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| United States Patent | 5611294 |
| Link to this page | http://www.wikipatents.com/5611294.html |
| Inventor(s) | Burg; Donald E. (Miami, FL) |
| Abstract | An improved multi-hull gas cushion supported marine vehicle that is, in its
preferred embodiment, capable of transition to airborne surface effect
operation is presented. This marine vehicle, known as SeaCoaster, has
optional elongated knife shaped bows that slice into waves, very fine
entry and low angle of divergence supporting gas cushions, water rejecting
steps that extend high onto the sidehulls, and retractable water
stabilizers to insure optimum performance in heavy seas. The retractable
water stabilizers are in the form of inverted-T hydrofoils and/or small
boat shaped members. Several variations of hydrofoil configurations are
presented. It also has special, normally inverted-V shaped, gas cushion
and wetdeck aft seals to insure minimum effect of wave impacts in those
areas. The gas pressurization system normally includes powered blowers
where a flap-like sealing device can be installed to seal gas leakage.
This allows a gas pressurizing blower to either maintain cushion gas
pressure for minimum draft or evacuate the gas cushion from minimum above
water profile. The latter is valuable for patrol boat applications where a
minimum radar signature is desired. Connecting ducts between gas cushions
can include venturi's that restrict pressure pulses in one gas cushion
from traveling to another gas cushion. Retractable or fixed sidewings are
optionally proposed to add aerodynamic lift when SeaCoaster is airborne.
These sidewings may include outrigger hulls for added stability and
improved aerodynamic efficiencies. |
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Title Information  |
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| Publication Date |
March 18, 1997 |
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| Parent Case |
CROSS REFERENCE TO OTHER APPLICATIONS
This application is a continuation-in-part to applicant's earlier
applications, Ser. No. 737,403 filed Nov. 1, 1976, now abandoned; Ser. No.
818,303 filed Jul. 25, 1977, now U.S. Pat. No. 4,165,703 issued Aug. 28,
1979; Ser. No. 069,771 filed Aug. 27, 1979, now abandoned; Ser. No.
207,789 filed Nov. 17, 1980, now abandoned; Ser. No. 269,908 filed Jun. 3,
1981, now U.S. Pat. No. 4,392,445 issued Jul. 12, 1983; Ser. No. 289,769
filed Aug. 3, 1981, now abandoned; Ser. No. 343,289 filed Jan. 27, 1982,
now abandoned; Ser. No. 458,738 filed Jan. 17, 1983, now abandoned; Ser.
No. 465,670 filed Feb. 10, 1983, now abandoned; Ser. No. 584,728 filed
Feb. 29, 1984, now U.S. Pat. No. 4,587,918 issued May 13, 1986; Ser. No.
844,529 filed Mar. 27, 1986, now U.S. Pat. No. 4,735,164 issued Apr. 5,
1988; Ser. No. 862,300 filed May 12, 1986, now U.S. Pat. No. 4,739,719
issued Apr. 26, 1988; Ser. No. 183,588 filed Apr. 19, 1988, now U.S. Pat.
No. 4,890,564 issued Jan. 2, 1990; Ser. No. 458,575 filed Dec. 29, 1989,
now U.S. Pat. No. 5,000,107 issued Mar. 19, 1991; Ser. No. 653,724 filed
Feb. 11, 1991 now abandoned; Ser. No. 728,887 filed Jul. 10, 1991, now
U.S. Pat. No. 5,176,095 issued Jan. 5, 1993; Ser. No. 871,387 filed Apr.
21, 1992 now abandoned; Ser. No. 151,253 filed Nov. 12, 1993, now U.S.
