WO2001030560A1

WO2001030560A1 - Structure comprising core parts and reinforcing means

Info

Publication number: WO2001030560A1
Application number: PCT/GB2000/003971
Authority: WO
Inventors: Iain Norman Bridge
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-10-22
Filing date: 2000-10-16
Publication date: 2001-05-03
Anticipated expiration: 2002-04-22
Also published as: GB2355429A; GB2355429B; GB9924938D0; AU7807400A

Abstract

A core part (10) for use in forming a structure is in the general form of a lattice-like sheet having a length and breadth much greater than its thickness and incorporating male zones at (12), which are prominent, and female zones at (14) which are recessed. The arrangement and form of the male and female zones (12, 14) are such that two core parts can be brought together to fit with their surfaces being contiguous across substantially the whole of their areas, the assembled structure therefore forming a solid panel, without voids. Reinforcing means, such as fibre strands or mats are located between the core parts as they are brought together, so that they are located at the boundary between the core parts in the finished structure.

Description

STRUCTURE COMPRISING CORE PARTS AND REINFORCING MEANS

The present invention relates to structures which can be used in forming manufactured articles.

The present invention provides a structure for use in forming a manufactured article, the structure comprising first and second core parts each having male zones which are prominent and female zones which are recessed, the core parts being brought together to mate the male zones of each core part with the female zones of the other core part, the structure further comprising reinforcing means located substantially between the core parts as they are brought together, to be located at the boundary between the core parts in the finished structure.

Preferably the core parts are bonded together. The female zones are preferably recessed from a first face of the core part to the opposite face of the core part, to form an aperture in the opposite face, the tips of the male zones of the other core part being exposed through the apertures. The mating faces of the core parts are preferably contiguous across substantially their whole area, in the finished structure. The female zones of each core part are preferably contiguous with neighbouring male zones of the same core part. The zones are preferably arranged in lines of male zones and lines of female zones, alternately, across the core part. The positions of the male zones may be staggered relative to the positions of the female zones whereby to create lines of alternating male and female zones running at an angle to the lines of male zones and lines of female zones.

Preferably the male zones are rounded or geometric prominences, and preferably the female zones are complementary to the male zones. The female zones may be rounded or geometric recesses and the male zones may be complementary to the female zones.

The core material is preferably a foam or expanded material such as a polymeric or elastomeric material.

The core parts may be generally planar or non-planar.

The faces of the structure and/or of the core parts may be provided with additional reinforcing material. The additional reinforcing material may be bonded to the core parts and/or to the core reinforcing material. The core reinforcing material and additional reinforcing material may be in the form of strands, fibres, mats, fibrous mats or the like, and the reinforcing fibres may be intermingled where they come together. The core reinforcing material may be embedded in the surface of the core material.

The structure may comprise a plurality of layers, each formed by two core parts as set out above.

The invention also provides a core part for use in forming a structure as defined above, the core part having male zones which are prominent and female zones which are recessed, the male and female zones being so shaped as to allow two core parts to be brought together to mate the male zones of each core part with the female zones of the other core part.

Examples of the present invention will now be described in more detail, by way of example only, and with reference to the accompanying drawings, in which:

Fig. 1 is a perspective view of a core part according to the present invention;

Fig. 2 is a plan view of the core part of Fig. 1;

Fig. 3 a is a section along the line A-A of Fig. 2;

Fig. 3b is a side elevation as would be seen along the lines B-B or C-C of Fig. 2;

Fig. 4 is a partly schematic view of two core parts of Fig. 1, assembled to form a structure for use in forming a manufactured article;

Figs. 5a and 5b are, respectively, a plan view of the structure of Fig 4, and a section along the line V-V of Fig. 5a;

Fig. 6a is a section through two core parts and reinforcing material prior to the parts being brought together;

Fig. 6b is a section through the assembled structure formed from the parts of Fig. 6a;

Fig. 7 is a section through a multi-layer structure according to the present invention;

Figs. 8 and 9 correspond with Figs. 1 and 2, showing an alternative form of structure according to the present invention;

Fig. 10 is a section through a further alternative form of structure according to the present invention;

Fig. 11 illustrates a non-planar embodiment of the invention; and

Figs. 12a, b and c illustrate the response of a structure according to the present invention, under load.

