GB2283470A

GB2283470A - Means for controlling movement of the boom of a sailing boat

Info

Publication number: GB2283470A
Application number: GB9322830A
Authority: GB
Inventors: Donald Alan Scott
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-11-05
Filing date: 1993-11-05
Publication date: 1995-05-10
Anticipated expiration: 2013-11-05
Also published as: GB2283470B; GB9322830D0

Abstract

The boom 2 of a sailing boat is fitted with a clamping device 6 through which is passed a rope 7 fixed at both ends. The degree of clamping is controlled by a cord 9 from the cockpit of the boat. When the cord is pulled the device unclamps the rope and the boom is then free to swing laterally. When the cord 9 is released the device clamps the rope 7 which prevents lateral movement of the boom. The clamping device 6 comprises a spring-loaded two part linkage consisting of a lever 19 and link 20, the rope 7 being clamped between a movable clamp bar 16 and a pair of side bars 18. <IMAGE>

Description

MEANS FOR CONTROLLING MOVEMENT OF THE BOOM OF A SAILING BOAT This invention relates to means of controlling the movement of the boom of a sailing boat.

The lateral position of the boom of a sailing boat is normally controlled only by a rope purchase known as the main sheet one end of which is attached to a point on the boom and the other end to a point near the longitudinal centreline of the boat. It is possible for a boat to be sailed in such a way that the wind acts on the opposite side of the sail to that which normally drives the boat forwards with the result that the sail causes the boom to swing violently over to the other side of the boat at a speed which cannot be controlled by the main sheet. This can happen unexpectedly and cause injury to the crew of the boat or damage to the rigging.

The object of the present invention is to enable the helmsman or a crew member to lock the boom in any selected position by remote control from the cockpit so that it is prevented from swinging over as described above. A further object is to allow the boom to swing over slowly under the same remote control.

According to the present invention there is provided a boom movement control means comprising in combination a clamping device that is attached to the boom of a sailing boat and a rope fixed at both ends and passing through the device and means for controlling from a remote point the degree of clamping between the device and the rope passing through it.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows in perspective a sailing boat with the clamping device mounted on the boom and the associated rope and control cord; Figure 2 shows the side elevation of the clamping device in the locked position; Figure 3 shows the side elevation of the clamping device in the free position; Figure 4 shows the end elevation of the clamping device.

Figure 5 shows alternative methods of passing the rope through the clamping device.

Referring to the drawings Fig 1 shows a boat with mast 1, boom 2, sail 3, main sheet 4 and boom vang 5. The boom movement control means consists of a clamping device 6 mounted on the underside of boom 3 and a rope 7 which runs between fixed points 8 on either side of the boat and through clamping device 6. A control cord 9 runs from clamping device 6 through a pulley block 10 located in substantially vertical alignment with boom pivot 11 and then back to a jamming cleat 12 within reach of cockpit 13.

Fig 2 shows the clamping device in the locked position. The body 14 is pivotally connected to straps 15 which are fastened to boom 2. In an alternative construction body 14 may be rigidly fastened to boom 2 but the pivoted method more easily accommodateS the wide variety of boom crosssectional shapes.

A clamp bar 16 is pivotally connected to body 14 by pivot 17 and can move up and down between the pair of side bars 18 of body 14. A 2-part linkage consisting of a lever 19 and link 20 extends between pivot 21 on body 14 and pivot 22 at the end of clamp bar 16. A pair of tension springs 23 are connected between extended pivot pins 24 and 17 and act to bring the 2-part linkage 19 and 20 to a top dead centre position with pivots 21 22 and 24 substantially in line. When this position is reached lever 19 strikes the end of clamp bar 16 and prevents further movement.

Rope 7 passes through body 14 between clamp bar 16 and side bars 18 of body 14. Fig 5 shows two alternative ways of threading rope 7. In method A rope 7 passes underneath clamp bar 16. In method B rope 7 passes over clamp bar 16 for either one and a half or two and a half turns. Method B gives a more powerful clamping action than method A.

The vertical position of clamp bar 16 when in the locked position in relation to side bars 18 is adjustable by means of screw 25 and stiff nuts 26.