Pat. 5,415,120 issued May 16, 1995; Ser. No. 283,647 filed Aug. 1, 1994
now abandoned, Ser. No. 347,859 filed Dec. 1, 1994 now abandoned. |
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Title Information  |
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Public's "Guesstimation" of Royalty Value
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Market Review  |
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Technical Review  |
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Claims  |
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What I claim is:
1. In an improved marine vehicle including a propulsion system and with
multiple hulls where said multiple hulls are in mechanical communication,
the improvement comprising:
port and starboard sidehulls with each sidehull comprising an open bottomed
recess that is artificially pressurized with gas from at least one gas
pressurization means to thereby form a weight supporting gas cushion when
said marine vehicle is waterborne with boundaries of said recess at least
partially defined by water contacting substantially rigid sidekeels and a
recess aft seal and where, as seen in a calm sea surface water-line with
the gas cushions pressurized and the marine vehicle waterborne and moving
forward at high speed, the sidehulls are separated by a water clearing
wetdeck and are individually substantially boat shaped with narrow bows
forward that then diverge, by way of the water contacting substantially
rigid sidekeels, and with said sidekeels transforming to more parallel
sections over their aft portions and wherein an average total divergence
angle of the water contacting sidekeels of said sidehull recess, as
measured from the narrow bow to where the sidekeels become more parallel
over their aft portions, is on average less than twenty-two degrees and
where each of said sidekeels diverges on average over a minimum of one
third of its water contacting length going aft from the narrow bow forward
to where the sidekeels become more parallel over their aft portions.
2. The improved marine vehicle of claim 1 wherein an average total
divergence angle of water contacting gas cushion restraining sidekeels of
said sidehull recesses is less than eighteen degrees.
3. The improved marine vehicle of claim 1 which further comprises an
artifically pressurized gas cushion that supports part of the weight of
the marine vehicle, when said marine vehicle is waterborne, disposed at
least partially in an open bottomed recess in a multiple hull with said
multiple hull positioned, at least in part, between the port and starboard
sidehulls as a third hull and where said third hull's open bottomed recess
is at least in part defined by substantially rigid water contacting
sidekeels and a recess aft seal and where said third hull, as seen in a
calm sea surface waterline when the marine vehicle is waterborne and
traveling forward at high speed, is individually boat shaped with a narrow
bow forward that then diverges, by way of the substantially rigid water
contacting sidekeels, over at least a third of a water contacting length
of each of the sidekeels going from the narrow bow forward to where the
sidekeels develop more parallel sections over their aft portions.
4. The improved marine vehicle of claim 3 wherein an average total
divergence angle of water contacting gas cushion restraining sidekeels of
said third hull's open bottomed recess is less than twenty-two degrees.
5. The improved marine vehicle of claim 1 which further comprises a port
sidehull and a starboard sidehull retractable water stabilizer assembly
where said water stabilizer assemblies are at least partially positioned
in the respective port and starboard sidehull gas cushion restraining open
bottom recesses and when said water stabilizers are extended to their
lowered positions they extend substantially below the sidekeels.
6. The improved marine vehicle of claim 5 wherein the retractable water
stabilizer assemblies are, at least in part, of an inverted-T shape with a
single vertically oriented strut and with a lower portion of the
Inverted-T shape comprising, at least in part, a hydrofoil.
7. The improved marine vehicle of claim 5 wherein said retractable water
stabilizer assemblies are, at least in part, configured like a small boat
hull.
8. The improved marine vehicle of claim 1 wherein a sidehull's bow disposed
proximal a waterline has a forward section of bow that extends forwardly
of a lower forward portion of one of the multiple hulls and wherein such
forward section of bow further comprises a portion of a sidehull's gas
cushion recess.
9. The improved marine vehicle of claim 1 which further comprises multiple
vertically oriented water deflecting sidesteps in side surfaces of at
least one of the multiple hulls and with at least one of said sidesteps
extending upward from proximal a lower portion of a sidekeel to proximal a
height of an upper surface of a gas cushion recess.
10. The improved marine vehicle of claim 1 wherein the recess aft seals
are, as seen in a vertical transverse plane of the marine vehicle with the
marine vehicle being right side up, at least in part of an inverted-V
shape.
11. The improved marine vehicle of claim 1 wherein the recess aft seals
are, as seen in a vertical transverse plane of the marine vehicle, at
least in part of an inverted-V shape.
