AU2020202137A1

AU2020202137A1 - A surfboard and spring assembly

Info

Publication number: AU2020202137A1
Application number: AU2020202137A
Authority: AU
Inventors: Stuart Douglas Campbell
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-03-25
Filing date: 2020-03-25
Publication date: 2021-10-14

Abstract

A surfboard having a core, and an elongate spring member substantially centrally located relative to the core, wherein the elongate spring member extends 5 substantially from a nose portion of the surfboard to a tail portion of the surfboard. 2/7 CN 000 CN~ CN, co C~C4

Description

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A SURFBOARD AND SPRING ASSEMBLY

FIELD OF INVENTION The present invention relates to a surfboard. The present invention has particular but not exclusive application for a surfboard with energy recovery. The patent specification describes this use but it is by way of example only and the invention is not limited to this use.

BACKGROUND OF THE INVENTION Surfboards are typically made of polyurethane or polystyrene foam covered with layers of fiberglass cloth, and polyester or epoxy resin. The use of these materials results in a light and strong surfboard that is buoyant and manoeuvrable. Fiberglass surfboards typically have a degree of flex. Flex allows a surfboard to build energy through turns by bending into a turn, this results in a greater vertical curve of the surfboard between the nose and the tail and stored energy. As the surfboard comes out of a turn, the surfboard snaps back to its original shape, releasing the stored energy and propelling the surfboard out of the turn. However, there is typically a trade-off between strength and flexibility, with more flexible surfboards typically more likely to snap or lose their springiness over time. Many surfboards have one or more stringers to increase the surfboard's overall strength. However, these stringers also reduce a surfboards flexibility. A single stringer down a board's centre will provide strength but less flexibility along the centre of the board and can lead to torsional flex which can slow down a surfboard. Some boards have two stringers, each close to a rail of the surfboard. Surfboards with two stringers are typically stronger than surfboards with a single stringer, with the flex coming from the centre of the surfboard with two stringers.

OBJECT OF THE INVENTION It is an object of the present invention to overcome or at least alleviate one or more of the above mentioned problems with surfboards and/or provide the consumer with a useful or commercial choice.

