GB2160831A

GB2160831A - Landsailing craft

Info

Publication number: GB2160831A
Application number: GB08416402A
Authority: GB
Inventors: David Henry Johnston
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-06-27
Filing date: 1984-06-27
Publication date: 1986-01-02
Also published as: GB8416402D0

Abstract

The craft comprises a hollow hull 10 having socketed in the deck 12 thereof a mast carrying a sail 54 and a control boom 56 for controlling that sail. From the lower part 14 of the hull project the ground-engaging surfaces of three preferably spherical, air-inflated wheels 22 to 26, which wheels are disposed in hollows 16 to 20 formed in the underside of the hull, and are carried for rotation on transverse axles. The surface of the central wheel 24 projects further than those of the other two wheels, so that the hull may ride on the central wheel alone, or on that wheel and either one of the other wheels, and the camber of those wheel surfaces enables the craft to ride stably over the ground even when the hull is tilted sideways to a substantial extent under the force of the wind striking the sail. <IMAGE>

Description

SPECIFICATION Landsailing craft Technical Field This invention relates to a landsailing craft, and particularly to such a craft for enabling skills analogous to those used in the sport of windsurfing on water to be applied to a land-based sport.

Background Art In the sport of windsurfing on water, the craft employed comprises essentially a long, stream-lined surf board having at its aft end a downwardlyextending stabilising fin, and located in a socket near the centre of its upper, deck surface an upstanding, pivoted mast carrying a sail, which sail is extended within an elongate, loop-shaped control boom, and which sail is manipulated by a windsurfer standing on the deck surface of the surf board, by means of said control boom. During sailing, such a windsurfing board can assume any posture as dictated by the surface and movement of the water in which it is floating, whilst the sail is held in a relatively steady position by the windsurfer, independently of the posture of the board.

Sailing on land has been accomplished in the past by means of a land yacht which has comprised a flat, wheeled trolley on which was rigidly carried a mast and conventional yacht sailing rig, the wheeled trolley having comprised a flat board having two pairs of wheels mounted on respective axles carried on the board and the wheels having been mounted at the respective sides of the board.

Disclosure of the Invention According to the present invention, a landsailing craft comprises a hull in which are carried at least three ground-engaging wheels for supporting the hull from the ground, which wheels are disposed substantially in line with one another and for rotation about respective parallel axes which are transverse to and spaced apart along the fore and aft direction of the hull, the central wheel having its ground-engaging surface projecting further from the base surface of the hull than the corresponding surfaces of the other wheels, so that the hull can ride on the central wheel alone, or on that wheel and either one of the other two wheels, and the ground-engaging surface of each said wheel having a profile transverse to said fore and aft direction which is convex outwardly, and a curvature transversely of said fore and aft direction that will allow the hull to ride stably over the ground even when the hull is tilted over in a sideways direction to a substantial angle relative to its normal upright position.

Preferably, all of the said wheels are disposed in line with one another on the central fore and aft axis of the hull; and all the wheels are similar, the axis of rotation of the central wheel being disposed lower in the hull than the axes of rotation of the other two wheels.

Advantageously, each such wheel is spherical in shape, or nearly so, and is pneumatically inflated.

Conveniently, said craft includes socketed into the upper, deck surface of said hull a mast, which mast carries a sail and control boom which are similar to those used on aquatic windsurfing craft.

Preferably, braking means are provided on said hull for effecting braking of at least the central wheel, said braking means being preferably arranged for foot operation by a landsailor standing on the said deck surface of the hull.

Other features of the present invention will appear from the description that follows hereafter, and from the claims appended at the end of that description.

One landsailing craft according to the present invention will now be described by way of example and with reference to the accompanying diagrammatic drawings.

Brief Description of the Drawings In the drawings: Figure 1 shows a side elevation of the whole of the craft as seen proceeding in the direction from right to left across the drawing sheet, but without the landsailor standing on the deck; Figure 2 shows to a much larger scale a side view of the hull and the associated lower parts of the sailing rig of the craft; and Figure 3 shows a front view of the parts of the craft shown in the Figure 2 (i.e. as seen from the left hand side of the Figure 2), and to the same scale as that of Figure 2.

Best Mode of carrying out the Invention Referring now to the drawings, the landsailing craft there shown comprises a hollow hull 10 of a glass reinforced plastics material, which hull has an upper, deck surface 12 on which the landsailor stands, that deck surface being substantially linear in the fore and aft (i.e. longitudinal) direction, and upwardly convex in the transverse direction.The lower part 14 of the hull is shaped in the streamlined manner shown, somewhat in the manner of a shallow boat hull, but with this difference, that three large, longitudinally-spaced, upwardly-extending hollows 16,18,20 formed in the lower parts of the hull accommodate three similarly sized, pneumatically inflated, spherical, rubber wheels 22,24,26, which wheels have axles 28,30,32 carried for rotation about transverse axes in sealed, preferably ball, bearing units 34,36,38 carried in the hull structure. The central wheel 24 is carried at a lower position in the hull as compared with the positions of the leading and trailing wheels 22 and 26, so that the hull normally rests on the central wheel and one or the other of the two other wheels according to the distribution of weight and other forces acting on the hull for the time being.

The hull is also provided with a foot-operated brake pedal 40 which protudes above the deck surface 12 for operation by the land sailor standing on the deck surface, the brake pedal being coupled throuyh a braking mechanism 42 with a brake pad 44 which is pivoted at its front end and arranged for angular movement to and from the spherical surface of the central wheel 24. A tension spring 46 extending between a mounting 48 on the hull and the brake pad holds the brake pad normally off the wheel surface. If desired, the braking mechanism may also be coupled with similar pivoted brake pads (not shown) arranged to cooperate in a braking manner with one or both of the fore and aft wheels.