12. The improved marine vehicle of claim 1 which further comprises an air
flow restricting seal on an underside of a wetdeck, where said wetdeck is
in communication with a sidehull and connects said sidehull to another
hull member, with said air flow restricting seal proximal an aft portion
of said wetdeck and whereby said wetdeck is in mechanical communication
with the port and starboard sidehulls.
13. The improved marine vehicle of claim 1 which further comprises a
venturi positioned as part of a duct that interconnects port and starboard
sidehull open bottomed recesses whereby when separate gas pressurization
means are employed to pressurize the port and the starboard sidehull open
bottomed recesses the venturi dampens pressure pulses between said
separate port and starboard recesses and the gas pressuization means.
14. The improved marine vehicle of claim 1 which further comprises a gas
flow restricting means that is independent of a water level in a gas
cushion recess to restrict gas flow leakage out through one of the gas
pressurization means in such instance where the gas pressurization means
is inoperative.
15. The improved marine vehicle of claim 14 wherein the gas flow
restricting means is a flap-like device disposed downstream of the gas
pressurization means.
16. The improved marine vehicle of claim 14 wherein a gas pump can evacuate
gas from the gas cushion when the gas flow restricting means is positioned
to restrict gas flow.
17. The improved marine vehicle of claim 1 which further comprises a water
stabilizer positioned, at least in part, proximal to and between a forward
portion of the port and starboard sidehulls.
18. The improved marine vehicle of claim 17 wherein the water stabilizer
is, at least in part, boat shaped.
19. The improved marine vehicle of claim 17 wherein the water stabilizer
is, at least in part, a hydrofoil.
20. The improved marine vehicle of claim 17 wherein the water stabilizer is
at least partially retractable into a recess in a wetdeck.
21. The improved marine vehicle of claim 1 which further comprises a
sidewing with said sidewing being, on average, more than fifty percent of
an overall length of the marine vehicle.
22. The improved marine vehicle of claim 21 wherein at least a portion of
said sidewings are retractable.
23. The improved marine vehicle of claim 1 which further comprises
outrigger wings extending outward beyond the sidehulls with said outrigger
wings further comprising downwardly extending outrigger hulls.
24. In an improved marine vehicle including a propulsion system and with
multiple hulls where said multiple hulls are in mechanical communication,
the improvement comprising:
an artificially pressurized gas cushion that supports part of marine
vehicle weight, when said marine vehicle is waterborne, disposed at least
partially in an open bottomed recess in a multiple hull with said multiple
hull positioned, at least in part, between port and starboard sidehulls as
a third hull that is in mechanical communication with and separated from
said port and starboard sidehulls by water clearing wetdecks and where
said third hull's open bottomed recess is at least in part defined by
water contacting substantially rigid sidekeels and a recess aft seal and
where said third hull, as seen in a calm sea surface waterline when the
marine vehicle is waterborne and traveling forward at high speed, is
individually boat shaped with a narrow bow forward that diverges, by way
of the substantially rigid water contacting sidekeels, over at least one
third of a water contacting length of said sidekeels going from the narrow
bow forward to where the sidekeels develop more parallel sections aft and
wherein an average total divergence angle, from the narrow bow forward to
where the sidekeels become more parallel, of said sidekeels is less than
twenty-two degrees.
25. The improved marine vehicle of claim 24 wherein an average total
divergence angle of water contacting gas cushion restraining sidekeels of
said third hull's open bottomed recess is less than eighteen degrees.
26. The improved marine vehicle of claim 24 which further comprises
vertically oriented water deflecting sidesteps in side surfaces of at
least one of the multiple hulls wherein at least one of said sidesteps has
a chine that extends downwardly going from forward to aft to proximal a
level of a chine preceding said sidestep.
27. The improved marine vehicle of claim 24 wherein the third hull's recess
aft seal is, over a majority of its width as seen in a vertical transverse
plane of the marine vehicle, angled to horizontal.