SUMMARY OF THE INVENTION In one aspect, the present invention broadly resides in a surfboard having a core; and an elongate spring member substantially centrally located relative to the core, wherein the elongate spring member extends substantially from a nose portion of the surfboard to a tail portion of the surfboard. Preferably the core is made predominantly from a foamed material. Preferably the core is a foam core. Preferably the foamed material is polyurethane foam. In another embodiment, the foam is polystyrene foam. Preferably the polystyrene foam is expanded polystyrene foam. Alternatively, the polystyrene foam can be extruded polystyrene foam. Preferably the core includes two body portions. Preferable the two body portions are spaced from one another. The elongate spring member is preferably located between the two body portions. Preferably the two body portions are symmetrical about the elongate spring member. Preferably the elongate spring member is located centrally relative to a longitudinal axis of the surfboard. Preferably the elongate spring member includes a plurality of layers of resilient material. Preferably the number of layers of resilient material defines the thickness of the elongate spring member. Preferably the number of layers of resilient material is greater in a central portion of the elongate spring member compared to a portion of the elongate spring member towards the nose of the surfboard. Preferably the number of layers of resilient material is greater in a central portion of the elongate spring member compared to a portion of the elongate spring member towards the tail of the surfboard. Preferably the plurality of layers is between 2 to 12 layers of resilient material. More preferably the plurality of layers is between 4 to 10 layers of resilient material. Preferably the plurality of layers of resilient material are bonded together to form the elongate spring member. More preferably the plurality of layers of resilient material are bonded together using an epoxy to form the elongate spring member. Preferably a thin portion of the elongate spring member is less than 50% of the thickness compared to a thick portion of the elongate spring member. Preferably the thin portion includes 1 to 2 layers of resilient material. Preferably the thick portion includes 4 to 10 layers of resilient material. Preferably the plurality of layers of the elongate spring member are made of a resilient material. In one embodiment, the plurality of layers are made of a fibreglass composite material. Preferably the plurality of layers are made of a fibreglass and resin composite material. In another embodiment, the plurality of layers are made of a carbon fibre composite material. Preferably the plurality of layers are made of a carbon fibre and resin composite material. Preferably the fibre is substantially unidirectional. Preferably the fibre is substantially unidirectional in the longitudinal direction of the surfboard. Preferably the elongate spring member is part of a spring assembly. Preferably the spring assembly includes an upper portion and a lower portion. Preferably the upper portion and the lower portion are at least partially spaced from one another by the elongate spring member. Preferably the upper portion is made predominantly from a foamed material. Preferably the foamed material is polyurethane foam. In another embodiment, the foam is polystyrene foam. Preferably the polystyrene foam is expanded polystyrene foam. Alternatively, the polystyrene foam can be extruded polystyrene foam. Preferably the upper portion has a thickness of substantially between 5mm to 100mm. Preferably the upper portion has a thickness of substantially between 10mm to 80mm. More preferably the upper portion has a thickness of substantially between 20mm to 50mm. Preferably the lower portion is made predominantly from a foamed material. Preferably the foamed material is polyurethane foam. In another embodiment, the foam is polystyrene foam. Preferably the polystyrene foam is expanded polystyrene foam. Alternatively, the polystyrene foam can be extruded polystyrene foam. Preferably the lower portion has a thickness of substantially between 5mm to 100mm. Preferably the lower portion has a thickness of substantially between 5mm to 50mm. More preferably the lower portion has a thickness of substantially between 10mm to 20mm. Preferably each layer of the plurality of layers of resilient material of the elongate spring member has a different length. Preferably in use, the layer(s) of resilient material towards the lower portion is/are shorter than the layer(s) of resilient material towards the upper portion. Preferably the length of each layer of the plurality of layers of resilient material is substantially from 100mm to 1800mm. More preferably the length of each layer of the plurality of layers of resilient material is substantially from 250mm to 1650mm. Preferably the elongate spring member tapers from a thicker portion to a thinner portion towards the nose of the surfboard. Preferably the elongate spring member tapers from a thicker portion to a thinner portion towards the tail of the surfboard. Preferably the elongate spring member tapers to a point at or towards the nose of the surfboard. Preferably the elongate spring member has a width of substantially between 15mm to 200mm. Preferably the elongate spring member has a width of substantially between 15mm to 80mm. More preferably the elongate spring member has a width of substantially between 20mm to 40mm. In one embodiment, the elongate spring member is pretensioned. Preferably the elongate spring member is pretensioned in a first direction. Preferably the elongate spring member is biased to bend upwardly in use. In another embodiment, the elongate spring member is pretensioned in a second direction. Preferably the elongate spring member is biased to bend downwardly in use. Preferably the surfboard includes a shell layer. Preferably the shell layer substantially covers the core. Preferably the shell layer substantially covers the spring assembly. It will be understood that a shell layer may also be referred to as a skin layer. Preferably the shell layer includes a fibreglass and resin composite material. Alternatively or additionally the shell layer can include a carbon fibre and resin composite material. Preferably the shell layer is bonded to the core. Preferably the shell layer is bonded to the spring assembly. Preferably the surfboard is between 170cm to 260cm in length. More preferably the surfboard is between 180cm to 210cm in length. Preferably the surfboard has a partially concave lower surface. Preferably the surfboard has a partially convex upper surface. In another aspect, the present invention broadly resides in a spring assembly for a surfboard, including: an elongate spring member, and an upper portion and a lower portion at least partially spaced from one another by the elongate spring member, wherein in use, the spring assembly is substantially centrally located in the surfboard. Preferably the spring assembly extends substantially from a nose portion of the surfboard to a tail portion of the surfboard. Preferably the elongate spring member includes a plurality of layers of resilient material. Preferably the number of layers of resilient material defines the thickness of the elongate spring member. Preferably the number of layers of resilient material is greater in a central portion of the elongate spring member compared to a portion of the elongate spring member towards the nose of the surfboard. Preferably the number of layers of resilient material is greater in a central portion of the elongate spring member compared to a portion of the elongate spring member towards the tail of the surfboard. Preferably the plurality of layers is between 2 to 12 layers of resilient material. More preferably the plurality of layers is between 4 to 10 layers of resilient material. Preferably the plurality of layers of resilient material are bonded together to form the elongate spring member. More preferably the plurality of layers of resilient material are bonded together using an epoxy to form the elongate spring member. Preferably a thin portion of the elongate spring member is less than 50% of the thickness compared to a thick portion of the elongate spring member. Preferably the thin portion includes 1 to 2 layers of resilient material. Preferably the thick portion includes 4 to 10 layers of resilient material. Preferably the plurality of layers of the elongate spring member are made of a resilient material. In one embodiment, the plurality of layers are made of a fibreglass composite material. Preferably the plurality of layers are made of a fibreglass and resin composite material. In another embodiment, the plurality of layers are made of a carbon fibre composite material. Preferably the plurality of layers are made of a carbon fibre and resin composite material. Preferably the fibre is substantially unidirectional. Preferably the fibre is substantially unidirectional in the longitudinal direction of the surfboard. Preferably the upper portion is made predominantly from a foamed material. Preferably the foamed material is polyurethane foam. In another embodiment, the foam is polystyrene foam. Preferably the polystyrene foam is expanded polystyrene foam. Alternatively, the polystyrene foam can be extruded polystyrene foam.

