|1.||A windpropelled, wheeled vehicle comprising a foot board structure (4,5), on which a rider (6) may stand, supported between inline front and rear wheels (1,2), and a mast foot structure (32) located on the vehicle adjacent the front wheel (1) for swingably mounting on the vehicle a rotatable mast ( 20) for a sail rig (30), characterised in that at least one of the front and rear wheels (1,2) is steerable and the mast foot structure (32) is adapted to constrain the mast to swing in the foreandaft direction of the vehicle.|
|2.||A vehicle as claimed in claim 1, characterised in that the axis of steer of the or each steerable wheel (1), is located substantially in the plane of the axis of rota¬ tion of the wheel and the point of contact between the wheel and the ground.|
|3.||A vehicle as claimed in claim 1 or 2, characterised in that the or each steerable wheel (1) is rotatably mount¬ ed on a stub axle (9) pivotally coupled to the free end of a cantilever support arm (7) projecting from a chassis structure (3) of the vehicle and is turnable about the pivotal coupling to permit steering of the wheel.|
|4.||A vehicle as claimed in claim 1, 2, or 3, having one steerable wheel (1) characterised in that the non steerable wheel (2) is rotatably mounted at the free end of a cantilever support arm (8) projecting from the chassis structure (3) of the vehicle.|
|5.||A vehicle as claimed in claims 3 and 4, characte¬ rised in that the chassis structure comprises a single beam (3) extending in the fore and aft direction of the vehicle and the cantilever support arm(s) (7,8) are integral with the beam.|
|6.||A vehicle as claimed in any preceding claim, cha¬ racterised in that the wheels are of relatively large diameter and the chassis structure (3), between the wheels (1,2), is located generally below the wheel axles (9,10) so as to achieve a low centre of gravity for the vehicle.|
|7.||A vehicle as claimed in any preceding claim, cha¬ racterised in that the mast foot structure (32) comprises rockable means (34) for connection to the foot of the mast (29) and solely permitting swinging movement of the mast in the fore and aft direction of the vehicle.|
|8.||A vehicle as claimed in claim 7, characterised in that the rockable means comprises a link member (34) rocka bly mounted on a pivot pin (36) extending substantially perpendicularly to the central vertical foreandaft plane of the vehicle, said link member having means (39) for supporting the mast (29) for rotation about its own longi¬ tudinal axis.|
|9.||A vehicle as claimed in claim 8, wherein the pivot pin (36) is mounted between bracket arms (35) projecting upwardly from chassis structure (3) of the vehicle.|
|10.||A vehicle as claimed in any preceding claim, cha¬ racterised in that the foot board structure includes a steering section (4) which is rockable transversely of the vehicle and is coupled to a steering mechanism (11) of the steerable wheel (1) .|
|11.||A vehicle as claimed in any preceding claim, cha¬ racterised in that at least one wheel (1,2) is fitted with brakes controlled by foot operated means on the foot board structure (4,5) or handoperated means disposed on the mast (29) or sail rig (30) .|
|12.||A vehicle according to any preceding claim, cha¬ racterised by a mast (29) or a mast (29) and sail rig (30) mounted on the mast foot structure (32).|
The present invention relates to a wind-propelled, wheeled vehicle, primarily intended for leisure purposes, and more particularly, to a scooter-like vehicle on which the rider stands and which is wind-propelled by means of a sail rig similar to that utilised on the well known sail- board.
The present invention consists in a wind-propelled, wheeled vehicle comprising a foot-board, on which a rider may stand, supported between tandem or in-line front and rear wheels, at least one of which is steerable, and a mast foot structure located on the vehicle adjacent the front wheel for swingably mounting on the vehicle a rotatable mast for a sail rig, said mast foot structure being adapted to constrain the mast to move in the fore-and-aft direction of the vehicle.
In conventional sailboards, and known wheeled vehi¬ cles propelled by the sail rigs of such boards, the mast foot is attached to the sailboard or vehicle by a mast foot structure embodying a universal joint. This enables the sail rig to be swung fore-and-aft as well as side-to-side. The design is such that the mast and sail rig can also rotate through 360° about the mast foot structure.
