[0001] The present invention relates to a sail of the type as recited in the preamble of
the first claim.
[0002] In detail, the invention relates to a sail usable in a vehicle exploiting the action,
for example as a propulsion, of wind such as a hang glider, windsurf, kitesurf, hot
air balloon, parachute or preferably a boat.
[0003] As is well known, sailing boats, whether single- or multi-hulls, have their propulsion
mainly entrusted to the exploitation of wind and the engine has merely a supporting
action.
[0004] These crafts are equipped with anti-boarding systems that allow to communicate particular
navigation conditions or even merely their presence. These systems consist of lights
and, in case of fog, a siren and optionally a gong.
[0005] Such anti-boarding systems are often inadequate and therefore a craft must be equipped
with one or more radar reflectors.
[0006] Radar reflectors are devices designed to reflect the waves of a radar and thus increase
the ability of a craft, otherwise too small, to be visible to a radar.
[0007] The radar reflectors on the market today consist of metal objects and can have various
shapes such as tubular, octahedral, ovoid.
[0008] They are placed at the top of the mast.
[0009] It should be noted that the use of radar reflectors or other detection systems is
sometimes also used on a hang-glider, hot air balloon, parachute or other means of
transport exploiting the wind and for which it may be useful to identify the position
in conditions of poor visibility.
[0010] The prior art described has several significant drawbacks.
[0011] In particular, despite the presence of radar reflectors, parachutes, hang gliders
and hot air balloons are difficult to locate using radar.
[0012] In fact, radar reflectors have a limited extension and are therefore either not detected
by radar or, if located, can be mistaken for other objects, not allowing the precise
identification of the craft because of their small size.
[0013] Another drawback is that in crafts, where free space is limited, radar reflectors,
although limited in size for their detection, take up a lot of space compared to the
size of the craft and can be an obstacle to manoeuvring.
[0014] In this situation the technical purpose of the present invention is to devise a sail
able to substantially overcome at least some of the drawbacks mentioned.
[0015] In the context of said technical purpose one important object of the invention is
to obtain a vehicle equipped with a sail that is easily identifiable in any condition
of visibility.
[0016] The technical purpose and specified aims are achieved by a sail as claimed in the
appended Claim 1. Examples of preferred embodiments are described in the dependent
claims.
[0017] The characteristics and advantages of the invention are clearly evident from the
following detailed description of preferred embodiments thereof, with reference to
the accompanying drawings, in which:
Fig. 1 shows a possible preferred application of the sail according to the invention; and
Fig. 2 shows an exploded view of the sail according to the invention. Herein the measures,
values, shapes and geometric references (such as perpendicularity and parallelism),
when used with words like "about" or other similar terms such as "approximately" or
"substantially", are to be understood as except for measurement errors or inaccuracies
due to production and/or manufacturing errors and, above all, except for a slight
divergence from the value, measure, shape or geometric reference which it is associated
with. For example, said terms, if associated with a value, preferably indicate a divergence
of not more than 10% of said value.
[0018] In addition, where used terms such as "first", "second", "upper", "lower", "main"
and "secondary" do not necessarily refer to an order, a priority relationship or relative
position, but may simply be used to more clearly distinguish different components
from each other.
[0019] The measurements and data presented herein are to be considered, unless otherwise
indicated, as carried out in ICAO International Standard Atmosphere (ISO 2533).
[0020] With reference to the Figures, reference numeral
1 globally denotes the sail according to the invention.
[0021] The sail 1 is adapted to be used in any vehicle exploiting the action of wind, for
example for propulsion. For example, it can be used in a hang glider, windsurf, kitesurf,
hot air balloon or parachute.
[0022] Advantageously, the sail 1 is adapted to be used on a craft
10 (Fig. 1). It can be a mainsail, a jib (or Genoa), a storm jib, a spinnaker, a gennaker,
a multi-purpose sail, a Code Zero.
[0023] The craft 10 may therefore comprise one or more sails 1.
[0024] The sail 1 comprises a structural layer
2 of the sail.
[0025] The structural layer 2 defines the load-bearing part of the sail 1, that is, adapted
to support the action of the wind.
[0026] The structural layer 2 defines at least one load-bearing surface
2a on which the wind acts during navigation.
[0027] It should be noted that the structural layer 2 defines two load-bearing surfaces
2a adapted to position themselves one downwind and one upwind depending on the wind
striking said sail 1 when in use.
[0028] The structural layer 2 may comprise at least one sheet extending along said load-bearing
surface 2a and in detail a single sheet or multiple sheets (laminate).
[0029] Each of said sheets may be in a material normally used for a known sail such as nylon,
dacron®, mylar®, pentex®, spectra®, vectran®, kevlar®, technora®, carbon (carbon fibre)
or cuben fiber®.
