GB2200881A - Wishbone boom for a sailing craft - Google Patents

Abstract

A wishbone boom has a outhaul end 27 for attachment to the clew of a sail and a mast end 26 for attachment to the mast. The mast end 26 has an outer surface 23 corresponding to the outer surface of the mast and is thus attached to the mast in such a way that any force applied to the outhaul end of the boom will tend to force the boom towards the mast so as to more securely attach the boom to the mast. <IMAGE>

Description

Description of Invention An apparatus for a soiling craft.

THE PRESENT APPARATUS relates to an apparatus comprising a wishbone boom and most for a sailing craft, and more particularly to a wishbone boom and mast apparatus for a sailboard, as well as to a sailing craft, especially a sailboard, provided with such an apparatus.

Many sailing craft at present employ "wishbone" booms, which wishbone booms generally comprise two substantially parallel tubular members, joined together at each end and bowed away from each other. Examples of such sailing craft, employing wishbone booms, include ssilboards and windsurfers.

At present, the standard wishbone boom, shown in Figure 1 of the accompanying drowings, comprises an outhaul end which outhaul end is attached to the clew of a sail, which is the corner of a sail remote from the mast, and a mast end having a cupped portion 3 on the inner surface of the boom, which cupped portion 3 corresponds with the outer surface of the mast.

The procedure for rigging a sailboard comprising such a wishbone boom is as follows: the mast is threaded into loops along the luff of the sail.

Battens are slotted into the leech of the sail and the sail is fastened to the mast, usually by means of a downhoul. The wishbone boom is then placed over the mast and sail with the cupped portion 3 of the mast end placed in contact with the outer surface of the mast II. The outhaul end of the boom is moved upwardly or downwardly to pivot the boom, about the cupped portion 3, towards the mast. The mast end is then attached to the mast by means of a rope (called the inhaul) which is inserted through the rope hole I of the mast end of the boom, wrapped around the surface of the mast opposite to the cupped portion 3 of the boom, and then fastened through the second rope hole 2 of the boorn.When the boom has been attached to the ma tI the boorri is moved bock to a position normal to the most levering the rope holes I and 2 oway from the most and so tightening the rope attachment of cupped portion 3 to mast II. The clew of the sail is then fastened to the outhaul end of the boom by a rope called the outhaul.

The standard wishbone boom and mast arrangement has several disadvantages. The most importont disadvantage is that the forces placed upon the outhaul end of the boom, by rigging the sail, by the wind and by the sailor, tend to force the mast end of the boom away from the most. It has been found that, despite the tightest rope connection of the mast end of the boom to the mast, such forces will tend to loosen, undo or break the connection between the boom and the mast. It is also found thot synthetic ropes used today tend to stretch when in contact with water, a condition which is exaggerated by the application of such force on the outhaul end.

Such force on the outhaul occurs when rigging and when the sailor pulls the sail against the wind, thus forcing the sail away from the outhaul and mast ends of the boom, so pulling the outhaul end towards the mast and so forcing the mast end away from the boom. A particular consequence of this is that the boom to mast connection is always loose which limits control of the sailboard or windsurfer. Furthermore, because of the forces placed upon the connection between the mast and the boom, alternative forms of fastening the mast to the boom, other than rope, are limited.

The presently used wishbone boom and mast arrangement further gives rise to a complicated rigging procedure. The consequences of this is that any adjustment made to tighten or change the position of the boom entails dismantaling the entire boom, sail and mast arrangement to raise or lower the boom in respect to its position on the mast. This procedure is especially difficult when the craft is on the water.

An object of the present invention is to overcome, or at least mitigate, the disadvantages described above.

According to the present invention there is provided an apparatus for a sailing craft, which apparatus comprises a mast, a wishbone boom, the wishbone boom comprising a mast end, securing means remote from the mast end, first attachment means attaching the boom to the mast and second attachment means attaching the securing means to the mast so that, when the sailing craft is in use, force applied to the securing means by the second attachment means applies a force to the first attachment means so as more securely to attach the boom to the mast.

Preferably the first attachment means attaching the boom to the mast comprises means extending away from one end of the boom, which means is in use secured around the mast. More preferably, the first attachment means comprises a clip, hinged on one side of the end of the mast to be secured to the boom, which releasably attachable to the other side of the end of the boom to be attached to the mast. Most preferably, the end of the boom to be attached to the mast comprises an outer surface corresponding to the outer surface of the mast.

Preferably the second attachment means comprises a sail, and more preferably the second attachment means further comprises an outhaul.

The present invention has the advantage that the greater the force exerted on the outhaul end of the boom, by either the outhaul or the sail, the greater the force urging the mast end of the boom towards the mast.