Turning first to Fig. 1, there is shown a core part 10 for use in forming a structure according to the present invention. The core part 10 is in the general form of a lattice-like sheet having a length and breadth much greater than its thickness, and incorporating male zones at 12, which are prominent, and female zones at 14, which are recessed. The arrangement and form of the male zones 12 and female zones 14 can be understood by consideration of Figs. 1 to 3. As can be seen, lines of male zones 12 and lines of female zones 14 are formed alternately across the core part 10. That is to say, nearest neighbour lines of male zones 12 are separated by a line of female zones 14. The male zones 12 are aligned to form a square lattice of prominences. Similarly, female zones 14 are aligned to form a square lattice of recesses. However, the male zones 12 and female zones 14 of neighbouring lines of zones are off-set. This creates lines of alternating male and female zones, these lines running diagonally relative to the square lattices of male zones 12 and female zones 14. Thus, in Fig. 2, there are shown lines 16 of male zones 12, lines 18 of female zones 14, and diagonal lines 20 of alternating male and female zones.

The male zones 12 have tips 22 in the form of flat summits, best seen in Figs. 1 and 3a. The female zones 14 are recessed into the core part 10 through to the face opposite the face formed by the tips 22, forming a lattice of apertures 24 in the opposite face, each aperture 24 being circular and of the same diameter as a tip 22. This allows the tips 22 to be exposed through the apertures 24 when core parts are assembled, as will be described.

The core part 10 has a complex sloping surface 26 formed between the tips 22 and apertures 24, being generally of smooth rounded form, as seen in Figs. 1 and 3b, but angular when viewed along the section line of Fig. 3a.

As has been indicated, the diameter of the apertures 24 is the same as the diameter of the tips 22. In consequence, a core part 10 can be brought together with another core part of the same form but upside down relative to the first core part, so that the male zones of each core part are mated with the female zones of the other core part, to form a panel structure of the type illustrated in Fig. 4.

Fig. 4 illustrates the lattice of tips 22 visible through apertures 24 on the upper surface of the structure 18. For the purposes of understanding of the invention, schematic markings are also used to indicate the location of apertures 24 on the lower face of the structure 28, and also to indicate contours along the surfaces of the core parts 10, between the tips 22 and apertures 24.

The shape of the surfaces 26 is such that the shape of the surface 26 will be complementary across the whole of its area with another surface of the same shape, on another core part 10. Thus, when two core parts 10 are brought together as illustrated in Fig. 4, the surfaces 26 of the two parts 10 are contiguous to each other across the whole of their areas, and the assembled structure 28 is therefore a solid panel, without voids. These features can clearly be seen in Fig. 5b, taken along a line corresponding with the section of Fig. 3a.

It is to be appreciated that while fully complementary core parts 10 are preferred, some applications of the invention may require the surfaces to be complementary only at certain locations, such as at the tips of the male zones and the wells of the female zones, but not necessarily in between. This would result in a panel in which voids are present.

The core parts 10 are preferably bonded to each other when brought together. The core parts 10 may be made of a foam or expanded material such as flexible polyurethane foam, or other polymeric or elastomeric material. Core parts may be bonded together by means of a bonding material appropriate to the core material.

The structure 28 described above has a form of cellular structure. .Along any section line, the structure 28 consists of blocks forming part of the two core parts alternately, these being bonded to each other. The resulting cellular structure is expected to be stronger than either component core part individually, and stronger than a simple homogeneous panel of the same material and of the same external dimensions as the structure 28.

The strength of the cellular structure 28 can be further enhanced by the use of reinforcing material, as illustrated in Figs. 6a and 6b. Fig. 6 illustrates two core parts 10 prior to assembly. A first sheet of reinforcing material 30 is located between the two parts 10. Thus, as the core parts 10 are brought together, the tips 22 of the male zones on each part 10 will push the first sheet 30 into the recesses of the female zones 14 of the other part 10 so that once the core parts 10 are fully assembled (Fig. 6b), the material 30 will form a zigzag shape running partly through the structure 28 (for instance at 32) and partly exposed at the surfaces of the structure 28, through the apertures 24 (such as at 34). In this way, the whole of the area of the surfaces 26 and of the exposed tips 22 is covered with the first material 30. The material 30 may be bonded to the surfaces by appropriate bonding materials, either after or during the process of forming the structure 28. The material 30 is illustrated as a plane sheet, but may be preformed to a shape complementary to the surfaces 26, to avoid excessive crumpling while being sandwiched between the core parts.

