GB2570012A

GB2570012A - Skateboard

Info

Publication number: GB2570012A
Application number: GB1809021.7A
Authority: GB
Inventors: Anthony Curzon Price John; Gabriel de Pourtales Paul
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-01-05
Filing date: 2018-06-01
Publication date: 2019-07-10
Also published as: GB201809021D0; GB201800212D0

Abstract

A skateboard 100 comprises a board 112, first and second wheels 114, 116 connected to opposing ends of the board 112, and a middle wheel 118 connected to a middle part of theboard between the ends, the wheels 114, 116, 118 being arranged to rotate in substantially the same direction, a common tangent (T1) of the first and middle wheels 114, 118 meeting a common tangent (T2) of the second and middle wheels 116, 118 at an obtuse angle (Ɵ), in use providing a wheel arrangement where one of the first and second wheels 114, 116 is raised off the ground when the other of the first and second wheels 116,114 is ground-engaging. The first, second and third wheels may be provided in an in-line configuration.

Description

SKATEBOARD

The present invention relates to a skateboard.

BACKGROUND TO THE INVENTION

Skateboards are usually used on roads, pavements and in dedicated skate parks, where there are substantially smooth surfaces. It is less common for skateboards to be used on other terrains, such as grass, dirt or sand, because these surfaces tend to be uneven and the wheels in conventional skateboards do not perform as well on them.

Various developments have improved skateboard performance on non-smooth or offroad surfaces. Two of the more successful attempts include the ‘Mountainboard’ and the ‘Dirtsurfer’ (described in US6398237). Both of these skateboards have been used in situations where the rider is ‘powered’, for example by a kite or a sail, as well as applications where the rider uses the board to go down hills or to push along flat surfaces.

The Mountainboard is a skateboard with wheels which are substantially larger than those of a normal skateboard, e.g. around 15 cm to 30 cm in diameter. As mentioned in US6398237, this results in either a higher deck, creating instability during use, or a much wider structure with large wheels extending out past the edge of the deck, which makes the board quite cumbersome and sluggish to ride. These drawbacks limit the size of the wheels which can be used, which in turn makes the Mountainboard relatively ill-suited for use on anything other than smooth dirt, hard-packed sand, or short-cut and smooth grassy terrain.

The Dirtsurfer addresses some of these limitations by providing a skateboard with two wheels aligned along a central axis (also referred to as in-line). The board or frame is pivotally connected to the leading wheel by an articulated front fork for turning and improved stability, and delivering a smoother ride than the Mountainboard. However, this means that the Dirtsurfer is not ‘bi-directional’ because the fork must always be front-facing, i.e. the board cannot be ridden in either direction, unlike the Mountainboard. The turning radius of the Dirtsurfer board is also considerably larger than the Mountainboard due to the combination of the articulated fork and a long wheel base.

The in-line wheel arrangement in the Dirtsurfer permits bigger wheels to be used (up to 60 cm in diameter) than in the Mountainboard. This delivers better performance in terms of speed and the smoothness of the ride, and allows travel over rougher terrain than the Mountainboard can handle.

The in-line wheels of the Dirtsurfer also allow “edging”. This is the riding practice where the board and wheels can be readily tilted to counter a perpendicular force that would otherwise tend to pull the rider off the board - for example when the skateboard is being used with a kite, or when being towed.

Edging is familiar to kite-surfers, snow-kiters and wakeboarders from the intrinsic qualities of the water or snow on which these sports are practised, which can make the Dirtsurfer easier to adjust to than to the Mountainboard for a person switching between the different sports. This is because the construction of the Mountainboard does not make edging easy - the four wheels are usually in contact with the ground during use, restricting the ability of the board to tilt towards the ground. This means that the rider must bear a greater amount of the strain coming from any perpendicular pulling force.

Whilst each of the Dirtsurfer and Mountainboard have certain advantages, they also come with their own drawbacks as discussed above. Both boards also tend to be quite heavy. In particular, the long wheel base and front-fork articulation on the Dirtsurfer requires a heavy frame, making it inconvenient for aerial activities such as jumping with a kite.

It is an object of the present invention to reduce or substantially obviate the aforementioned problems.