One advantage of the present invention is that, in certain embodiments of the present invention, no rope need be employed to connect the boom to the mast and thus the connection between the boom and the mast cannot stretch and so loosen the connection. Furthermore, there are more alternative forms of attaching the boom to the mast. The present boom and mast arrangement is easier to assemble and takes less time.

Accordingly, the present invention provides a mast and boom arrangement for use with a sailing croft, such asa sailboard, which mast and boom arrangement provides a tighter connection between the mast and the boom and thus leads to greater control of the craft and, furthermore, the present mast and boom arrangement is osier to assemble and to adjust, especially on the water.

In order that the present invention may be more readily understood and so that further features thereof may be appreciated, the invention will now i, des.ritssctl by way of example with reference to the occomponying drawings: FIGURE I shows a plan view of a wishbone boom and cross-section of a mast according to the prior art; FIGURE 2 shows a plan view of a wishbone boom and cross-section of a mast according to one embodiment of the present invention; FIGURE 3 shows a second embodiment of the attachment means of the wishbone boom and mast of Figure 2; FIGURE 4 shows a third embodiment of the attachment means of the wishbone boom and mast shown in Figure 2; and FIGURE 5 shows an exploded view of a fourth embodiment of the attachment means of the wishbone boom of Figure 2.

As shown in Figure I, the wishbone boom of the prior art comprises two longitudinal members 4 and 5, joined at each end and bowed away from each other. The wishbone boom of Figure I comprises a mast end 6 and an outhaul end 7. The outhaul end 7, which may be attached to the sail of the craft and an outhaul by means of a rope or ropes inserted through a hole 9 in the outhaul end 7. The length of the boom may be adjusted by sliding the outhaul end 7 within the longitudinal members 4 and 5. The outhaul end 7 may be fastened in position, to obtain optimum length of the boom, by insertion of pins through the appropriate holes 10 in longitudinal members 4 and 5 and appropriate corresponding holes in the outhaul end 7 to secure the outhaul end 7 with respect to the longitudinal members 4 and 5.

The mast end 6 of the wishbone boom of Figure I further comprises rope holes I and 2 and a cupped member 3, the inner surface of which cupped member 3 corresponds to the outer surface of the mast 11.

When rigging a sailboard comprising the wishbone boom of Figure I, the mast II is threoded into the luff of the sail, and battens are fastened into the leech of the sail between the mast 11 and the edge of the sail remote from the most. The boom of Figure I is then placed over the mast II and the sail arvi the mast end I of the boorn is placed with the cupped member 3 pressed against the appropriate point of the mast II about which the boom is intended to be- fastened. A rope is then affixed through the rope hole I and passed around the mast II so that the rope contocts the surface of the mast II remote from the cupped member 3.The rope is then pulled tight around the mast 11 and is secured through a second rope hole 2 of the boom.

The outhaul rope is then affixed to the end 7 of the boom remote from the most by threading the rope through hole 9 and fastening one end of the rope to the hole 9. This outhaul is then threoded through the clew of the sail and back several times through a pulley block 8 before fastening the other end of the rope in a cleat 12.

A wishbone boom and mast arrangement according to the present invention is shown in Figure 2. The wishbone boom of Figure 2 comprises two longitudinal members 24 and 25 which are joined at either end and are bowed away from each other. The wishbone boom comprises a mast end 26 and an outhaul end 27, the outhaul end 27 having a pulley block 28 and an outhaul rope hole 29. A sail and/or outhaul may be connected to the outhaul end by means of the outhaul hole 29 and the pulley block 28. The length of the boom may be adjusted by means of holes 210 in the longitudinal members 24, 25, appropriate holes 210 being secured to corresponding holes in outhaul end 27 by means of pins, the outhaul end being slidable within longitudinal members 24 and 25 as is the current method in the prior art.

The mast end of the wishbone boom according to the present invention comprises two rope holes 21 and 22 and the outer surface of the end of mast end 26 is formed into a cupped member 23 which cupped member 23 corresponds to the outer surface of the mast 211.

To assemble or rig a sailboard using the wishbone boom and mast arrangement of the present invention, one embodiment of which is shown in Figure 2, the boom is placed over a sail. The mast 211 is then threoded into the luff of the sail. Battens are fastened with the leech and one end of an outhaul rope is fastened through hole 29. The other end of the outhaul is fastened, by way of pulley block 28, to the clew of the sail which is the point of the sail remote from the mast. The outer surface 23 of the mast end of the boom 2C is then positioned against the point of the mast 211 around which the boom is to be fastened.