A control cord 9 is threaded through a hole at the end of lever 19 and held by a stop knot 27. It passes over a guide pulley 28 attached to the underside of boom 2 and thence to pulley block 10 and back to a jamming cleat 12 within reach of cockpit 13.

Fig 3 shows the clamping device when control cord 9 has been pulled and held in jamming cleat 12. When clamp bar 16 is in this position rope 7 is free to move through body 14 and this allows boom 2 to swing freely from side to side.

When control cord 9 is released tension springs 23 force the 2-part linkage 19 and 20 into the top dead centre position and clamp bar 16 compresses rope 7 between itself and side bars 18 thus preventing lateral movement of boom 2.

If control cord 9 is only pulled a short distance, movement of lever 19 causes the clamping force on rope 7 to be reduced and in this way boom 2 is allowed to swing over slowly and under control.

Claims

1 A means for controlling movement of the boom of a sailing boat comprising in combination a clamping device that is attached to the boom of a sailing boat and a rope fixed at both ends and passing through the device and means for controlling from a remote point the degree of clamping between the device and the rope passing through it.

2 A means as claimed in Claim 1 wherein the clamping action of the clamping device is provided by a pivoted clamping element which compresses the rope passing through the device against a part or parts of the body of the device.

3 A means as claimed in Claim 2 wherein the free end of the pivoted clamping element of the clamping device is pivotally connected to a spring loaded 2-part linkage in which the the pivot joining the two links reaches a point substantially on a line joining the pivots at the other ends of the links when the clamping element is in the fully clamped position.

4 A means as claimed in Claim 3 wherein one link of the 2-part linkage of the clamping device is extended to form a lever by which the degree of clamping may be controlled.

5. A device as claimed in Claim 4 wherein the lever of the clamping device is actuated by a cord running through a pulley block attached to a fixed point on the boat or the mast substantially in vertical alignment with the boom pivot and then back to a jamming cleat near the cockpit of the boat.

6 A device as claimed in any preceding claim wherein the degree of clamping exerted by the clamping device can be adjusted by means of altering the length of offset between the clamping element and the pivot about which the clamping element rotates.

7 A device as claimed in any preceding claim wherein the clamping device is pivotally connected to the boom by means of a pivot whose axis is substantially parallel to the axis of the boom.

8 A device as claimed in Claims 1 - 6 wherein the clamping device ls rigidly connected to the boom.

9 A device for controlling movement of the boom of a sailing boat substantially as described herein with reference to Figures 1-5 of the accompanying drawings.

5. A means as claimed in Claim 4 wherein the lever of the clamping device is actuated by a cord running through a pulley block attached to a fixed point on the boat or the mast substantially in vertical alignment with the boom pivot and then back to a jamming cleat near the cockpit of the boat.

6 A means as claimed in any preceding claim wherein the degree of clamping exerted by the clamping device can be adjusted by means of altering the length of offset between the clamping element and the pivot about which the clamping element rotates.

7 A means as claimed in any preceding claim wherein the clamping device is pivotally connected to the boom by means of a pivot whose axis is substantially parallel to the axis of the boom.

8 A means as claimed in Claims 1 - 6 wherein the clamping device is rigidly connected to the boom.

9 A means for controlling movement of the boom of a sailing boat substantially as described herein with reference to Figures 1-5 of the accompanying drawings.

Amendments to the claims have been filed as follows l A device for controlling movement of the boom of a sailing boat comprising in combination a clamping device that is attached to the boom of a sailing boat and a rope fixed at both ends and passing through the device and means for controlling from a remote point the degree of clamping between the device and the rope passing through it.

2 A device as claimed in Claim 1 herein the clamping action cf the clamping device is provided by a pivoted clamping element which compresses the rope passing through the device against a part or parts cf the body of the device.

3 A device as claimed in Claim 2 wherein the free end of the pivoted clamping element of the clamping device is pivotally connected to a spring loaded 2-part linkage in which the the pivot joining the two links reaches a point substantially on a line joining the pivots at the other ends of the links when the clamping element is in the fully clamped position.

4 A device as claimed in Claim 3 wherein one link of the 2-part linkage of the clamping device is extended to form a lever by which the degree of clamping may be controlled.