STATEMENT OF INVENTION

According to the present invention, there is provided a skateboard comprising a board, first and second wheels connected to opposing ends of the board, and a middle wheel connected to a middle part of the board between the ends, the wheels being arranged to rotate in substantially the same direction, a common tangent of the first and middle wheels meeting a common tangent of the second and middle wheels at an obtuse angle, in use providing a wheel arrangement where one of the first and second wheels is raised off the ground when the other of the first and second wheels is ground-engaging.

This provides a skateboard suitable for riding on all types of land terrain, whether rugged or smooth. Providing a middle wheel effectively halves the wheelbase of the skateboard, since only two of the three wheels are ground-engaging at a given time. This enables faster, sharper turns during use, particularly relative to conventional offroad skateboards like the Mountainboard and Dirtsurfer.

Furthermore, there is no need for a heavy articulated fork/truck or intricate mechanism, so the skateboard is bi-directional, i.e. it can be ridden either way round. The skateboard can be turned with ease by transferring weight over the middle wheel and optionally using the edge of the skateboard against the ground at various angles. This allows the skateboard to remain lightweight, which is much better for doing aerial stunts. The rider can of course switch their stance on the board to face the other way and make a turn, due to the board’s bidirectionality.

In use, the back wheel and the middle wheel are in contact with the ground. The front wheel is in the air. To turn, the user shifts their weight to control the load on the back wheel. The middle wheel can act as a pivot during this process. Note that turning does not require the airborne (front) wheel to become ground-engaging, or for the ground-engaging (rear) wheel to become airborne. The load on the back wheel is controllably reduced by the rider during a turn. The user may lean to either side of the centreline to aid turning. Since the wheelbase is considerably shorter than in a conventional skateboard, the user can change direction by 180° (often called a “jibe” in sail- or kite-based practices) with a very small radius or turning circle. This is helped by using a kite to apply a corresponding sideways force, for example. Board stability is controlled mechanically, without electronic stabilisation.

The term skateboard should be interpreted as meaning a wheeled board rideable on land. Equivalents terms for the purpose of this specification include landboard, mountain board, all-terrain board, off-road board, or dirtboard. In some instances, the skateboard can be used as a land kiteboard / kite landboard, or land sailboard, for example.

The board can be a full deck, or can be a frame. If a frame is provided, then there should be areas in the frame adapted for a rider to stand on, preferably to either side of the middle wheel. The board or deck may have a length in the range 0.85 to 1.5 metres. This size of wheelbase is preferred for activities such as kiteboarding on land.

The obtuse angle is taken from a side view of the board, in a plane substantially perpendicular to the axes of rotation of the wheels. The obtuse angle may be in the range 135° to 178°. A 135° angle may be suitable for an extreme mountain bike version of the board. This is suitable for including larger shock absorbers suited to extremely rocky terrain, for example. A 178° angle is suitable for riding on smooth concrete, for example. The obtuse angle may preferably be in the range 145° to 175°. Flatter angles approaching 180° are more suitable for flatter terrain, whilst smaller obtuse angles are preferred for rockier terrain.

The middle wheel may be provided substantially centrally between the first and second wheels. The first, second and middle wheels may be provided in an in-line configuration. Providing an in-line configuration makes it easier for the user to perform edging when riding the board.

One or more additional wheels may be provided. The additional wheel may be arranged to rotate on the same axis as any one of the first, second or middle wheels. The arrangement of wheels will then differ from the 1-1-1 board arrangement (the key for the number of wheels at the different parts of the board is: end - middle - end). Extra wheels may be provided towards either end and/or between the ends of the board. Having additional wheels can be useful for stability over rough terrain.

The additional wheel may be the same size as the other wheel(s) on the same axis. A given additional wheel may be equivalent to any one of the first, second or middle wheels. If so, then the common tangent(s) involving that additional wheel should still meet at an obtuse angle with the other common tangent of the other wheels.

If a second middle wheel is provided, it may be arranged to rotate on the same axis as the first middle wheel. Together, the four wheels may be arranged in a diamond-shaped configuration, for example.

