GB2475555A

GB2475555A - Wind deflector for sports board

Info

Publication number: GB2475555A
Application number: GB0920517A
Authority: GB
Inventors: Robin David Knowles; Robert William Lewis
Original assignee: UK Sport Ltd
Current assignee: UK Sport Ltd
Priority date: 2009-11-24
Filing date: 2009-11-24
Publication date: 2011-05-25
Also published as: GB0920517D0

Abstract

A sports' board comprises a wind deflector 22 extending rearwards from the nose of the board. The board may be a snowboard in which the deflector 22 has a maximum height product approximating to the height of the top of a user's' boot sole when the user is attached to the board. The deflector 22 may form of shroud over the leading edge 20 of the sports' board. The deflector serves to reduce the drag on the board.

Description

SPORTS' BOARDS This invention relates primarily to snowboards and skis. However, it is applicable to other sports boards (as herein defined).

n this specification a "sports' board" is a snowboard, ski, or similar board which is attached to a boot to be worn by a sports person to enable the wearer is easily to traverse a surface. Sports' boards of this kind have a generally flat underside for contact with the surface, and curve up towards their leading edges to a nose or tip is such that their leading edges are normally clear of the surface concerned to help the ride over the surfaces and prevent the nose or tip from digging in. In the case of snowboards and skis the surface will be snowed or artificial snow, in the case of water skis or water boards the surface would be water.

n this specification the word "nose" includes a tip.

n sports' boards of this kind which are used at speed, reduction in drag caused by wind pressure generated by the speed of the user is highly desirable.

According to the present invention a sports' board is characterised in having a wind deflector extending rearwards from the nose of the sport's board.

Best results are obtained when the deflector has a maximum height above the upwardly curving portion of the board substantially aligned with the mid height of a user's boot when fitted to a board.

Best results are obtained when the deflector forms a shroud over the leading edge of the sports' board.

n one embodiment of the invention the deflector extends rearwardly from the nose to between the upwardly curved leading edges of the board and the foremost boot position of a user.

In such an embodiment if the deflector height reduces steadily from its maximum height to its trailing edge turbulence of air flow over the board is minimised.

If the maximum height extends substantially across the width of the board better performance is achieved. Preferably the edges of the deflector are rounded.

The invention is particularly apposite for snowboards.

Best drag reduction is obtained if the deflector extends beyond the rear foot position of a user, however in some cases this may mean loss of flexibility in the board, and increased manufacturing costs.

n this design, apertures to receive boots which are substantially the same dimensions as the footprint of boots of a prospective user reduces drag considerably. Thus with such deflectors, sports' boards would need to be "sized" to ensure that aperture on different boards matched different boot sizes. For many applications a shorter deflector pinching before the leading boot position of a user allows for greater flexibility in that the presence of a deflector does not dictate the appropriate size to be worn without deflector and board combination.

It has been found that where the deflector extends beyond the rear foot of a prospective user, best results are obtained if the rear of the deflector forms a shroud around the trailing edge of the board.

In another embodiment of the invention a wind deflector for use in association with a sport's board is characterised in that the deflector has a shroud portion to fit over the leading edge and those of the sports board.

A wind deflector according to this latter embodiment performs best if the maximum height of the deflector is substantially aligned with the mid height of a user's boot when fitted to a board.

It has been found, that although best results are obtained where the deflector extends substantially rearwards of the rear foot of a user (or in the case of a ski the foot), such an arrangement may reduce flexibility of the board and costs substantially more to manufacture, a deflector extending rearwards from the nose to between the upward forward curve of the board and the leading boot position achieves reasonable reduction in drag in use without compromising the overall flexibility of the board, and is easy to manufacture.

The deflectors can be made of any suitable materials including plastics, GRP and carbon fibre materials.

Although originally designed as an attachment to sports' boards, there is no reason why deflectors in accordance with this invention should not be part of the original design of the sports' board itself.

Aspects of the invention are described in the accompanying drawings, by way of example only, describing snowboards having deflectors in accordance with the invention: figures 1A, lB and 1C show perspective, partial longitudinal section on the line B-B' of figure 1A, and top view respectively of a short deflector according to the invention used in conjunction with a snowboard; figure 2 shows the impact of the deflector of figures 1A to 1C on the drag performance of the board; figures 3A to 3D show longer deflectors used in conjunction with a snowboard; and figures 4A to 4D show the impact of the deflectors of figures 3A to 3D on drag; figure 5 shows the impact on drag of a deflector that is roughly the height of a normal user's boot; and figure 6A shows a further modified deflector and figure 6B its performance.

In figure 1 a snowboarder 1 is shown attached by bindings 3 to a snowboard 10. As will be seen the snowboarder has boots 5 (leading) and 6 (trailing) each with a sole 7.

The snowboard 10 itself has a raised areas 9 onto which the bindings 3 are mounted.

The bindings 3, boots 5 and 6, soles 7 and raised areas 9 for binding attachment are entirely conventional in the field of snowboard design.

The snowboard has an upper surface 12, side edges 14 leading edges 16, rounded trailing edge 18 and a nose 20 formed between the leading edges 16. The board has an upwardly curving portion 19 curved upwards towards its nose 20, such as in use nose is clear of a snow surface over which the board is to travel, thus directing snow beneath the board and minimising the risk of the nose 20 digging in. Again this part of the design is entirely conventional.

A deflector 22 is fitted to the snowboard 20. The deflector 22 has an area 24 extending across the width of the board, roughly above a mid transverse line across the upwardly curving portion 19 of the board. The deflector has rounded edges 30 which extend downwards and shroud the leading edges 16 and nose 20. The side edges 14 are not shrouded ensuring that edge contact with snow is not hindered and maximum flexibility of the snowboard is maintained.