[0030] The structural layer 2 may include pockets or other similar elements adapted to allow
the sail 1 to be engaged to a craft 10.
[0031] The sail 1, as shown in Fig. 2, comprises at least one outer layer
3 integral with the structural layer 2.
[0032] In particular, the sail 1 may comprise a single outer layer 3.
[0033] Preferably the sail 1 comprises two outer layers 3 enclosing the structural layer
2 between them. Advantageously, the sail 1 of a craft 10 comprises two outer layers
3 enclosing the structural layer 2.
[0034] Each outer layer 3 covers at least in part, preferably almost entirely, the structural
layer 2. It has a surface area of at least 50%, and in detail 75%, of the load-bearing
surface 2a, i.e. of the sail 1. Preferably it has a surface extension substantially
equal to the extension of the load-bearing surface 2a and therefore of the sail 1.
[0035] An outer layer 3 comprises at least one radar-reflecting under-layer
31, preferably only one, suitable to reflect radar waves allowing the sail to be visible
on a radar. The radar-reflecting under-layer 31 has a surface extension substantially
at least equal to the extension of the outer layer 3. It extends and therefore covers
at least 50%, in particular 75%, of the load-bearing surface 2a, and preferably the
entire load-bearing surface 2a.
[0036] Suitably the outer layer 3 comprises at least one radar-reflecting under-layer 31,
preferably only one, adapted to reflect the radar waves and allowing the sail to be
visible on a radar.
[0037] Preferably, the radar-reflecting under-layer 31 is reflective, in addition to radar
waves, also to light and in particular infrared and/or UV rays.
[0038] The radar-reflecting under-layer 31 is metallic and in particular aluminium.
[0039] It may have a thickness of substantially less than 100 µm, in particular 10 µm, and
more in particular than 1 µm and preferably than 0.1 µm. It may be substantially in
the range of 0.01 µm to 0.04 µm.
[0040] The radar-reflecting under-layer 31 can be made by high vacuum deposition and, preferably,
by the PVD process.
[0041] The expression high vacuum deposition identifies those coating processes carried
out in vacuum chambers, namely, in environments with very low internal pressure and,
more precisely, in high vacuum, that is, with internal pressure substantially between
10-1 Pa and 10-5 Pa. Among the most important high vacuum processes is the aforementioned
known PVD method. PVD, or "Physical Vapor Deposition" is an atomic deposition process
in which the material to be deposited is evaporated from a solid phase and transported
in the vapour phase to the pieces to be covered where it deposits to form a thin film.
[0042] To this end, the outer layer 3 may comprise a deposit under-layer
32 of the radar-reflecting under-layer 31.
[0043] The deposit under-layer 32 is non-woven or polymer fabric preferably selected from
polyester, polypropylene or polyamide (such as nylon®).
[0044] The deposit under-layer 32 is placed between the radar-reflecting under-layer 31
and the structural layer 2. In detail, it is integrally bound to the structural layer
2, for example by gluing or by suitable thermal bonding.
[0045] It has a thickness substantially less than 1 mm and, in particular substantially
between 0.1 µm and 100 µm, in particular between 1 µm and 50 µm and more in particular
between 7 µm and 20 µm.
[0046] It should be noted that in some cases the outer layer 3 may be without the deposit
under-layer 32 and the radar-reflecting under-layer 31 may be directly bound and in
particular deposited on the structural layer 2.
[0047] The outer layer 3 may comprise a protective under-layer
33 of at least part and, in detail, of the totality of the radar-reflecting under-layer
31.
[0048] The protective under-layer 33 defines the outer surface of the sail 1. It is on the
opposite side to the radar-reflecting under-layer 31 with respect to the structural
layer 2 and in particular to the deposit under-layer 32.
[0049] Preferably the protective under-layer 33 is transparent to light.
[0050] The protective under-layer 33 may be made by lacquering.
[0051] The protective under-layer 33 is made of resin.
[0052] It has a thickness substantially less than 1 mm and, in particular substantially
between 0.1 µm and 100 µm, in particular between 1 µm and 50 µm and more in particular
between 7 µm and 20 µm.
[0053] The functioning of the sail 1 described above in structural terms, is as follows.
The functioning refers to the preferred non-limiting example of a craft 10.
[0054] The sail 1, when opened, defines a wide-ranging radar-reflecting surface.
[0055] Thus, when the craft 10 is sailing, it has a particularly large reflecting radar
surface and is therefore readily identifiable by a radar of a second craft approaching
the craft 10.
[0056] The invention comprises a new method of making a sail.
[0057] The method comprises a step of forming the structural layer 2.
[0058] The forming step may be of a known type.
[0059] Once the forming step has been completed, the method involves a step of binding at
least one outer layer 3 integrally to the structural layer 2 and comprising at least
one radar-reflecting under-layer 31.
