Adjustable fin system

Abstract

An adjustable fin for use on a surfboard, the adjustable fin comprising: a base which comprises a mounting means for mounting the adjustable fin to a surfboard, and a member extending in a direction contrary to the mounting means. The adjustable fin further comprises a fin section comprising two outer fin surfaces which meet at a leading edge and a trailing edge; an underside surface comprising an opening to an internal cavity, the internal cavity configured to house the member and enable slidable movement of the member in a direction towards the leading edge or the trailing edge; and a locking means that is manipulate and which projects into the internal cavity, wherein the locking means can releasably couple to the member at one of two or more locking positions thereby preventing slidable movement of the member. The fin section can be adjusted relative to the base by manipulating the locking means to uncouple the locking means from the member at a first locking position, slidably move the member through the internal cavity, and releasably couple the locking means to the member at a second locking position.

Claims

1. An adjustable fin for use on a surfboard, the adjustable fin comprising: a base comprising: a mount for attaching the adjustable fin to a surfboard; and an insert member extending in a direction contrary to the mount; a fin section comprising: two outer fin surfaces which meet at a leading edge and a trailing edge; an underside surface comprising an opening to an internal cavity within the fin section, the internal cavity within the fin section configured to house the insert member of the base and enable slidable movement of the insert member in a direction towards the leading edge or the trailing edge; and a lock that is manipulable and which projects into the internal cavity, wherein the lock can be releasably coupled to the insert member at one of two or more locking positions thereby preventing slidable movement of the insert member; wherein the fin section is configured to adjust relative to the base by manipulating the lock from an outer fin surface to uncouple the lock from the insert member at a first locking position, slidably moving the insert member through the internal cavity, and releasably coupling the lock to the insert member at a second locking position.

2. The adjustable fin according to claim 1, wherein the lock is biased towards being releasably coupled to the insert member at a locking position.

3. The adjustable fin according to claim 1, wherein the lock comprises a button at an outer fin surface for manipulating the lock, and depressing the button uncouples the lock from the insert member.

4. The adjustable fin according to claim 3, wherein releasing the button releasably couples the lock to the insert member.

5. The adjustable fin according to claim 3, wherein a surface of the undepressed button is flush with the outer fin surface.

6. The adjustable fin according to claim 3, wherein a user can apply sufficient manual force by hand to depress the button and adjust the position of the fin section relative to the base when the adjustable fin is attached to a surfboard.

7. The adjustable fin according to claim 1, wherein the insert member is planar.

8. The adjustable fin according to claim 1, wherein the insert member comprises a hole, and the hole is configured to receive the lock.

9. The adjustable fin according to claim 8, wherein the lock releasably couples to the insert member at any one of two or more locking positions in the hole.

10. The adjustable fin according to claim 8, wherein the hole comprises one or more teeth, wherein either side of a tooth is a valley, and the valley forms a locking position.

11. The adjustable fin according to claim 10, wherein the one or more teeth are aligned parallel to the underside surface.

12. The adjustable fin according to claim 10, wherein the one or more teeth point in a direction away from the underside surface.

13. The adjustable fin according to claim 10, wherein at least a portion of the lock is received at a locking position in a valley thereby coupling the lock to the insert member, and is configured such that depressing the button aligns the teeth with a slot in the lock, uncoupling the lock from the insert member and enabling slidable movement of the teeth through the slot.

14. The adjustable fin according to claim 13, wherein the fin is configured such that releasing the button when the lock is aligned with a valley releasably couples the lock to the insert member.

15. The adjustable fin according to claim 1, wherein a second fin section is attached to the fin section by one or more attachments, the second fin section comprising two outer fin surfaces which meet at a leading edge and a trailing edge, and an underside surface.

16. The adjustable fin according to claim 15, wherein the one or more attachments comprise one or more ribs.

17. The adjustable fin according to claim 15, wherein the one or more attachments preserves a minimum distance between the fin section and the second fin section of between approximately 0.25 mm and 1.5 mm.

18. The adjustable fin according to claim 15, wherein the fin section and the second fin section comprise flat foils having a flat outer fin surface that faces the same direction, and a curved outer fin surface, and wherein the second fin section is positioned parallel to the fin section and offset such that the leading edge of the second fin section is not aligned with the leading edge of the fin section.