Carried in a socket 50 formed in the deck of the hull, forward of the central wheel 24, is a conventional form of mast 52 and associated sail 54 and control boom 56, all of a form similar to those used on conventional aquatic windsurfing craft. If desired, the conventional pivotal connection at the base of the mast may be omitted. In that case the mast is rigidly connected to the hull.

By setting the central wheel 24 lower in the hull than the two other wheels, the craft is enabled to pivot from one course to another, the craft resuming a straight line course whenever it reverts to running on two wheels. To turn from running in a straight line, body weight is transferred by the landsailor over the central wheel, and the shift in body weight and our the force of the wind is used to effect the desired turn.

The dotted lines 58,60 in the Figure 2 represent the ground surface when the craft is running in a straight line.

The spherical shape of the wheels allows the hull to heel over sideways to the force of the wind striking the sail.

Instead of the depicted arrangement of the three spherical wheels, in an alternative form of the craft, the axles of the wheels are all carried at the same depth within the hull, and the front and rear wheels have a smaller diameter than the central wheel.

Other wheel shapes, besides spherical, may be used, provided that stable operation of the craft can be achieved when the hull is heeled over in a sideways direction. For example, wheels in the form of a rugby football may be used.

Other wheel constructions may be used instead of the hubless wheels shown. For example, wheels comprising central hubs carrying toroidal shaped typres of large transverse cross section may be used, said hubs being arranged for rotation relative to the hull.

If desired, various modifications may be made in the design of the craft indicated and described above, for example, (a) the braking means may operate instead on a braking disc or hub connected to the relevant wheel; (b) the mast socket may be moved to other positions relative to the central wheel, though the results achieved under those circumstances may not be so good; (c) the hull may comprise a more rudimentary form of structure (e.g.a flat board) on which the wheels are carried without being largely enveloped by the hull; (d) small outrigger wheels may be fitted to the hull at predetermined positions spaced transversely from the hull, so as to limit the extent to which the hull may heel over sideways. Such outrigger wheels are preferably disposed aft of the central wheel, and may comprise spherical wheels similar to the ground-engaging wheels 22 to 26.

Moreover, such outrigger wheels may be rotatably carried in hollows formed in the sides of the hull; (e) either or both of the fore and aft wheels may be displacable transversely relative to the hull so as to change the trim of the craft, in which case means may be provided for adjusting the transverse position of the or each such transversely displacable wheel during the course of landsailing under the control of the landsailor.

(f) the aft wheel may be replaced by two similar wheels disposed side by side. Preferably, such wheels would be spherical or ellipsoid in shape, though other forms of wheel may be used instead.

Such a pair of wheels would provide an enhanced stability for the craft when running on those wheels, which greater stability would be advantageous for those newly learning to use a landsailinc craft according to the present invention; and (g) the hull may be made by any preferred alternative method of construction, for example, by using injection moulding of a suitable plastic mate rial.

Claims

1. A landsailing craft having a hull in which are carried at least three ground-engaging wheels for supporting the hull from the ground, which wheels are disposed substantially in line with one another and for rotation about respective parallel axes which are transverse to and spaced apart along thi fore and aft direction of the hull, the central wheel having its ground-engaging surface projecting further from the base surface of the hull than the cor responding surfaces of the other wheels, so that the hull can ride on the central wheel alone, or on that wheel and either one of the other two wheels.

and the ground-engaging surface of each said wheel having a profile transverse to said fore and aft direction which is convex outwardly, and a cur vature transversely of said fore and aft direction that will allow the hull to ride stably over the ground even when the hull is tilted over in a sideways direction to a substantial angle relative to its normal upright position.

2. A landsailing craft according to claim 1, wherein all of the said wheels are disposed in line with one another on the central fore and aft axis c the hull.

3. A landsailing craft according to claim 1, wherein all of the wheels are similar, and the axis of rotation of the central wheel is disposed lower in the hull than the axes of rotation of the other two wheels.

4. A landsailing craft according to claim 3, wherein the said wheels are spherical in shape, oi nearly so.

5. A landsailing craft according to claim 4, wherein the said wheels are pneumatically inflate wheels.

6. A landsailing craft according to claim 1, wherein the fore and aft wheels are of a smaller diameter than the central wheel, and the axes of rotation of all the wheels are disposed at the same depth in the hull.

7. A landsailing craft according to claim 6, wherein the said wheels are spherical in shape, or nearly so.

8. A landsailing craft according to claim 7, wherein the said wheels are pneumatically inflated wheels.

9. A landsailing craft according to claim 1, wherein the axis of rotation of the central wheel is spaced longitudinally from a mast socket provided in said hull for receiving a mast.

10. A landsailing craft according to any preceding claim, wherein the hull is provided in a lower surface thereof with upwardly extending hollows in which the said wheels are disposed, said wheels protruding from said hollows for engaging the ground.

11. A landsailing craft according to any preceding claim, wherein the hull also carries two outrigger wheels disposed respectively on either side of the hull so as to limit the extent to which the hull may heel over in a sideways direction.

12. A landsailing craft according to any preceding claim, wherein the hull is provided with a braking means for applying a braking effort to at least the central wheel, which braking means includes a foot pedal projecting above an upper, deck surface of the hull for operation by a landsailor standing on that deck surface.

13. A landsailing craft according to any preceding claim, including a mast socketed into an upper, deck surface of the hull, which mast is rigged with at least one wind sail and a control boom for enabling control of the sail by a landsailor standing on said deck surface of the hull.

14. A landsailing craft according to any preceding claim, substantially as hereinbefore described with reference to and as illustrated by the accompanying diagrammatic drawings.