WO2004071876A2

WO2004071876A2 - Explosion-proof device for storing goods

Info

Publication number: WO2004071876A2
Application number: PCT/NL2004/000090
Authority: WO
Inventors: Erik Jan Kroon; Jan Willem Gunnink
Original assignee: Stichting Fmlc
Priority date: 2003-02-17
Filing date: 2004-02-10
Publication date: 2004-08-26
Also published as: TW200508106A; NL1022709C2; WO2004071876A3

Abstract

The invention relates to an explosion-proof device (1) for storage of goods, comprising: a receiving space for goods enclosed by a plurality of mutually connected wall parts (2, 3, 4), which wall parts are manufactured at least substantially from a metal fibre laminate. The device according to the invention is particularly suitable for use during transport of goods in an aircraft.

Description

Explosion-proof device for storing goods

The invention relates to an explosion-proof device for storing goods, ^pmprising: a receiving space for goods enclosed by a plurality of mutually connected wall parts, which wall parts are manufactured at least substantially from a metal fibre laminate.

As a result of recent terrorist attacks in and around aircraft, protection of the aircraft, and therefore the people seated in the aircraft, has increasingly become an issue. In order to improve safe (air) transport of high-risk and/or suspect goods, the device stated in the preamble was developed some years ago, this device being known on the market as ECOS³™ (Explosion Containment System). Since metal fibre laminates have the favourable property, among others, of having a relatively high resistance during a considerable impact or blast, such as for instance an explosion, the wall parts of the known device are manufactured from this material, and in particular from Glare ®. The wall parts are mutually connected by means of (angle) profiles in which mechanical fixing means are arranged. As well as the above mentioned advantages of the known device, the known device also has drawbacks. In addition to the considerable high resistance to impacts of the device, the known device has the significant drawback that the required profiles and mechanical fixing means for mutual fixing of a plurality of wall parts form a relatively weak location in the construction, whereby the overall explosion-absorbing capacity is in general reduced considerably.

The invention has for its object to provide an improved device, wherein the device has an increased energy-absorbing capacity per unit of mass.

The invention provides for this purpose a device of the type stated in the preamble, characterized in that at least two adjacent wall parts are formed from a single plate, wherein a transition between the adjacent wall parts is formed by at least one bend present in the plate. Application of the bend, also referred to as fold, on an edge of the device instead of the above stated profile with mechanical fixing elements results in a reduction of the number of profiles and mechanical fixing elements required, and therefore in a reduction of the number of weak locations, which enhances the strength and thus the energy-absorbing capacity of the device. The plate is preferably provided with a plurality of bends, whereby more than two adjacent wall parts can be formed from a single plate, which results in an increased reduction in additional conventional fixing means. Application of a plurality of bends in a plate to replace the conventional fixing means will result in a (further) increased resistance to an impact or explosion. In addition to the advantage that the device according to the invention is relatively strong and relatively explosion-resistant, a reduced number of components is required for manufacture of the device compared to manufacture of the already known device. The use of a reduced number of components to manufacture the device will generally have a favourable effect on the total mass and the cost price of the device. The decreased total mass of the device according to the invention is usually very relevant, since the total costs of air transport of the device, in particular the fuel costs, are closely related to this total mass. It is generally assumed that one pound (about 0.5 kg) dead weight costs US$ 100 in fuel costs annually. The reduction of the total weight of the device, and therefore saving of transport costs, is therefore generally of great relevance for airlines. Application of the device according to the invention thus results generally in a saving in (transport) costs as well as an improved protection against explosion.

In a preferred embodiment the device is provided with at least one closable access to the receiving space of the device. It is thus possible in simple manner to place goods in or remove goods from the receiving space. The access is here preferably also manufactured from a metal fibre laminate. The dimensioning of the access can vary; the access can be formed by a wall part, but can also be arranged in a wall part of the device, wherein the wall part and the access lie at least substantially in the same plane.

The metal fibre laminate is preferably formed at least partially by a glass fibre metal laminate, in particular Glare®, which includes aluminium in particular as metal. The above stated glass fibre metal laminates have the particular property of possessing a very high explosion-absorbing capacity. Furthermore, the above stated glass fibre metal laminates also have a relatively low material density, whereby these materials are generally very suitable for use during (air) transport. In addition, Glare® has a relatively high resistance to burn-through, which makes Glare® even more suitable for use in an aircraft. Glare® is constructed from a laminate structure of relatively thin aluminium material layers and adhesive glass fibre-reinforced material layers. In a preferred embodiment the metal fibre laminate is formed by at least one fibre layer enclosed on two sides by a metal layer. In the case Glare® is applied, such a configuration of material layers is also referred to as a Glare® 2/1 configuration. Such a configuration then has the advantage that a metal fibre laminate is applied with a relatively small thickness, which can result in a significant saving in the transport costs for the device according to the invention.

