GB2464565A

GB2464565A - Skateboard with inclined steering axis

Info

Publication number: GB2464565A
Application number: GB0901755A
Authority: GB
Inventors: John Kevin Luff
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-10-21
Filing date: 2009-02-03
Publication date: 2010-04-28
Also published as: GB0819206D0; GB2464676A; GB0901755D0

Abstract

The skateboard has front and rear decks 1 and 2 mounted on respective wheels 8 and 9, and the decks are arranged to tilt about a steering axis A which is inclined relative to the front-rear direction of the skateboard. The front deck 1 has a single wheel mounted on or near the mid line of the deck and rotates about axis which is fixed relative to the front deck. Such a skateboard gives a user more precise control over steering. The steering axis may be downwardly inclined towards the front deck 1 and the adjacent ends of the front and rear decks may be inclined relative to the front-rear direction. The decks may be spring-loaded towards an aligned, co-planar configuration. Both front and rear wheels may be mounted to rotate about an axis fixed relative to the decks, and may project into holes on the respective decks. A motor may be incorporated into one of the wheels.

Description

STEERABLE SKATEBOARD

TECHNICAL FIELD OF THE INVENTION

This invention relates to skateboards, and more particularly to the steering arrangements which are used to enable the rider to change direction during forward motion.

BACKGROUND

A skateboard essentially comprises a flat board or deck which is mounted on wheels. The user stands on the board, and with skill and practice, they can use their weight and body movements to propel the board along and steer it in the required direction.

In known skateboards, steering is usually facilitated by providing a combination of movement and spring loading in the wheel mountings. For example, in a typical four-wheel skateboard each pair of wheels is arranged to rotate about a vertical steering axis as the user tilts the board.

Such a steering arrangement is disclosed in US 2007/0114743 Al and US 4 076 267. These documents also disclose that the deck may be split into front and rear sections which can pivot about a longitudinal axis.

In a two wheeled skateboard having a single wheel mounted in front of the other, as disclosed in US 2007/0257459 Al for example, the wheels usually have a castor action. Such wheels are generally spring loaded to produce forward movement in a straight line in the absence of steering forces. A similar arrangement is also disclosed in WO 2004/105901 Al.

These documents again disclose that the deck may be split into front and rear sections which can pivot about a longitudinal axis.

US 6 832 765 BI discloses a wheeled skate having a steerable front wheel and a fixed rear wheel.

JP 09 103 534 A discloses a scooter or skateboard in which the deck is formed in two sections each mounted on a pair of wheels having fixed axes of rotation. The deck sections can tilt about a steering axis which is inclined relative to the front-rear axis of the board.

In the known two wheeled skateboards in which the deck is in two sections which can tilt relative to each other the effective use of such a board is an acquired skill. The steering and balance essentially involve rocking movements of the front and rear feet.

The present invention seeks to provide a new and inventive form of skateboard which is of simple construction whilst giving the user more precise control over steering.

SUMMARY OF THE INVENTION

The present invention proposes a skateboard having a front deck and a rear deck mounted on respective front and rear wheels, and the decks are arranged to tilt about a steering axis which is downwardly inclined relative to the front-rear direction of the skateboard, in which the front deck has a single wheel mounted on or near the mid line of the said deck to rotate about an axes which is fixed relative to the respective deck.

It may assist some users if the board is biased to a position in which the two decks are substantially coplanar.

Preferably the steering axis is downwardly inclined towards the front deck.

In a preferred arrangement, when the skateboard is placed on a flat surface the steering axis intercepts the said surface in front of the point of contact between the front wheel and the said surface.

The wheels may have relatively simple mountings such that each wheel rotates about an axis which is fixed relative to the respective deck. The front deck will normally have a single wheel mounted near the mid line of the said deck. However, the rear deck may have a single wheel mounted near the mid line or a pair of wheels mounted on opposite sides of the mid line.

Preferably the adjacent ends of the front and rear decks are inclined relative to the front-rear direction of the skateboard.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description and the accompanying drawings referred to therein are included by way of non-limiting example in order to illustrate how the invention may be put into practice. In the drawings: Figure 1 is a plan view of a skateboard in accordance with the invention; Fjgure 2 is a side view of the skateboard; Figure 3 is a front view of the skateboard; Figure 4 is a bottom view of the skateboard; Figure 5 is a detailed longitudinal section taken on the steering axis of the skateboard; Figure 6 is side view of a modified form of the skateboard; Fkure 7 is a plan view of another modified form of the skateboard; Figure 8 is a longitudinal section through the skateboard of Fig. 7; Figures 9 and 10 are plan views of the skateboard of Fig.s I to illustrating how the board is ridden; and FLgures 11 to 13 are similar plan views showing further modifications; Fgiure 14 shows another modified form of the skateboard viewed in section along the front-rear axis; Figure 15 is a bottom view of the modified skateboard shown in Fig. 14; FIgure 16 is a plan view of yet another modified form of the skateboard; and Figure 17 is a longitudinal section through the skateboard of Fig. 16.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring firstly to Fig. 1, the skateboard has a front deck I and a rear deck 2. In this particular example the front deck is shorter than the rear deck, and it will also be noted that the adjacent ends of the two decks are inclined relative to the longitudinal axis of the skateboard (see below).