28. The improved marine vehicle of claim 24 which further comprises a gas
flow restricting means that is independent of a water level in a gas
cushion recess to restrict gas flow leakage out through a gas
pressurization means in such instance when said gas pressurization means
is inoperative.
29. In an improved marine vehicle including a propulsion system and with
multiple hulls where said multiple hulls are in mechanical communication,
the improvement comprising:
port and starboard sidehulls with each sidehull comprising an open bottomed
recess that is artificially pressurized with gas from at least one gas
pressurization means to thereby form a weight supporting gas cushion with
boundaries of said recess at least partially defined by water contacting
substantially rigid sidekeels and a recess aft seal when said marine
vehicle is waterborne and where, as seen in a calm sea surface waterline
with the gas cushions pressurized and the marine vehicle is waterborne and
moving forward at high speed, the sidehulls are separated by a water
clearing wetdeck and are individually substantially boat shaped with
narrow bows forward that then diverge, by way of the sidekeels, to more
parallel sections aft and wherein an average total divergence angle of the
water contacting sidekeels of said sidehull recess is less than twenty-two
degrees going from the narrow bow to where the sidekeels become
substantially more parallel and which further comprises vertically
oriented water deflecting sidesteps in side surfaces of at least one of
the multiple hulls wherein at least one of said sidesteps has a chine that
extends downwardly going from forward to aft to proximal a level of a
chine preceding said sidestep.
30. In an improved marine vehicle including a propulsion system and with
multiple hulls where said multiple hulls are in mechanical communication,
the improvement comprising:
port and starboard sidehulls with each sidehull comprising an open bottomed
recess that is artificially pressurized with gas from at least one gas
pressurization means to thereby form a weight supporting gas cushion, when
said marine vehicle is waterborne, with boundaries of said recess at least
partially defined by water contacting substantially rigid sidekeels and a
recess aft seal and where, as seen in a calm sea surface water-line with
the gas cushions pressurized and the marine vehicle waterborne and moving
forward at high speed, the sidehulls are separated and substantially boat
shaped with narrow bows that then diverge, by way of the sidekeels, to
more parallel sections aft and which further comprises a port and a
starboard sidewing with said port and starboard sidewings extending
outward beyond their respective port and starboard sidehulls such that,
when the improved marine vehicle is at least primarily airborne, said
sidewings provide much of the aerodynamic lift required to support the
improved marine vehicle and which further comprises at least one water
stabilizer that is positioned proximal a forward portion of the improved
marine vehicle and that extends downward below the sidekeels whereby said
at least one water stabilizer provides stability during water landing of
the improved marine vehicle.
31. The improved marine vehicle of claim 30 which further comprises a
downwardly extending outrigger hull in mechanical communication with said
sidewing.
32. The improved marine vehicle of claim 30 wherein at least a portion of
said sidewing is retractable.
33. The improved marine vehicle of claim 30 wherein the sidewing further
comprises a downwardly extending wingcap.
34. The improved marine vehicle of claim 30 wherein said at least one water
stabilizer is, at least in part, shaped like a boat hull.
35. The improved marine vehicle of claim 30 wherein a wetdeck that connects
the sidehulls is, at least in part, airfoil shaped.
36. In an improved marine vehicle including a propulsion system and with
multiple hulls where said multiple hulls are in mechanical communication,
the improvement comprising:
port and starboard sidehulls with each sidehull comprising an open bottomed
recess that is artificially pressurized with gas from at least one gas
pressurization means to thereby form a weight supporting gas cushion when
said marine vehicle is waterborne and with boundaries of said recess at
least partially defined by substantially rigid water contacting sidekeels
and a recess aft seal and where, as seen in a calm sea surface waterline
with the marine vehicle waterborne and moving forward at high speed, the
sidehulls are separated by a water clearing wetdeck and are each
substantially boat shaped with narrow bows that then diverge by way of the
substantially rigid water contacting sidekeels such that an average total
divergence angle of the sidekeels of each sidehull is less than 22 degrees
and wherein said sidekeels then become more parallel from at least one
third of a distance aft of the narrow bow forward and which further
comprises a port and a starboard sidewing with said port and starboard
sidewings extending outward beyond their respective port and starboard
sidehulls such that, when the improved marine vehicle is at least
partially airborne, said sidewings provide much of the aerodynamic lift
required to keep the improved marine vehicle at least partially airborne.
