Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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MULTIHULLED PARTIALLY AIR SUPPORTED MP~RINE VEHICLE
CROSS REFERENCE TO OTHER APPLIC;~rTIONS
This application is a continuation-in-part to
applicant's earlier applications, Ser. No. 728, 887 filed Jul.
10, 1991 now Pat. No. 5,176,095 issued Jan. 5, 1993; Ser. No.
871,387 filed Apr. 21, 1992 now abandoned; Ser. Na. 151,253
filed Nov. 12, 1993 now Pat. No. 5, 415,120 issued May 16,
1995; Ser. No. 283,647 filed August 1, 1994 now abandoned;
Ser. No. 347,859 filed Dec. 1, 1994 now abandoned; Ser. No.
468,876 filed Jun. 6, 1995 now Pat. No. 5,611,294 issued
March 18, 1997; and Ser. No. 483,791 filed June 7, 1995 now
Pat. No. 5,626,669 issued May 6, 1997.
FIELD OF THE INVENTION
This invention relates to multiple hulled marine
vehicles that are partially supported by artificially
pressurized gas cushions. There are numerous ref inements to
the invention that, in addition to other significant
advantages over the prior art, define the instant invention
advanced marine vehicle as having multiple hulls with built
in recesses that restrain the upper 'portions of the
pressurized gas cushions.
BACKGROUND OF THE INVENTIOIIJ
This invention is a further improvement upon and
definition of applicant's earlier inventions in this field.
These include applicant's issued United States Patents
5,176,095 and 5,415,120 that show multiple hulled air
cushioned marine vehicles. The instant invention presents
further important developments and definitions to the
technology over those earlier.
Applicant has determined that very fine entry bows with
defined limitations on the angle of the divergence of the
multiple supporting hulls greatly aids ride: qualities of his
invention. It was found that divergence angles of less than
twenty-six (26j degrees of the recess sidsskeels and of the
sides of the multiple supporting hulls are necessary for good
ride qualities with angles of less than ninsaeen (19) degrees
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actually preferred. This is described anct defined in some
detail in this application covering the instant invention.
German patent DE 3813-105-A shows a non-pressurized air
cushioned catamaran side hull that has a series of parallel
transverse steps in its undersurface that strap air bubbles.
DE 3813-105-A has longitudinally parallel ridges (sidekeels),
certainly not the lower sidehull surface wave slicing
diverging sidekeels of applicant's in:atant invention.
Further, DE 3813-I05-A does not have a recess aft seal that,
as seen in a vertical transverse plane of the sidehull, is
angled to vertical over a majority of ita width as is an
important feature of applicant's instant invention to insure
best ride qualities in rough seas. Sundquist, U.S. Patent
3,606,857, offers a catamaran hull that kind or shape as his
intent is to propel his hull by having pressurized air expel
freely from the aft end of each sidehulls where the upper
portions of his gas cushion recess is curved over a majority
of its width: however, that cross section :is taken proximal
the bow of his sidehull so it bears no relation to or use as
the preferred recess aft seal of applicant's invention that
is angled to horizontal, as seen in a vez-tical transverse
plane of the sidehull, over a majority of its width. The
reason that the instant invention angles the shape of his
recess aft seal in such manner is to reduce the impact of
waves that have traveled the length of his sidehull gas
cushion. Therefore, Sundquist's gas cushion recess shape
near his bow has no bearing on the shape of the instant
invention's recess aft seal.
The invention also offers water deflecting steps inset
into the sides of his sidehulls that are more vertically than
horizontally oriented at their forward pe~rt~.ons as can be
seen in FIG. 2 of this application. This differs extensively
from the water deflecting guides or project:Lons of Rook, U.S.
Patent 527,511, that, on average, are much more horizontally
oriented over their forward portions and mare importantly are
not inset into the sides of his boat hull. Rook's guides or
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projections actually extend outwardly from adjacent lower
portions of his hull and actually drive t:he water away from
the hull whereas the instant invention h.as inset steps so
that water will just cease contact with the sides of the hull
over the inset portion of the steps as such water simply
becomes free of hull contact at the forward portion of the
inset step.
de Pingon, French Patent 0 271 372 offers a catamaran
air cushioned boat; however, his air cushion recess sidekeels
9,10 diverge rearward from their intersection point 11 at a
total divergence angle of approximately 45 degrees total
divergence area. de Pingon's high sidekee:l and side surface
divergence angles are totally unacceptable for good ride
qualities. Applicant has further defined over de Pingon and
the other prior art by way of other important features of his
instant invention.