With the tandem or in-line wheels utilised in the present invention, it would be difficult, if not impossi¬ ble, to balance with a mast mounted on the vehicle via a conventional universal joint. Accordingly, a feature of the design of this invention is a structure for coupling the mast foot to the vehicle which mounts the mast foot between the wheels and substantially in-line with them and which permits fore-and-aft movement of the rotatable mast substantially in the central vertical longitudinal or fore-and-aft plane of the vehicle, but restrains movement
of the mast transversely to the wheels, either wholly, in part, or in proportion to its movement from the vertical. Such restraints on the movement of the mast, and sail rig supported thereby, about an axis extending in the fore-and-aft direction of the vehicle, enable the rider to balance on the vehicle. In other words, the mast is con¬ strained to swing in a plane generally perpendicular to the plane containing the wheel axles.
It will be understood that, within the context of this invention, it is not essential for the front and rear wheels to be individual wheels. They may also be wheel assemblies, for example, comprising double wheels, and in this specification and the appended claims the terms front and rear wheels are also intended to connote such wheel assemblies. In the broadest sense, the invention is di¬ rected to a vehicle which has front and rear wheels or wheel assemblies and which lacks lateral stability.
Preferably, the front and rear wheels are of rela¬ tively large diameter so as to reduce rolling resistance and the foot-board structure is suspended between the wheels and below the wheel axles so as to achieve a low centre of gravity.
To permit steering of the vehicle, the foot-board structure may incorporate a steering section which is rockable transversely of the vehicle and is suitably cou¬ pled to the steering mechanism of a steerable wheel so as to permit the rider to control steering by rocking the steering section of the foot-board with one foot.
One or both wheels may be fitted with brakes opera¬ ble either by a foot pedal mounted on the foot-board struc¬ ture in a convenient position for actuation by a rider's foot, or by a hand grip or grab cord attached to the sail rig.
In order that the present invention may be more readily understood, reference will now be made to the accompanying drawings, in whic :-
Figure 1 is a side elevation of one embodiment of the invention illustrating how the vehicle is ridden,
Figure 2 is a plan view of the wheels and chassis assembly of the vehicle,
Figure 3 is a fragmentary perspective view illus¬ trating the mast foot structure,
Figure 4 is a horizontal section through the front wheel steering mechanism, and
Figure 5 an end view of the steering mechanism, partly in section.
Referring to Figures 1 and 2 of the drawings, the vehicle is generally similar to a conventional child's scooter, but having a sail rig for propelling the vehicle in place of the usual handlebars. It comprises in-line front and rear wheels 1,2, of relatively large diameter compared to a typical scooter, mounted at opposite ends of a chassis member 3 supporting a foot-board structure 4,5 on which a vehicle rider 6 stands. The chassis member 3 com¬ prises a single tube or tubular beam extending in a fore- and-aft direction, and the foot-board structure is divided into two sections, that is, a rear fixed section 5 secured to the chassis member, and a front steering section 4 which is mounted on the chassis member so as to be rockable transversely of the vehicle to permit steering of the vehicle, as will be more fully described below.
The front wheel 1 is steerable and is mounted at the front end of a tubular cantilever support arm 7 which projects from the adjacent end of the tubular chassis member 3 and is integral therewith, and which is bent or offset in an arch-like configuration to one side of the chassis member, as shown more particularly in Figure 2. This arch arrangement of the support arm 7 permits the
front wheel to be mounted in-line with the chassis member 3 and to be steered in both directions about a generally vertical steering axis. The rear wheel 2 is mounted on the rear end of a similarly bent or offset and integral canti¬ lever support arm 8 at the rear end of the tubular chassis member 3 so as to be in-line with the latter. The front and rear support arms 7,8 are also inclined upwardly from the adjacent ends of the chassis member 3 so that the chassis member and foot-board structure 4,5 are suspended below the wheel axles 9,10 to achieve a low centre of gravity.