19. The adjustable fin according to claim 18, comprising a passage through the second fin section through which water can pass, wherein: the passage comprises an opening on the flat outer fin surface, and an opening on the curved outer fin surface, and the opening on the curved outer fin surface is located between the trailing edge of the second fin section and the minimum distance between the fin section and the second fin section; the opening of the passage on the flat outer fin surface is located closer to the leading edge of the second fin section than the opening of the passage on the curved outer fin surface of the second fin section; and water can enter the opening on the flat outer fin surface, pass through the passage, and exit through the opening on the curved outer fin surface.

20. The adjustable fin according to claim 15, comprising a passage through the second fin section through which water can pass, wherein the passage comprises an opening on each outer fin surface of the second fin section through which water can enter and/or exit.

21. The adjustable fin according to claim 1 comprising an extended base, wherein when the adjustable fin is mounted on a surfboard, the extended base forms a gap between the outer surface of the surfboard and the underside surface of the fin section.

22. The adjustable fin according to claim 1, wherein the one or more mounts are mounting blocks capable of attaching to commercially available fin plug and fin box systems.

23. The adjustable fin according to claim 1, wherein the mount comprises a base attachment surface and an adhesive for mounting the adjustable fin to an outer surface of a surfboard.

24. The adjustable fin according to claim 1 for mounting to any one of the boards in the group comprising: surfboard, shortboard, kneeboard, longboard, minimal, soft board, kiteboard, wind surfer, stand up paddleboard, wakeboard, rescue board, bodyboard, or another board used in surface water sports or activities.

25. A process comprising the step of mounting an adjustable fin according to claim 1, to any one of the boards in the group comprising: surfboard, shortboard, kneeboard, longboard, minimal, soft board, kiteboard, wind surfer, stand up paddleboard, wakeboard, rescue board, bodyboard, or another board used in surface water sports or activities.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1. are illustrations showing oblique views of an exploded (A) and assembled (B) embodiment of the first aspect of the adjustable fin of the invention. Mount comprises mounting blocks which attach to FCS fin plugs.

(2) FIG. 2. are illustrations showing a top view (A), oblique view (B), side view (C) and front view (D) and the internal mechanism of an embodiment of the first aspect of the adjustable fin of the invention. Mount comprises mounting blocks which attach to FCS fin plugs.

(3) FIG. 3. are illustrations showing oblique views of an exploded embodiment of the first aspect of the adjustable fin of the invention (A) and when mounted to a surfboard (B). Mount comprises a base attachment surface and an adhesive.

(4) FIG. 4. are illustrations showing side view cross sections of an embodiment of the second aspect of the adjustable fin of the invention with the base in the (A) front position, (B) during adjustment between positions, and (C) back position, relative to the fin section. Mount comprises mounting blocks which attach to FCS fin plugs.

(5) FIG. 5. are illustrations showing a side view cross section and a top view cut-away cross section of one half of a fin section of an embodiment of the second aspect of the adjustable fin of the invention.

(6) FIG. 6. are illustrations showing a side view cross section and a top view cut-away cross section of the other half of the fin section of FIG. 5.

(7) FIG. 7. are illustrations with measurements (in mm) of a front, side and partial bottom view of an embodiment of the base of the second aspect of the adjustable fin the invention. Mount comprises mounting blocks which attach to FCS fin plugs.

(8) FIG. 8. are illustrations with measurements (in mm) of a front, side and partial bottom view of an alternative embodiment to FIG. 7 of the base of the second aspect of the adjustable fin of the invention. Mount comprises mounting blocks which attach to FCS fin plugs.

(9) FIG. 9. (A) is a photograph of the side view of half a fin section and a base as illustrated in FIG. 4(C); (B) is a photograph of the side view of half a fin section and a base as illustrated in FIG. 4(A); (C) is a photograph of an end view of an embodiment of the second aspect of the adjustable fin of the invention showing the underside surface of the fin section with opening to the internal cavity, and the base. Mount comprises mounting blocks which attach to FCS fin plugs.

(10) FIG. 10. are illustrations showing a side view (A), the opposing side view (B), front view (C) and top view (D) of an embodiment of the third aspect of the adjustable dual fin of the invention. Mount comprises mounting blocks which attach to FCS fin plugs.