The board may include one or more longitudinal slots for the wheels. The width of the slot(s) may be about half the width of the board or less. If the board is a frame, then the width of the slots may be up to about 70-80% of the width of the frame. One or more of the wheels may extend through the board (or deck). One or more of the wheels may be mounted to rotate through the slot(s). Providing the wheels through the board means that the board can sit closer to the ground in use. This makes it easier to perform edging.

The middle wheel may be mounted through the board. A minor segment or minor arc of the middle wheel may be disposed below the board as the ground-engaging portion in use. A major segment of the middle wheel may be disposed to another side of the board. Similarly, if the end wheels are mounted through the board, minor segments/arcs of those wheels may be disposed to the same side of the board as the minor segment of the middle wheel. This brings the obtuse angle closer to 180°.

The skateboard may be substantially symmetrical about a plane perpendicular to the longitudinal axis of the board for enabling bidirectional use. In other words, the board is functionally symmetrical when viewed from the side. There is no dedicated front or rear end. The user can mount and ride the board facing in either direction.

The first and second wheels may each have a radius r. The or each middle wheel may have a larger radius R than the first and second wheel radii r. This provides a smooth and fast ride during use. Alternatively, the first, second and middle wheels may each have substantially the same radius, or the middle wheel may have a smaller radius than the end wheels (as long as it is mounted in a way which still gives the board ground clearance in use). In any of these cases, the middle part of the board may include a step or a change of angle at or adjacent to the middle wheel. This provides the obtuse angle between the common tangents of neighbouring wheels. In some cases, the first and second wheels may have different radii.

If the middle wheel has a radius R, a common tangent of the first and second wheels may pass within a distance of R or less from the point where the other common tangents intersect, i.e. the common tangents of either end wheel to the middle wheel. This ensures that the relative positions and/or sizes of the wheels are not too dissimilar, which would make it harder to ride the skateboard. A height adjustment mechanism may be provided for at least one of the wheels for varying the obtuse angle between the wheels. This also allows the ride height or clearance of the board to be optimised according to the terrain to be ridden on. This may be achieved by mounting the middle wheel at a particular height prior to use of the board. For example, for more uneven ground, a larger clearance is preferred to reduce the risk that an edge of the board inadvertently catches on a bump. Of course, the rider may still deliberately use the edge for turning and/or braking, and the ride height is selected taking this into account.

At least one of the wheels may be connected to the board by a flexible connector. This enables the associated wheel, e.g. the end wheels, to pivot slightly when turning, allowing for a shorter turn radius. The flexible connector may include a flexible material, e.g. rubber. For example, the flexible connector may include a stiff rubber joint. In one version of the skateboard, one or both of the first and second wheels may be connected to the board via rubber joints. Axle plates of the wheels may be mounted on the rubber joints. At least one of the wheels may include a shock-absorbing mechanism, optionally as part of or provided by the flexible connector.

One or more of the wheels may be motorised. The middle wheel may be motorised, since this wheel is in contact with the ground when the board is not airborne. This can be useful for maintaining momentum over rough or sandy terrain, for example. A cover or mudguard may be provided on the middle part of the board. The cover may extend over at least part of the middle wheel, and optionally all of the middle wheel. This protects the user’s legs from the rotating wheel and any debris flung upwards by it in use, as well as reducing the likelihood that anything catches on the wheel during use, e.g. loose clothing.

At least one foot strap or binding may be provided on the board to either side of the middle wheel. Preferably, two foot straps are provided, one to each side of the middle wheel. This is useful when being towed along, e.g. when kiting, particularly for jumps.

At least one of the wheels may be mounted to the board by a quick-release mechanism. This allows for fast interchange of the wheels when changing between terrains.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings, in which:

Figure 1 shows a perspective view of a first embodiment of a skateboard according to the present invention;

Figure 2 shows a side view of a second embodiment of a skateboard;

Figure 3 shows a top view of the skateboard in Figure 2, omitting wheels;

Figure 4 shows a side view of a third embodiment of a skateboard;

Figure 5 shows a side view of a fourth embodiment of a skateboard; and

Figure 6 shows a perspective view of a wheel mount for a skateboard.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring firstly to Figure 1, a first embodiment of a skateboard (or landboard) is indicated generally at 10. The skateboard 10 includes an elongate board or deck 12. The deck 12 is substantially planar or flat in this embodiment. The deck 12 is made of conventional material, e.g. a lightweight polymer, wood, metal (such as aluminium), composite material, or laminate.

