Abstract
Marine fender for impact protection comprising a core of closed cell foam, wherein said core comprises at least one chamber substantially entirely surrounded by said closed cell foam and enclosing an elastically deformable closed object. The marine fender can comprise an intermediate layer that at least partly encloses the core and/or a coating that at least partly covers the intermediate layer.
Claims
1. A marine fender for impact protection comprising: a core of closed cell foam, wherein said core comprises at least one chamber substantially entirely surrounded by said closed cell foam; and an elastically deformable closed object enclosed in said at least one chamber, wherein the core of closed cell foam comprises at least first and second blocks of closed cell foam, wherein said first block is located adjacent to said second block, wherein said at least one chamber is formed in and extends between said first and second blocks of closed cell foam, wherein a first chamber part of the at least one chamber is provided in the first block and a second chamber part of said at least one chamber is provided in the second block, and wherein the first and second blocks are joined together so that the first and second chamber parts form the at least one chamber and enclose the elastically deformable closed object.
2. The marine fender according to claim 1, wherein the elastically deformable closed object tightly fits in said at least one chamber.
3. The marine fender according to claim 1, wherein said at least one chamber comprises a plurality of chambers, each chamber comprising an elastically deformable closed object.
4. The marine fender according to claim 1, wherein said first and second blocks of closed cell foam have a mutually different density.
5. The marine fender according to claim 1, wherein said elastically deformable closed object is a substantially spherical object.
6. The marine fender according to claim 1, wherein said elastically deformable closed object comprises rubber.
7. The marine fender according to claim 1, wherein said elastically deformable closed object is a hollow object.
8. The marine fender according to claim 1, wherein said elastically deformable closed object is a ball-like object comprising a substantially spherical closed shell.
9. The marine fender according to claim 8, wherein said elastically deformable closed object is a resilient ball.
10. The marine fender according to claim 1, further comprising an intermediate layer at least partly enclosing the core and a coating at least partly covering the intermediate layer.
11. A method for manufacturing a marine fender comprising: providing at least first and second blocks of closed cell foam, wherein the first block is located adjacent to the second block; providing in the first and second blocks of closed cell foam at least one hollow chamber entirely surrounded by said closed cell foam, wherein the at least one hollow chamber comprises a first chamber part in the first block and a second chamber part in the second block; inserting a first end of an elastically deformable closed object into the first chamber part of the first block, and placing a second end of the elastically deformable closed object into the second chamber part in the second block to enclose the elastically deformable closed object and seal the chamber.
12. The method according to claim 11, wherein the at least one hollow chamber is carved out of the first and second blocks of closed cell foam.
13. The method according to claim 11, further comprising: providing an intermediate layer at least partly enclosing the at least first and second blocks of closed cell foam; and providing a coating at least partly covering the intermediate layer.
Description
(1) The present invention will be further elucidated with reference to a drawing comprising figures. In the drawing shows FIG. 1 a schematic cross-section of a preferred embodiment of a marine fender according to a first aspect of the invention;
(2) FIG. 2a a schematic side view of blocks of closed cell foam usable for manufacturing a fender according to a first aspect of the invention;
(3) FIG. 2b a schematic side view of the opened-up blocks of closed cell foam of FIG. 2a along the line A-A;
(4) FIG. 2c a schematic perspective view on the blocks of closed cell foam of FIG. 2b;
(5) FIGS. 3a and 3b schematic perspective views on two alternative opened-up blocks of closed cell foam;
(6) FIG. 4 a schematic perspective view on a preferred step of a method for manufacturing a marine fender according to a second aspect of the invention;
(7) FIG. 5 a schematic side view on a preferred step of a method for manufacturing a marine fender according to a second aspect of the invention.
(8) It is understood that the figures are given by way of exemplary embodiments only. Corresponding elements are designated with corresponding reference signs.
(9) FIG. 1 shows a schematic cross-section of a preferred embodiment of a marine fender 1 according to a first aspect of the invention. The marine fender can be attached to a marine structure 2, for example a vessel or a mooring platform, to protect that structure against impact, for example due to unwanted collisions between vessels and/or marine structures. Marine fenders are particularly useful for vessels which often moor close to other ships and risk coming into contact with them, such as tender, patrol or pilot vessels. The fender 1 can be attached to the marine structure 2 by known attachment means such as screws, bolts, adhesives, such as for example Sikaflex®, or other attachment means known to the person skilled in the art. Advantageously, adhesives can be used such that the fender can become an inextricable part of the structure, e.g. of a vessel hull. By providing the fender as an inextricable part of e.g. the vessel hull, the marine fender can be taken into account in the vessel's design, and/or the buoyancy of the marine fender can be taken into account for stability calculations of the vessel. The marine fender 1 comprises a core of closed cell foam 3, an intermediate layer 4 at least partly enclosing the core 3 and a coating 5 at least partly covering the intermediate layer 4.