The front and rear ends 4 and 5 of the decks 1 and 2 are curved. In addition, the rear end 5 has a kick" or upturn, as best seen in Fig. 2, which may assist in the performance of certain stunts. The front deck may also have a similar leading kick if desired, or neither deck may have a kick.

The front and rear decks 1 and 2 are provided with respective pairs of downwardly-extending mounting brackets 6 and 7 which are fixed to the respective deck on opposite sides of the longitudinal mid line L of the skateboard, representing the normal direction of movement. A single inverted-U shaped bracket can also be used in place of two separate brackets if desired. The front and rear mounting brackets 6, 7 each receive an axle upon which a respective wheel 8, 9 is rotatably mounted, also shown in Fig.s 3 and 4. Thus, the wheel mountings are relatively simple, inexpensive and reliable since the rotational axis of each wheel is substantially fixed perpendicular to the mid line.

The front and rear decks 1 and 2 are connected by a pivot coupling which allows the front deck I to tilt about a steering axis A, shown in Fig.s I to 4, which extends along the mid line L downwardly inclined towards the front deck. Fig. 5 shows an effective form of pivot coupling, which comprises a pivot rod 12, fixed with the forward end of the rear deck 2, such that the rod 12 extends from the mid line of the skateboard, downwardly inclined to pass below the front deck 1. A pivot block 13 is fixed with the front deck 1 to receive the rod 12 passing through bearing bushes 14 and 15. The pivot rod is rotatably held within the pivot block 13 by a lock nut 16 and washer 17.

The majority of riders will stand on the skateboard with their left foot on the front deck I and the other foot on the rear deck 2 in the positions illustrated in Fig. 9. In normal riding the left foot is positioned behind the front wheel, so that the inclined gap between the front and rear decks allows the riders foot to be positioned as far back as possible whilst at the same time being at a comfortable angle. Forward motion of the board is produced by removing the right foot from the board and pushing against the ground as shown in Fig. 10, but steering and balance of the board are primarily achieved by the rider using rocking and turning movements of their front foot so that the front deck I rotates relative to the rear deck 2 about the steering axis A. It can be an advantage for the rider to move their left foot into the position shown in Fig. 10 when propelling the board with their right foot, so that the left foot bridges the front and rear decks to keep them coplanar.

Steering, manoeuvrability and feel of the board are affected by the inclination of the steering axis A. In general, the arrangement shown, in which the steering axis intercepts the ground slightly in front of the point of contact between the front wheel and the ground, results in a board which is both stable and highly manoeuvrable. On the other hand, reducing the inclination of the steering axis so that it intercepts the ground at an greater distance ahead of the front wheel requires steering to be produced more by a rocking motion of the front foot rather than a turning motion. This better mimics the effect of a snowboard for example.

The basic steering arrangement described above requires no spring loading of the steering pivot. However, it may be desirable to bias the two decks to an aligned co-planar configuration, e.g. to assist novice users or to facilitate the performance of certain stunts. Such spring loading can easily be incorporated as in Fig. 6 for example, which shows an elastomeric bush 20 mounted from the rear deck on a bracket 21 to press against the pivot block 13 on opposite sides of the steering axis. Rocking movements of the front deck 1 compress the bush assisting the front deck to return to the aligned position when steering forces are no longer applied. Clearly other effective spring loading arrangements could be devised.

The simplification of the wheel mountings compared with many existing boards facilitates additional features which are not easily achieved with known boards. Fig.s 7 and 8 show a further modification in which the wheels 8 and 9 extend into holes 28 and 29 in the front and rear decks I and 2. This has several advantages, including the possibility of allowing larger wheels to be used without a corresponding increase in overall height and allowing the centre of gravity of the board to be lowered.

Permitting the rider to make contact with the wheels through the board may also allow them to produce a controlled braking action, using their feet to apply a variable pressure to the wheels.

