FR2766155A1 - DEVICE FOR RECALLING AT THE OPTIMAL ANGLE A COILING BOOM TO ENSURE THE CORRECT WIND-UP OF THE SAIL - Google Patents

Abstract

Device intended to automatically recall as soon as the sheet is released a sail furling boom (6) at the optimum angle (alpha) that it must determine with the slide or groove (16) which guides the sail's luff , characterized in that it comprises an extendable jack (1), (2), (3), (4) pushed by a spring (19) up to a stop (20) included in the jack.

Description

- 1 -

  DEVICE FOR RECALLING AT THE OPTIMAL ANGLE A HOSE REEL

TO ENSURE

  THE GOOD WIND-TRIP OF THE SAIL

  In furling booms intended to wind and unwind a mainsail on a rotating mandrel located substantially in the axis of the boom, it is necessary to obtain good windings-unwindings of the sail that the mandrel, and consequently the boom, do a precise angle with the slide or the groove positioned along the mast and which guides the windlass of the sail. On the other hand, it is necessary that after modification of the sail surface that the end of the boom, opposite to that attached to the gear of the mule can be lowered by bordering the mainsheet when the sailing conditions, especially at close gaits, require the flattening of the

mainsail.

  In general, booms with reels are positioned at the angle required for operation by a rope called "(swing)), stretched between the end of the boom and the head of the mast. The rope, generally made of textile, is lengthens according to the load it supports, which is partially variable due to the forces

  fluctuating inertials due to the roll and pitch movements of the boat.

  On the other hand, this rope sees its elongation characteristics modified by

  humidity. As a result, the precise angle is never obtained.

  The invention provides a device which positions, as soon as listening to large-

  sail is released, the boom at the optimal angle necessary for good winding-

  unfolding of the sail, and which makes it possible to flatten the sail if necessary when

listening is bordered.

  In the invention, the boom is returned to the desired angular position by the action of a jack whose extension is produced by the thrust of a gas spring, which has the advantage of having little elastic force. dependent on the stroke, and to present a damping at the end of the stroke when it contains oil, in order to avoid shocks harmful to the device and its attachments

  end to mast and boom.

  In the invention, the extension of the jack is limited when the boom has reached its optimum angle by a stop incorporated in the jack. When the -2- end of the boom must be lowered under the effect of the listening tension, the

  cylinder stressed in compression by the boom is shortened by compressing the spring.

  To avoid overloading the spring, the lower stroke of the cylinder is limited by a

stop incorporated in the latter.

  The appended drawing single plate illustrates an embodiment in accordance with the invention. It is understood that this example is not limiting of

  the invention which could be implemented with other technical solutions.

  The jack consists of two sliding tubes (1 and 2), one of their ends is respectively fixed by rivets (3), for example to two yokes (4 and 5), the yoke (4) being linked to the boom (6) by an articulation (7) forming part of a support (8), sliding in a groove formed in the boom and immobilized after longitudinal positioning at the boom by two sets of studs (9), washers and nuts (11) . The yoke (5) is articulated on a part (12) which can pivot around an axis (13) linked to the mast (14) by a support (15), the axis (13) being aligned with the axis xx 'around which the boom can be oriented so that the angle determined by the boom (6) and the slide (16) linked to the mast and in which slides the rope or the slides of the sail (17) remains constant whatever the orientation of the boom around the axis x x '. Consequently, the mandrel (18) around which the sail (17) is wound, the axis of rotation of which is fixed relative to the boom at its angle 13 which it determines with the slide (1 6) constant, these angles a and 13 are constant when the jack, pushed in extension by the gas spring (19) which tends to spread the two sliding tubes is stopped by the stop (20), linked to the inner tube (2) when it comes to bear with a sleeve (21) fixed to the outer tube (1) by threading

example.

  In the invention, when the jack has come to a stop as described above, the spring (19) has a residual thrust to give the jack sufficient axial rigidity for the boom, although subject to the inertial forces inherent in the movements pitch and roll during navigation is permanently recalled to the optimal angle as soon as the sheet is released. The adjustment of the angle a and consequently of the optimal angle 13 for the good winding-unwinding of the sail is carried out according to the example by -3- adjusting the position of the support (8) which slides in the groove of the boom then immobilization by the sets of studs (9), washers (10) and tightening

nuts 65 (11).

  In the invention, when the boom must be lowered, the sheet hoist forces the boom down and consequently the cylinder and its spring, the length of the cylinder is thus reduced. In order to avoid overloading the spring, the invention provides a lower stop produced according to the example by stopping the sleeve (21) on the yoke (5) whose outer reach exceeds the

  diameter of the inner tube (2), adjusted in the sleeve (21).

  To avoid wear of the tubes during their sliding, the inner tube comprises an end piece (22) on which the spring rests or is fixed, the periphery of which comprises a bearing made of self-lubricating material (23). On the other hand, a second bearing (24) is enclosed in a housing formed in the sleeve

  (21) to guide the inner tube (2).

  In the invention, the bearings are made by cylinders of self-lubricating material of the graphite polyamide type, a generator of which is split to allow them to be mounted in the groove of the end piece (22) and in the housing

of the sleeve (21).

  The invention applies to sailing boats.

-4-

Claims (7)

  1) Device intended to automatically recall as soon as the sheet is released a sail furling boom (6) at the optimal angle (a) which it must determine with the slide or the groove (16) which guides the windlass of the sail, characterized in that it comprises an extendable cylinder (1), (2), (3), (4) pushed by a spring (19) up to a stop (20) included in the cylinder. 2) Device according to claim 1, characterized in that the spring (19) exerts a residual force when the cylinder is at the end of its travel, so that it generates sufficient force for the boom (6) to reach the angular position   (a) when the mainsheet is released.   3) Device according to the preceding claim, characterized in that the   thrust is provided by a gas spring (19).   4) Device according to claim 3, characterized in that the gas spring contains oil to give it a damping characteristic during   rapid variations in the cylinder stroke.   5) Device according to claim 1, characterized in that it comprises a stop (5) intended to limit the stroke and therefore the overload of the spring   when the cylinder is at its shortest length.   6) Device according to claim 1, characterized in that the guidance between the inner tube (2) and the outer tube (1) is provided by bearings (23) and (24) of self-lubricating material, one of which is split for allow their installation in the circular housings formed in the rooms (22) and (21) intended to receive them.   7) Device according to claim 1, characterized in that the spring (19) allows the compression of the cylinder to allow the lowering of the   boom (6) when the sail must be flattened.