(10) In this preferred embodiment, the intermediate layer 4 encloses the core on three sides, in particular three sides which are most exposed to possible impacts, i.e. the surfaces of the fender 1 which will be external once the fender is mounted to a marine structure 2. On the fourth side, which adheres to the marine structure 2, the intermediate layer 4 encloses the corners, providing an extra protection, but does not necessarily enclose the core. The intermediate layer 4 is preferably a fiber reinforced cloth, to reinforce the strength and durability of the fender 1 and to improve the core's protection against impact, as the cloth can provide resistance against tearing. The fibre reinforced cloth may for example be a PVC-cloth or a neoprene cloth reinforced with known fibres such as canvas fibres, glass fibres or other known fibres. The cloth can for instance comprise Hypalon®. The cloth can for example be glued to the core to obtain a firm connection, for which typically a two-component adhesive can be used. The glueing of the cloth may form an airtight layer around the core, at least there where the core is covered by the intermediate layer, supporting the closed cell foam core during compression and reacting as a pneumatic fender.
(11) The intermediate layer 4 can be covered by a coating 5, which can cover the entire intermediate layer 4, and which may also cover the core 3, where the core is not covered by the intermediate layer 4. Preferably, the coating 5 fully encloses the entire external surface of the fender 1, also the side of the fender 1 that will be attached to the marine structure 2. The coating can provide the fender with additional protection and resistance, for example against tearing, wear, or against UV radiation, and can provide the fender 1 with a water-tight layer. The coating 5 can for example be sprayed onto the intermediate layer 4, wherein the thickness of the coating can vary along the fender, adapting said thickness in zones of the fender which are more or less prone to wear. The thickness of the coating 5 may for example vary between 3-20 mm. The coating 5 can for example comprise PolyUrea™ or any other material with similar characteristics. In this embodiment, there is provided an intermediate layer 4 and a coating 5. Of course, many variants, with or without intermediate layer and/or with or without coating are possible.
(12) In the fender 1 according to the invention, the core 3 comprises at least one chamber 6 substantially entirely surrounded by said closed cell foam 3 and enclosing an elastically deformable closed object 7. In the preferred embodiment represented in FIG. 1, said core comprises a plurality of said chambers 6, each chamber 6 comprising an elastically deformable closed object 7. The core 3 comprises at least two blocks of closed cell foam, in this case four blocks 3a, 3b, 3c, 3d of closed cell foam. Every chamber 6 extends into two adjacent blocks of closed cell foam. Compared to a prior art fender, the marine fender comprising a core 3 of closed cell foam with chambers 6 therein and elastically deformable objects 7 therein, can be lighter and/or smaller and/or more compact to obtain the same or similar energy absorbing capacity as the prior art fender. Should a vessel nevertheless require a relatively large area of the hull to be covered by the fender and/or a relatively large thickness of the fender, a layer of relatively high density foam may be provided additionally, which still may result in a lighter fender than using a prior art fender.
(13) FIG. 2a shows a schematic side view of blocks of closed cell foam which are usable for manufacturing a fender according to a first aspect of the invention. FIG. 2b shows a schematic side view of the opened-up blocks of closed cell foam of FIG. 2a along the line A-A, and FIG. 2c shows a schematic perspective view on the blocks of closed cell foam of FIG. 2b. As closed cell foam is typically provided in solid premanufactured blocks, the blocks can be piled up to obtain a desired thickness of a fender. In case of substantially cuboid blocks, the sides with the largest surface area of two adjacent blocks can face each other to form two different layers. In FIGS. 2a, 2b and 2c, there are three layers 8a, 8b, 8c of such cuboid blocks of closed cell foam. Said different blocks and/or layers 8a, 8b, 8c of closed cell foam preferably have a mutually different density. As can be seen in FIGS. 2b and 2c, the core 3 comprises a plurality of chambers 6 substantially entirely surrounded by said closed cell foam 3. Each chamber 6 extends into two adjacent blocks 8a, 8b or 8b, 8c of closed cell foam. Each chamber 6 encloses an elastically deformable closed object 7. Said elastically deformable closed object 7 preferably tightly fits in said chamber 6. In the embodiment of FIGS. 2b and 2c, the elastically deformable closed object 7 is a substantially spherical object. FIGS. 3a and 3b show schematic perspective views on two alternative opened-up blocks of closed cell foam, where the elastically deformable objects 7 have a different shape, i.e. a cylindrical shape with spherical ends. In this alternative embodiment, a longitudinal axis of said elongated elastically deformable closed objects 7 can extend along three different axes, of which two examples are shown in FIGS. 3a and 3b. The position of these objects 7 can vary along the fender, and