In the wishbone boom and mast arrangement of Figure 2, the mast end 26 of the boom is attached to the mast 211 by means of a rope which is secured to the first rope hole 21, passed around the surface of the mast 211, remote from the cupped member 23 of the mast end 26 of the boom, and is then tightened against the outer surface of the mast 211 and secured through second rope hole 22.

When, in use, any force placed upon the outhaul end 27 of the boom by the sail or the outhaul, for example, by wind forcing the sail outwards towards one of. the longitudinal members 24, 25 thus reducing the distance between the mast and the point of the sail furthest from the mast, the outhaul end 27 will be forced towards the mast 211. This force will be transmitted along longitudinal members 24 and 25 to mast end 26, and thus mast end 26 will be forced towards the mast 211. In this way the cupped member 23 of mast end 26 will be forced against the mast 211 by any force placed on the outhaul hole 29 and/or the pulley block 28 by the sail or the outhaul, thus providing a tight connection between the mast 211 and the outer surface 23 of the mast end 26.This tight connection will give greater control of the sailboard than is provided by the connection of the prior art boom and mast and, furthermore, the attachment of the mast 211 to the boom (in the case of Figure 2 the rope affixed to the rope holes 2 1 and 22) will not be placed under any stress and thus will be in no danger of breaking or stretching.

Figure 3 shows alternative means for attaching the mast end 36 of the boom to the mast 311. The mast end 36 of the boom has an outer surface formed as a cupped member 33 which outer surface corresponds to the outer surface of mast 311. A second cupped member 312 having an inner surface corresponding to the outer surface 311 remote from the cupped member 33 of the mast end 36 is pivoted about point 313 on one side of the mast end 36.

The second cupped member 312 has, secured to its outer surface, a resilient tongue 314 which resilient tongue 314 is biased away from the outer surface of cupped member 312. The resilient tongue 314 has a projection 315 extending outwardly from the resilient tongue 314 on the side remote from the outer surface of the second cupped member 312. The side of the mast end 36 of the boom, opposite to the side of the mast end 36 about which the cup-shoped member 312 is pivoted has a longitudinal hole 316 corresponding to resilient tongue 314, which longitudinal hole 316 has a width greater than the combined width of the resilient member 314 and the projection 315.

To attoch the boom to the mast 311 the outer surface 33 of the mast end 36 is placed against the appropriate point of the mast 311 about which the boom is to pivot. The second cupped member 312 is pivoted about the point 313 toward the mast 311 and the resilient tongue 314 is inserted into the hole 316 until the projection 315 opposes a corresponding inlet 317 of hole 316. In this position the second cupped member 312 is flush with the outer surface of the mast 311 remote from the outer surface 33 of the mast end 36, and the bias of the resilient tongue 314 will tend to force the projection 315 into the inlet 317. In this manner, the second cupped member 312 will be prevented from pivoting away from the mast 311 about point 313 by the contact between the projection 315 and the inner surface 318 of the inlet 317.

To release the attachment shown in Figure 3, the resilient tongue 314 is forced towards the second cupped member 312 so that the projection 315 is moved out of the inlet 317. In this position the resilient tongue 314 may be withdrawn from the hole 316 in the mast end 36 and thus the second cupped member 312 may be pivoted away from mast 311 around point 313, so allowing the mast end 36 of the boom to be moved away from the mast 311.

Figure 4 shows an alternative embodiment of the mast end of a wishbone boom according to the present invention. The mast end 46 has an outer surface comprising a cupped member 43 which cupped member 43 corresponds to the outer surface of the mast 411. On one side of the mast end 46 of the boom is positioned a bracket 419. Pivoted about the bracket 419 is a lever 420. Extending from the lever 420, on the side of the lever420 remote from the boom, is a projection 421. Pivoted about a point 422 on the projection 421 is a second cupped member 41 2. At the end of the second cupped member 412, remote from the pivot point 422, is a metal loop 423, which metal loop 423 is pivoted about the end of the second cupped member 412 remote from the pivot point 422.On the side of the mast end 46, opposite the side of the mast end 46 on which is positioned the bracket 419, is o projection 424, extending away from the cupped member 43. The projection 424 has, at its end remote from the mast end 46, annular flange 425, which flange 425 extends normally to the longitudinal axis of the cylidrical projection 424. The diometer of the flange 425 is less than the diameter of the loop 423.