In the skateboards described above the adjacent edges of the front and rear decks are angled to make them suitable for use by the majority of riders. However, a minority of riders prefer to stand with their right foot forward, in which case the gap between the decks would be better oppositely inclined as in Fig. 11. Fig. 12 shows a form of skateboard which is designed to accommodate both kinds of stance.

The precise outline of the decks is not important as it depends upon the intended use of the skateboard. Almost any shape is suitable for cruising downhill. For example, Fig. 13 shows a shape which is inspired by surfboards for downhill riding. No kick is required at the rear end of the board.

Additional modifications not shown in the drawings are also possible. For example, since the steering action is primarily achieved using the front deck it would be possible to provide the rear deck with two wheels mounted on opposite sides of the mid axis, possibly giving greater stability for novice users. It is also feasible to drive the board by means of an electric motor, e.g. a brushless DC motor, integrated into the front or rear wheel (or possibly both wheels) powered by an on-board battery pack.

Integrating the motor into a wheel assembly avoids the need for a mechanical transmission, which reduces the braking effect of the motor when no power is applied. Other advantages might include low noise level and good efficiency since there is no transmission system which might incur a power loss.

Fig.s 14 and 15 show a modified form of pivot coupling between the front and rear decks I and 2 which allows the front deck I to tilt about an inclined steering axis A, which again extends along the mid line downwardly inclined towards the front deck. In this embodiment the pivot coupling comprises a first pivot rod 30, fixed with the rearward end of the front deck 1, which is pivotally received in an elastomeric bearing 31 formed in the forward end of the rear deck 2 substantially on the mid-line of the skateboard. A second pivot rod 32 extends from the forward end of the rear deck 2 below the mid line of the skateboard, passing below the front deck 1. An elastomeric bush 33 is fixed below the front deck 1 to receive the rod 32, held to the front deck by a clamp 34 which is in turn secured to the deck by screws 35 and 36. The pivot rod 32 is held within the elastomeric bush 33 by the clamp 34. The inherent resilience of the bearing 31 and the bush 32 allows the front deck I to tilt about a steering axis A which is downwardly inclined in a forward direction, and the resilience of the steering is determined by how much the screws 35 and 36 are tightened to compress the bush 33 around the rod 32. It should be noted that in this case the steering axis A does not precisely coincide with the axis of the pivot rod 30. Again, the front and rear decks I and 2 are provided with respective wheels 8 mounted in downwardly-extending mounting brackets 6 which are fixed to the respective deck such that the wheels rotate about axes which are fixed relative to the respective decks.

Fig.s 16 and 17 show a modification to the wheel mountings such that the wheels 8 and 9 rotate in notches 48 and 49 in the front and rear decks 1 and 2. This again allows larger wheels to be used without a corresponding increase in overall height and allows the centre of gravity of the board to be lowered. The rider can again make foot contact with the wheels through the board allowing them to produce a controlled braking action by applying a variable pressure to the wheels.

Whilst the above description places emphasis on the areas which are believed to be new and addresses specific problems which have been identified, it is intended that the features disclosed herein may be used in any combination which is capable of providing a new and useful advance in the art.

* * * * * * * * -11 -

Claims

CLAIMS1. A skateboard having a front deck and a rear deck mounted on respective front and rear wheels, and the decks are arranged to tilt about a steering axis which is downwardly inclined relative to the front-rear direction of the skateboard, in which the front deck has a single wheel mounted on or near the mid line of the said deck to rotate about an axes which is fixed relative to the respective deck.

2. A skateboard according to Claim 1 in which the decks are spring loaded towards an aligned substantially co-planar configuration.

3. A skateboard according to Claim I or 2 in which the steering axis is downwardly inclined towards the front deck.

4. A skateboard according to Claim 3 in which, when the skateboard is placed on a flat surface, the steering axis intercepts the said surface in front of the point of contact between the front wheel and the said surface.

______A skateboard according to any preceding claim in which-the rear deck has a single wheel mounted on or near the mid line of the said deck.

6. A skateboard according to Claim 5 in which the wheel is mounted to rotate about an axis which is fixed relative to the rear deck.

7. A skateboard according to any of Claims I to 4 in which the rear deck has a pair of wheels mounted on opposite sides of the mid line of the said deck.

8. A skateboard according to Claim 6 in which the wheels are mounted to rotate about respective axes which are fixed relative to the rear deck.

9. A skateboard according to any preceding claim in which the adjacent ends of the front and rear decks are inclined relative to the front-rear direction of the skateboard.

10. A skateboard according to any preceding claim in which at least one of the wheels projects into a hole in the respective deck.

11. A skateboard according to any preceding claim in which at least one of the wheels incorporates a motor.

12. A skateboard substantially as described with reference to the drawings.* * * * * * * *