(11) FIG. 11. are illustrations showing an oblique view (A), blueprint of the oblique view (B), side view (C), blueprint of the side view (D), and an exploded oblique view (E) of an embodiment of the third aspect of the adjustable dual fin of the invention. Mount comprises mounting blocks which attach to FCS fin plugs.

(12) FIG. 12. are illustrations showing side, front, and bottom views of an embodiment of the base of the third aspect of the adjustable dual fin of the invention. Mount comprises mounting blocks which attach to FCS fin plugs.

(13) FIG. 13. are illustrations showing oblique view (A), oblique exploded view (B), and (clockwise from top left) top, side, oblique and front view (C) of adjustable fins of the invention mounted by a base attachment surface and an adhesive to a surfboard, with adjustable dual fins of an embodiment of the third aspect of the invention mounted as side fins, and an adjustable fin of an embodiment of the first aspect of the invention mounted as the centre fin.

DESCRIPTION OF PREFERRED EMBODIMENTS

(14) Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in the specification, individually or collectively and any and all combinations or any two or more of the steps or features.

(15) The present invention is not to be limited in scope by the specific embodiments described herein, which are intended for the purpose of exemplification only. Functionally equivalent products, compositions and methods are clearly within the scope of the invention as described herein.

(16) Throughout this specification, unless the context requires otherwise, the word comprise, or variations such as comprises or comprising, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

(17) Other definitions for selected terms used herein may be found within the detailed description of the invention and apply throughout. Unless otherwise defined, all other scientific and technical terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which the invention belongs.

(18) Features of the invention will now be discussed with reference to the following preferred embodiments.

First Aspect of the Invention

(19) A preferred embodiment of the first aspect of the adjustable fin of the invention is shown in FIG. 1. FIG. 1A illustrates an exploded view (and FIG. 1B an assembled view) wherein the fin section 100 has a leading edge 102 and a trailing edge 104 and outer fin surfaces 106 of which only one is visible in FIGS. 1A and 1B.

(20) The base 200 comprises a mount 214 comprising two mounting blocks 202 which are compatible with the existing commercially available FCS fin plugs fitted to a majority of existing surfboards. When the adjustable fin is mounted on to a surfboard, the mounting blocks 202 are secured within FCS fin plugs and the underside surface 108 of the fin section 100 and bottom surface 204 of the base abut, i.e. align with the bottom surface of the surfboard.

(21) The base 200 comprises a member 206 which extends in a direction contrary to that of the mounting blocks 202. The member 206 comprises a planar surface with a hole 208 cut out. The hole 208 is shaped to comprise teeth 210 and valleys 212.

(22) The fin section 100 comprises a lock 110 which is shown in FIG. 1A disassembled into three components, one component comprising the button 112 of the lock 110, another component comprising a button support 116, and the other component comprising a button support pin 118 that connects the button support 116 to the button 112. FIG. 1B shows that the button 112 on the assembled fin lies flush to the outer fin surface 106. The underside of the button 112 comprises a slot 114 which when the button 112 is depressed on the assembled adjustable fin, the slot 114 aligns with the teeth 210 enabling the teeth 210 which have a width thinner than the width of the slot 114, to pass through the slot 114. The button 112 is biased towards releasably coupling the lock 110 to the insert member 206, and lying flush to the outer fin surface 106.

(23) FIG. 2 illustrates the internal mechanism and interaction between fin section 100 and base 200 when this preferred embodiment of the first aspect of the adjustable fin of the invention is assembled.

(24) In FIG. 2, the lock 110 is releasably coupled in a locking position formed by a valley 212 in the hole 208 of the insert member 206. The internal cavity 120 in the fin section 100 is configured to enable the insert member 206 to slidably move by manual force in a direction towards the trailing edge 104. This can take place after the lock 110 is uncoupled from the insert member 206 when the button 112 is depressed by manual force and the slot in the button 112 is aligned with the teeth 210 allowing the teeth 210 to pass through the slot of the button 112. When the lock 110 is in alignment with another locking position, for example, formed by a second valley 220, release of the button 112 will move the slot of the button 112 out of alignment with the teeth 210 and the teeth 210 will no longer be able to pass through the slot of the button 112. As a result, the lock 110 will be restrained in the locking position formed by the second valley 220 and therefore releasably coupled to the insert member 206.

