GB2225303A

GB2225303A - An apparent wind direction indicator

Info

Publication number: GB2225303A
Application number: GB8825471A
Authority: GB
Inventors: Dan Primrose
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-11-01
Filing date: 1988-11-01
Publication date: 1990-05-30
Also published as: GB8825471D0

Abstract

An apparent wind direction indicator for a sailing vessel has a body portion 1 mounted to pivot around the forestay 2 and to engage the luff of the foresail whereby to indicate the direction of the luff of the sail. A vane 5 is mounted on the body portion to indicate the direction of the apparent wind. The vane provides an electrical output of the apparent wind direction, which may be displayed. The display may include a light 9 for illumination when the wind is parallel with the sail, to indicate that the sail is correctly trimmed, and auxiliary lights 10 for illumination when the wind is on either side of the sail, to indicate that the sail should be sheeted in or out. The degree of sensitivity of the lights 10 may be varied by the control knobs 11. The indicator may be connected to (a) power operated winches to enable the sails to be trimmed automatically, (b) a self-steering system, or (c) to an on-board computer for evaluating sail efficiency. A series of indicators may be attached to the luff of the sail at intervals up the forestay. <IMAGE>

Description

SAIL ?RIMMh'R This invention is a sail trimming system.

Sails are usually trimmed by interpreting the action of wool tell-tales situated on the luff line and whether the sail must be sheeted in or out. However, these, although cheap, are prone to several disadvantages. They have a certain degree of tolerance, meaning there is a degree of error.

During night sailing these tell-talea cannot be seen, unless an external light source is used.

If the wool becomes wet, it will hang down, wakeing it useless.

This invention is in three main parts:1. A vane which tells you the direction of the apparent wind.

2. A clip to fit on to the luff of the sail to show the angle of the luff of the headsail to the apparent wind.

3. An electronic circuit, to work GUt the relative positions of l. and 2.

Put these three together and you have a wind vane which always points into the apparent wind, a clip which follows the position of the luff of the sail and a circuit which will compare the two positions.

A circuit has been used so that the degree of error in both directions could be altered to allow for the acceptable tolerance in different situations: Close tolerance (small window) for raoing.

Wide tolerance (large window) for cruising.

The invention is described by way of example with reference to the accompanying drawings, in which: Fig 1. shows the unit attached to a section of headsail with the display unit.

Fig 2. shows a plan view of the main unit with sections of forestay and headsail luff shown.

Referring to the drawing, the unit comprises of a single unit 1 which pivots round the forestay 2 of a yacht, in relation to the direction of the luff of the headsail 3.

This is held securely by 4.

The direction of the wind is shown by the vane 5 which relays the reading back to the display unit 6. This is connected to a circuit in the display unit 6 by means of wires 7. There is a connection 8 which allows the single unit 1 to be detached from the display unit 6.

When the vane 8 is in line with the unit 1, i.e. the wind is coming from straight ahead, a signal 9 will be lit. This shows the sail is correctly trimmed. If the sail is either over or under-sheeted, the corresponding signal 10 will light up showing whether the sail need be sheeted in or out. The degree of tolerance can be adjusted from Oo (very sensitive) to 0 avobe 90 by the two knobs 11.

The whole unit can be switched off by the button 12.

To fit the unit to the sail, the rear end splits, as in Fig 2. and then is tightened around the forestay 2 and the luff of the sail 3.

Claims

SAIL TRIMMER

CLAIMS 1. Enables sail to be trimmed accurately.
2. Shows direction of the apparent wind.
3. An Electronic Sail Trimmer as described herein with reference to figures 1 and 2 of the accompanying drawing.

3. Shows direction of leading edge ot sail.

4. ShowS relative position of CLaims 2 and 3.

5. Claim L is related back to a display unit in the sail trimming position.

6. Shows correct position of Claim 4 by way of an electronic circuit.

7. Enables the sail to be trimmed accurately when it is dark.

8. The system can be connected to power operated winches enabling the sail to be trimmed automatically.

9. The unit can be set for coarse or fine setting, suitable for cruising or racing respectively.

10. On larger yachts multiple units can be attached to the luff of the sail at intervals up the forestay, enabling more accurate trimming.

11. The sail trimmer could be interfaced with an electronic self-steering systenl to achieve the most efficient sailing angle.

12. The sail trimmer could also be interfaced with on-board computer equipment for evaluating sail efficiency.

Amendments to the claims have been filed as follows 1. An Electronic Sail Trimmer comprising of a main unit and means for securing the unit to the yacht and detatching from the yacht, a wind vane and a.

display unit.

2. An Electronic Sail Trimmer as claimed in 1. that displays the relative position of the wind vane and the main unit.