37. The improved marine vehicle of claim 36 which further comprises at
least one water stabilizer positioned proximal a forward portion of the
improved marine vehicle whereby said at least one stabilizers provides
stability during takeoff and landing of the improved marine vehicle.
38. The improved marine vehicle of claim 37 wherein said water stabilizer
is, at least in part, shaped like a boat hull.
39. The improved marine vehicle of claim 37 wherein said water stabilizer
comprises, at least in part, a hydrofoil.
40. The improved marine vehicle of claim 36 which further comprises a
downwardly extending outrigger hull in mechanical communication with said
sidewing.
41. The improved marine vehicle of claim 36 wherein at least a portion of
said sidewing is retractable.
42. The improved marine vehicle of claim 36 wherein the sidewing further
comprises a downwardly extending wingcap.
43. The improved marine vehicle of claim 36 wherein the wetdeck that
connects the sidehulls is, at least in part airfoil shaped.
44. In an improved marine vehicle including a propulsion system and with
multiple hulls where said multiple hulls are in mechanical communication,
the improvement comprising:
port and starboard sidehulls with each sidehull comprising an open bottomed
recess that is artificially pressurized with gas from at least one gas
pressurization means to thereby form a weight supporting gas cushion when
said marine vehicle is waterborne with boundaries of said recess at least
partially defined by substantially rigid water contacting sidekeels and a
recess aft seal with said recess aft seal, as seen in a vertical
transverse plane of the improved marine vehicle, angled to horizontal over
a majority of its width and where, as seen in a calm sea surface waterline
with the gas cushions pressurized and the marine vehicle waterborne and
moving forward at high speed, the sidehulls are separated by a water
clearing wetdeck and are individually substantially boat shaped with
narrow bows forward that then diverge, by way of the substantially rigid
water contacting sidekeels, to become more parallel over their aft
portions and where each of said water contacting sidekeels on average
diverges over a minimum of one third of its water contacting length going
from the narrow bow forward aft to where the sidekeels become more
parallel over their aft portions.
45. The improved marine vehicle of claim 44 which further comprises a port
and a starboard sidewing with said sidewings providing a majority of the
lift required to support the marine vehicle when said marine vehicle is
primarily airborne. |
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Claims  |
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Description  |
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FIELD OF THE INVENTION
The instant invention describes marine vehicles that operate in a surface
effect condition by entrapping a cushion(s) of artifically pressurized gas
between the vehicle and a water surface and/or a ram effect of ambient air
that is sandwiched between the vehicle and a water or other surface at
higher vehicle speeds. The first are most commonly called hovercraft or
Surface Effect Ships (SES's) and the latter Wing in Ground Effect (WIG),
Wing in Surface Effect Craft, or simply wingships. The common thread of
all of these is that the pressurized gas disposed between the vehicle and
the supporting medium carries most of vehicle weight. In any case, overall
efficiencies of the SES are much greater than conventional marine vehicles
and overall efficiencies of the WIG are much greater than commercial
aircraft.
Applicant's earlier developments of marine vehicles using artifically
pressurized supporting gas cushions have been successful and have resulted
in a number of vehicles being built. What promises to be far superior to
any of its predecessors is now called the SeaCoaster marine vehicle that
uses multiple hulls with a long and slender air cushion in at least one of
such hulls. The multiple hulls have very fine entry bows and controlled
divergence of their gas cushions back to a point where the sides of the
gas cushions become parallel in the preferred embodiments. Applicant has
conducted extensive model tests to establish allowable ranges of
divergence of the gas cushions and has also devised an optional new knife
type bow that is now referred to as the SeaSaber bow for its wave slicing
abilities. The clearly defined low divergence angles of the gas cushions
are invaluable for rough sea operation of SeaCoaster. When coupled with
the optional SeaSaber bow there are further advantages realized in some
speed and sea conditions that makes SeaCoaster an exceptionally good sea
boat.