In a particular preferred embodiment, the metal fibre laminate is provided with a plurality of fibre layers, which fibre layers are positioned at least partly in a +45°/-45° orientation relative to each other. In a +45 -45° orientation of the fibre layers the fibres and the bend enclose an angle of about 45°, whereby an explosion in the device will generally result in a relatively good and at least substantially homogeneous distribution of stress in the (critical) fibre layers, whereby the metal laminate will usually collapse less quickly. In addition to an improved distribution of stress in the plate, such a +457- 45° orientation also results in a lower surface density of the fibre layers compared to a 0790° orientation of the fibre layers, which may result in a final reduction in the weight of the device. The +457-45° orientation is preferably applied in a Glare® 2/1 configuration. In the case a local impact is inflicted on a fixed wall part of the device according to the invention, the greatest deformations will then occur in a centre of the wall part, and the smallest stresses close to each edge of the wall part. In a 0790° orientation of the fibres, the length of each fibre is substantially identical. When the local impact is inflicted upon such a wall part, the fibres in the centre will reach their maximum deformation relatively quickly, while fibres located in the edge will still not yet be deformed to the maximum. When the above stated +457-45° orientation is applied, fibres of a relatively short length will be located in the edges of the wall part, while fibres of a greater length are positioned in the centre. Since the (long) fibres located in the centre will deform (lengthen) a relatively large amount during a local impact and the (short) fibres positioned in the edges relatively little, a better efficiency will be achieved for the specific energy absorption. This improved efficiency will generally result in a large overall deformation and therefore a (further) increased energy-absorbing capacity.

Since only plates of limited dimensions, i.e. with a width of about 1.5 metre, are as yet being produced, at least one metal layer of the metal fibre laminate is preferably formed by two metal layer parts mutually overlapping at the position of the bend, also referred to as 'splice'. In this manner a lengthened plate can be applied in which a plurality of bends can be arranged, resulting in a relatively great freedom of design in respect of the geometry of the device. Devices according to the invention can moreover be manufactured with larger dimensions by applying the lengthened plate. Although the elasticity is reduced by the overlapping metal layer parts, such a preferred embodiment can still be applied, since the (glass) fibres present in the metal fibre laminate determine the actual explosion resistance of the device. It is noted that the thickness of the plate at the position of the bend has increased slightly because of the overlapping metal layer parts although, compared to the radius of the bend, this thickening is negligible, whereby the thickening will not therefore generally result in problems during bending of the plate.

In a preferred embodiment the metal fibre laminate comprises an aluminium alloy, in particular a 7000-series or a 2024-T81 aluminium alloy. In the known ECOS³™ container Glare® is applied which includes a 2024-T3 aluminium alloy as metal layer. This aluminium alloy can be deformed up to about 20%, although the deformation, is determined by the fibre layers, which fibre layers can be lengthened by about 4.5%. For this reason another aluminium alloy can be applied with a lower elongation at break, but with a higher yield point and better properties in respect of surface pressure. Aluminium alloys from the 7000-series, such as for instance 7075-T6, and the 2024-T81 aluminium alloy comply with the above properties and are therefore very suitable for use in the metal fibre laminate of the wall parts.

The invention will be elucidated with reference to non-limitative exemplary embodiments shown in the following figures. Herein: figure 1 shows a perspective view of an explosion-proof device according to the invention, figure 2 shows a basic exploded view of the device of figure I,- and figure 3 shows a detailed view of a part of the device of figure 1.