Further strengthening can be provided by second sheets of reinforcing material 36 applied across the external surfaces of the structure 28 after the core parts 10 have been brought together. Again, the second material 36 can be bonded to the core parts 10 and preferably also to the first reinforcing material 30.

The reinforcing material 30,36 may be in the form of strands or fibres, such as glass fibres, or may be in the form of mats, particularly mats of fibres. Where the material 30,36 comes together, it is preferable to intermingle the fibres of the two materials 30,36 prior to bonding, in order to improve the structural integrity of the structure 28 at that location.

Fig. 7 shows a section through a multi-layer structure 40, consisting of two structures of the type shown in Figs. 6a and 6b. Each layer includes first reinforcing material 30 zigzagging between the respective core parts 10 and in addition, further reinforcing material is preferably provided across the exposed faces of the structure 40, and at the mid-plane, where the two component structures meet.

It is apparent from Figs. 6b and 7 that the presence of the reinforcing material 30,36 makes the cellular structure further pronounced. The reinforcing material also produces additional strengthening, as will be described.

Figs. 8 and 9 illustrate a further design of core part generally similar to the part illustrated in Figs. 1 and 2. In view of the similarity, numerals for features shown in Figs. 8 and 9 are the same as the numerals used for corresponding features in Figs. 1 and 2, but suffixed "A".

The principal difference between the core parts 10 and 10A is that the core part 10A has a surface 26A which is more angular or geometric, resulting in tips 22A which are square rather than round. Consequently, the apertures 24A are also square. However, the core part 10A is able to mate with another core part of the same form, in the manner described above with reference to Figs. 1 to 7.

Fig. 10 is a section through a structure 42 which is broadly similar to the structures described above, but differs primarily in that the female zones 14 are less deep and the male zones 12 are less pronounced than in the core parts 10. In view of the similarities, like numerals are used in this figure to indicate features with equivalents in earlier drawings, and are suffixed with "B". Thus, in the structure 42, the surfaces 26B meet along a line which is wholly contained within the body of the structure 42, the two core parts 10B having unbroken outer surfaces 44. Reinforcing material (not shown) will be provided between the surfaces 26B.

Fig. 11 is a section through a further structure 46 according to the present invention and of generally similar form to the structures described above (particularly the structure 40), but with the principle difference of being non-planar. The structure 46 may be formed from non-planar core parts, or may be formed from planar core parts and then subsequently deformed to the non-planar form shown, for instance by heat forming, vacuum forming, pressing or the like. The choice of an appropriate technique will depend in part on the nature of the material to be deformed, and in part on the shape to which it is to be deformed. Thus, a structure such as the structure 28 or 40 can be constructed in planar form and then used for forming a manufactured article, such as a car body part, of non-planar shape.

Figs. 12a, b and c illustrate the structure 28 under load F. In Fig. 12a, a force FI within the normal working limits of the structure 28 is applied, and borne by the structure 28, in particular by forces being dissipated through the structure to be absorbed by the cells formed by the material of the core part and the reinforcing material. The structure will flex to some degree and as it does so, tension in the structure (particularly in the fibres of the reinforcing material) will increase, resulting in energy dissipation. The interconnection of the cells by means of the strands of reinforcing material will ensure that many cells take part in the energy dissipation process, further enhancing the effect.

As the load increases (F2 in Fig. 12b), the structure 28 will begin to deform to a visible extent and in due course (under the force F3 in Fig. 12c) fractures 48 will begin to occur within the structure 28, particularly at boundaries between complementary surfaces 26. Thus, the bonding between the surfaces of adjacent cells will break down, causing failure of the structure 28, but absorbing significant energy as a result of the bonding. It is for this reason that the structure 28 is expected to be stronger than a simple panel of core material of the same exterior dimensions.

It will be apparent from the above description that in order to make a rectilinear panel, the edges of the two core parts will finish at different lines through the lattices of male and female zones. Thus, one part may finish along a line of male zones, in which case the other part would finish along a line of female zones at that edge of the structure 28. However, one or other panel could be extended to overhang the edge to allow mating with a similar overhang on another panel. This would provide a convenient and strong form of interconnection between panels, and one which allows the integrity of the cell structure to continue substantially unbroken across the boundary between the panels. In this manner, a relatively large strong structure can be constructed from relatively small panels. Typically, a core part will have an overall thickness in the region of 25mm and an area of between 1.2 x 0.8m and 5.0 x 1.2m. The drawings show an area typically of about 400mm x 400mm.

