The present invention relates to boards for sports like skateboarding where specific properties of the board can be important to performance and safety in the sport. in particular, the present invention may relate to a skateboard with a central reinforcement element.
A skateboard traditionally includes three major parts: the deck (the board upon which the rider stands), the trucks (the construction that attaches the wheels to the deck), and the wheels. Originally, decks were made of wood, but later they were also made of aluminium, fibreglass, and plastic. The rear part of the deck is bent upward to form the kicktail, as is the front (“nose”) on modern designs. The truck includes an axle, a hangar (which houses the axle), and a cushion that both absorbs shocks and provides flexibility for steering.
Boards are measured length in a longitudinal direction between a first end and a second end, a width measured along a transverse direction between a first edge and a second edge, and a height measured between a bottom and a top. Most skateboards are about 80 cm long and 23 cm wide. One variation of the skateboard is the longboard, which can run from 96 to 152 cm length.
During conventional use of a skateboard, a user places one or both feet on the board, and the feet are generally oriented in a substantially transverse direction of the board. Acrobatic acts are performed and for this reason skateboarding is often considered one of the so-called extreme sports. Skateboarding as a sport features tricks performed in a real or simulated urban environment with stairs, rails, ledges, and other obstacles. Acrobatic acts of jumping and then landing again on the ground are often performed. During use boards are subjected to substantial forces, especially when landing on the ground after the user has performed a jump. Forces can be impulse or continuous forces in several directions. The board may also be subjected to twisting forces. Forces are often in the form of impulses.
Important attributes of a board include board flexibility, board pop-up, strength, and board weight.
A board traditionally includes a core, reinforcements above and below the core. Reinforcements below the core are those closest to the ground when the board slides or rolls under normal conditions of use. Reinforcements above the core are those furthest from the ground when the board rolls under normal conditions of use. Traditionally the board has a sandwich structure.
Acrobatic performances are easier with a lighter board and there is effort to reduce weight. But whilst reducing weight, it is also important to have a board that is strong, that has a flexibility and pop-up that matches the experience, weight, and skill of the user. The structure of the deck is critical in achieving these attributes. At the same time, the possibility of board customisation is important to provide the user with the desired feeling according to the user's skill and the user's own weight.
Boards described in prior art use a core and reinforcements above and below the board in a sandwich structure. For example, EP2000180B1 teaches a board having a core extending along the surface and having upper and lower reinforcement layers made of natural or synthetic fibres. The construction is a sandwich structure. Similarly, CN100534556C discloses another sandwich structure where the core and the upper and lower layers are held by adhesive. All sandwich structures potentially suffer from risk of delamination. It is also difficult to achieve a combination of low weight, high strength, and flexibility.
There is the need for a board structure that does not suffer from risks of delamination, and whilst being lightweight can offer an optimal combination of strength, bob-up, and board flexibility. There is a further need to customise a combination of attributes of a board whilst being able to manufacture such custom board economically.
The present invention provides a board that can provide an excellent combination of low weight, high strength, and flexibility whilst also having high durability.
A core of the board may include a material of a higher density than a material of adjacent layers. The core may include a material having a higher young's modulus than the material of the adjacent layers. The core may have a higher flexural stiffness than the adjacent layers.
The present invention therefore provides methods of manufacturing boards and boards in accordance with the claims.
Examples of preferred embodiments of the invention will now be described by referring to the accompanying drawings:
The present invention refers to board deck for use as skateboard or longboard in extreme sports, having a length measured along a longitudinal direction between a first end and a second end, a width measured along a transverse direction between a first edge and a second edge, as well as a thickness measured between a bottom and a top. The board has customizable performance parameters including board flexibility, board pop-up, and strength, which can be customized economically during manufacture. The board deck includes a core extending along a surface, a lower structure located beneath the core, an upper structure located above the core, and a peripheral structure around the core wherein said lower structure, upper structure, and peripheral structure including plastic or plastic composite materials. The board deck is characterized in that said lower, upper, and peripheral structures include multiple layers of plastic or plastic-composite materials which during manufacture are heated to above melting point and then allowed to cool so that said multiple layers fuse and resolidify to form a monolithic structure. The core is therefore encapsulated by a monolithic plastic or plastic composite structure and the properties of the board are defined by a combination of attributes of the core, of the upper structure, lower structure, and peripheral structure and the interface between the core and the upper and/or lower surfaces. Adjustment of the manufacturing parameters such as the number of layers and the structure of the core provides tuneable properties of the board.