The deck 12 includes longitudinal slots 12a, 12b towards either end of the deck 12. These slots are closed, i.e. they have four internal edges within the perimeter of the deck 12. Each end slot 12a, 12b has a width which is about 25% of the width of the deck 12. There is also a third longitudinal slot 12c in the deck 12. The third slot 12c has a width which is about 40% of the width of the deck 12. Each slot 12a, 12b, 12c extends through the deck 12. The slots 12a, 12b, 12c are all aligned or colinear along a central longitudinal axis of the deck 12 in this embodiment. The length of the deck 12 is about 1.25 metres in this embodiment.

First and second wheels 14, 16 are mounted towards either end of the deck 12. A middle wheel 18 is mounted substantially centrally through a middle part of the deck 12. The three wheels 14, 16, 18 are provided in an in-line arrangement. Each slot 12a, 12b, 12c is wider and slightly longer than the wheel it hosts. Common tangents of neighbouring wheels in the skateboard 10 meet at an obtuse angle (not shown) on the circumference of the middle wheel.

The wheel arrangement in the board 10 makes the board substantially symmetrical about a vertical lateral plane across a midpoint of the board 10. The plane of symmetry' intersects the axis of rotation of the middle wheel 18 in this embodiment, but may be offset in other embodiments - the board 10 just has to be symmetric enough for bidirectional riding.

The first and second wheels 14, 16 are substantially the same size in this embodiment. The middle wheel 18 is substantially larger than the first and second wheels 14, 16 in this embodiment. The ratio of wheel sizes is approximately 1:3:1. The middle wheel 18 has a diameter of approximately one third of the length of the deck in this embodiment, i.e. about 42cm. The other wheels 14, 16 each have a diameter of approximately 40% of the diameter of the middle wheel 18, i.e. about 17 cm. These dimensions include both the wheel hub and the tyre on it, which together form the wheel. A range of wheel sizes from about 9 cm to about 35 cm diameter may be used in other embodiments.

Although Figure 1 depicts the middle wheel 18 as a spoked wheel from a bicycle, it will be appreciated that the middle wheel 18 may be any form of wheel. The depiction of a bicycle wheel is purely exemplary.

The first wheel 14 is mounted to rotate through one of the end longitudinal slots 12a. The second wheel is mounted to rotate through the other of the end longitudinal slots 12b. The middle wheel is mounted to rotate through the middle slot 12c.

Mounting bracket and axle arrangements 14a, 16a, 18a are provided for each wheel. Each mounting arrangement 14a, 16a, 18a includes a pair of mounting brackets or axle plates disposed to either side of one of the slots 12a, 12b, 12c. The mounting arrangement 18a for the middle wheel 18 is larger than the other arrangements 14a, 16a to accommodate the larger wheel 18. The larger wheel mounting arrangement 18a includes one embodiment of a height adjustment mechanism. The mounting arrangement 18a is constructed to be flexible and absorb shocks during use.

Each mounting arrangement 14a, 16a, 18a includes an axle for the wheel for that slot. For example, the axle for the middle wheel is indicated at 18b. Each axle is disposed to one side of the deck 12 in this embodiment. This means that the axis of rotation of each wheel is located in a plane over the deck 12 in use. Therefore, the portion of each wheel which is disposed to the other side of the deck 12 is a minor segment or portion of that wheel. In use, the minor segments are ground-engaging portions of the wheels.

Each of the end wheels 14, 16 is spaced apart from the middle wheel 18. This provides regions 20 on the deck 12 to either side of the middle wheel 18 for the rider to stand on during use.

When riding the skateboard 10, the wheelbase is usually provided by two of the three wheels 14, 16, 18. Normally, the frontmost wheel is airborne, whilst the middle wheel 18 and rearmost wheel are ground-engaging. The flat deck 12 thus runs at an angle to the average level of the ground during use. The rider’s weight mainly acts through the rear section of the board 12, between the ground-engaging wheels.

