center-to-center distance between adjacent perforations is approximately between 5.5 mm and approximately 10 mm.

Air cargo pallet according to one of the preceding claims, wherein the top plate and / or the bottom plate are connected to the core layer by means of adhesives.

Air cargo pallet as claimed in any of the foregoing claims, wherein an edge zone of the core plate is free from perforations to enable fixation of the edge profile.

The air cargo pallet of claim 9, wherein a width of the non-perforated edge zone is between about 2.5 cm and about 5 cm.

A method for manufacturing an aluminum air cargo pallet, comprising providing at least an aluminum top plate, an aluminum bottom plate and an aluminum core plate, perforating the core plate, assembling the at least top plate and bottom plate with the perforated core plate between them , connecting edge profiles to each edge of the panel.

An air cargo container comprising a panel according to any of claims 1 to 10, wherein the panel is a sandwich panel comprising at least one aluminum solid top plate, an aluminum perforated core plate and an aluminum solid bottom plate.