SUMMARY OF THE INVENTIOrf
The object of the instant invention is to provide
advantages of applicant's previous multihu.lled air cushioned
vehicles coupled with further improvement; to ride qualities
that are largely brought about by clearly defined bow shapes
that must be adhered to for good ride qualities.
A related object of the invention is that with the bow
of a supporting multihull submerged by a .defined angle as a
function of waterline length, there is a clear limitation on
the divergence angle going aft from the bow of recess
sidekeels from each other and of the sides of the supporting
multihull from each other for acceptable rough water ride
qualities. Twenty-six degrees is considered an upper limit
with twenty degrees a better comfort level limit.
It is a further object of the invention that any
divergence of the recess sidekeels or of the sides above the
recess sidekeels does not have to be symmetrical about a
vertical centerline plane of a supporting hull.
It is a directly related object of th.e invention that a
crass section of the supporting hull is not required to be
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symmetrical about a vertical transverse plane of the hull.
It is a related object of the invention that further
submergence of the multihull bows, as occurs when passing
through large waves, still requires similar limitations on
sidekeel and side divergence angles of the supporting
multihull to allow a knifing of the supporting multihull
through such large waves minimum shock or impact loads to the
hulls.
A further object of the invention is. that the recess
sidekeels and outboard surfaces of the supporting hulls can
include water deflecting steps with such water deflecting
steps best applied at higher vehicle speed to length ratios.
A directly related object of the invention is that, at
mid-range vehicle speed to length .ratios, recess sidekeels
and outboard surfaces can be of simple h<~rd chine planing
design.
It is a further directly related object of the invention
that, at lowest vehicle speed to length ratios, the recess
sidekeels are preferably of curvilinear :shape to minimize
water contact area as well as turbulence generation.
Yet another object of the invention is that a recess aft
seal be employed to restrict gas flow leakage aft, provide a
structure for installation of propulsors, and, by means of
its shape, insure a good ride in rough seas.
It is a directly related object of tb~e invention that,
as seen in a vertical transverse plane of the hull, the
recess aft seal preferably has a shape that is angled to
horizontal over a majority of its width.
Another directly related object of the invention is that
the recess aft seal can have an inverted-V shape.
Another object of the invention is that a downwardly
extending pylon that is normally at least partially airfoil
shaped can be installed in way of the recess aft seal to aid
in obtaining clean water that has reduced amounts of
entrained air from the gas cushion for a w<nterjet propulsor.
Use of a similar downwardly extending pylon shape can be
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made when propellers, such as surfacing propellers, are
installed aft of such pylon whereby such pylon directs water
with heavy amounts of entrained air way from the propeller.
The invention will become better understood upon
reference to the drawings and the detailed description of the
invention which follow in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 presents a bottom plan view of a catamaran
version of the instant invention showing 'the. fine entry of
the recess as well as the chine area at the bow. Other
features of the invention including sidesteps and a
downwardly extending pylon used to provide clean water to a
waterjet propulsor are also shown.
FIG. 2 is a profile view of the :instant invention
showing several, A, B, and C, submergence levels of the bow
that occurs when operating in waves or when trimmed down by
the bow.
FIG. 3 is a view, taken through a vertical centerline
plane of a supporting catamaran hull, that: shows a waterjet
propulsor and inlet in a pylon, recess aft seal, gas cushion
recess, and blower.
FIG. 4 presents a waterplane outline, as seen in a calm
sea waterline with the gas cushion pressurized, of the
optimum C submergence level shaven in FIG. 2.
FIG. 5 is a waterplane outline, as seen in a calm sea
waterline with the gas cushion pressurized, of the condition
B submergence level shown in FIG. 2.
FIG. 6 gives a waterplane outline, as seen in a calm sea
waterline with the gas cushion pressurized, of the condition
A submergence level shown in FIG. 3.
FIG. 7 presents a cross section, as taken through line
7-7 of FIG. 1, that shows details of the gas cushion recess
aft seal in its preferred inverted-V configuration.
FIG. 8 is a cross section, as taken through line 8-8 of
FIG. 1, that shows a forward portion of a downwardly
extending pylon upstream of its waterjet propulsor water
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inlet.
DETAILED DESCRIPTION
FIG. 1 present a bottom plan view of i:.he invention hull
30 that shows a catamaran arrangement with two supporting
hulls 46. Note the fine entry bows of theae hulls that are
essential for good ride qualities in rough seas. Note also
the fact that each supporting hull 46 is essentially boat
shaped with more narrow bows 49 than sterns 44 and separated
from each other by connecting structure or wetdeck 50. Note
that, while not shown, more than two supporting hulls can be
used with one additional hull on the main hull centerline 41
an attractive arrangement. Additional supporting hulls to
those shown can be either with a gas cushion recess as shown
in the catamaran supporting hulls shown here oar as more
standard hulls less a gas cushion recess.
