U.S. patent application number 09/771656 was filed with the patent office on 2001-07-12 for personal hydrofoil water craft.
Invention is credited to Dynes, Richard, Freeland, Peter C., Higgins, Robert Justin.
Application Number | 20010007235 09/771656 |
Document ID | / |
Family ID | 26792440 |
Filed Date | 2001-07-12 |
United States Patent
Application |
20010007235 |
Kind Code |
A1 |
Dynes, Richard ; et
al. |
July 12, 2001 |
Personal hydrofoil water craft
Abstract
A hull-less personal water craft is provided which reduces air,
water, noise, and wake pollution over personal water craft
presently on the market. The craft includes a strut assembly having
forward and rearward ends, with an operator platform attached at
the rearward end, and having at least one hydrofoil positioned
substantially underneath the operator platform at a predetermined
distance. A propulsion system is provided at the forward end of the
strut, and is operatively coupled to a control column which
provides the operator interface when the craft operator is kneeling
or standing on the operator platform. The hydrofoil provides
substantially all of the lift for the craft when in operation, and
the elimination of a hull greatly reduces the power requirements
and wake generated by the craft in operation.
Inventors: |
Dynes, Richard; (Fairfax,
VA) ; Higgins, Robert Justin; (Springfield, VA)
; Freeland, Peter C.; (Springfield, VA) |
Correspondence
Address: |
John C. Kerins
MILES & STOCKBRIDGE P.C.
Suite 500
1751 Pinnacle Drive
McLean
VA
22102
US
|
Family ID: |
26792440 |
Appl. No.: |
09/771656 |
Filed: |
January 30, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09771656 |
Jan 30, 2001 |
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09177622 |
Oct 23, 1998 |
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6178905 |
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60097053 |
Aug 19, 1998 |
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Current U.S.
Class: |
114/55.54 ;
114/55.55; 114/55.57 |
Current CPC
Class: |
B63B 34/40 20200201;
B63B 34/10 20200201 |
Class at
Publication: |
114/55.54 ;
114/55.55; 114/55.57 |
International
Class: |
B63B 001/24; B63B
001/00; B63B 035/73 |
Claims
What is claimed is:
1. A hull-less personal water craft comprising: a strut assembly
having a forward end and a rearward end; an operator platform
disposed at and operatively coupled to said rearward end of said
strut assembly; a hydrofoil positioned at an underside of said
operator platform and spaced apart therefrom at a predetermined
distance; a control foil system disposed at and operatively coupled
to said forward end of said strut assembly; a propulsion system;
and a control column having a proximal end operatively coupled to
said propulsion system, said control column having an operator
interface disposed at a distal end thereof.
2. A hull-less personal water craft as recited in claim 1 wherein
said operator interface is a handlebar element having at least one
control element thereon for controlling said propulsion system.
3. A hull-less personal water craft as recited in claim 2 wherein
said control column is pivotably coupled to said strut assembly,
whereby said column can pivot between a raised and a lowered
position.
4. A hull-less personal water craft as recited in claim 1 wherein
said hydrofoil is secured to said strut assembly by at least one
foil strut extending downwardly from the strut assembly
substantially underneath said operator platform.
5. A hull-less personal water craft as recited in claim 1 wherein
said hydrofoil has a ventilator for introducing air onto an upper
surface of said hydrofoil when said hydrofoil is submerged in
water.
6. A hull-less personal water craft as recited in claim 5, wherein
said ventilator comprises a tube having a lower opening positioned
immediately adjacent said upper surface of said hydrofoil and an
upper opening at a predetermined distance above said hydrofoil.
7. A hull-less personal water craft as recited in claim 5, wherein
said hydrofoil has a plurality of orifices disposed along a width
of said upper surface, and said ventilator comprises a tube having
an upper opening at a predetermined distance above said hydrofoil,
and a lower end which extends into an interior of said hydrofoil
and which is in fluid communication with said orifices in said
upper surface of said hydrofoil.
8. A hull-less personal water craft as recited in claim 1 wherein
said propulsion system further comprises a motor housing mounted to
said strut assembly and containing a gas-powered motor therein;
said gas powered motor being operatively coupled to a propulsor
positioned beneath said strut assembly, wherein said propulsor is
designed to remain substantially submerged in water during
operation of said personal water craft.
9. A hull-less personal water craft as recited in claim 1, wherein
said control foil system comprises at least a first pivotable foil
extending laterally from a control housing extending below said
control column, and means operatively coupled to said at least
first pivotable foil for pivoting said at least first pivotable
foil to control a depth under a surface of a body of water at which
a lower end of said control housing will travel when said craft is
in operation.
10. A hull-less personal water craft as recited in claim 8, wherein
said propulsion system includes a propulsor housing substantially
rigidly coupled to said propulsor, and wherein said craft has means
for pivotably changing an orientation of said propulsor housing
relative to a longitudinal axis of said strut assembly.
