U.S. patent application number 14/377321 was filed with the patent office on 2015-01-08 for wing profile sail.
The applicant listed for this patent is AIR WING SAIL S.r.l. Invention is credited to Filippo Buzzi, Edoardo Lombardi.
Application Number | 20150007761 14/377321 |
Document ID | / |
Family ID | 46001463 |
Filed Date | 2015-01-08 |
United States Patent
Application |
20150007761 |
Kind Code |
A1 |
Buzzi; Filippo ; et
al. |
January 8, 2015 |
WING PROFILE SAIL
Abstract
A wing profile sail for sailboats and sailboards, formed by a
flexible sheet having a leading edge configured to be coupled to a
mast, includes inflatable bladder means extending along the
direction of the leading edge, rearward thereto, to provide a wind
profile to the sail. The inflatable bladder means includes multiple
pockets fixed to the opposite surfaces of the flexible sheet and
localized behind its leading edge.
Inventors: |
Buzzi; Filippo; (Torino,
IT) ; Lombardi; Edoardo; (Prato, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AIR WING SAIL S.r.l |
Torino |
|
IT |
|
|
Family ID: |
46001463 |
Appl. No.: |
14/377321 |
Filed: |
February 12, 2013 |
PCT Filed: |
February 12, 2013 |
PCT NO: |
PCT/IB2013/051129 |
371 Date: |
August 7, 2014 |
Current U.S.
Class: |
114/102.12 |
Current CPC
Class: |
B63H 9/0615 20200201;
B63H 9/067 20200201 |
Class at
Publication: |
114/102.12 |
International
Class: |
B63H 9/06 20060101
B63H009/06 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 15, 2012 |
IT |
T02012A000131 |
Claims
1. A wing profile sail for sailboats and sailboards, formed by a
flexible sheet having a leading edge configured to be coupled to a
mast and comprising inflatable bladder means extending in a
direction of said leading edge rearward thereto and arranged to
provide a wing profile to the sail, wherein the inflatable bladder
means are fixedly secured to the opposite surfaces of the flexible
sheet.
2. The sail according to claim 1, wherein said inflatable bladder
means include two groups of multiple flexible pockets arranged
side-by-side.
3. The sail according to claim 2, wherein said multiple pockets are
substantially inextensible.
4. The sail according to claim 2, wherein said multiple pockets are
directly inflatable.
5. The sail according to claim 2, wherein said respective tubular
inflatable resilient members are housed within said multiple
pockets.
6. The sail according to claim 2, wherein said pockets have a
differentiated width.
7. The sail according to claim 6, wherein said pockets have a
smaller width at a proximal end and at a distal end of said two
pocket groups and have a greater width in correspondence of
intermediate zones of said two pocket groups.
8. The sail according to claim 7, wherein said intermediate zones
are located at a variable position in a range of 1/3 or less of the
width of said two pocket groups starting from said leading
edge.
9. The sail according to claim 7, wherein a maximum width of said
two pocket groups is greater than a transverse section of the
mast.
10. The sail according to claim 2, wherein said pockets have a
progressively increasing width towards the foot of the sail.
11. The sail according to claim 2, wherein said pockets terminate
at a distance from a head and/or from a foot of the sail.
12. The sail according to claim 2, wherein each pocket group is
covered, on its side opposite to the respective surface of the
sheet, by at least one flexible panel generally parallel to said
sheet.
13. The sail according to claim 12, further comprising two
additional flexible joining panels enclosing said two pocket groups
and extending from said leading edge as far as an area of said
sheet located rearward to said two pocket groups.
14. Sail The sail according to claim 13, wherein said two
additional flexible joining panels are at least in part
elastic.
15. The sail according to claim 13, wherein said area is located in
correspondence of at least half width of the sheet.
16. The sail according to claim 2, further comprising two flexible
baffles designed to join said two pocket groups to the front
surface of the mast at opposite sides of said leading edge.
17. The sail according to claim 2, wherein each group of multiple
pockets is formed as a prefabricated mat.
18. The sail according to claim 17, wherein each prefabricated mat
is designed to be applied onto the respective surface of the sheet
in a releasable fashion.
19. The sail according to claim 1, wherein said inflatable bladder
means are configured to be inflated according to a joint or
independent and selective or combined mode.
20. The sail according to claim 1, wherein said leading edge is
designed to be connected to the mast through a single or a multiple
connecting system.