[0060] In the binding step two outer layers 3 can be integrally constrained to the structural
layer 2 which is thus enclosed between the two layers 3.
[0061] The deposition step comprises a deposition sub-step, preferably in high vacuum, of
the radar-reflecting under-layer 31.
[0062] The high vacuum deposition sub-step can be realized directly on the structural layer
2. The radar-reflecting under-layer 31 is thus directly constrained to the structural
layer 2.
[0063] Alternatively, the high vacuum deposition sub-step may be realized on a deposit under-layer
32 described above. In this case, the deposition step may comprise a sub-step of constraining
the deposit under-layer 32 to the structural layer 2.
[0064] The deposition step may comprise a sub-step of coating the radar-reflecting under-layer
31.
[0065] In the coating sub-step a protective under-layer 33 preferably transparent to light
is made on the radar-reflecting under-layer 31.
[0066] The coating sub-step may be a lacquer.
[0067] The sail 1 according to the invention achieves important advantages.
[0068] In fact, the radar-reflecting under-layer 31, especially if made of aluminium, reflects
radar waves from, for example, other crafts 10, thus making the craft 10 very visible,
increasing its safety. It is to be noted that the sail 1, when closed, still has a
greater extension than the known radar reflectors, thus making the craft 10 easy to
locate. This advantage can be seen even if the sail is used in another vehicle (hang
glider, windsurf, kitesurf, hot air balloon, or parachute) making it extremely easy
to locate the position of the vehicle by radar and therefore facilitate boarding in
an emergency and/or avoiding an accident with such a vehicle.
[0069] Another advantage is that the outer layer 3, as described above, is reflective of
infrared rays, so that the sail 1 does not heat by irradiation and consequently remains
at a lower temperature than normal sails. Consequently, the sail 1 makes it more comfortable
to shelter from the light beneath it.
[0070] An important advantage is that the outer layer 3 does not absorb UV rays, thus protecting
the structural layer 2.
[0071] A no lesser advantage is that in a craft 10 the use of the sail 1 makes the adoption
of other radar reflectors unnecessary, thereby improving the use of space on board.
Moreover, the sail 1, thanks to the reduced thickness of the outer layer 3, has substantially
the same weight and equal dimensions as a known sail.
[0072] Variations may be made to the invention described herein without departing from the
scope of the inventive concept defined in the claims. In said context all the details
may be replaced with equivalent elements and the materials, shapes and dimensions
may be as desired.
1. A sail (1) comprising:
- a structural layer (2) of said sail (1) defining at least one load-bearing surface
(2a) of said sail (1);
and characterised in that it comprises
- at least one outer layer (3) which is external to said structural layer (2) and
comprising at least one radar-reflecting under-layer (31) covering at least part of
said load-bearing surface (2a) and adapted to reflect the radar waves, allowing said
sail (1) to be detectable by a radar.
2. The sail (1) according to claim 1, wherein said radar-reflecting under-layer (31)
covers at least 50% of said load-bearing surface (2a).
3. The sail (1) according to claim 2, wherein said radar-reflecting under-layer (31)
covers said load-bearing surface (2a) entirely.
4. The sail (1) according to at least one preceding claim, wherein said radar-reflecting
under-layer (31) is formed by high vacuum deposition.
5. The sail (1) according to at least one preceding claim, wherein said radar-reflecting
under-layer (31) has a thickness substantially less than 10 µm.
6. The sail (1) according to claim 4, wherein said outer layer (3) comprises a deposit
under-layer (32) of said radar-reflecting under-layer (31).
7. The sail (1) according to at least one of the preceding claims, wherein said outer
layer (3) comprises a protective under-layer (33) of said radar-reflecting under-layer
(31).
8. The sail (1) according to claim 4, wherein said protective under-layer (33) is made
by lacquering.
9. A craft (10) comprising at least one sail (1) according to one or more of the preceding
claims.
10. A method of constructing a sail (1) comprising
- a step of forming a structural layer (2) defining at least one load-bearing surface
(2a) of said sail (1);
- a step of bonding at least one outer layer (3) to said structural layer (2); said
at least one outer layer (3) comprising at least one radar-reflecting under-layer
(31) covering at least part of said load-bearing surface (2a) and adapted to reflect
the radar waves, allowing said sail (1) to be detectable by a radar.
11. The method of constructing a sail (1) according to the preceding claim, wherein said
depositing step comprises a sub-step of high-vacuum deposition wherein said radar-reflecting
under-layer (31) is deposited by high vacuum deposition with a thickness substantially
less than 10 µm.
12. The method of constructing a sail (1) according to the preceding claim, wherein said
high-vacuum deposition sub-step in which said radar-reflecting under-layer (31) is
deposited on a deposit under-layer (32); and a sub-step of bonding said deposit under-layer
(32) to said structural layer (2).