The plastic material includes polypropylene (PP) composite containing PP copolymer as matrix and stretched PP homopolymer as reinforcement.
In one embodiment, the core includes a honeycomb structure which may be characterised in that upper and lower skins of the honeycomb include of a fabric of polypropylene-based thermoplastic, which have a thickness between 0.05 mm and 3 mm, most preferable between 1 mm and 2 mm. The material said skin of the honeycomb can be for example “Self-reinforced” thermoplastic composites which is a plastic matrix (PP, Polyester) plus same class fibres.
The thickness of the layers of plastic material ranges from 0.05 mm to 3 mm and is preferably from 0.05 mm to 1 mm. In a preferred embodiment the plastic material is polypropylene (PP). Preferably the plastic material includes PP composite containing random PP copolymer as matrix and stretched PP homopolymer as reinforcement.
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It is also possible that the core may include a non-uniform cross-sectional area.
Apart of the layers of plastic material above and below the core, board properties of strength, flexibility, and pop-up are also determined by the shape, thickness, material properties, and other attributes of the core. For example, the core may include slots or cuts at the upper or lower surface of the core body.
The core includes of several layers of high strength composite material which are heated and pressed to form a single body. Each layer of the core material has a thickness between 0.05 mm and 3 mm. The core material typically includes carbon fibre reinforced plastic. The carbon fibres may have orientation in both along the length of the board and along the width of the board. Different kitting patterns of carbon fibres are known the produce different mechanical properties. In some embodiments, anisotropy may be desired while in other embodiments anisotropy is undesired and knotting patters are arranged to minimise anisotropy. The core is generally manufactured separately.
In a preferred embodiment the manufacturing of the core includes the steps of:
Typically, the core material has a melting temperature above 180° C. whereas the melting temperature of the plastic material is below 180° c., preferably below 170° C. The core includes multiple layers which are cut to shape, stacked together, heated to a temperature between 180 deg C. and 240 deg C. and pressed to bond or fuse together, so that upon cooling the core is a single solid body.
In one embodiment, the core top and/or bottom surface is rough and/or undulated. This offers improved adhesion between the core and the plastic material.
In a preferred embodiment, the core and the players of plastic material are placed in a mould and heated together to fuse the layers of plastic material before the core is fully cooled to room temperature. Therefore, when the core is cooled to below 100° C., so that it is in a stable solid form and can be handled safety, it is placed together with the layers of the plastic material in a second mould. In this second mould the materials are heated together to about 160° C. so that the plastic material melts and fuses together to produce a monolithic structure. At this temperature, which is below the melting point of the core, the core remains solid and retains its shape.
A selection of temperatures and pressures are selected so that different degrees of adhesion between core and surrounding plastic can be achieved as may be desired. The degree of adhesion between the core and the surrounding plastic material is one of the variables can influence the board properties, and specifically board flexibility and pop-up.
The board further includes a layer with printed graphics and a protective layer at the outer surface.
One preferred method of manufacture of a board as herein described, includes preparing a core as a single body, said core including a plurality of layers which are fused together by application of heat and pressure cutting a plurality of layers of a lower structure cutting a plurality of layers of a peripheral structure to a shape to create a hollow space to accommodate the shape of the core, and placing said layers of said peripheral structure on top of the layers said lower structure, placing said core into said hollow space of the peripheral structure, cutting a plurality of layers of said upper structure, and placing said layers of said upper structure on top of the core and the layers said peripheral structure to form a sandwich assembly, placing said sandwich structure into a press mold preheating said sandwich structure to a temperature between 8° and 100° C., applying a pressure of 10 to 20 Bar onto the sandwich structure while raising the temperature to 150 to 160° C. for a period of 5 to 10 minutes, allowing the sandwich structure to cool to 60 deg C. while said sandwich structure is within the press mold, removing said sandwich structure from said press mold and allowing it to cool to room temperature.
The customization of boards can be based the following parameters:
User weight is entered as an actual number in Kgs. For shock absorption, pop-up and strength which as performance parameters, the user can enter relative values. The user can also assign a priority among there three performance parameters. For example, one use may designate as first priority pop-up and second priority shock-absorption.
Based on user preferences an algorithm makes a selection of the most appropriate board for that user, among a finite number of standardised boards. For example, for production efficiency there may be five standardised boards. Based on the user selections, an algorithm determines which of the five standard boards is closest to the optimal conditions.