21. The sail according to claim 1, wherein said inflatable bladder
means are localized immediately behind said leading edge and extend
substantially for 1/2 or less of the width of the sheet.
Description
FIELD OF INVENTION
[0001] The present invention is related to a sail for sailboats and
sailboards, formed by a flexible sheet having a leading edge
configured to be coupled to a mast, and provided with inflatable
bladder means extending along the direction of the leading edge,
rearwardly thereto, in order to provide a wing profile to the
sail.
STATE OF THE PRIOR ART
[0002] From Italian patent IT-1353528B such a sail is known having
a tubular inflatable portion with an aerodynamic profile having a
variable section, maximum in substantial correspondence of a
generally central area of the leading edge or an area of larger
sail surface, and minimum in correspondence of the ends of the
leading edge or of areas of smaller sail surface. This arrangement
enables improving the aerodynamic performance at the transition
area between the mast and the sail, thus enhancing its efficiency.
From the manufacturing viewpoint, this solution contemplates
providing the sail with an inflatable tubular portion either
directly, or with the aid of resilient air chambers housed within
such a tubular portion, which evidently requires manufacturing
techniques which need to be different and more complex as compared
with those of the traditional sails.
[0003] Similar drawbacks are affecting the wing profile sails
having inflatable bladder means as disclosed in documents U.S. Pat.
No. 5,347,946, GB1153056, U.S. Pat. No. 3,391,668, US-2002/0100406
e U.S. Pat. No. 5,775,249, all of which are providing for the whole
sail a double or triple wall arrangement and in some instances
fitting inflatable bladders therein.
[0004] Namely, in the case of the wing profile sail disclosed and
illustrated in document US-2002/0100406A the inflatable bladders
are housed within hollow spaces formed between an inner flexible
sheet and two flexible outer sheets extending rearwardly along the
entire width of the inner sheet, and also forming an outer shell
surrounding forwardly the mast. This arrangement involves a number
of drawbacks: firstly it cannot be directly applied to a
conventional sail consisting of a single flexible sheet, but
requires instead a complex sail construction formed by an inner
flexible sheet, necessarily provided with transverse battens, and
by an outer shell. Secondly, it does neither allow any adjustments
of the maximum thickness of the aerodynamic profile, nor it can
even be employed with traditional masts since it necessarily
requires that the mast be able to rotate around its axis so as to
provide the desired aerodynamic wing profile to the leading edge of
the sail. Moreover the battens of which the inner sheet is equipped
need to be coupled forwardly to the rotatable must to transfer the
necessary tension to the wing so as to maintain its aerodynamic
profile, which further complicates the structure formed by the sail
and mast assembly. Lastly, in order to avoid that the inflatable
bladders may shift randomly inside the hollow spaces between the
inner sheet and the outer shell, thus negatively affecting the
aerodynamic profile, flexible retainer flaps are provided which
connect individually in a loose fashion each bladder with the inner
sheet and which, besides not ensuring proper maintenance of the
optimum aerodynamic profile, involve additional noticeable
constructive complications.
[0005] Also in the case of document U.S. Pat. No. 5,775,249 the
inflatable profile is obtained by means of complex structure
composed by two parts: a leading edge portion fixed around the mast
and consisting of two inflatable cells enclosed within a partially
semi-non-elastic and partially rigid outer cover, and a main body
portion in turn containing two inflatable cells enclosed within an
outer cover made of elastic material and extending for the entire
width of the sail as far as its trailing edge. In addition to a
constructive complexity, neither this solution enables adjusting
the position of the maximum thickness of the aerodynamic profile
with respect to the mast. Moreover, the presence of the rigid part
of the leading edge portion prevents applying this solution to
conventional masts provided with crosstrees for rigging.
SUMMARY OF THE INVENTION
[0006] The object of the present invention is to overcome the
above-mentioned drawbacks, and more particularly to provide a wing
profile sail enabling to maintain unchanged the general
construction of the traditional sails, thus implementing the wing
profile with a simple and relatively economical arrangement.
[0007] A further object of the invention is to provide a wing sail
whose profile thickness can be easily adjusted so as to achieve an
enhanced efficiency in terms of greater lift, even at low angles of
incidence of the wind, i.e. even at close-hauled sailing of the
boat equipped with the sail according to the invention.