Turning can be aided by using a kite, for example, especially where sharp turns are desired. In addition or as an alternative, edges of the board 12 can be used to help turn the board, optionally in combination with a hand-drag or similar. This may be useful on sand or other loose surfaces, for example.

Referring also to Figures 2 and 3, another embodiment of a skateboard is indicated generally at 100. The features of this skateboard 100 are substantially similar to the first embodiment, with like parts being denoted by like reference numerals, unless otherwise noted.

In this embodiment, end wheels 114, 116 are mounted through open-ended slots in the ends of a deck 112. This allows part of each wheel to lie beyond the maximum longitudinal extent of the deck 112. This lengthens the wheelbase, improving stability during use. A middle wheel 118 is again mounted centrally in the deck 12. A common tangent of the first and middle wheels 114, 118 is indicated by the imaginary' line designated Tl. A common tangent of the second and middle wheels 116, 118 is indicated by the imaginary line designated T2. The common tangents Tl, T2 run in a central longitudinal plane of the deck 112. The common tangents Tl, T2 meet at the lowermost point of the circumference of the middle wheel 118, below the deck 112. When viewed side-on, the common tangents Tl and T2 meet at an obtuse angle Θ. The angle Θ is about 166° in this embodiment. This description applies correspondingly to the first embodiment of a skateboard 10.

It is of course possible to take common tangents on the other (top) side of the deck, where major segments of the wheels are located. The obtuse angle where those tangents meet has a lower value due to the difference in wheel size. However, whilst it is possible to ride the board in an upside-down configuration, where major segments of each wheel are under the board when ridden, it is less practical.

Referring to Figure 4, another embodiment of a skateboard is indicated generally at 200. There are many similarities to the previous embodiments. However, in this case, a longer board 212 is used than in the other embodiments (about 20% longer). End wheels 214, 216 are mounted outside the board 212, rather than through it. Corresponding wheels (not shown) are paired with those end wheels 214, 216. This provides an X-shaped configuration of five wheels, including a middle wheel 218.

Two bindings 222 are provided on the board 212. A two-part mudguard is also provided on the upper surface of the board 212, around part of the middle wheel 218. The mudguard includes leading and trailing portions 224a, 224b. The portions curve over and around the middle wheel 218.

Referring now to Figure 5, another embodiment of a skateboard is indicated generally at 300. This embodiment has several differences to the foregoing embodiments, as discussed below.

Instead of having a substantially planar deck, the skateboard includes an angled or ‘bent’ deck. The deck includes a first planar portion 312 and a second planar portion 313, joined together (or integrally formed) at an angle Θ’ at the region indicated generally by 326. Although alternative versions are not illustrated, it will be appreciated that the deck could instead incorporate a step, so that the deck portions run in parallel but offset planes to achieve the same thing. Furthermore, it will be appreciated that another version might include a curved deck, or a deck with a series of three or more incrementally angled planar portions.

Also, first and second end wheels 314, 316 and a middle wheel 318 connected to the deck are all substantially similar in size. The middle wheel 318 is connected at the point where the deck portions 312, 313 meet. The wheels 314, 316, 318 are each mounted with their axles in the same plane as one of the deck portions 312, 313 in this embodiment. Therefore, roughly equal segments of each wheel are disposed to either side of a given deck portion 312, 313. Fess than half of the middle wheel 318 is exposed above deck during use, so if provided then a mudguard can be correspondingly smaller.

Since the wheels are all the same size, the obtuse angle between common tangents of the middle wheel 318 to each end wheel 314, 316 is achieved by providing the non-planar deck. The illustration in Figure 2 applies in a correspondingly modified way. It will be appreciated that the obtuse angle Θ between those common tangents will be approximately the same as the angle Θ’ between the deck portions 312, 313.

Referring also to Figure 6, an embodiment of a height adjustment mechanism is indicated generally at 400. The height adjustment mechanism 400 is effectively an axle mount or axle plate for the middle wheel of a board. The axle mount includes a base 402 and an upright portion 404. The upright portion 404 runs along an edge of the base 402. The base 402 has a series of holes 402a for securing the axle mount 400 to a board. Two axle mounts 400, 400’are secured to opposite sides of a slot for receiving a wheel. The second axle mount 400 usually mirrors the shape of the first axle mount 400.