Figure 1 shows a perspective view of an explosion-proof device 1 according to the invention. Device 1 comprises a base structure 2 and a top structure 3 connected to base structure 2. The base structure 2 is herein constructed from a lower plate 4 provided with three fold lines 5. Top structure 3 is constructed from an upper plate 6 provided with two fold lines 7. Base structure 2 and top structure 3 are connected to each other by means of profiles 8 and mechanical fixing means, in particular bolts 9, received therein. Both base structure 2 and top structure 3 are at least substantially manufactured from metal fibre laminate, in particular a glass fibre laminate, such as for instance Glare®, preferably Glare® with a 2/1 configuration. Details of this configuration are also shown in figure 3. As will be apparent, base structure 2 and top structure 3 enclose a receiving space for goods, which goods can then be stored and transported in relatively safe manner. Owing to the presence of fold lines 5, 7 instead of mechanical fixing elements at these positions, there is created a strengthened and therefore relatively explosion- resistant device 1. The device is moreover relatively light in weight and it is therefore generally less costly to manufacture and/or transport the device 1. Top structure 3 is provided with an access 8 in which a closing element 9 is arranged. Access 8 increases the accessibility of the receiving space. Closing element 9 can optionally be connected hingedly to top structure 3. Closing element 9 is provided with a handgrip 10 to simplify opening and closing of access 8. The specific design of device 1 is modified to the application of device 1. The shown device 1 is thus suitable for transport in a freight hold of an aircraft.

Figure 2 shows a basic exploded view of the device 1 of figure 1. Shown clearly are base structure 2 and top structure 3 which are adapted to be connected to each other. As will be apparent, only two components 2, 3 are now required to obtain a receiving space for goods, while in the prior art there are still seven components required, i.e. seven separate wall parts, to achieve a receiving space of the same shape for goods.

Figure 3 shows a detailed view of a part of device 1 of figure 1, in particular the lower plate 4 of base structure 2. As already stated, lower plate 4 is manufactured at least substantially from metal fibre laminate. In the shown embodiment lower plate 4 is manufactured from Glare® 11 with a 2/1 configuration. Base structure 2 is thus built up of a lower metal layer 12 and an upper metal layer 13, between which one or more (glass) fibre layers 14 are arranged. As lower plate 4 of base structure 2 is relatively long compared to the plates manufactured from Glare® known on the market, both the lower metal layer 12 and the upper metal layer 13 are subdivided into a plurality of metal layer segments 15, 16. As shown, metal layer segments 15, 16 lying mutually in line partially overlap each other. At the position of this overlap the lower plate can be bent to form, a fold line 5. The folds or bends 5 to be arranged are indicated here by means of a dotted line. The upper metal layer 13 is partially omitted in figure 3 to allow a view of fibre layers 14. Here is shown, in somewhat exaggerated manner, that the fibres 17, 18 present in fibre layers 14 are positioned at least substantially in two directions. Present in fibre layers 14 are fibres 17 which enclose an angle V with a fold line 5 to be arranged which amounts to about +45°, while fibres 18 are present in another fibre layer 14 which enclose an angle 3 of substantially -45° with the fold line 5 to be arranged. By orienting the fibres in the above stated manner relative to the fold lines 5 (to be arranged) there is created a fibre structure wherein the fibres will be loaded more efficiently in the case of an impact on fibres 17, 18, which generally results in an increased explosion resistance of fibres 17, 18. The further functioning and further advantages of such a +457-45° configuration of fibres 17, 18 has already been described above. It is noted that top structure 3 can be constructed in the same manner.

It will be apparent that many variants of the invention are still possible for the skilled person within the scope of the claims.

Claims

1. Explosion-proof device for storage of goods, comprising: a receiving space for goods enclosed by a plurality of mutually connected wall parts, which wall parts are manufactured at least substantially from a metal fibre laminate, characterized in that at least two adjacent wall parts are formed from a single plate, wherein a transition between the adjacent wall parts is formed by at least one bend present in the plate.

2. Device as claimed in claim 1, characterized in that the device is provided with at least one closable access to the receiving space.

3. Device as claimed in claim 1 or 2, characterized in that a number of the wall parts are mutually connected via mechanical fixing means.

4. Device as claimed in any of the foregoing claims, characterized in that the metal fibre laminate is formed at least partially by a glass fibre laminate, in particular Glare®.

5. Device as claimed in any of the foregoing claims, characterized in that the metal fibre laminate is formed by at least one fibre layer enclosed on two sides by a metal layer.

6. Device as claimed in any of the foregoing claims, characterized in that at least one metal layer of the metal fibre laminate is formed by two metal layer parts mutually overlapping at the position of the bend.

7. Device as claimed in any of the foregoing claims, characterized in that the metal fibre laminate is provided with a plurality of fibre layers, which fibre layers are positioned at least partly in a +457-45° orientation relative to each other.

8. Device as claimed in any of the foregoing claims, characterized in that the metal fibre laminate comprises an aluminium alloy, in particular a 7000-series aluminium alloy.