(25) FIG. 3A shows an illustration of an embodiment of the first aspect of the adjustable fin of the invention with a mount 232 on the base 200 which comprises a base attachment surface 230 to which an adhesive and, in some non-limiting examples, screws, are used to attach the adjustable fin to a surfboard (FIG. 3B).

Second Aspect of the Invention

(26) An embodiment of the second aspect of the adjustable fin of the invention is shown in FIG. 4 with the fin section 300 in three different positions relative to the base 400. The base 400 comprises a mount 422 comprising a front mounting block 410 and a rear mounting block 420 which can attach to existing available FCS fin plugs. The base 400 also comprises a planar member 430, and attached to which is a flange 440 which extends in a direction perpendicular to the planar member 430. The fin section 300 comprises a leading edge 310 and a trailing edge 320, and an underside surface 330 which abuts the base and outer surface of a surfboard to which it is mounted on. The cross sections through the centre of the adjustable fin from leading edge 310 to trailing edge 320 of the fin section 300 show the internal cavity 340 comprising an opening 350 on the underside surface through which the planar member 430 can enter and be housed by the internal cavity 340.

(27) As shown in the three cross sections, the internal cavity 340 is configured to allow slidable movement of the base 400 towards the leading edge 310 and a front position, or towards the trailing edge 320 and a rear position upon application of sufficient manual force on the fin section 300 in opposition to the base 400.

(28) This embodiment of the adjustable fin of the invention further comprises fixing teeth 450 at the end of the planar member 430 furthest from the mounting blocks 410, 420. Recesses 360 in the internal cavity 340 are able to receive the teeth 450 on the insert member to assist to restrain movement of the insert member in the internal cavity 340. When applying sufficient manual force to adjust this embodiment of the adjustable fin, the application of sufficient manual force will further comprise movement of the fin section 300 in a direction away from the base 400, against the elastic pressure of the resiliently deformable material, to dislocate the one or more teeth 450 from the recesses 360 to enable slidable movement of the planar member 430 within the internal cavity 340, and the flange 440 within the channel as shown in the centre cross section. As the teeth 450 are positioned at the end of the planar member 430 in closest proximity to the trailing edge 320 of the fin section 300, the application of sufficient manual force will further comprise movement of the fin section 300 in a direction away from the base 400 at the leading edge 310 or trailing edge 320 of the fin section 300. To provide for this movement of fin section 300 away from the base 400 to dislocate the teeth 450, the flange 440 is preferably curved at each one or both ends.

(29) An embodiment of the second aspect of the adjustable fin of the invention is shown in FIG. 5. The fin section 300 comprises a channel 370 for housing an extension, and preferably a flange, wherein the channel 370 contains a resiliently deformable material 372. An extension such as a flange is situated in the gap 374 between the resiliently deformable material 372 and the upper wall 376 of the channel 370. The resiliently deformable material 372 forces the flange against the upper wall 376 of the channel 370 to restrict movement of the base relative to the fin section 300. Measurements for the embodiment of the adjustable fin in FIG. 5 are shown (in mm).

(30) The other half of the fin section of FIG. 5 is shown in FIG. 6. This half of the fin section 300 in FIG. 6 shows the outline of the internal cavity 340 and measurements for this embodiment of the adjustable fin are shown (in mm).

(31) FIGS. 7 and 8 show two alternative versions of bases for embodiments of the second aspect of the adjustable fin of the invention with measurements in mm. The bases comprise mounting blocks which can attach to existing available FCS fin plugs.

(32) The photographs in FIG. 9A and FIG. 9B show cross sections of embodiments of a fin section and a base as illustrated in FIG. 4A and FIG. 4B, respectively. The photograph in FIG. 9C shows an embodiment of the second aspect of the adjustable fin of the invention with the underside surface of the fin section and the planar member of base projecting from the internal cavity. The bases comprise mounting blocks which can attach to existing available FCS fin plugs.

