GB2374330A

GB2374330A - Carriage unit for a vang system

Info

Publication number: GB2374330A
Application number: GB0108972A
Authority: GB
Inventors: Stephen Roy Atkins
Original assignee: RWO
Current assignee: RWO
Priority date: 2001-04-10
Filing date: 2001-04-10
Publication date: 2002-10-16
Anticipated expiration: 2021-04-10
Also published as: GB2374330B; GB0108972D0

Abstract

A carriage unit 22 for a vang system (3, Fig 1) on a sailing boat is mounted on two spaced apart co-axial ring-shaped tracks 19 and 21 for movement about an axis defined by the tracks, the carriage unit having an upper part (23, Fig 5) containing track engaging means to engage the upper track and a lower part (24, Fig 5) containing track engaging means to engage the lower track. The track engaging means may comprise a plurality of rollers (25, 26 and 27, Fig 5), three engaging the upper track and three engaging the lower track. The carriage unit may also support a cleat assembly (26, Fig 5) which engages a cord or rope 13 that forms part of a pulley system of the vang system. The carriage unit maybe mounted on a mast 1 of the sailing boat at a position below the boom (2, Fig 1).

Description

DESCRIPTION OF INVENTION "Improvements in or relating to a Carriage Unit".

This invention relates to a carriage unit and more particularly relates to a carriage unit forming part of a vang assembly as used in a sailing boat or yacht.

A vang assembly is used in a sailing boat or yacht to keep the boom, which extends at the under-side of the sail, in a desired orientation relative to the mast. The vang system is of particular use when the boom is extending outwardly of the gunwales of the vessel. The present invention is of particular relevance to a vang system comprising a pulley-block arrangement extending between a point on the boom and a point on the mast. Such a pulley-block arrangement may be used to apply a downward force to the boom, to stop the boom moving upwards when the sails are filled with wind.

Many vang systems have been proposed previously, but it is often desirable to control the vang system when trapezing. A preferred embodiment of the present invention is a vang system which can be controlled when trapezing.

According to this invention there is provided a carriage unit, the carriage unit being mounted on two spaced apart co-axial ring-shaped tracks for movement about an axis defined by the tracks, the carriage having an upper part

containing track engaging means to engage the upper track and a lower part containing track engaging means to engage the lower track.

Conveniently the track engaging means comprise rotatable elements.

Preferably the rotatable elements comprise a plurality of rollers.

Advantageously the rollers each have an axis substantially aligned with the axis defined by the ring-shaped tracks.

Preferably three rollers engage one track and three rollers engage the other track, there being two of said rollers engaging the radially exterior part of each track and one roller engaging the radially inner part of each track.

Conveniently the carriage supports a cleat assembly.

The invention also relates to a vang system on a sailing boat or yacht incorporating a carriage unit of the invention as defined above.

Conveniently the carriage is provided with a cleat and the cleat engages a cord or rope that forms part of a pulley system.

Advantageously a plurality of rollers are provided to guide the cord or rope, the rollers having a throat located substantially in alignment with the axis defined by the ring-shaped tracks.

Preferably the carriage unit is mounted on a mast at a position below the boom.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which: FIGURE I is a view of a mock-up of a mast and boom provided with a vang system in accordance with the invention, FIGURE 2 is an enlarged view of part 6 the mock-up shown in Figure 1 illustrating part of the boom and the associated vang system, FIGURE 3 is an enlarged view of another part of the mock-up of Figure 1 illustrating part of the mast and part of the vang system in one position, FIGURE 4 is a view which is similar to that of Figure 3 showing the illustrated part of the vang system in a different orientation, and FIGURE 5 is a partially exploded view of the carriage unit that forms part of the vang system.

Referring initially to Figure 1 of the accompanying drawings a sailing boat or yacht will typically have a vertical mast 1 from which extends a generally horizontal boom 2. The boom 2 is capable of some pivotal movement about a pivot axis adjacent the mast. The boom is connected to the lower edge of the sail. A vang assembly 3 is provided in the form of a pulley system which extends from a lower unit 4 which is mounted on the mast 1 to an upper unit 5 which is connected to the boom.

As can be seen in Figure 2, the upper unit 5 comprises a plate 6 which is secured to the boom 2, the plate 6 being connected to a pulley block 7. Pulley block 7 may be a multiple-sheave pulley block which is reeved with a cord or rope 8 which has one free end 9 secured to the pulley block 7 and the other free end 10 secured to a second pulley block 11. The pulley block 11 has one free

end 12 of a second 13 secured thereto, and is reeved with that second cord or rope.

Turning now to Figure 3, the lower unit 4, which is secured to the mast 1 is illustrated. The lower unit 4 comprises two spaced apart identical vertical support plates 14 which support between them twin pulley wheels 15 which receive turns 1 of the first cord or rope 8. The plates 14 also support between them a single pulley wheel 16 which receives a turn of the second cord or rope 13 and, at a lower position than the twin pulley wheels 15 and the single pulley wheel 16, a further single pulley wheel 17 which receives the free end of the second cord or rope 13. It is to be appreciated by pulling on the free end of the second cord or rope 13 the pulley system constituted by the second pulley block 11 and the single pulley wheel 16 effectively applies force to the free end 10 of the first cord or rope 8, and thus causes the pulley system constituted by the cord 8, the pulley block 7 and the twin pulley wheel 15 to apply a very substantial generally downward force to the mounting plate 6 connected to the boom 2.

