GB2108569A - Braking device for the boom of sailing boats - Google Patents

Abstract

Braking device for the boom of a sailing boat, comprising a rope 6 secured to the sides of the boat said rope 6 winds around reels 7, 8, 9, inside a casing 10 connected to the boom; the reels 7, 8, 9 are provided with guiding grooves (13 Fig. 3, not shown) for the rope 6 having opposite helicoidal directions so that the apertures for entrance 11 and exit 12 of the rope 6 are situated on the same plane at right- angles to the axis of the reels 7, 8, 9. <IMAGE>

Description

SPECIFICATION Braking device This invention concerns a braking device and relates particularly but not exclusively to a braking device for the boom of a sailing boat, by means of which it is possible to halt the swinging of the boom whenever, due to an incorrect manoeuvre or to other unforeseen circumstances, there is a sudden change in the direction of the wind which causes the boom to swing suddenly from one part of the vessel to the other, with a consequent danger for those on board.

As it is known, the boom of a sail is usually secured, in the direction of the wind, by means of a rope or the like, whereas it is free in the opposite direction; consequently, any sudden change in the direction of the wind gives rise to the aforementioned effects. A number of braking devices to be fitted onto the boom of a sailing boat have been proposed, however, the devices put forward so far present various problems, amongst which, an insufficient braking of the boom, excessive weight and cost, together with a certain irregularity in the tension exerted upon both sides of the rope of the device.

A particular, but not exclusive, aim of this invention is to provide a braking device for the boom of sailing boats which is simple in construction, compact, relatively inexpensive and highly reliable.

A further aim of this invention is to provide a braking device, as mentioned previously, which is not subject to stress or uneven tension by the braking rope.

A still further aim of this invention is to provide a braking device as previously defined, which contains, in a limited space, parts capable of providing a differentiated braking effect which increases according to the tension exerted upon the braking rope of the device itself.

According to the present invention there is provided a braking device comprising a frame, a first and at least a second braking reel, and a rope which in operation winds around and runs along frictional surfaces of the braking reels, the frame being provided with an inlet and an outlet aperture for the rope, the inlet and outlet apertures lying in the same plane, said reels being fixed relative to the frame and presenting helical or part helical grooves around which the rope runs, the helical or part helical grooves having opposite directions.

In some applications, it is preferred that the said inlet and oulet apertures are angularly spaced apart relative to a general axis of the frame perpendicular to the said same plane.

Conveniently the said frame comprises a casing within which the reels are fixed.

The invention finds particular advantage where the braking device is intended for braking movements of the boom of a sailing boat, the braking device having means for attaching the frame to the boom, and the rope being adapted to be secured to the sides of the boat.

Conveniently a rope guiding reel is interposed between one braking reel and the next.

In such a case, preferably the braking reels present a groove which substantially extends for one spiral, while the intermediate reel presents a circular groove.

In accordance with a preferred feature of the invention, the braking reels present a groove having a cross-section which narrows towards the bottom to a greater extent that the diameter of the rope. For example it may be arranged that the groove presents circular sides having a radius of curvature substantially similar to the radius of the braking rope, and a bottom having a smaller radius of curvature.

In accordance with a particular application a braking device is provided for the boom of sailing boats comprising a rope secured tithe sides of the vessel, which winds and runs around the frictional surfaces of a braking mechanism, comprising a casing having an inlet and an outet aperture for the rope angularly spaced apart from each other and lying on the same plane, a first and at least a second braking reel around which the rope winds and runs, said reels being secured within the casing and presenting guiding spiral grooves for the rope, which run in opposing directions. The spiral grooves preferably present a differentiated cross section, decreasing towards the bottom of the groove itself, so as to increase the braking effect as the pull on the rope increases.

These and further features of the braking device of this invention will be more fully illustrated hereunder, with reference to the example of the attached drawings in which: Figure 1 shows a perspective view of a sailing boat provided with a boom-braking device, according to this invention; Figure 2 shows an enlarged cross-section of the braking device; Figure 3 shows the detail of a braking reel; Figure 4 shows an enlarged cross-section of the groove in a braking reel.

With reference to the figures, the numerical reference 1 indicates a generic sailing boat, onto the mast 2 of which is hinged a cross bar or boom 3 for securing, in the known way, the base or lower edge of the sail 4. As is known, the boom 3, according to the direction of the wind, rests at a certain angle, to one side of the boat; therefore a sudden change in the direction of the boat or the wind, would cause an equally sudden shifting of the sail and the boom, from one side of the boat to the other. In these circumstances, the boom could hit anybody who happens to be in the vicinity due to the relatively limited space on the boat.

Therefore, 5 indicates a device for braking the boom 3, which enables the latter to swing slowly from one side of the boat to the other, without any danger whatsoever for those on board. The braking device 5 substantially comprises a rope 6 which winds and runs around a number of braking reels 7, 8, 9 fixed within a circular casing 10, as shown, hanging from, or otherwise fixed to the boom 3. Numeral 11, indicates an inlet aperture for the rope 6, whereas 1 2 indicates the outlet aperture, angularly spaced apart from each other on the peripheral surface of the casing 10.