de Pingon, French Patent 0271372 has catamaran-like sidehulls in a marine
vehicle with pressurized air cushions under each sidehull; however, the
entry of each of his sidehulls is rather blunt and the total divergence of
his air cushion sides, as seen in a waterline plane of the hull, is very
abrupt with total divergence angles of over 45 degrees. Applicant has
established that such divergence angles will contribute to a totally
unacceptable ride in rough seas. As a point in fact, applicant limits the
total divergence angle of SeaCoaster's gas cushions to less than 22
degrees, with at least part of such divergence preferably on either side
of a vertical longitudinal plane of the hull. A divergence angle closer to
15 degrees is optimum while under 18 degrees is set as a good target for
good rough sea ride qualities combined with enough divergence to obtain
sufficient cushion area to properly support the vehicle. Some discussion
is now in order regarding the relevance of the proper divergence angle of
the gas cushion from the narrow bow going aft to where the substantially
rigid sidekeels bounding a recess in the hull become more parallel. This
angle is referred to as the total divergence angle of the sidekeels.
First, a rectangular gas cushion with a squared off front end and widely
spaced substantially parallel sidehulls that are not joined by a narrow
bow forward will actually be the most efficient in calm seas as that
squared off bow arrangement has the largest gas cushion area and hence the
lowest most efficient gas cushion pressure, the bow seal will actually be
clear of the water at high speed resulting in minimum bow seal drag, and
the sidekeels will be parallel over their entire length which is a least
drag situation. However, such squared off bow seal designs have very poor
rough sea performance. Tests have been conducted on Applicant's narrow
pointed bow designs with reduced sidekeel total divergence angles. Bow
movement or pitching in rough seas starts to fall into an acceptable range
at just under 22 degrees total divergence angle. It is a compromise as to
how far to lower the total divergence angle and still have sufficient gas
cushion area to properly support the vessel. Tests with a sidekeel
divergence angle of just under 18 degrees showed a good compromise between
rough sea ride qualities and sufficient cushion area. Therefore, the
necessary limits of sidekeel divergence angle for the instant invention
are less than 22 degrees with less than 18 degrees preferred. Also,
SeaCoaster's SeaSaber bow knifes through waves and also gives a longer
water-line length which is invaluable for this high speed marine vehicle.
In its preferred embodiment, SeaCoaster combines the SeaSaber bow with a
very fine entry gas cushion which has total average divergence of less
than 18 degrees, a series of vertically high water friction reducing steps
down the length of its hulls, and a unique retractable water stabilizer
system. Any one of these features, taken individually or collectively,
make the instant invention far superior to and widely separate it from de
Pingon.
Wilson, U.S. Pat. No. 3,191,572; Gunther U.S. Pat. No. 3,473,503; and
Crowley, U.S. Pat. No. 3,742,888 present multiple air cushion hulls.
Wilson and Gunther do not have open bottomed recesses in their individual
hulls but rather plates with air discharge holes drilled in them as can be
seen in FIG. 7 of Gunther and FIG. 2 of Wilson. Further, Gunther does not
have air cushion sidekeels on his sidehulls and neither Gunther nor Wilson
have recess aft seals in their multiple hulls which is a critical part of
the instant invention as such aft seals are required to maintain a
pressurized air cushion. Yet another difference is that Wilson's water
contacting sidekeels are parallel from their forwardmost portions and do
not diverge as specified in the instant invention. Wilson has upwardly
curved angled surfaces that become bows forward; however, they, very
importantly, do not make water contact in a calm sea surface when the
blowers are operating and his boat is traveling forward at high speeds.
Crowley, in his closest concept as shown in his FIGS. 9 and 10, does not
have individual boat shaped multiple hulls but rather simply multiple air
cushions all having a common center bow. As such, neither Wilson, Gunther,
nor Crowley have concepts that resemble applicant's instant SeaCoaster
invention.