The maximum height of the area 24 is roughly half the height of the user's boot. The deflector 22 gradually reduces in height from the area 24 to a rounded rear edge 28 extending across the top of board between the rear of the upwardly curving portion 19 and the forward bindings 3.

Wind model tests on a snowboard fitted with a deflector as shown in figure 1 are illustrated in figure 2. As will be seen the presence of the deflector was slightly detrimental to the drag performance in the torso area, but this was substantially outweighed by the reduction in drag on the snowboard itself resulting in an overall drag reduction when the snowboard is used by a snowboarder of 1.9%.

Figures 3A to 3D show alternative deflectors. The deflectors extend from the nose 20 rearwards to behind the rear boot 6. In these figures those parts that are in common with the snowboard and deflector of figure 1 have the same labels.

In figure 3A, the deflector 22 above the top 12 the snowboard 10 now extends back behind the rear boot 6 of a snowboarder 1 before being rounded down at its trailing edge 32 to the top surface 12 of the board ahead of the board's trailing edge 18. The height of area 24 is roughly half the height the users' boots 5 and 6. In the case illustrated this would be just above the level of the top 8 of the soles 7.

In figure 3B a similar arrangement is shown save that the trailing edge of the deflector 22 is formed into a wedge shaped tail 34.

The snowboard and deflector figure 3C is again similar to the arrangement in figure 3A save that the trailing edge of the deflector 22 forms a shroud 36 around the trailing edge 18 of the snowboard.

The deflector of figure 3D is similar to that of figure 3A except that the leading edges 16 of the snowboard 10 are not shrouded by the leading edge of the deflector. Instead the defector increases to its maximum height 24 from the leading edge 38 substantially behind the nose 20 of the snowboard 10.

In each of the examples of figures 3A to 3D the deflector 22 has apertures 40 matching external perimeter of the soles of boots 5 and 6.

In figures 4A to 4C which involve deflectors corresponding to figures 3A to 3C and shrouding the leading edges 16 and nose 20 of the snowboard 10, significant drag reduction of just under 3% on the left boot were obtained, and overall drag reductions of over 3% achieved. In the case of figure 4D, which corresponds to deflector of figure 3D without the leading shroud, the drag reduction achieved was no more than 2%.

The best overall results can be seen in figure 3C where the deflector shrouds the leading edges, nose and trailing edge of the snowboard. Here the drag reduction was 3.5%.

The comparative figure 5 shows drag measurements obtained from a deflector similar to that of figure 3A but where the maximum height of the deflector was the same as the user's boot. In this case excellent drag reduction around the leading foot (6%) was achieved but this was partially offset by increased drag around the torso (1%) and the snowboard itself (5%), resulting in an overall drag reduction of 2% substantially the same as the much simpler deflector of figure L Figure 6A shows a deflector of the kind illustrated in figure 3A but with a larger aperture 40 to receive a variety of boot sizes. Figure 6B shows a substantial increase in the drag on the leading foot. This figure clearly illustrates the importance of the design of the apertures 40 if a deflector is used extending rearwards of the boot positions.

Other possible variations in the design illustrated in figures 3A to 3D and the comparator deflectors of figures 5 and 6 include provision of flicks ahead of apertures 40, especially the leading aperture to reduce drag caused by the boots, this will substantially improve the performance of the defector discussed in figure 6 and variations of the height of the deflector rearwards of the maximum height area 24.

However it is again noted that the short deflector illustrated in figure 1 produces a significant drag reduction without substantially increasing the weight or stiffness of the board it is also readily manufactured and incorporated in a snowboard or ski design.

Claims

CLAIMS1. A sports' board having a wind deflector extending rearwards from the nose of the board.
2. A sports' board according to claim 1 in which the deflector has a maximum height above the upwardly curving portion of the board substantially aligned with the mid height of a user's boot when fitted to a board.
3. A sports' board according to claim 1 or 2 in which the deflector forms of shroud over the leading edge of the sports' board.
4. A sports' board according to any one of claims 1 to 3 in which the deflector extends rearwardly from the nose to between the upwardly curved leading edges of the board and the foremost boot position of a user.
5. A sports' board according to claim 4 in which the deflector height reduces steadily from its maximum height to its trailing edge.
6. A sport's board according to any preceding claims in which the maximum height extends substantially across the width of the board.
7. A sport's board according to any preceding claim in which the edges of the deflector are rounded.
8. A sport's board according to any preceding claim characterised in the sport's board is a snowboard.
9. A sport's board according to claim 8 characterised in at the deflector extends beyond the rear foot position of a user.
10. A sport's board according to claim 9 having apertures substantially the same dimensions as the footprint of boots of a prospective user.
11. A sport's board according to any one of claims 8 to 10 including a flick ahead of the leading boot position to direct wind up above the user's boot.
12. A sport's board according to any one of claims 8 to 11 in which the trailing edge of the deflector forms of shroud around the trailing edge of the board.
13. A wind deflector for use in association with a sport's board characterised in that the deflector has a shroud portion to fit over the leading edge and those of the sports board.
14. A wind deflector according to claim 13 characterised in the maximum height of the deflector is substantially aligned with the mid height of a user's boot when fitted to a board.
15. A sport's board substantiates hereinbefore described with reference to the accompanying drawings.
16. A wind deflector for use with a sport's board substantially as hereinbefore described with reference to the accompanying drawings.