Preferably the upper portion has a thickness of substantially between 5mm to 100mm. Preferably the upper portion has a thickness of substantially between 10mm to 80mm. More preferably the upper portion has a thickness of substantially between 20mm to 50mm. Preferably the lower portion is made predominantly from a foamed material. Preferably the foamed material is polyurethane foam. In another embodiment, the foam is polystyrene foam. Preferably the polystyrene foam is expanded polystyrene foam. Alternatively, the polystyrene foam can be extruded polystyrene foam. Preferably the lower portion has a thickness of substantially between 5mm to 100mm. Preferably the lower portion has a thickness of substantially between 5mm to 50mm. More preferably the lower portion has a thickness of substantially between 10mm to 20mm. Preferably each layer of the plurality of layers of resilient material of the elongate spring member has a different length. Preferably in use, the layer(s) of resilient material towards the lower portion is/are shorter than the layer(s) of resilient material towards the upper portion. Preferably the length of each layer of the plurality of layers of resilient material is substantially from 100mm to 1800mm. More preferably the length of each layer of the plurality of layers of resilient material is substantially from 250mm to 1650mm. Preferably the elongate spring member tapers from a thicker portion to a thinner portion towards the nose of the surfboard. Preferably the elongate spring member tapers from a thicker portion to a thinner portion towards the tail of the surfboard. Preferably the elongate spring member tapers to a point at or towards the nose of the surfboard. Preferably the elongate spring member has a width of substantially between 15mm to 200mm. Preferably the elongate spring member has a width of substantially between 15mm to 80mm. More preferably the elongate spring member has a width of substantially between 20mm to 40mm. Preferably the spring assembly has a thickness as same as an attached portion of a foam core of the surfboard. In one embodiment, the elongate spring member is pretensioned. Preferably the elongate spring member is pretensioned in a first direction. Preferably the elongate spring member is biased to bend upwardly in use. In another embodiment, the elongate spring member is pretensioned in a second direction. Preferably the elongate spring member is biased to bend downwardly in use. In a further aspect, the present invention broadly resides in a method of manufacturing a surfboard, including the steps of locating a spring assembly between two body portions of a surfboard core; shaping the two body portions to form the surfboard core; and covering the spring assembly and the surfboard core with a shell layer. Preferably the step of locating a spring assembly between two body portions of a surfboard core is completed before shaping of the surfboard core. Alternatively the step of locating a spring assembly between two body portions of a surfboard core is completed after shaping of the surfboard core. Preferably the method further includes step of shaping the spring assembly to conform to the surfboard core. Preferably the spring assembly is a spring assembly as described in this specification. Preferably the surfboard is a surfboard as described in this specification. In one embodiment, the surfboard is a paddleboard. The features described with respect to one aspect also apply where applicable to all other aspects of the invention. Furthermore, different combinations of described features are herein described and claimed even when not expressly stated.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the present invention can be more readily understood reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention and wherein: Figure 1 is a section perspective view of a surfboard according to an embodiment of the present invention; Figure 2 is a section perspective view of the surfboard of Figure 1; Figure 3 is a top view of the surfboard of Figure 1; Figure 4 is an exploded view of the surfboard of Figure 1; Figure 5 is a section view of the surfboard of Figure 1; Figure 6 is an exploded section view of a spring assembly according to an embodiment of the present invention; and

