GB2255540A - Sailboard harness linking device - Google Patents

Abstract

Means for maintaining the distance between points of force exerted on a sailboard boom by a harness line comprises a link. The link may be movable freely along the boom and comprise one or more tubes and include a cleat or pulley arrangement to adjust the length of the harness line. <IMAGE>

Description

LINKING DEVICE This invention relates to a harness line for use in windsurfing.

The harness line is commonly used to permit a force to be transferred by ties or lines from one object to another. Harness lines are used by sailors, in particular windsurfers, who use their body weight to counter a force applied to a sail. The harness line is intended to take the strain out of windsurfing and allows the sailor to stay on the water for longer periods. Rather than weary arms taking the strain, the harness lines do, allowing maximum use of body weight whilst letting the arms make fine adjustments to the sail. (See fig A) Previous harness lines have consisted of a loop of rope attached to the boom by application of an appropriate knot, or else by various clamping devices made from various materials.

Normally the harness line is set before the sailor leaves the beach. The rig is held on the beach in a sailing position with the wind in the sail. Still with the wind in the sail the hands are moved close together. Provided the rig is balanced, the point where they meet is the balance point of the sail. The harness line is attached to the boom at two positioning points equally spaced either side of the balance point.

It should be long enough to enable sailing with almost straight arms.

Too short will make hooking in and out difficult, as this is achieved by the sailor pulling the boom sharply towards him and letting the line swing up to meet the hook. Hooking out is achieved by taking the full weight of the rig back on the arms, thereby allowing the rope to fall out of the hook.

The method of setting harness lines described above is widely used, as existing lines currently in use do not allow the positioning points to be relocated without both the use of one hand, and the releasing of the tension in the line. Repositioning on the move requires the sailor to 'sheet out' the sail, move the positioning points, and sheet in once more: during this procedure the sailor may have difficulty keeping balance and will lose speed.

The setting of the lines on the beach is not entirely satisfactory. The balance point of a sail may change with wind speed and angle of attack.

By definition, the sailor must be above the water line and so may be subjected to a greater wind speed than on the water by virtue of height.

The setting of lines whilst stationary does not account for the apparent wind speed once the sailor in under way. Vind conditions away from the beach often are dissimilar to those close in, especially in off-shore winds. Finally, the wind conditions can change rapidly, even on open water.

Should the harness lines be incorrectly set, one arm will be forced to balance the sail and will tire over a period of time. The present invention allows the points of force transfer from the harness to the boom to be moved along the boom, thereby effecting an adjustable harness line. This allows the sailor to adjust the positioning of the harness lines without 'sheeting out' the sail, nor losing control of the sail.

The harness lines then can be balanced either side of the balance point of the sail at all times, considerably reducing energy expenditure.

According to the present invention the positioning or attachment points of the line are linked, so as to preserve their spacial correlation (that is to say the distance between them). The length of link may be adjustable if required.

The link itself may effect the transfer of force between the attachment points and the boom if required, and as such, may be an integral part of the attachment of the lines to the boom.

The linking device may act as either a strut (member under compression) or else a tie (member under tension, fig 5), or both when preserving the afore mentioned distance.

The linking device may be attached to the boom in any way which allows the device to move freely or otherwise, along the length of the boom.

Examples would include, a tube or multiple tube or ring arrangement enclosing the boom (fig 1-5), strut or tie hung from a rail which itself is attached to the boom or incorporated into the boom' structure (fig 6 & ). The shape of an enclosing device should allow the linking device to travel along the curved parts of the boom (as in fig 1-5 & 7).

Furthermore, the tubes or rings may be composed of any number of parts; for example a tube may be composed of two parts such that the two separate parts resemble a tube split longitudinally, allowing the tube to be placed around the boom without dismantling the latter.