In order to provide a steering geometry which is symmetrical in behaviour, the axis of steer of the front wheel 1 is located in the plane containing the axis of rotation of the front wheel and the point of contact between the wheel, or wheel tyre, and the ground. A centre hub steering mechanism 11 is used to achieve this whilst enabling the chassis structure to be maintained below the wheel axles 9,10. As shown in detail in Figures 4 and 5, the front wheel 1 is rotatably mounted on a stub axle 9 by two ball or other antifriction bearings 12,13. The stub axle is fixed adjacent one end to a support cup 14 and has a spigot part 15 projecting through the back of the cup towards the adjacent front end of the support arm 7. The cup 14 is linked to the front end of the support arm 7 by means of a bifurcated member 16 having a male part 17 secured in the opening at the front end of the tubular support arm 7 and two arcuate fingers 18 projecting from the male part 17 and pivotally connected to the support cup 14. The fingers 18 are pivoted to the cup by trunnions 19 projecting inwardly of the cup and journalled in cooperat¬ ing apertures 20 in the adjacent ends of the fingers. These trunnions are formed by countersunk machine screws 21 screwed through the cup 14 into bushes 22 on the inside of the cup.
The spigot part 15 of the stub axle 9 projecting from the back of the cup 14 forms a suitable mounting for a steering control arm (not shown) which is coupled to the rockable foot-board section 4 by means of a Bowden cable 23 and a lever 24 fixed to the section 4 in such a manner that rocking of the foot-board section in opposite directions produces a push-pull movement of the Bowden cable 23 and, via the steering control arm, turning of the steerable front wheel in opposite directions.
The rear wheel 2 is supported from the rear end of the support arm 8 by means of a metal bracket 25 secured to the rear end portion of the arm and having the stub axle 10 projecting therefrom at right angles to the fore-and-aft direction of the vehicle (see Figure 2). The rear wheel may be mounted on the stub axle by a conventional ball bearing assembly.
The wheels are fitted with mud guards 26,27 and may also be fitted with pneumatic or solid tyres 28.
The mast and sail rig are a conventional type of sail board rig comprising a hollow fibre-glass mast 29, a Bermudan-style sail 30 and a wishbone boom 31. The mast 29 is mounted on the vehicle with its axis located substan¬ tially in the central vertical longitudinal or fore-and-aft plane of the vehicle and so as to be rotatable about its own axis by means of a mast foot structure 32 projecting upwardly from the chassis member 3 adjacent the front wheel 1. The mast foot structure is illustrated in detail in Figure 3 and comprises an upwardly projecting clevis-like bracket 33 secured about the chassis tube 3 and having an inverted U-shaped link 34 pivotally mounted between the upper ends of the two upwardly projecting arms 35 of the bracket 33. The link 34 is pivoted between the upper ends of the arms 35 by a pivot pin 36 extending at right angles to the vertical fore-and-aft plane of the vehicle and through the arms of the link. A central web 37 disposed
between the arms 35 provides torsional rigidity to the mast foot bracket 33.
In a similar manner to a conventional sail board rig, the foot of the mast, itself, is attached to the top platform part 38 of the link 34 by a male fitting (not shown) which is fastened to the platform part in a rotata¬ ble manner by a bolt 39 projecting from the platform part into the bottom of the male fitting. The latter fits into the bottom end of the hollow mast 29 or a hollow mast extension, and the mast can rotate about its own longitudi¬ nal axis on the fitting. The link 34 and fitting and, hence, the mast, are swingable on the mast foot structure and constrained thereby to move solely in the fore-and-aft direction of the vehicle substantially in its central vertical longitudinal plane.
As illustrated in Figure 1, when the vehicle is used, the rider 6 stands with the rear foot on the fixed rear foot-board section 5 and the front foot on the steer¬ ing section 4 whilst holding the boom 31 of the sail rig in the customary sailboard manner. By sheeting-in the sail 30 forward motion is achieved. The arrangement allows the rider to balance the vehicle by wind pressure in the sail whilst steering the vehicle by applying foot pressure on the steering section 4 so as to rock the steering section in one direction or the other to steer or turn the vehicle in the required direction. The speed of the vehicle may readily be controlled by the rider operating a brake pedal or brake cord, if brakes are fitted. For example, calliper brakes may be fitted to the rear wheel 2 and be operated by a foot pedal (not shown) mounted on the steering section 4 or a grab cord hanging from the mast or sail rig. The brakes may be operated via a Bowden cable link.
Whilst a particular embodiment has been described, it will be understood that modifications can be made with¬ out departing from the scope of the invention. For exam¬ ple, in the embodiment described, the chassis is a single tube 3 having a series of bends which create a three dimensional form. However, if a suspension arrangement is to be incorporated, a multi-tube chassis frame may be employed.