Third Aspect of the Invention

(33) In an embodiment of the third aspect of the present invention, an adjustable dual fin is shown in FIG. 10. The adjustable dual fin comprises the adjustable fin of the first aspect of the invention with a fin section 500 and a base 600, wherein a second fin section 550 is attached to the fin section 500 by five ribs 510 of different lengths. Both the fin section 500 and the second fin section 550 are flat foils with substantially flat outer fin surfaces on one side and curved outer fin surfaces on the other side. The leading edge of the fin section 500 is positioned forward of the leading edge of the second fin section. Leading edge passages 552 and trailing edge passages 554 through the second fin section 550 are angled towards the curved outer fin surface which forces water to pass through the passage and into the gap between the fin section 500 and second fin section 550. The embodiment further comprises an extended base member 610 such that when the adjustable dual fin is mounted on a surfboard, there is a gap between the outer surface of the surfboard and the underside surfaces of the fin section 500 and second fin section 550. The bases of the embodiment comprise mounting blocks which can attach to existing available FCS fin plugs.

(34) Without wanting to be limited by any one theory, it is believed that this embodiment of the adjustable dual fin of the third aspect of the invention provides a benefit of increased thrust and therefore speed in a direction substantially towards the front of a surfboard it is mounted to when in normal use, for the following reasons.

(35) As shown in the embodiment in FIG. 10, the distance between the flat outer fin surface 520 of the fin section 500, and the curved outer fin surface 560 of the second fin section 550 is nearest at the peak 562 of the curved outer fin surface 560 of the second fin section 550. This distance is preferably between approximately 0.1 mm and 5 mm, more preferably between approximately 0.25 mm and 1.5 mm, and even more preferably approximately 1 mm. The proximity and position of the fin section 500 and the second fin section 550 forms a V-shaped channel 564 between the peak 562 and the leading edge 566 of the fin section 500 and the leading edge 568 of the second fin section 550, the V-shaped channel 564 extending along the curved length of the fin sections to their tips 570. On the other side of the peak 562 is a rear chamber 572 formed between the peak 562 and the trailing edge 574 of the fin section 500 and the trailing edge 576 of the second fin section 550.

(36) During normal use when mounted on a surfboard, water passes into the V-shaped channel but only a small amount of this water can pass between the thin gap between the fin section and the second fin section. The majority of the water is forced along the length of the V-shaped channel towards the tip of the fin sections at a higher velocity than the normal speed that water is passing the fin sections. This higher velocity is generated due to the higher pressure behind the water forced into the channel than the pressure of the water in front of the water leaving the channel adjacent to the tips of the fin sections according to Newton's 2nd law. In accordance with Bernoulli's principle, the increase in the velocity of the water occurs simultaneously with a decrease in pressure. Therefore, a region of low pressure is created in this V-shaped channel.

(37) Conversely, some water passes through the thin gap between the fin section and the second fin section, and passages direct water through the second fin section from the side of the substantially flat outer fin surface into the rear chamber. The effect of forcing all of this water into the limited space of the rear chamber results in the creation of a region of high pressure.

(38) The pressure differential between the area of low pressure in the V-shaped channel and the area of high pressure in the rear chamber results in a lift force acting perpendicular to the direction of the fluid flow in the V-shaped channel. That is, in a direction towards the front of the fin on a slight downward angle. The thrust provided by this lift force acts to increase the overall speed of the fins in this direction, and therefore, the board through the water.

(39) FIGS. 11B and 11D show the internal structure and mechanism from different views of the same embodiment of the third aspect of the adjustable dual fin of the invention shown in FIGS. 11A and 11C, respectively. FIG. 11E shows an exploded view of the same embodiment. The bases comprise mounting blocks which can attach to existing available FCS fin plugs.

(40) An alternative embodiment of the base of an adjustable dual fin of the invention is shown in FIG. 12. The base comprising two members and extensions which can be housed within the internal cavities of two independent fin sections that are adjustable according to the second aspect of the invention as described herein. Measurements are shown (in mm). The base comprises mounting blocks which can attach to existing available FCS fin plugs.

(41) Embodiments of the adjustable fin and adjustable dual fin of the invention which have been mounted onto a surfboard are shown in FIG. 13. The mount for these embodiments comprises a base attachment surface which attaches to the surfboard by an adhesive. An adjustable fin according to the first aspect of the invention is mounted to the surfboard as a centre fin. Mounted to the surfboard as side fins are adjustable dual fins according to embodiments of the third aspect of the invention.