[0008] A further object of the invention is to enable achieving
those advantageous effects even by means of a simple and relatively
unexpensive modification of already existing sails even already in
use.
[0009] According to the invention these objects are obtained by
virtue of a wing profile sail of a type set forth in the preamble
of claim 1, whose primary characteristic resides in that the
inflatable bladder means are fixedly secured to the opposite
surfaces of the flexible sheet.
[0010] The inflatable bladder means conveniently include two groups
of multiple side-by-side, flexible and substantially inextensible
pockets localized immediately behind the leading edge of the sail
so as to conveniently occupy about 1/2 of its width.
[0011] The multiple pockets can be inflatable directly, or
inflatable resilient tubular bladders can be housed within the
pockets.
[0012] The pockets have advantageously a differentiated width,
smaller in correspondence of the proximal and distal ends of each
group and greater in correspondence of the intermediate areas.
[0013] Moreover the pockets have preferably a progressively
increasing width towards the area of the maximum chord of the wing
surface, i.e. towards the foot of the sail.
[0014] According to a preferred embodiment of the invention, each
group of multiple pockets is formed by a prefabricated mat,
designed to be firmly applied to a respective surface of the sheet
either permanently or in a detachable fashion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention will now be disclosed in detail with reference
to the accompanying drawings, purely provided by way of non
limiting example, in which:
[0016] FIG. 1 is a diagrammatic and partially broken perspective
view of a wing sail according to the invention, coupled to the mast
of a boat,
[0017] FIG. 2 is a lateral elevational view of FIG. 1,
[0018] FIG. 3 shows a variant of FIG. 1,
[0019] FIG. 4 is a horizontally sectioned view in a larger scale
along line IV-IV of FIG. 1,
[0020] FIG. 5 is a partial enlargement of FIG. 4,
[0021] FIG. 6 is a horizontally sectioned view along line IV-IV of
FIG. 3,
[0022] FIG. 7 shows a variant of FIG. 6 in an enlarged scale;
[0023] FIG. 8 is an elevational diagrammatic view of a
pre-fabricated construction of one of the inflatable pockets of a
sail according to the invention,
[0024] FIG. 9 is a perspective view from below of FIG. 8,
[0025] FIG. 10 is a perspective view from above of FIG. 8,
[0026] FIG. 11 is a top plan view showing diagrammatically the
application of each pre-fabricated group of inflatable pockets
according to FIGS. 8-10 to the sail,
[0027] FIG. 12 is a view similar to FIG. 11 which shows
diagrammatically the application of each pre-fabricated group of
inflatable pockets according to FIGS. 4 and 5 to the sail,
[0028] FIGS. 13 and 14 show two variants of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
[0029] The wing profile sail according to the invention consists of
a usual and conventional mainsail formed by traditional techniques
as a single flexible sheet typically made by cloth, mylar.RTM. ,
dacron.RTM. or similar materials, whose leading edge or luff is
provided in a way also known per se with slides 3 or similar
conventional systems for coupling thereof for instance to the hoist
of the vertical mast 4 of a sailboat. The mast 4, whose cross
section is for instance the one depicted in FIGS. 4, 6 and 7, is
also of a conventional type and is normally stationary, i.e. non
rotatable.
[0030] In order to provide a wing profile to the sail 1, by means
of which the lift and thus the efficiency of the sail are
appreciably enhanced, the invention consists of applying an
inflatable bladder system conveniently localized immediately behind
its leading edge 2, along at least 1/2 of the width of the sheet 1,
without requiring any modifications of the usual conformation of
the sail beside such an addition.
[0031] As it is better visible in FIGS. 4 and 5 the inflatable
system, generally designated as 5, occupies for instance 1/2 of the
width of the sail 1 and comprises two groups 6, 7 of multiple
pockets (four in the shown example) 6a, 6b, 6c, 6d and 7a, 7b, 7c,
7d, which are flexible and generally inextensible. Each group 6, 7,
which as it will be pointed out in the following is conveniently
pre-fabricated, is directly and firmly fixed on a respective
surface of the sheet 1, in a permanent or, preferably, in a
detachable fashion.
[0032] In the case of the example here disclosed the multiple
pockets 6a, 6b, 6c, 6d and 7a, 7b, 7c, 7d are to say so built on
the sheet 1: they are delimited by the opposite faces 1a, 1b, of
the sheet 1, by respective flexible transverse baffles 8 projecting
outwardly from the faces 1a, 1b, and by respective outer flexible
walls 9, 10 generally parallel to the faces 1a, 1b and possibly in
part of totally elastic.
