SURFCRAFT FIN ASSEMBLY
A surfcraft fin assembly includes a generally rectangular open mounting box recessed into the underside of surfcraft and having lugs projecting internally at the front and rear of its open edge to retain a notch in the leading edge of the base of the fin and a flexible hook in the rear edge of the base of the fin which flexes allowing insertion into and removal from the mounting box.
This invention relates to surfcraft fins and in particular to assemblies for fixing of fins to surfcraft such as surfboards, standup paddle boards and surf skis.
BACKGROUND OF THE INVENTIONIt should be noted that reference to the prior art herein is not to be taken as an acknowledgement that such prior art constitutes common general knowledge in the art.
The earliest surfboard fins were made as an integral part of the board. This meant that if a fin became damaged or needed to be changed for a different sized/shaped fin, the job of replacing it involved major reworking. Accordingly various methods of attaching fins to boards were devised to facilitate replacement of the fin.
U.S. Pat. No. 3,516,099 teaches an early example of a removable surfboard fin in which the board has a channeled mounting box recessed into its rear underside. The sidewalls of the box are tapered to receive the complementary base of the fin which is secured in the box by screws at the front and rear of the base. As the screws are tightened the fin is wedged tightly into the box to prevent movement between the fin and the board.
A more recent example is disclosed in US 2010/0173546 wherein a receptacle mounting base receives a connecting section of the fin. The body section of the fin protrudes outside the under surface of the surf board and has front and rear ends inclined outwardly. Two mating blocks which fit over the front and rear protruding sections of the fin are screwed onto the mounting base to secure the fin to the board.
Although the above fins allow replacement of a fin without major reworking of the board, it still takes time to release them from the board and attach a replacement fin.
Clearly it would be advantageous of the present invention to provide a contrivance which ameliorates the disadvantages set forth above or at least provides an alternative to the prior art.
STATEMENT OF THE INVENTIONAccording to the present invention a surfcraft fin assembly comprises a generally rectangular open mounting box and a fin with a base, the base having a notch in one end and a flexible portion at the other end, the mounting box being adapted to be recessed into the underside of a surfcraft and having two long side edges and short front and rear edges, said front and rear edge having lugs projecting internally to retain the fin in the box by engaging the notch in the base and the flexible portion of the base which flexes to allow insertion into and removal from the mounting box.
Preferably, the flexible portion is biased away from the fin such that during insertion it flexes towards the fin to allow insertion and once pressed past the lug springs away from the fin and under the lug to retain the fin in the mounting box. In one embodiment, the surfcraft fin assembly further includes a lever which can be used to prise the flexible portion of the fin base away from the lug to remove the fin from the mounting box.
In one embodiment, the fin base has a leading edge with a notch and a rear edge with a flexible portion. In an alternative embodiment the fin base has a leading edge with a flexible portion and a rear edge with a notch.
Preferably, the flexible portion is a flexible hook.
Preferably, the lugs are integrally formed with the box. Alternatively, the lugs are removably fastened to the box and are designed to snap off when the fin encounters an obstacle thus releasing the fin. In another embodiment the lugs are screwed into the box and are designed to snap off when the fin encounters an obstacle thus releasing the fin.
In yet another embodiment, the flexible portion of the fin base is adapted to snap off when the fin encounters an obstacle thus releasing the fin.
An embodiment of the invention is now described by way of example only with reference to the accompanying drawings in which:
The surfcraft fin assembly shown in
Fin 3, shown in
Front lug 2 can engage notch 5 in base 4 and rear lug 2 can engage flexible portion 6 to retain fin 3 in box 1. Notch 5 ensures that base 4 fits tightly under lug 2. Flexible portion 6 is normally biased away from fin 3 such that during insertion into box 1 it flexes towards fin 3 and once pressed past lug 2 it springs away from fin 3 and under lug 2 to retain fin 3 in mounting box 1 as shown in
Box 1 is ideally constructed of a hard plastic but may also be constructed from other suitable hardwearing material. Lugs 2, as shown in
A surfcraft may employ only a single fin assembly, for example a surf ski, or may employ a number of assemblies, such as a three finned surfboard 14 as shown in
It will be obvious that notches 5 and 12 together with flexible portions 6 and 13 allow rapid insertion and removal of fins to and from a surfcraft while maintaining secure engagement with mounting box 1 while the craft is in use. In the case of surfboard 14 with three fins as shown in
It will be realized that the foregoing has been given by way of illustrative example only and that all other modifications and variations as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as herein set forth. For example, it would be obvious that alternative methods of engaging the lugs may be used such as flexible protrusions on the base which provide an interference fit with the inside of box 1 or any other suitable arrangement. Alternative methods of joining the lugs to the mounting box may also be used such as clip in lugs or other suitable methods.
Throughout the description and claims of this specification the words “comprise” and variations of that word such as “comprises” and “comprising” are not intended to exclude other additives components integers or steps.
The drawings herein do not display definitive specifications as they are for explanatory and demonstration purposes only. The dimensions, appearance or materials used in this accessory may be varied to suit different surfcraft or fin shapes and sizes.
Claims
1. A surfcraft fin assembly comprising a generally rectangular open mounting box and
- a fin with a base;
- the base having a notch in one end and a flexible portion at the other end,
- the mounting box being adapted to be recessed into the underside of a surfcraft and having two long side edges and short front and rear edges, said front and rear edge having lugs projecting internally to retain the fin in the box by engaging the notch in the base and the flexible portion of the base which flexes to allow insertion into and removal from the mounting box.
2. The surfcraft fin assembly of claim 1 wherein the flexible portion is biased away from the fin such that during insertion it flexes towards the fin to allow insertion and once pressed past the lug springs away from the fin and under the lug to retain the fin in the mounting box.
3. The surfcraft fin assembly of claim 1 further comprising a lever which can be used to prise the flexible portion of the fin base away from the lug to remove the fin from the mounting box.
4. The surfcraft fin assembly of claim 1 wherein the fin base has a leading edge with a notch and a rear edge with a flexible portion.
5. The surfcraft fin assembly of claim 1 wherein the fin base has a leading edge with a flexible portion and a rear edge with a notch.
6. The surfcraft fin assembly of claim 1 wherein the flexible portion is a flexible hook.
7. The surfcraft fin assembly of claim 1 wherein the lugs are integrally formed with the box.
8. The surfcraft fin assembly of claim 1 in which the lugs are removably fastened to the box and are designed to snap off when the fin encounters an obstacle thus releasing the fin.
9. The surfcraft fin assembly of claim 1 in which the lugs are screwed into the box and are designed to snap off when the fin encounters an obstacle thus releasing the fin.
10. The surfcraft fin assembly of claim 1 wherein the flexible portion of the fin base is adapted to snap off when the fin encounters an obstacle thus releasing the fin.
Type: Application
Filed: May 2, 2013
Publication Date: Nov 14, 2013
Inventors: Stephen Douglass Schweikert (Burleigh Heads), Peter Ronald Crutch (Elanora), David Pacheco (Hope Island)
Application Number: 13/875,792
International Classification: B63B 35/79 (20060101);