At the level of board structure, customisation is achieved by the core structure, the number of layers above the core and the number of layers below the core.
The present disclosure provides, in accordance with the following clauses:
A1. A board for use in skateboarding or other extreme sports, having a length measured along a longitudinal direction between a first end and a second end, a width measured along a transverse direction between a first edge and a second edge, as well as a thickness measured between a bottom and a top, and having, during manufacture, customizable performance parameters including board flexibility, board pop-up, and strength, the board including a core extending along a surface, the board including a lower structure located beneath the core, an upper structure located above the core, and a peripheral structure around the core wherein said lower structure, upper structure, and peripheral structure including plastic or plastic composite material characterized in that said lower, upper, and peripheral structure include multiple layers of plastic or plastic-composite material which during manufacture is heated to near and/or slightly above melting point and then allowed to cool, so that said multiple layers fuse and resolidify to form a monolithic structure so that said core encapsulated by a monolithic plastic or plastic composite structure and wherein the properties of the board are defined by a combination of attributes of the core, of the upper structure, lower structure, and peripheral structure and the interface between the core and the upper and/or lower surfaces wherein adjustment of said attributes provides tunable properties of the board.
A2. A board according to any preceding clause, wherein the plastic material is arranged in layers which are stacked together and then heated and pressed to fuse and melt so that a monolithic structure is produced.
A3. A board according to any preceding clause, wherein pressure of 10-20 Bar is applied within an autoclave environment.
A4. A board according to any preceding clause, wherein the plastic material includes polypropylene (PP), preferably the plastic material includes PP composite containing PP copolymer as matrix and stretched PP homopolymer as reinforcement.
A5. A board according to any preceding clause, wherein there is an equal thickness of plastic material above and below the core.
A6. A board according to any preceding clause, wherein the thickness of plastic material above and below the core is not equal, and the wherein the number of layers of plastic material above the core in relation to the number of layers of plastic material below the core are arranged in a way as to produce the desired properties of the board for flexibility, strength, and pop-up for a given board weight.
A7. A board according to any preceding clause, characterized in that said core includes of several layers of high strength composite material which are heated and pressed to form a single body.
A8. A board according to any preceding clause, characterized in that each of the layers of the core material has a thickness between 0.05 mm and 3 mm, said layers being stacked together prior to heating and fusing.
A9. A board according to any preceding clause, characterized in that said layers of said core include carbon fibre reinforced plastic.
A10. A board according to any preceding clause, characterized in that the core includes an essentially ring-shaped body having a hollow central region.
A11. A board according to any preceding clause, characterized in that the core includes multiple layers which are cut to shape, stacked together, heated to a temperature between 180° C. and 240° C. and pressed to bond or fuse together, so that upon cooling the core is a single solid body.
A12. A board according to any preceding clause, characterized in that the core includes a top and or bottom surface of rough and/or undulated surface.
A13. A board according to any preceding clause, characterized in that the core includes a plurality of slots or cuts at the upper or lower surface of the core.
A14. A board according to any preceding clause, characterized in that the core includes a non-uniform cross-sectional area.
A15. A board according to any preceding clause, wherein the lower structure further includes a layer with printed graphics and a protective layer at the outer surface.
A16. A board according to any preceding clause, wherein the core includes several discrete reinforcing strips within a matrix of plastic material.
A17. A board according to any preceding clause, wherein the plastic matrix surrounding the core, at the same level as the core, includes pockets of lightweight material.
A18. A board according to any preceding clause, wherein said pockets of lightweight material include balsa wood.
A19. A board according to any preceding clause, having a method of manufacture of including preparing a core as a single body, said core including a plurality of layers which are fused together by application of heat and pressure cutting a plurality of layers of a lower structure cutting a plurality of layers of a peripheral structure to a shape to create a hollow space to accommodate the shape of the core, and placing said layers of said peripheral structure on top of the layers said lower structure, placing said core into said hollow space of the peripheral structure, cutting a plurality of layers of said upper structure, and placing said layers of said upper structure on top of the core and the layers said peripheral structure to form a sandwich assembly, placing said sandwich structure into a press mold preheating said sandwich structure to a temperature between 8° and 100° C., applying a pressure of 10 to 20 Bar onto the sandwich structure while raising the temperature to 150 to 160° C. for a period of 5 to 10 minutes, allowing the sandwich structure to cool to 60 deg C. while said sandwich structure is within the press mold, removing said sandwich structure from said press mold and allowing it to cool to room temperature.