Distinctions are also noted from applicant's U.S. Pat. Nos. 5,176,095 and
5,415,120 that show a total gas cushion divergence angles of over 30
degrees and also from an article in the May 1992 issue of "Ship & Boat
International" magazine that shows applicant's earlier concepts where gas
cushion divergence angles of approximately 30 degrees are shown. Neither
of these divergence angles are acceptable for tolerable seakeeping
characteristics. Importantly also, neither applicant's earlier issued
patent nor the "Ship & Boat International" article talk of the SeaSaber
bow or water stabilizer systems that are preferred components of the
instant invention's SeaCoaster hull concepts.
SeaCoaster offers attention to details including the optional use of a
venturi positioned in an interconnecting duct that connects gas cushion
recesses in separate multiple hulls. The benefit of such a venturi is that
is restricts gas pressure pulses from traveling from one multiple hull's
gas cushion to another and thereby helps insure a smooth bounce free ride.
Freygang, U.S. Pat. No. 2,399,670, uses a venturi as part of an air
induction system for inflating a life raft. It is only used when inflating
the raft and does not in any way connect two separate gas cushions in a
multiple hull air cushion boat. As such, there is little or no resemblance
to applicant's instant SeaCoaster invention.
A very serious additional benefit is the use of water stabilizers in the
form of a lifting hull(s) or hydrofoil(s) with the SeaCoaster instant
inventive hull. The hydrofoils especially reduce pitch of SeaCoasters bows
in very rough seas. In their ideal form, these water stabilizers can be
retracted up into the gas recesses in the hulls during calm sea or shallow
water operation but lowered during operation in heavy seas. Applicant's
model tests have shown at least a fifty percent reduction in bow pitch
with hydrofoils in use.
Meyer, Jr., U.S. Pat. No. 3,968,762, offers hydrofoils that retract into a
single air cushion generic flexible seal SES. He does not offer a multiple
hull air cushioned craft as is applicant's instant invention and therefore
cannot offer multiple hydrofoils that retract into air cushion recesses.
In its most important arrangement, SeaCoaster utilizes retractable
hydrofoils widely separated in port and starboard sidehull air cushion
recesses. Cathers, et al, U.S. Pat. No. 3,141,436, presents hydrofoils
that extend inwardly from outboard sidewalls in a two air cushion craft
where such cushions are separated by a narrow skeg and further are each of
movable fore and aft seal SES arrangements. Cathers has no way to retract
his hydrofoils and does not have boat shaped multiple hulls as does the
instant invention so he bears little resemblance to the instant invention.
Johnson, U.S. Pat. No. 3,456,611, is a catamaran with hydrofoils but with
no gas cushion recesses to withdraw them into so therefore offers little
resemblance to the instant invention.
Another important feature of the SeaCoaster instant inventive hull is its
use of sidesteps to reduce water friction by keeping water off of the
sides of the multiple hulls. This is accomplished by a series of
downwardly extending steps that start about midship. Very importantly, the
chines of SeaCoaster's sidesteps start highly elevated and swoop down to
proximal the level of the chine preceding such sidestep. This is not so of
either Pipkorn, U.S. Pat. No. 4,907,520, nor With, U.S. Pat. No.
3,977,347. Pipkorn uses a vertical inset into the side of his hull that
remains essentially constant in elevation over its entire after length.
With has outwardly extending rearwardly facing steps, noted as 3 in his
FIG. 3, and does not have the downwardly swooping chine steps of the
instant invention either. As such, neither the patents of Pipkorn nor With
have relevance to the instant invention's very efficient sidesteps with
downwardly swooping chines.