To attach the mast end 46 to the mast 411, the outer surface 43 of the mast end 46 is positioned against the surface of the mast 411 at a point at which the boom is to be attached to the mast 411. The second cupped member 412 is then pivoted, about point 422 on the projection 421 on the lever 420, towards the mast 411 until the second cupped member 412 is opposed to the mast 411. The loop 423 is then pivoted about the end of the cup-shoped member 412 remote from the pivot point 422 so that the loop 423 lies around projection 424. The lever 420 is then pivoted, about bracket 419, towards the boom. This movement of the lever 420 moves the projection 421 away from the mast 411 and towards the boom. This movement of the projection 42 1 in turn causes the pivot point 422 to move away from the side of the mast end 46 and towards the boom.This in turn forces the inner surface of the second cupped member 412 towards the mast 411 and, further, forces the end of the second cupped member 412 remote from the pivot point 422 against the side of the mast end 46. This causes the loop 423 to be urged towards the projection 424 on the side of the projection 424 opposing the boom, and thus brings the loop 423 forceably into contact with the side of the projection 424. The loop 423 is prevented from slipping off the projection 424 by the presence of the flange 425.

To release the attachment shown in Figure 4, the lever 420 is moved away from the mast end 46 and so moves the projection 421 and pivot point 422 away from the boom and towards mast 411. This movement of the pivot point 422 away from the boom and towards the mast 411 causes the second cupped" member 412 to be released from engagement with the mast 411 and causes the force urging the loop 423 towards the projection 424 to be released. In this way the loop 423 may be pivoted, about the end of the second cupped member 412 opposite the pivot point 422, to be removed from the projection 424 thus allowing the second cupped member 412 to be pivoted, about point 422, away from the mast 411.

Thins allows the boom to be detoched from the mast 411.

Figure 5 shows an exploded view of a fourth embodiment of the present invention showing a rnast end 56, having a first rope hole 51 and a second rope hole 52 ond an outer surface 53 corresponding to the shape of the mast, which is detachable from the longitudinal members 54 and 55 of the boom.

Two projections 526, 527, extending away from the outer surface 53, of the mast end 56, may be positioned so as to be slidably retained within the longitudinal members 54 and 55. The projections 526 and 527 possess pin holes 528 and 529 respectively , which pin holes 528 and 529 correspond with similar sized holes 530 and 531 on the longitudinal members 54 and 55 respectively.

To attach the mast end 56 to the longitudinal members 54 and 55 of the boom, the projections 526 and 527 are slidably inserted into the longitudinal member 54 and 55 respectively and the corresponding pin holes 528 and 530 and 529 and 531 are aligned. A pin is then inserted through holes 528 and 530, and a second pin is inserted through holes 531 and 529, to secure the mast end 56 with respect to the longitudinal members 54 and 55. To remove the mast end 56, for example, to replace the mast end 56 with a second mast end having an outer surface 53 of different dimensions to fit a differently dimensioned mast, the pins are removed from holes 528 and 530, and 529 and 531, thus allowing the projections 526 and 527 and thus the mast end 56 to be slidably removed from longitudinal members 54 and 55.

Claims (13)

1. CLAltU,5

   I. An apparatus for a sailing craft, which apparatus comprises a mast, a wishbone boom, the wishbone boom comprising a mast end, securing means remote from the mast end, first attachment means attaching the boom to the mast and second attachment means attoching the securing means to the mast so that, when the sailing craft is in use, force applied to the securing means by the second attachment means applies a force to the first attachment means so as more securely to attach the boom to the mast.
2. 2. An apparatus according to Claim I, wherein the securing means is positioned at the end of the wishbone boom remote from the mast.
3. 3. An apparatus according to Claim I or 2, wherein the first attachment means attaching the boom to the mast comprises an end of the boom having an outer surface shaped to correspond with the outer surface of the mast.
4. 4. An apparatus according to Claim 1, 2 or 3, wherein the first attachment means comprises second securing means, extending away from one end of the boom which second securing means is, in use, secured around the mast.
5. 5. An apparatus according to Claim 4, wherein the second securing means comprises a mechanical clip.
6. 6. An apparatus according to Claim 4 or 5, wherein the second securing means is hinged on one side of the one end of the boom.
7. 7. An apparatus according to any one of of the preceding claims, wherein the second attachment means comprises a sail.
8. 8. An apparatus according to any one of the preceding claims, wherein the second attachment means further comprises an outhaul.
9. 9. An apparatus according to any one of the preceding claims, wherein the first attachment means is releaseably secured to the boom.
10. 10. An apparatus for a sailing craft, substantially as hereinbefore des cried, with reference to, ond as shown in, the accompanying Figures 2 to 5.
11. II. A soiling croft provided with an apparatus in accordance with any one of the preceeding claims.
12. 12. A sailing craft according to Claim 11, which comprises a sailboard.
13. 13. Any novel feature or combination of features as disclosed herein.