Other items shown are the chines 45, main hull vertical
centerline plane 41, supporting hull vertical centerline
planes 42, blower discharge 48, chines 45., air flow arrows
34, waterjet inlets 43 J downwardly extending pylon 36, recess
aft seal 35, propulsors 32, stern or transom 44, sidekeels
38, water deflecting steps 37, blower a:ir inlets 31, and
sides of supporting hulls 46.
FIG. 2 offers a profile view of the inventive hull 30
that shows calm sea A waterline 51, calm sea B waterline 52,
and calm sea C waterline 53 that are used for illustration of
different bow 49 submergences in calm seas. The C waterline
53 is, of course, the least resistance case and illustrates
a condition where the supporting hull keels 38 are flat with
or even with the calm water surface. The B waterline 52
represents a two and three tenths (2.3) degree angle of a
calm sea waterline going from the keel 38 at the stern 44 to
the bow. This represents for a vehicle: with a 100 foot
waterline a depth of submergence of the bow of four (4} feet.
This is a made to represent an encounter with a four {4) foot
wave. Using the same terminology, the A waterline 51 uses a
four and six tenths (4.6) degree angle which corresponds to
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an eight (8) foot wave at the bow. FIG. 2 also shows that
the sidehull water deflecting steps 37 are, at least in their
majority, inset into the sides of the hull, and further are
oriented more vertically than horizontally over their forward
portions.
FIG. 3 is a cross sectional view, as taken through a
vertical centerline plane of a supporting hull 46 that shows
the blower system 31, propulsor 32, waterjet inlet 43, and
pylon 36. Note that other propulsor types including
surfacing or standard underwater propellers can be used and
in each case the pylon shown is valuable to direct water with
air entrained away from the propulsor.
FIG. 4 shows the water contacting hull sections or C
waterplane 54, as seen in a calm sea surface waterline, for
the C waterline 53. Note that this has the least wetted area
contact and hence the least resistance. Angle G represents
the total divergence angle of the supporting hull's outside
surfaces or sides 57 in that plane and angle F the partial
angle, as measured from a vertical centerline plane 42 of the
supporting hull. Note that angle G is de!°ined as being on
average less that a maximum of 26 degrees with less than 20
degrees preferred for best ride qualities. The total average
divergence angle of a supporting hull's outside surfaces 57
from each other over a forward enlarging portion 58 of a
supporting hull is defined as occurring over a forward
enlarging portion 58 that goes aft from a supporting hull's
bow 59 to where said forward enlarging portion 58 reaches a
substantially maximum width. Angle E is the; total divergence
angle of the recess sidekeels and is defined as being less
than 26 degrees with less than 20 degrees preferred also.
Angle D is the partial angle as measured from a vertical
centerline plane 42. Note that angle D does not have to be
one half of angle E and angle F does~not have to be one half
of angle G as the supporting hulls can be nonsymmetrical in
some situations. Note also that it is a preferred embodiment
of the invention that the divergence of t:he secondary hull
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sidekeels shall occur over more than twenty-five (25) percent
of said secondary hull s waterline lengi~h and then become
more parallel.
FIG. 5 is a similar view a s given in FIG. 6 but with
the B waterplane 55. Angle I is the total divergence angle
and angle H the partial divergence angle. The defining angle
for maximum total divergence angle I is 26 degrees with a
lesser value of 20 degrees preferred.
FIG. 6 is a similar view to that given in FIG~s 4 and 5
but for the A waterplane 56 where the supporting hull bow is
most deeply submerged. The defining angles for the K total
divergence angle is a maximum of 26 degrees with the
preferred being a maximum of twenty (20) degrees for best
ride qualities.
FIG. 7 presents a cross section, as taken through line
7-7 of FIG. 1, that shows details of the gas cushion recess
aft seal 35 in its preferred invented-V configuration. Also
to be noted are portions of the waterjet propulsors 32.
FIG. 8 is a cross section, as taken i~hrough line 8-8 of
FIG. 1, that shows preferred shape of the gas cushion recess
aft seal 35 near its forward portion and that also shows a
forward portion of a downwardly extending pylon 36 upstream
of its waterjet propulsor water inlet.
While the invention has been described in connecting
with a preferred and several alternative embodiments, it will
be understood that there is no intention to thereby limit the
invention. On the contrary, there is intended to be covered
all alternatives, modifications and equivalents as may be
included within the spirit and scope of the invention as
defined by the appended claims, which are 'the sole definition
of the invention.
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