[0033] The transverse baffles 8 are fixedly secured to the faces
1a, 1b of the sheet 1 for instance by sewing. According to a
variant, shown in FIG. 6, the transverse baffles 8 can be mutually
joined by, or formed in one piece with, respective inner flexible
walls 8a, fixed to the faces 1a, 1b of the sheet 1. Thus the
pockets 6a, 6b, 6c, 6d and 7a, 7b, 7c, 7d present, along with the
outer flexible walls 9, 10, a tubular configuration. According to a
further variant, which will be disclosed in the following and is
presently considered as the preferred embodiment of the invention,
each group of multiple pockets 6a, 6b, 6c, 6d and 7a, 7b, 7c, 7d is
pre-fabricated and then applied to the respective surfaces 1a, 1b
of sheet 2, even in a releasable way.
[0034] As it is evident from FIGS. 4 and 5, the pockets 6a, 7a
arranged in correspondence of the proximal end (i.e. the one
adjacent to the leading edge 2)of each group 6, 7, as well as the
pockets 6d, 7d located in correspondence of the distal end (i.e.
the one which is far away from the leading edge 2) of those groups
6, 7 have a lesser width (as measured transversally of the sail)
than the width of the intermediate pockets 6b, 6c and 7b, 7c.
Typically the pockets having the maximum width are the pockets 6b,
7b located at about 1/3 or less of the total width of the groups 6,
7, towards the side of the leading edge 2: this configures the
inflatable system 5 essentially as a NACA profile.
[0035] As it can be partially seen in FIG. 1 and in FIG. 2, the two
groups 6, 7 may start superiorly from a certain distance from the
top or head 1c of the sail and are extending inferiorly down to a
certain distance from its foot 1d which is usually designed (in the
case of a sailboat) to be coupled to a boom. Moreover the width of
the pockets 6a-6d and 7a-7d (measured parallelly to the sail) is
progressively increasing towards the clew 1d, which in this case
normally corresponds to the area of maximum chord of the sail
surface.
[0036] In the embodiment here disclosed, within each one of the
pockets 6a-6d and 7a-7d, which are closed at the respective upper
and lower ends, a respective inflatable bladder is housed which is
consisting of an elastic tubular element 11, typically having a
thin wall for instance of the type employed in inflatable traction
kytes.
[0037] The bladders 11 are connected, for instance inferiorly and
through respective valves not shown since within the skill of the
practitioner, to an inflating device in turn controlled so as to
supply air under pressure to the bladders 11 jointly or
independently from one other, in a selective and differentiated
fashion or even in a combined way, according to logics intended to
adjust the aerodynamic conformation of the wing profile of the
inflatable system 5 in the transition area between the mast 4 and
the leading edge 2, and immediately behind the latter. This enables
to achieve an increased global efficiency of the sail 1 as a
function of the different angles of incidence of the wind and thus
for the different sailing points of the sailboat fitted out with
the sail itself.
[0038] Theoretical calculations and experimental tests which are
being presently carried out by the applicants demonstrated that the
configuration now considered as the preferred one is that shown in
FIG. 4 in which under equilibrium conditions, i.e. without any wind
pressure on either surface 1a, 1b of the sail 1, the inflatable
system 5 has a maximum width at the area of the pockets 6b, 7b
which, as stated, are arranged at about 1/3 of the total width of
the inflatable system 5, towards its proximal end. This maximum
width is greater than the width, i.e. of the cross section, of the
mast 4.
[0039] This area of maximum width can be advantageously shifted
forwardly or rearwardly, evidently acting on the pressure of the
air supplied to the bladders 11, in the way which is deemed most
proper to further increase the efficiency of the sail for each
sailing point.
[0040] In order to make the outer surfaces of the two groups of
pockets 6, 7 as smooth as possible, the related flexible walls 9,
10 can be partially or totally covered and enclosed by respective
flexible joining panels 14, 15 extending, starting from the leading
edge 2, as far as the surfaces 1a, 1b of the sail 1, for instance
beyond half or more of its extension, or which may simply connect
the surfaces of maximum width of the pockets 6 and 7 to one
another.