The upright portion 404 is substantially triangular in shape. The ‘hypotenuse’ includes a curved side 404a. Another side of the upright portion 404 includes a number of axle receiving areas, indicated generally at 406. The receiving areas 406 are vertically offset from each other along the upright portion 404. One receiving area 406 is adjacent to the base, and each successive receiving area 406 is further away from the base 402. In this case there are four receiving areas, but it will be appreciated that a greater or lesser number may be provided, as long as the wheel can still engage the ground when mounted. The receiving areas 406 are separated from each other by projections or interstitial arms 408. The projections 408 are angled downwardly towards the base 402 in this embodiment. The wheel is typically secured in one of the receiving areas 406 via nuts and bolts, or using a quick-release mechanism.

When the middle wheel is mounted in the uppermost receiving area, the obtuse angle is closer to 180 degrees (for a given size of wheel). When the middle wheel is mounted in the lowermost receiving area, the obtuse angle is closer to 135 degrees. Mounting the middle wheel in one of the other receiving areas gives an obtuse angle between those values.

The embodiments described above are provided by way of example only, and various changes and modifications will be apparent to persons skilled in the art without departing from the scope of the present invention as defined by the appended claims.

Claims

1. A skateboard comprising a board, first and second wheels connected to opposing ends of the board, and a middle wheel connected to a middle part of the board between the ends, the wheels being arranged to rotate in substantially the same direction, a common tangent of the first and middle wheels meeting a common tangent of the second and middle wheels at an obtuse angle, in use providing a wheel arrangement where one of the first and second wheels is raised off the ground when the other of the first and second wheels is ground-engaging.

2. A skateboard as claimed in claim 1, in which the first, second and middle wheels are provided in an in-line configuration.

3. A skateboard as claimed in claim 1, in which one or more additional wheels are provided and arranged to rotate on the same axis as one of the first, second or middle wheels.

4. A skateboard as claimed in claim 3, in which a second middle wheel is provided and arranged to rotate on the same axis as the first middle wheel, the four wheels being arranged in a diamond-shaped configuration.

5. A skateboard as claimed in any of claims 1 to 4, in which the middle wheel is mounted through the board.

6. A skateboard as claimed in any preceding claim, in which a minor segment of the middle wheel is disposed to one side of the board for engaging the ground in use, and a major segment of the middle wheel is disposed to another side of the board.

7. A skateboard as claimed in any preceding claim, in which the skateboard is substantially symmetrical about a plane perpendicular to the longitudinal axis of the board for enabling bidirectional use.

8. A skateboard as claimed in any preceding claim, in which the first and second wheels each have a radius r, and the middle wheel has a larger radius R.

9. A skateboard as claimed in any of claims 1 to 7, in which the first, second and middle wheels each have substantially the same radius, or the middle wheel has a smaller radius than the first and second wheels.

10. A skateboard as claimed in any preceding claim, in which the middle part of the board includes a step or a change of angle at or adjacent to the middle wheel.

11. A skateboard as claimed in any preceding claim, in which the middle wheel has a radius R, and a common tangent of the first and second wheels passes within a distance of R or less from the point where the other common tangents meet.

12. A skateboard as claimed in any preceding claim, in which the board includes one or more longitudinal slots for the wheels, and one or more of the wheels is mounted to rotate through the respective slot(s).

13. A skateboard as claimed in any preceding claim, in which a height adjustment mechanism is provided for at least one of the wheels for varying the obtuse angle between the wheels.

14. A skateboard as claimed in any preceding claim, in which at least one of the wheels is connected to the board by a flexible connector.

15. A skateboard as claimed in any preceding claim, in which at least one of the wheels includes a shock-absorbing mechanism.

16. A skateboard as claimed in any preceding claim, in which one or more of the wheels are motorised.

17. A skateboard as claimed in any preceding claim, in which a cover is provided on the middle part of the board over at least part of the middle wheel.

18. A skateboard as claimed in any preceding claim, in which at least one foot strap or binding is provided on the board to either side of the middle wheel.