The reinforcing material may be man made or natural fibres, preferably recyclable and may be juxtaposed against the core material, or embedded in the surface. The bonding materials used are preferably recyclable, as is the material of the core parts. The core part and/or the bonded fibres may be rigid or flexible. The core may be of an expanded material, such as one having self- skinning properties.

The reinforcing fibres may be single or multi strand fibres or may be in sheet form, such as a woven fabric. When in sheet form, the sheets may be partly or wholly preformed to the shape of the core parts (the surfaces 26) by any appropriate means, such as heat forming, pressing or the like. Bonding may be by means of a liquid, tacky or dry material introduced to the surfaces to be bonded. The reinforcement means may be integrally moulded with one or more faces of the core, or embedded into or with the core. The reinforcement means may be embedded by means of adhesive, heat or self-curing resin, or polymeric molten sheet. The reinforcement means may be provided by a skin of a self- skinning foam.

Many other variations and modifications can be made to the apparatus described above, without departing from the scope of the invention. In particular, many different materials, combinations of materials, shapes, forms and dimensions can be used. The final choices made for these parameters will depend on the application to which the resultant structure is to be put.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1. A structure for use in forming a manufactured article, the structure comprising first and second core parts each having male zones which are prominent and female zones which are recessed, the core parts being brought together to mate the male zones of each core part with the female zones of the other core part, the structure further comprising reinforcing means located substantially between the core parts as they are brought together, to be located at the boundary between the core parts m the finished structure.

2. A structure according to claim 1, wherein the core parts are bonded together.

3. A structure according to claim 1 or 2, wherein the female zones are recessed from a first face of the core part to the opposite face of the core part, to form an aperture m the opposite face, the tips of the male zones of the other core part being exposed through the apertures.

4 A structure according to any preceding claim, wherein the mating faces of the core parts are contiguous across substantially their whole area, m the finished structure.

5 A structure according to any preceding claim, wherein the female zones of each core part are contiguous with neighbouring male zones of the same core part.

6. A structure according to any preceding claim, wherein the zones are arranged in lines of male zones and lines of female zones, alternately, across the core part.

7. A structure according to any preceding claim, wherein the positions of the male zones are staggered relative to the positions of the female zones whereby to create lines of alternating male and female zones running at an angle to the lines of male zones and lines of female zones.

8. A structure according to any preceding claim, wherein the male zones are rounded or geometric prominences.

9. A structure according to claim 8, wherein the female zones are complementary to the male zones.

10. A structure according to any of claims 1 to 7, wherein the female zones are rounded or geometric recesses.

11. A structure according to claim 10, wherein the male zones are complementary to the female zones.

12. A structure according to any preceding claim, wherein the core material is a foam or expanded material.

13. A structure according to claim 12, wherein the core material is a polymeric or elastomeπc material.

14. A structure according to any preceding claim, wherein the core parts are generally planar.

15. A structure according to any of claims 1 to 13, wherein the core parts are non-planar.

16. A structure according to any preceding claim, wherein the faces of the structure and/or of the core parts are provided with additional reinforcing material.

17. A structure according to claim 16, wherein the additional reinforcing material is bonded to the core parts and/or to the core reinforcing material.

18 A structure according to claim 16 or 17, wherein the core reinforcing material and additional reinforcing material are m the form of strands, fibres, mats, fibrous mats or the like.

19. A structure according to any preceding claim, wherein the reinforcing means and/or additional reinforcing material is fibrous and the reinforcing fibres are intermingled where they come together.

20. A structure according to any preceding claim, wherein the core reinforcing material is embedded in the surface of the core material.

21. A structure according to any preceding claim and comprising a plurality of layers, each formed by two core parts as aforesaid

22. A core part for use in forming a structure according to any preceding claim, the core part having male zones which are prominent and female zones which are recessed, the male and female zones being so shaped as to allow two core parts to be brought together to mate the male zones of each core part with the female zones of the other core part.

23 A structure substantially as described abo\ e with reference to the accompanying drawings.

24. A core part substantially as described above with reference to the accompanying drawings.

25. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.