GB2151195A

GB2151195A - Pivoting mast for water-borne or land based vehicles

Info

Publication number: GB2151195A
Application number: GB08332427A
Authority: GB
Inventors: Michael David Craig
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-01-26
Filing date: 1983-12-06
Publication date: 1985-07-17
Also published as: GB8302188D0; GB8332427D0

Abstract

A pivoting mast 2 allows the hull of a vessel or body of a vehicle to resist the tilting or heeling action produced by excessive strengths of wind on that particular vessel or vehicle. Adjustable springings allows the vessel or vehicle to be trimmed or tuned in accordance with varying weights of crew and equipment carried. <IMAGE>

Description

SPECIFICATION Pivoting mast for water-borne vessels or landbased vehicles This invention relates to a pivoting mast for waterborne vessels of single multihulied design, or land based vehicles powered by means of the action of wind on a set of sails. In order to describe and illustrate the invention I have used the example of a single-hulled vessel.

Sailing boats with fixed masts tilt or heel over when the force of the wind exceeds the resistance of the weight of the boat together with crew and equipment and the resistance to tipping provided by the keel. The continued tipping of such a vessel reduces the effective height of the sail and reduces the effective depth of the keel. Loss of sail height reduces the effective sail area but as the hull is forced to rise on the windward side the effect of the wind on the hull increases, thus adding to the forces causing the boat to tip. Loss of keelp depth allows the boat to drift sideways and a course which was being steered cannot be maintained.

The boat must come about or tack in order to gain its objective by means of a zig-zag course. 'Windsurfing' boards employ a mast which is pivoted at its lower end, the board or hull remaining level in the water and the varying strengths of the wind being compensated for by the operator shifting his body weight and bending and stretching his arms and legs. In strong gusts of wind the effective height of the sail is reduced by stretching the arms and allowing the sail to move to lee-ward thus spilling part of the wind. As this is being done the body weight is moved to windward thus increasing the downward force on the windward side of the board. The sail area on a sailing boat with a fixed mast is reduced by reefing the sails.

I refer to the drawings on the attached sheets A and B. The invention proposes that a mast, pivoted about a point above its foot stayed by means of cables and metal or rubber springs below deck or gunwhale level allows the mast to tilt to port and starboard. The system of pulleys and anchoring points allows that the forces are distributed at four points, two on each side of the longitudinal axis.

Conventional rigging employs the stays on the windward side only. The tension in the springs may be adjusted in relation to the weight of the boat and the varying weight of crew in order that the springs allow the mast to tilt at the point where a conventionally rigged boat would begin to heel.

The hull and keel do not alter their position in the water, thus retaining directional stability.

Explanatory date in respect of formal drawings attached FIGURES 1, 2 and 3 Note: Figure 3 shows a vertical section through the mast.

1. Hull of boat 2. Mast 3. Cable 4. Fixed pulley wheels 5. Springs 6. Pivot pin 7. Locking pin 8. Bearing plates 9. Supporting framework 10. Washer 11. Securing eye 12. Securing eye

CLAIMS 1. A single or multi-hulled water borne sailing vessel or land based vehicle powered by means of the action of the wind on sails mounted on a mast which is pivoted at a point above its foot, the distance of the pivot point from the foot of the mast varying according to the size of the vessel or vehicle. The mast stayed by means of cables fixed to the foot of the mast, passing round pulley wheels, attaching to metal or rubber springs anchored to the hull of the boat or outer edge of the vehicle allowing the mast to pivot from side to side but not fore and aft. The springs set to maintain the mast in an upright position to the point at which the force of the wind causes the vessel to heel or tip over.

2. The point at which the vessel or vehicle starts to heel or tip varying according to the laden weight of the vessel or vehicle allied to the resistance to tipping or heeling provided by the keel or anti-roll bar the springs are adjustable in order to allow for variations in the weight and heeling or tipping resistance.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Pivoting mast for water-borne vessels or landbased vehicles This invention relates to a pivoting mast for waterborne vessels of single multihulied design, or land based vehicles powered by means of the action of wind on a set of sails. In order to describe and illustrate the invention I have used the example of a single-hulled vessel. Sailing boats with fixed masts tilt or heel over when the force of the wind exceeds the resistance of the weight of the boat together with crew and equipment and the resistance to tipping provided by the keel. The continued tipping of such a vessel reduces the effective height of the sail and reduces the effective depth of the keel. Loss of sail height reduces the effective sail area but as the hull is forced to rise on the windward side the effect of the wind on the hull increases, thus adding to the forces causing the boat to tip. Loss of keelp depth allows the boat to drift sideways and a course which was being steered cannot be maintained. The boat must come about or tack in order to gain its objective by means of a zig-zag course. 'Windsurfing' boards employ a mast which is pivoted at its lower end, the board or hull remaining level in the water and the varying strengths of the wind being compensated for by the operator shifting his body weight and bending and stretching his arms and legs. In strong gusts of wind the effective height of the sail is reduced by stretching the arms and allowing the sail to move to lee-ward thus spilling part of the wind. As this is being done the body weight is moved to windward thus increasing the downward force on the windward side of the board. The sail area on a sailing boat with a fixed mast is reduced by reefing the sails. I refer to the drawings on the attached sheets A and B. The invention proposes that a mast, pivoted about a point above its foot stayed by means of cables and metal or rubber springs below deck or gunwhale level allows the mast to tilt to port and starboard. The system of pulleys and anchoring points allows that the forces are distributed at four points, two on each side of the longitudinal axis. Conventional rigging employs the stays on the windward side only. The tension in the springs may be adjusted in relation to the weight of the boat and the varying weight of crew in order that the springs allow the mast to tilt at the point where a conventionally rigged boat would begin to heel. The hull and keel do not alter their position in the water, thus retaining directional stability. Explanatory date in respect of formal drawings attached FIGURES 1, 2 and 3 Note: Figure 3 shows a vertical section through the mast.

1. Hull of boat

2. Mast

3. Cable

4. Fixed pulley wheels

5. Springs

6. Pivot pin

7. Locking pin

8. Bearing plates

9. Supporting framework

10. Washer

11. Securing eye

12. Securing eye

1. A single or multi-hulled water borne sailing vessel or land based vehicle powered by means of the action of the wind on sails mounted on a mast which is pivoted at a point above its foot, the distance of the pivot point from the foot of the mast varying according to the size of the vessel or vehicle. The mast stayed by means of cables fixed to the foot of the mast, passing round pulley wheels, attaching to metal or rubber springs anchored to the hull of the boat or outer edge of the vehicle allowing the mast to pivot from side to side but not fore and aft. The springs set to maintain the mast in an upright position to the point at which the force of the wind causes the vessel to heel or tip over.