INTRODUCTION
[0001] As it is well known, the sudden increase of the tilting moment on a sailing boat
due to an increase of the wind intensity ("squall") acting on the sails, or to a change
of the direction of the wind ("wind stage") can bring to anomalous heeling angles.
To the opportune action of the crew is usually remitted the duty of obviating to this
occurrence by a suitable slackening of the sheets and/or correction of the course,
to bring the boat toward the wind.
[0002] However, particularly in case of very difficult weather conditions, all the above,
besides requiring a high attention level, with the consequent stress for the crew,
cannot be sufficient in view of the amount and rapidity of the occurring of the heeling.
[0003] If in case of ballast monohull, it can bring in the most serious cases to the damaging
of the equipment (boom entering within the water and its consequent breaking, etc.),
in the multi-hulls it can even induce the irreversible tilting of the boat, with the
very serious consequences.
SPECIFICATION OF THE INVENTION
[0004] In view of the above, and making reference to figures 1 and 2, the present finding
aims to solve the problem automating the release action of the sheets 1 of a boat
2 in case of sudden increase of the wind action.
[0005] The above object is obtained on the basis of the constant monitoring of the stresses
on the shrouds and/or sheets carried out by suitable transducers 3, possibly integrating
the signals with further information such as the heeling angle, the wind intensity
or any other information that could constitute the element for the individuation of
the heeling moment acting on the boat.
[0006] These signals suitably processed by a suitable station 4 comprised of electric/electronic
circuits or computer provided with dedicated software, will produce the control signal
that will be send to the sheet holding system.
[0007] Holding systems, such as sheet clamping devices can be provided opening when receiving
the control signal, or hydraulic or pneumatic or electro-mechanical pistons 5, upon
which the sheets can be transmitted, thus allowing the release of the sheets and the
following recovery when the heeling moment acting on the sailing boat reached again
the normal value, on the basis of the processed control signal.
[0008] In figure 1, it is shown the application on a catamaran (seen from the stern) by
the use of a piston 5 on which the boom sheet 1 has been transmitted.
[0009] In figure 2, the transmission is shown in detail. It is possible to see that the
manoeuvring of the sheet 1 by the crew usually can occur by the spanker hoist with
the traditional sheet clamping device 6, while the automatic release would occur by
the piston 5, fixed to the boom, to which the end of the sheet is connected.
[0010] A similar connection to a (hydraulic, pneumatic or electro-mechanical) piston, for
example vertically fixed in front of the mast would occur for the sheets of the forward
sail (jib, Genoa).
[0011] Simply for illustrative purposes, in figure 3 a possible completely passive hydraulic
scheme is shown, i.e. without active elements such as hydraulic pumps, suitable to
perform the functions of the present finding for the part concerning the sheets operation.
[0012] In fact, until the station does not send the processing electric signal to the coil
of the electrovalve 7, said electrovalve is blocked and the piston 6 is consequently
blocked in the shown position.
[0013] As soon as the electronic station, due to the reaching of the established emergency
conditions (excessive stress on the shrouds, excessive heeling angle, or an adequate
combination of these and/or analogous parameters), the electronic station generates
the electric signal exiting the electrovalve 7, said electrovalve blocks, letting
the oil passing toward the accumulator 8, pretensioned and sized in such a way to
allow the adequate acceptation of the oil amount present within the cylinder 5, with
a stress remarkably lower with respect to the one causing the release of the electrovalve
7.
[0014] The motion of the cylinder thus determines the spilling of the sail and therefore
(in case the above mentioned emergency conditions do no more occur) said electrovalve
closes (lacking the electric signal) and therefore, in case the stress on the sail
diminished consequently, the compressed oil within the accumulator (acting as a hydro-pneumatic
spring) flows back within the cylinder through the check valve 9, thus restoring the
original conditions.
[0015] In more sophisticated "active" systems, representing a modification of the present
finding, either said recovery phase and said release phase can be carried out using
active components (hydraulic pumps) to obtain a faster, wider and different use field
of the same apparatus.
[0016] A particular embodiment of the finding could integrate the sheet release with the
contemporaneous automatic operation of the rudder, for example demanded to a conventional
automatic pilot interfaced with the electronic station, to bring the boat toward the
wind.
1. Release automatic system for sheets comprised of:
a) transducers measuring stresses acting on the shrouds and/or on the sheets, and/or
the heeling angle of the boat, and/or the wind intensity, and/or measuring any other
value or parameter suitable to define the heeling moment acting on the boat, such
as the stress on the trimaran arms;
b) suitable electric and/or electronic circuits, or an electronic computer, generating
a control signal on the basis of the above signals;
c) sheet clamping systems allowing their release on the basis of the processed control
signal, such as controlled opening sheet clamping devices, sheet transmission on one
or more hydraulic, electro-mechanical or pneumatic pistons, lengthening and releasing
the sheets following the control signal.
2. System according to claim 1, wherein besides the release action also the sheet recovery
action occurs, when the heeling moment acting on boat sails reached again the normal
values, said action being typically carried out when the sheet clamping system under
point 1 c) is made up of hydraulic piston(s) and suitable hydraulic circuits.
3. System according to claim 1) and 2) wherein the release action occurs in a passive
mode on the basis of the pressure within the hydraulic circuit without the processing
according to point 1 b).
4. System according to claim 1) and 2), wherein the recovery action occurs without the
use of power active systems (such as hydraulic pumps, electric motors, etc.), but
employing recovery springs, or pressure accumulators provided within the hydraulic
or pneumatic circuit and charged by the stress due to the wind during the preceding
release phase.
5. Anti-tilting system which on the basis of the information processed by components
of claim 1, points 1a and 1b, process a signal controlling a flexion of the rudder,
fro example by suitable interface with the automatic pilot, making the boat directing
toward the wind, at the same time or not of the contemporaneous release of the sheet
as described in the preceding claims.