Each braking reel 7, 9 as shown for the reel 7 in Fig. 3, presents a helicoidal groove 1 3 through which the rope 6 slides and winds, which extends substantially for a single spiral; the reel 8, being only for deviating the rope 6 from one braking reel to the other, presents a simple circular groove. By using two or more braking reels inside the casing 10, it is possible to obtain an adequate frictional surface and thereby an adequate braking effect, keeping the weight and dimensions of the device at a minimum; moreover, by providing grooves 1 3 for the rope, having opposing helical directions, it is possible to keep the rope inlet 11 and outlet 1 2 substantially on the same plane at right-angles to the axes of the braking reels.

This proves to be important for the correct functioning of the braking device, for the following reason: if the inlet 11 and the outet 1 2 were to be arranged on different planes, when the rope is pulled taut, a crosswise torque would be created which would turn the casing of the device and place it crosswise with respect to the direction of the pull exerted by the rope itself, on both sides; therefore the rope would either tend to slide out of place on the braking reels, or would tend to rub against the edges of the inlet and outlet apertures. Consequently, it is important that the number of the braking reels and the helical directions of the grooves are such as to always keep the inlet 11 and the outlet 1 2 in the same plane as described previously.The illustrated example shows three reels arranged in a triangle within a completely closed casing, however the number and the arrangement of the reels, together with the shape of the casing may vary with respect to that shown in the drawings, yet maintaining the principles previously described.

From tests carried out, it was also noted that a satisfactory braking effect is achieved when the groove 7 in the reels presents a cross-section which decreases towards the bottom to a greater degree than the diameter of the rope; a particular embodiment of the groove 1 3 is shown in the cross-section of Fig. 4; it can be seen from said figure, that the groove 1 3 of each braking reel comprises a first upper part with sides 14 having substantially the same radius of curvature as the rope 6 so that the latter may run freely therein, whereas the groove 1 3 narrows more, towards the bottom 15, for example, it presents a smaller radius of curvature, as shown.

In this way, a narrow space 1 6 is formed between the rope 6 and the bottom 1 5 of the groove in the reel, into which the rope 6 tends to penetrate when subjected to traction, thus increasing the degree of friction on the reels 7, 9, thereby increasing the braking effect. The greater the tension of the rope is, the greater the braking effect will be; it is obvious that another shape of cross-section may be used in place of the groove shown in Fid. 4 in order to obtain the desired effect.

It will be clear from the aforegoing description and from the attached drawings that this invention concerns particularly a braking device for boats in general, and in particular for the boom of sailing boats, which is characterized by the use of a number of fixed reels for braking a rope which runs inside the device, keeping the device and the braking rope lying in the same plane; from tests carried out, it was noted that by means of the device it is possible to achieve a smooth and gradual braking of the boom according to the tension applied to the rope, without hindering the normal use of the sail. In fact, by slackening the rope, and due to the particular shape of the grooves in the reels, it is possible, not only to graduate the braking power, but also to reduce it to negligible values without having to remove the device itself, should this be necessary.

It is understood that what has been described and shown herein, with reference to the attached drawings, is given merely by way of example and is in no way restrictive.

Claims (1)

1. A braking device comprising a frame, a first and at least a second braking reel,- and a rope which in operation winds around and runs along frictional surfaces of the braking reels, the frame being provided with an inlet and an outlet aperture for the rope, the inlet and outlet apertures lying the same plane, said reels being fixed relative to the frame and presenting helical or part helical grooves around which the rope runs, the helical or part helical grooves having opposite directions.

2. A braking device according to claim 1 in which the said inlet and outlet apertures are angularly spaced apart relative to a general axis of the frame perpendicular to the same plane.

3. A braking device according to claim 2 or 3 in which the said frame comprises a casing within which the reels are fixed.

4. A braking device according to any pre ceding claim in which the braking device is intended for braking movements of the boom of a sailing boat, the braking device having means for attaching the frame to the boom, and the rope being adapted to be secured to the sides of the boat.

6. Braking device for boats, in particular for the boom of sailing boats, comprising a rope secured to the sides of the boat, which winds around and runs along frictional surfaces of a braking mechanism, comprising a casing provided with an inlet and an outlet aperture for the rope, angularly spaced apart from each other and lying on the same plane, a first and at least a second braking reel around which the rope winds and slides, said reels being fixed within the casing and presenting helical grooves through which the rope runs, having opposite directions.

7. A braking device as claimed in any preceding claim, in which a rope guiding reel is interposed between one braking reel and the next.

8. A device as claimed in claim 2, in which the braking reels present a groove which substantially extends for one spiral, while the intermediate reel presents a circular groove.

9. A device as claimed in any of the previous claims, in which the braking reels present a groove having a cross-section which narrows towards the bottom to a greater extent that the diameter of the rope.

10: Device as claimed in claim 9, in which the groove presents circular sides having a radius of curvature substantially similar to the radius of the braking rope, and a bottom having a smaller radius of curvature.

11. A braking device as hereinbefore described with reference to the Figures of the accompanying drawings.