GB2358847A

GB2358847A - A device for controlling the lateral movement of the boom of a sailing boat

Info

Publication number: GB2358847A
Application number: GB0002252A
Authority: GB
Inventors: Donald Alan Scott
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-02-02
Filing date: 2000-02-02
Publication date: 2001-08-08
Also published as: GB0002252D0

Abstract

To increase the capacity of known devices 6 to control the lateral movement of the boom 2 of a sailing boat the rope 7 passing through such a device 6 has each of its ends passed round pulley blocks 14,15 attached to fixed points 8 near each side of the boat and then back to an attachment point 22 on the boom 2. In an alternative arrangement (see Figs 3 and 4) for other devices, one or both of these pulley blocks is attached to an additional rope which is passed round a further pulley block attached to a fixed point near the side of the boat and then back to the cockpit.

Description

2358847 A DEVICE FOR CONTROLLING THE LATERAL MOVEMENT OF THE BOOM OF A

SAILING BOAT This invention relates to an improvement to known devices for controlling the lateral movement of the boom of a sailing boat.

4, 1 Figure 1. shows a device 6 an example of which is described in my Patent GB2299798B and also of which other types exist which all use the friction between a rope 7 and part of the device 6 attached to the boom 2 of a sailing boat to control the lateral movement of the boom when a change in the direction of the wind relative to the centre-line of the boat causes the sail to drive the boom across the boat.

The tension in the rope 7 needed to restrain this lateral movement depends in part on the area of the sail 3 attached to the boom 2 and on the weight of the boom. If such area and weight are increased the tension in rope 7 required to restrain the lateral movement of the boom may reach the breaking point of the rope.

According to the present invention the capacity to restrain the lateral movement of the boom in any given circumstances of a given size of device 6 and diameter of rope 7 before the breaking point of the rope is reached is approximately doubled.

Figure 1 shows the arrangement of the device 6 as described in my Patent GB2299798B in a boat having a mast 1, boom 2, sail 3, main sheet 4 and boom vang 5 and a boom movement control device 6 mounted on the underside of boom 2. A rope 7 runs between fixed points 8 on either side of the boat and through the device 6. A remote control extended element 9 runs from device 6 through a pulley block 10 and. then back to a cleat 12 within of cockpit 13.

A specific embodiment ofthe invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 2 shows the same arrangement as in Figure 1 but with each end of 4 1 rope 7 being passed through pulley blocks 14 and 15 attached to the fixed points 8 and then back to an attachment 22 on the boom 2. This attachment may be anywhere on the boom but preferably adjacent to the device 6 and between it and the aft end of the boom.! If the attachment 6 is in this preferred position the tension in rope 7 in a given set of circumstances will be approximately half what it would have been had the arrangement been as described in my Patent GB2299798B and also the relative speed of rope 7 passing through the device 6 for any given rate of bnom swing will be approximately doubled.

Figure 3 shows how this invention can be applied to other boom controlling devices such as described in US Patent 4,138,962 in which the friction between device 6 and rope 7 is controlled not by a separate remote control extended element 9 but by exerting a tensioning force on one end of rope 7 while the other end remains fixed. In this application a second rope 17 is attached to pulley block 15 and then taken round another pulley block 16 and back to a winch 18 near the cockpit 13. This additional pulley block 16 and rope 17 can be fitted to either or both fixed points 8.

Figure 4 shows how this invention can be applied to other boom controlling devices of a type in which the friction between device 6 and rope 7 is controlled by bringing together the two parts of rope 7 extending between the device 6 and the fixed points 8 at a point adjacent to device 6 by means of two pulley blocks coupled together 23 which are pulled by one or other of two control ropes 20 which are led back to cleats 21 near the cockpit 13 via pulley blocks 19 attached near the fixed points 8. The effect of pulling the two parts of the rope together effectively shortens rope 7 and so increases friction between the rope 7 and the device 6. In this application of the invention each end of rope 7 is passed round pulley blocks 14 and 15 attached to fixed points 8 near the sides of the boat and then back to an attachment 22 on the boom 2. '., 1 In each of these applications of the invention, it would be pgssible to increase still further the effective resistance to boom lateral movement for any given rope tension by adding further pulley blocks to increase the rope purchase between the boom attachment point 22 and the fixed points 8 from 2-part to 3(or more)-part.

Claims

4 1 1. An improvement to a device for controlling the lateral movement of the boom of a sailing boat in which each end of the rope which passes though the device is passed round a pulley block attached to a fixed point near., each side of the boat and then back to an attachment point on the boom.
2. An improvement as described in Claim 1 in which one of the pulley blocks described in Claim 1 instead of being attached to a fixed point near the side of the boat is attached to a rope passed through another pulley block attached to the fixed point and then back to the cockpit.
3. An improvement as described in Claim 2 in which a similar and additional pulley block and rope arrangement is attached to a fixed point near the other side of the boat.
4. An improvement as described in Claim 1 in which the friction between the rope and the device is controlled by a pair of joined pulley blocks which draw together the parts of the rope on either side of the device by being pulled towards either side of the boat by other ropes.
5. An improvement as described in each of the preceding claims in which the rope purchase on either side of the boom is increased to 3-part or more.
6. An improvement to devices for controlling the lateral movement of the boom of a sailing boat substantially as described herein with reference to Figures 1 - 4 of the accompanying drawings.