As can be seen from Figure 3, the free end of the cord or rope 13, after passing around the single pulley wheel 17, extends horizontally between the plates 14 and then passes between two rollers (only one of which, 18, is visible in Figure 3) which each have a substantially vertical axis. The spacing between the operative surfaces of the rollers is only slightly greater than the diameter of the second cord or rope 13.

Located above the rollers 18 is a first horizontal ring-shaped track 19, formed from a rod or bar of circular cross section which is formed to have a substantially circular shape, with the ends of the rod or bar being secured 20 to appropriate points on the plates 14.

Located below the blocks 18 is a second corresponding horizontal ringshaped track 21. The ring-shaped tracks 19,21 are located about a common vertical axis.

Mounted on the ring-shaped tracks 19 and 21 is a carriage unit 22 which can move with a"circular"movement in a horizontal plane around the ringshaped tracks, thus moving about the vertical axis.

The carriage unit 22, as can be seen from the exploded view in Figure 5, comprises an upper roller housing 23 which is associated with the upper ring shaped track 19 and a lower roller housing 24 which associated with the ring shaped track 21. Contained within the upper roller housing 23 are three rollers, which are provided to engage the track, each roller having a"waisted"exterior, and each having a vertical axis. Two rollers, 25,26 engage the outer part of the ring-shaped track 19 and a third roller 27, located between the rollers 25 and 26, engages the inner surface of the ring-shaped track 19.

A similar trio of rollers is provided within the lower roller housing 24 co-operating with the lower ring-shaped track 21.

The roller housing 23 and 24 are interconnected and are associated with a horizontal support platform 25. Mounted on the support platform 25 is a cleat unit 26. The cleat unit 26 comprises a base 27 on which are mounted two rotatable cleat elements 28,29. The cleat elements have co-operating serrated faces 30. The cleat unit illustrated also has a fairlead 31 mounted on top of the cleat elements 28,29. The cleat unit 26 is described in more detail in EP-A- 0771723, although it is to be appreciated that any appropriate cleat unit may be utilised.

It is to be understood that the free end of the cord or rope 13 will pass through a passage formed, for that purpose, between the roller housing 23 and 24 and will then pass through the cleat 26. The free end of the cord or rope 13 may be engaged by the cleat elements 28,29, in order to jam the cord or rope to maintain tension in the second cord or rope 13 but this cord or rope may be released from the cleat elements by moving the rope or cord upwardly, within the fair lead 31, to enable the tension applied to the boom by the vang assembly to be altered.

It is to be appreciated that the carriage unit 22 may move freely around the entire extent of the ring-shaped tracks 19 and 21. Figure 3 illustrates the carriage in a substantially central position and Figure 4 illustrates the carriage unit in a terminal position up against one vertical plate 14. Thus the carriage may be positioned to feed the second cord or rope 13 to a sailor even if the sailor is trapezing, to enable the sailor to control the vang assembly.

It is to be appreciated that the vertical rollers 18 are preferably positioned so that the"throat"between the rollers which is directed towards the carriage 22 is located substantially in alignment with the central axis of the coaligned ring-shaped tracks 19 and 21. Thus, as the carriage 22 moves around the tracks there is no variation in the tension in the second cord or rope 13. Alternatively the throat between the rollers 18 could be located at a position slightly off-set from the axis of the ring-shaped tracks 19 and 21, being spaced slightly further away from the ends of the rods or bars which are secured to the plates 14 than the axis, and in such a situation the carriage 22 will, when the second cord or rope 13 is under tension,"self park"at a central position as illustrated in Figure 3.

Whilst, in the described embodiment of the invention, the carriage is provided with roller housings each containing three rollers to engage the ringshaped tracks, alternative means may be provided to engage the tracks which may include other rolling elements such as ball races and the like or which may include engaging elements in the form of blocks of self lubricating plastics material, such as nylon or polytetrofluoroethylene, which engage the ringshaped tracks to permit the carriage to move relatively freely around the ringshaped tracks.

Claims

CLAIMS: 1. A carriage unit, the carriage unit being mounted on two spaced apart coaxial ring-shaped tracks for movement about an axis defined by the tracks, the carriage having an upper part containing track engaging means to engage the upper track and a lower part containing track engaging means to engage the lower track.
2. A carriage according to claim 1 wherein the track engaging means comprise rotatable elements.
3. A carriage according to claim 2 wherein the rotatable elements comprise a plurality of rollers.
4. A carriage according to claim 3 wherein the rollers each have an axis substantially aligned with the axis defined by the ring-shaped tracks.
5. A carriage according to claim 3 or claim 4 wherein three rollers engage one track and three rollers engage the other track, there being two of said rollers engaging the radially exterior part of each track and one roller engaging the radially inner part of each track.
6. A carriage according to any one of the preceding claims wherein the carriage supports a cleat assembly.
7. A vang system on a sailing boat or yacht incorporating a carriage unit according to any one of the preceding claims.

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8. A vang system according to claim 7 wherein the carriage is provided with a cleat and the cleat engages a cord or rope that forms part of a pulley system.
9. A vang system according to claim 8 wherein a plurality of rollers are provided to guide the cord or rope, the rollers having a throat located substantially in alignment with the axis defined by the ring-shaped tracks.
10. A vang system according to any one of claims 7 and 9 wherein the carriage unit is mounted on a mast at a position below the boom.
11. A carriage substantially as herein described with reference to and as shown in the accompanying drawings.
12. A vang system substantially as herein described with reference to and as shown in the accompanying drawings.
13. Any novel feature or combination of features disclosed herein.