SeaCoaster lends itself ideally to transformation to an air-borne mode as a
WIG as vehicle speed is increased substantially. For example, a wide beam
100 foot SeaCoaster would achieve takeoff speeds to WIG operation at about
110-130 knots. A difficulty of other WIG types is getting up to takeoff
speeds efficiently. Various means have been attempted including the Power
Augmented Ram Wing (PAR) which simply rams the exhaust of turbojet engines
or air propellers under the WIG's wing at lower speeds to obtain
sufficient lift. This is an overpowering approach and generally requires
extra engines that are not used during high speed cruising WIG operation.
SeaCoaster optionally applies outrigger hulls attached to outrigger wings
outboard of its air cushioned sidehulls that are beneficial for stability
and for added lift. Further, additional winglets can be applied outboard
of the outrigger hulls and such would normally include downwardly
extending wing caps for improving aerodynamic efficiency.
Bixel, Jr., U.S. Pat. No. 5,105,898 approaches the WIG takeoff problem with
a hovercraft or SES that becomes a WIG after takeoff speeds are reached.
This is a workable approach as the SES is a very efficient high speed
marine vehicle. Bixel's shortcoming has to do with the shortcomings of all
SES's related to the movable seals fore and aft between his sidehulls.
These movable seals have poor seakeeping abilities, contribute to a
pulsing of pressures in the gas cushion that is felt by passengers as
severe jolts, and are subject to high maintenance. Also, Bixel, Jr. does
not have a water stabilizer system to improve ride qualities and to
augment takeoff and/or landing from SES waterborne into the WIG airborne
mode or vice versa as does the preferred variant of SeaCoaster.
The instant invention offers advancements over applicant's earlier
inventions as well as over the prior art. These advancements are discussed
in some detail in the following sections.
SUMMARY OF THE INVENTION
The object of the instant invention is to provide a superior marine vehicle
that is, in its majority, supported by pressurized gas.
It is a directly related object of the invention that gas for pressurized
gas cushions can be supplied by artificial means.
It is another object of the invention that at least part of the pressurized
gas for support of the marine vehicle can be obtained by a gas compression
effect that occurs between the vehicle and a supporting surface when the
vehicle is traveling forward at high speeds.
An important object of the invention is that multiple hulls are used with
pressurized gas supplied to a recess in at least one of such multiple
hulls by artificial means such as powered blowers.
It is a related object of the invention that, as seen in a calm sea surface
with the gas cushion(s) pressurized and the marine vehicle moving forward
at high speed, the sidehulls form either symmetrical or unsymmetrical boat
shaped patterns on the water surface with narrow bows that become more
parallel going aft.
A related object of the invention is that an aft portion of a pressurized
gas recess can be comprised of surfaces angled to horizontal, at least
over a portion of its longitudinal lengthened that such aft portion can be
called a recess aft seal.
Another object of the invention is that another recess seal can be at least
partially positioned in a gas cushion recess forward of the recess aft
seal.
Yet another object of the invention is that angled surfaces can be applied
to an underside of structure that connects two of the multiple hulls.
It is a related object of the invention that
Another object of the invention is that multiple hulls can include two or
more hulls in mechanical communication.
It is a related object of the invention that two or more pressurized gas
cushions disposed in separate hulls can be connected through hull
interconnecting structure such as ducts.
A directly related object of the invention is that a duct interconnecting
pressurized gas cushions in separate hulls can include a venturi to
thereby restrict pressure disturbances from traveling between the gas
cushions.
It is another object of the invention that movable structure, such as
flaps, disposed in blower ducts can be used to seal off gas flow through a
blower that may be inoperative.
It is a related object of the invention that a gas pumping device can be
used to maintain a multiple hull gas cushion pressurized when the main
blowers are inoperative.
It is another related object of the invention that a gas pumping device can
be used to evacuate gas from a multiple hull gas cushion when the main
blowers are inoperative and thereby lower the profile of the inventive
hull.
It is an object of the invention that average total divergence of the sides
of the gas cushion be less than 22 degrees for good ride qualities and low
resistance.
It is a directly related object of the invention that a further refinement
places the total divergence of the sides of the gas cushion at less than
18 degrees for best ride qualities and lowest resistance.
It is a further and optional object of the invention that a forwardly
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