[0041] Preferably, however not necessarily, each flexible panel 14,
15, or each rear pocket 6d and 7d, can be connected to the surfaces
1a, 1b of the sail 1 by means of a respective elastic portion 14a,
15a, for instance made of Lycra.RTM. . As an alternative the
flexible panels 14 and 15, when provided, can be entirely
elastic.
[0042] A first variant of the invention is shown in FIGS. 3 and 6
(in which parts which are identical or similar to those already
previously disclosed are designated by the same numeral references)
and enables to further improve the aerodynamic flow in the
transition area between the mast 4 and the leading edge 2 of the
sail 1, making it as undisturbed as possible. This variant consists
of the provision of two flexible baffles designated as 16, 17 in
FIG. 6, which connect the front surface of the mast 4 with the
inflatable system 5 on the side 1a and on the side 1b of the sail
1, respectively.
[0043] The variant of the invention depicted in FIG. 7 differs from
the embodiment of FIG. 6 in that the two flexible baffles 16, 17
are fixed on one side to the surfaces 1a, 1b of the sheet 1 and on
the opposite side to the mast 4 through a rope or cable system 18,
19 designed to provide the tension which is necessary to warrant
adherence between the surface of the mast 4 and the baffles 16, 17
during operation, and suitable to allow fitting out of the sail. To
such effect the ropes 18, 19 are wound around respective sheeves
(not shown in the drawings) provided on the masthead, one at each
side.
[0044] As previously pointed out, according to one embodiment which
is presently considered as the preferred one each pocket group 6, 7
is conveniently formed in one piece as a prefabricated mat, such as
shown as 21 in FIGS. 8-10 with reference to the group 6, which in
this case is including six pockets 6a-6f.
[0045] The pockets 6a-6f, which are flexible and substantially
inextensible, can be inflated directly, i.e. without employing the
elastic bladders 11 of the embodiments previously disclosed. In
this case each pocket 6a-6f is provided with one or more inflating
valves, diagrammatically indicated as 22. Each pocket 6a-6f can
also be divided longitudinally in separate compartments, each one
provided with a respective inflating valve.
[0046] Each mat 21 is configured to be easily applied onto a
respective surface 1a, 1b of the sheet 1 of any traditional sail,
even already existing, in a permanent fashion for instance by
gluing or heat welding, or more conveniently in a releasable
fashion with the aid of micro-hook strips (Velcro.RTM.) or similar
systems for quick attachment-detachment, in the way shown in FIG.
11. The mats 21 are not necessarily provided with the walls 9, 10,
or with the flexible panels 14, 15, or with the baffles 16, 17
disclosed in the above.
[0047] FIG. 12 shows the permanent or releasable application of the
pocket groups 6, 7 according to FIGS. 4 and 5 to the sheet 1 of the
sail.
[0048] FIGS. 13 and 14 are showing two simplified variants of FIG.
5, deprived of the elastic tubular bladders 11: in either case the
pockets 6a-6d and 7a-7b, mare of airtight material, are designated
to be directly inflated and thus do constitute themselves the
inflatable bladder means fixedly secured to the opposite faces 1a,
1b of the sheet 1 forming the sail. In the embodiment of FIG. 13
the flexible panels 14, 15 with the related rear elastic portions
14, 15a are provided at the outside of the pockets 6a-6d and 7a-7d,
while in the embodiment of FIG. 14 the flexible panels 14, 15 are
suppressed and only the elastic portions 14a, 15a are provided,
connecting the rear pockets 6d and 7d with the respective surfaces
1a, 1b of the sail 1.
[0049] Also in these variants the pockets 6, 7 are connected, for
instance inferiorly and through respective valves not shown in the
drawings, to an inflating device in term controlled so as to supply
air under pressure to the pockets 6, 7 jointly, or independently in
a selective and differentiated fashion, even variously combined,
according to control logics adapted to adjust the aerodynamic
conformation of the wing profile of the inflatable system 5. The
position of the area of maximum width, as already previously
explained, can be advanced or retracted with respect to the mast 4,
by differentiating the pressure of the air supplied to the pockets
6, 7 according to any mode which shall be considered proper to
optimize the efficiency of the sail at any different sailing
points.
[0050] Naturally the details of construction and the embodiments
can be widely vary with respect to what has been disclosed and
illustrated, without thereby departing from the scope of the
present invention such as defined in the appended claims. Thus, for
example, the general design of the sail can be different from the
one shown in the drawings, and be adapted for use with
sailboards.
* * * * *