Figure 7 is a side view of the spring assembly of Figure 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to Figures 1-5, there is shown a surfboard 10 according to an embodiment of the present invention. The surfboard 10 has a core 12 made of expanded foamed polyurethane. A spring assembly 14 is centrally located relative to the core 12. The core 12 includes two body portions 16,18. The spring assembly 14 is centrally located between the two body portions 16,18. The spring assembly 14 extends from a nose portion 28 of the surfboard 10 to a tail portion 30 of the surfboard 10. The spring assembly 14 is formed before shaping of the surfboard 10. The spring assembly 14 includes an elongate spring member 20 made of unidirectional carbon fibre and resin, an upper portion 24 and a lower portion 26. The upper portion 24 and the lower portion 26 are made of polystyrene foam. The surfboard 10 includes a shell layer 32 which covers the two body portions 16,18 of the core 12 and the spring assembly 14. The shell layer 32 is formed of a fibreglass and resin composite material. The surfboard 10 also includes one or more fin boxes (not shown). The fin boxes are inserted into the core 12 and/or the spring assembly 14. With reference to Figures 6, there is shown an exploded section view of a spring assembly 114 according to an embodiment of the present invention. The spring assembly 114 includes an elongate spring member 120, an upper portion 124 and a lower portion 126. The elongate spring member 120 includes a plurality of layers 122. The plurality of layers 122 are made of unidirectional carbon fibre and resin. The plurality of layers 122 are bonded together to form the elongate spring member 120. The number of layers 122 defines the thickness of the elongate spring member 120. The number of layers 122 is greater in a central portion of the elongate spring member 120 compared to the elongate spring member 120 towards a nose portion of a surfboard (not shown), and compared to the elongate spring member 120 towards a tail portion of the surfboard.

Each layer 122 of the elongate spring member 120 has a different length. As shown in Figure 6, the layers 122 towards the lower portion 126 are shorter than the layers towards the upper portion 124. With reference to Figure 7, there is shown a side view of the spring assembly 114 of Figure 6. The upper portion 124 and the lower portion 126 are spaced from one another by the elongate spring member 120.

ADVANTAGES An advantage of the preferred embodiment of the surfboard includes providing desired flex whilst enhancing longitudinal strength. Another advantage of the preferred embodiment of the surfboard includes the ability to control the amount of the flex by positioning the plurality of layers of the elongate spring member. A further advantage of the preferred embodiment of the surfboard includes that the spring assembly can be formed before or after shaping of the surfboard.

VARIATIONS While the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is herein set forth. Throughout the description and claims of this specification the word "comprise" and variations of that word such as "comprises" and "comprising", are not intended to exclude other additives, components, integers or steps.

Claims

1. A surfboard having a core; and an elongate spring member substantially centrally located relative to the core, wherein the elongate spring member extends substantially from a nose portion of the surfboard to a tail portion of the surfboard.

2. A surfboard as claimed in claim 1, wherein the elongate spring member includes a plurality of layers made of resilient material, wherein in use, the plurality of layers of resilient material are bonded together to form the elongate spring member.

3. A surfboard as claimed in claim 1 or 2, wherein the elongate spring member is part of a spring assembly, wherein the spring assembly includes an upper portion and a lower portion at least partially spaced from one another by the elongate spring member, and wherein the spring assembly is located between two body portions of the core.

4. A spring assembly for a surfboard, including: an elongate spring member, and an upper portion and a lower portion at least partially spaced from one another by the elongate spring member, Wherein in use, the spring assembly is substantially centrally located in the surfboard.

5. A method of manufacturing a surfboard, including the steps of locating a spring assembly between two body portions of a surfboard core; shaping the two body portions to form the surfboard core; and covering the spring assembly and the surfboard core with a shell layer.

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