A20. A board according to any preceding clause, wherein said board is customized by allowing a user to enter at an interface his weight and performance parameters including pop-up, shock-absorption, and strength, and define priorities among the properties of at least pop-up, shock-absorption, and strength, characterized in that based on user entries an algorithm makes a selection of the most appropriate board for that user among a finite number of standardized boards and wherein said customization is achieved by appropriate selection of the core structure, the number of layers above the core and the number of layers below the core.
A21. A board for use in skateboarding or other extreme sports, having a length measured along a longitudinal direction between a first end and a second end, a width measured along a transverse direction between a first edge and a second edge, as well as a thickness measured between a bottom and a top, said board includes a core extending along a surface, the board including a lower structure located beneath the core, an upper structure located above the core, and a peripheral structure around the core wherein said lower structure, upper structure, and peripheral structure including plastic or plastic composite material characterized in that said lower, upper, and peripheral structure include multiple layers of plastic or plastic-composite material which during manufacture is heated to near and/or slightly above melting point and then allowed to cool, so that said multiple layers fuse and resolidify to form a monolithic structure so that said core encapsulated by a monolithic plastic or plastic composite matrix structure and wherein the properties of the board are defined by a combination of attributes of the core, of the upper matrix structure, lower matrix structure, and peripheral matrix structure characterized in that said upper matrix structure and/or said lower matrix structure and/or said peripheral structure include(s) pockets of lightweight material, said lightweight material having a density less than 400 Kg/m3.
A22. A board according to any preceding clause, further characterized in that said core includes several discrete reinforcing strips within a matrix of plastic material.
A23. A board for use in skateboarding or other extreme sports, having a length measured along a longitudinal direction between a first end and a second end, a width measured along a transverse direction between a first edge and a second edge, as well as a thickness measured between a bottom and a top, including of plastic material and characterized in that the plastic material is arranged in layers which are stacked together and then heated and pressed to fuse and melt so that a monolithic structure is produced and wherein the plastic material includes polypropylene (PP) composite containing PP copolymer as matrix and stretched PP homopolymer as reinforcement.
A24. A board according to any preceding clause, wherein said board is customized by the number of layers that are stacked together and then fused to form a monolithic structure.
A25. A board according to any preceding clause, wherein said board is customized by allowing a user to enter at an interface his weight and performance parameters including pop-up, shock-absorption, and strength, and define priorities among the properties of at least pop-up, shock-absorption, and strength, characterized in that based on user entries an algorithm makes a selection of the most appropriate board for that user among a finite number of standardized boards and wherein said customization is achieved by appropriate selection of the number of layers.
A26. A board according to any preceding clause, wherein within the layers of plastic material are inserted pockets of lightweight material, said lightweight material including balsa wood.
A27. A board for use in skateboarding or other extreme sports, having a length measured along a longitudinal direction between a first end and a second end, a width measured along a transverse direction between a first edge and a second edge, as well as a thickness measured between a bottom and a top, the board including a core extending along a surface, the board including a lower structure located beneath the core, an upper structure located above the core, and a peripheral structure around the core wherein said lower structure, upper structure, and peripheral structure including plastic or plastic composite material characterized in that said lower, upper, and peripheral structure include multiple layers of plastic or plastic-composite material which during manufacture is heated to near and/or slightly above melting point and then allowed to cool, so that said multiple layers fuse and resolidify to form a monolithic structure so that said core is encapsulated by a monolithic plastic or plastic composite structure and wherein the properties of the board are defined by a combination of attributes of the core, of the upper structure, lower structure, and peripheral structure, characterized in that the plastic material includes polypropylene (PP), preferably the plastic material includes PP composite containing PP copolymer as matrix and stretched PP homopolymer as reinforcement.
A28. A board according to any preceding clause characterised in that there is variable rigidity along the longitudinal direction of the board between the first end and the second end, wherein said variable rigidity is achieved through variation of the reinforcing layers or structure.
Number | Date | Country | Kind |
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2116164.1 | Nov 2021 | GB | national |
This application is a National Stage application of PCT/EP2022/081133, filed Nov. 8, 2022, which claims the benefit of GB Application No. 2116164.1, filed Nov. 10, 2021, which are incorporated by reference in their entirety herein.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2022/081133 | 11/8/2022 | WO |