The involuntary movement of the linking device can be prevented by - supplying a locking or clamping mechanism, which may include the application of frictional forces, as in fig 1 where the frictional force is supplied by the juxtapostition of harness line and boom within the linking device, or as in fig 3 where continuous contact between linking device and boom is ensured by a curved sprung section (this latter effect could be achieved by transversely hinging the linking device in the middle, and supplying a separate spring accross and out of line of the hinge).

Stop members may also be provided to restrict the movement of the linking device to a range of positions.

Cleats or pulley arrangements may also be incorporated into the linking device to permit the shortening or lengthening of the harness line itself.

It should be noted that the figures are schematic, and only serve to demonstrate the essential features of the examples contained therein. In particular, in most cases it may be necessary for the harness lines to quit the linking device at an appropriate angle for the type of harness employed by the user.

By the application of such a linking device, the harness lines can now be adjusted in two possible ways, depending on the relative arrangement of the linking device employed, the harness lines and the boom.

To adjust the harness lines the sailor releases any locks, and when or if frictional forces are employed in preventing movement in use,partially takes the strain in his arms so as not to allow the line to fall from the harness hook . Depending on construction, at some stage the linking device will become sufficiently free to move along the boom to allow the sailor to drag the linking device by the harness lines: this can be achieved by moving the harness hook relative to the boom. Either locking devices and/or tension (if partially released) may be reapplied.

An alternative method of adjustment can be achieved by applying a force in the appropriate direction to move the linking device as required.

This force can be directly applied to the linking device by the sailor, or else indirectly by means of pulleys, or else in particular forms of construction, by applying force to the harness line itself (eg pulling on one decending line only, as in fig 4 & 5 where the line is held fixed with respect to the boom and free to slide past and through the parts of the linking device against which it contacts.).

Figures Follwing figures are for illustration only and are not intended to limit the invention in any way.

In the accompanying drawings: Fig A is a plan of a sailor using a set of harness lines.

Fig 1 shows an example of the present invention which consists of a tube shaped to allow the passage of the linking device around the bend in the mast end of the boom. The harness line has been passed through the linking device so as to impinge on both boom and linking device, thereby applying sufficient friction when unloaded to prevent involuntary movement.

Fig 2 shows an example of a linking device, shape of which allows the linking device to pass around the curve of the boom. The vertical section shows the angle of the harness lines to the vertical.

Fig 3 shows an example of a linking device in which a sprung section causes the tubular sections enclosing the boom to impinge on the boom when unloaded. When partially loaded the linking device straightens sufficiently to remove the contact between the tubular sections and the boom, so allowing the sailor to overcome the residual friction in the linking device to boom contact and move the device. Vhen fully loaded the linking device straightens completely and the amount of friction presented by the device as a whole is sufficient to prevent movement when in use.

Fig 4 shows and example of a linking device which allows the movement of the device by way of the sailor pulling on one decending line only.

Pulleys may be used to facilitate the movement of the harness line through the device, and the contact of the deivce to the boom may require rollers or bearings.

Fig 5 shows an example of a linking device where the device is acting as a tie, between two weight transfer rings.

Fig 6 shows an example of a linking device hanging from a rail which is itself attached to the boom.

Fig 7 shows an example of a linking device incorporated into the structure of a boom Fig 8 shows an example of a linking device which incorporates a sprung collar. The collar reduces contact with the boom when unloaded, but as load is applied, the diameter of the collar reduces and so increases the frictional force available by virtue of increased boom contact.

The linking device incorporates a longitudinally sprung section as in fig 3.

Fig 9 shows an example of a linking device which in corporates two sprung collars. Theses are shaped so as to cause a tie of any material including fabric, to impinge on the boom when unloaded. When load is applied the tie ceases to impinge on the boom and allows the device to be moved. When fully loaded the collar has the same effect as that in fig 8.

Claims (1)

1. Claims

   1. A link preserving the spacial correlation (separating distance) of the points of application of force of a harness'line, and, if required, transferring such a force to a boom