can for example be adapted to where the highest impact loads may be expected. The elastically deformable closed objects 7 can have other shapes, but in order to enhance their resiliency, it is preferred to avoid shapes comprising ribs and/or corners. In an advantageous embodiment, as represented in FIGS. 2b and 2c, said elastically deformable closed object may be a ball-like object comprising a substantially spherical closed shell, which shell can for example comprise rubber. Said shell may be typically filled with air, for example pressureless air, i.e. with a pressure equal to the surrounding air pressure, such that the ball-like object can produce a bouncing effect similar to a bouncing ball when experiencing a high impact load. A rubber-like shell comprising air inside can absorb relatively high impacts without tearing or breaking due to the high restoring capacities of such a ball-like object. This is contrary to other classical springs, for example metal spiral springs, which can easily break once an impact is higher than a given limit. Alternatively, said elastically deformable closed object 7 could also be filled with rubber, or with a closed cell foam having a different density than the density of the surrounding closed cell foam. The elastically deformable closed objects 7 could also be a hollow object different from a ball-like object, such as for example shown in FIGS. 3a and 3b.
(14) FIG. 4 shows a schematic perspective view on a preferred step of a method for manufacturing a marine fender according to a second aspect of the invention. In order to advantageously prepare blocks of closed cell foam, as represented in FIGS. 2a, 2b and 2c, for the manufacturing of a fender 1 according to a first aspect of the invention, the invention also provides an very advantageous method for manufacturing such a fender 1. According to said method, at least one block of closed cell foam is provided, in which at least one hollow chamber is made, for example carved out. It is however preferred to provide at least two blocks of closed cell foam, or for example three blocks 8a, 8b and 8c. Then a first chamber part 6a can be provided, for example carved out, in a first block, for example in block 8c, more specifically on one of the two large and wide sides 9, 10 of the cuboid block 8c. Preferably, a plurality of first chamber parts 6a is carved out in said side 9, which parts 6a are for example halves of a sphere. Corresponding second chamber parts 6b can then be provided in a second block, for example in a side 10 of block 8b, such that said first chamber parts 6a and second chamber parts 6b can together form a chamber extending over two adjacent blocks of closed cell foam. In a same block 8b, two sides 9 and 10 can both be provided with first and second chamber parts 6a, 6b. In a next step, an elastically deformable closed object 7 is inserted into the chamber 6, preferably, into a first chamber part 6a, preferably one elastic deformable closed object 7 in each first chamber part 6a. Advantageously, the balls are glued in the chambers, by means of an adhesive material well known the skilled person, e.g. glue or any other suitable adhesive material. The balls can alternatively be connected mechanically to the chamber e.g. by hooks or bayonet-connection. Many variants are possible.
(15) As is illustrated in FIG. 5, showing a schematic side view on a preferred step of a method for manufacturing a marine fender, the chambers 6 can then be closed by placing the other of the first or second chamber part, e.g. the second chamber parts 6b, in the first or second block, for example in block 8b, over the closed objects 7. The first and second chamber parts 6a, 6b are such that the closed objects 7 preferably tightly fit into the chamber 6 formed by said two chamber parts, and such that the closed cell foam of one block is in contact with the closed cell foam of an adjacent block in between said closed objects, as can be seen in FIG. 2a. Once the desired thickness for the fender 1 has been reached and the core structure 3 of the fender 1 is ready, an intermediate layer 4 can be provided, which at least partly encloses the at last one block of closed cell foam, for example as shown in FIG. 1. Then a coating 5 can be provided which at least partly, preferably fully, covers the intermediate layer 4. The coating 5 can also cover part of the core 3 which is not covered by an intermediate layer 4, as is for example the case in the embodiment of FIG. 1, where the side of the fender 1 that is attached to a marine structure 2 is not entirely covered by the intermediate layer 4, but is covered by the coating 5.
(16) For the purpose of clarity and a concise description, features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described. It may be understood that the embodiments shown have the same or similar components, apart from where they are described as being different.
(17) In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word ‘comprising’ does not exclude the presence of other features or steps than those listed in a claim. Furthermore, the words ‘a’ and ‘an’ shall not be construed as limited to ‘only one’, but instead are used to mean ‘at least one’, and do not exclude a plurality. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to an advantage. 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 defined in the following claims.