11. A hull-less personal water craft as recited in claim 10,
wherein said orientation changing means comprises linkage means
attached to and extending from said control column to said
propulsor housing, and wherein said control column is pivotably
coupled to said strut assembly, whereby said column can pivot
between a raised and a lowered position, and whereby said linkage
means is so constructed and arranged to angle a front end of said
propulsor housing downwardly and a rear end upwardly when said
control column is pivoted toward said lowered position.
12. A hull-less personal water craft as recited in claim 1, wherein
said strut assembly comprises a central axial strut having an
opening extending therethrough.
13. A hull-less personal water craft as recited in claim 12,
wherein an exhaust system for said propulsion system is disposed
within said opening in said central axial strut, and wherein said
exhaust system is in fluid communication with an opening at a rear
of said strut.
14. A hull-less personal water craft as recited in claim 1, wherein
said operator platform has a substantially foil-shaped
cross-section, and wherein said operator platform is so constructed
and arranged to provide a predetermined amount of floatation to a
rear portion of said craft, and wherein said operator platform has
an aspect ratio of about 1/2or greater.
15. A hull-less personal water craft as recited in claim 1, further
comprising a plurality of hydrofoils positioned at said underside
of said operator platform and spaced apart from said platform and
from each other hydrofoil.
16. A hull-less personal water craft comprising: an operator
platform having an aspect ratio of about 1/2or greater; a hydrofoil
positioned at an underside of said operator platform, and spaced
apart therefrom at a predetermined distance; and a propulsion
system operatively coupled to said operator platform.
17. A hull-less personal water craft as recited in claim 16,
wherein said operator platform is a substantially planar
element.
18. A hull-less personal water craft as recited in claim 17,
wherein said operator platform further comprises a seating member
secured to and extending upwardly from an upper surface of said
planar element.
19. A hull-less personal water craft as recited in claim 17,
wherein said operator platform has an aspect ratio of about one or
greater.
20. A hull-less personal water craft as recited in claim 16,
wherein said operator platform comprises two wing sections
extending laterally from a central raised saddle section.
21. A hull-less personal water craft as recited in claim 20 wherein
said operator platform is provided with nonskid surfaces on said
wing sections and on said saddle section.
22. A hull-less personal water craft as recited in claim 20 wherein
said operator platform has an aspect ratio of about one or greater.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is directed to a water craft for
personal recreational use, in which the water craft employs a
hydrofoil lift system.
[0003] 2. Description of Related Art
[0004] Personal water craft (PWC) vehicles have enjoyed immense
popularity in recent years. PWCs generally allow one, two or more
riders to sit, kneel or stand on the craft and to ride across the
surface of a body of water. The popularity of PWCs is also
attributable to the considerations that they are less expensive
than traditional power boats, are more easily transported over land
by smaller trailers, and storage and maintenance of the PWCs is
generally simpler than with full size power boats.
[0005] The popularity of such craft, and their operational
characteristics, have led to several significant problems. The
sheer number of such craft on some popular bodies of water has led
to congestion, which adversely impacts safety. More significantly,
existing PWC designs generate substantial noise, water, wake and
air pollution. These PWCs have disproportionately large engines,
with current models having 110+ horsepower engines, and, in the
quest for increased speed, the power plants are only likely to
become more powerful, in the absence of regulation. The hull form
of current PWCs generates substantial wakes, which are a
disturbance and a nuisance to other users of the waterways, and can
adversely affect the safety of operating craft, both PWCs and
boats.
[0006] Planing hulls are used in most recreational water craft,
including PWCs. The planing hull design has been popularized due to
its ability to permit craft operation at speeds in excess of the
craft's natural hull speed. These hulls produce a downward reaction
in the water by impacting the surface of the water with a low
aspect ratio wedge, which produces large wakes.
[0007] The problems and costs associated with wake generation
cannot be underestimated. The U.S. Coast Guard regulates speed, and
holds operators of water craft responsible for damage due to wakes.
Enforcement of the regulations is problematic, as wakes from motor
boats can travel large distances before being encountered and
causing damage, and identification of the offending vessel is often
difficult. Wakes can also impair the operation and control of other
water craft, with resulting detrimental impacts on safety. Wakes
further can cause damage to docks and docked water craft.
[0008] The prevalent PWCs employ a water jet as the propulsion
means. Water jets are prone to generating large amounts of noise
pollution, in that, due to wave action and the presence of wakes,
the PWC frequently lifts from the water sufficiently to break the
intake suction of the jet. Noise volume and pitch increase as a
result, due to the jet ingesting and expelling air.
[0009] Various other water recreation devices have been employed
over the years, most notably water skis. Many other towed devices,
ranging from inflated tubes to bicycle style devices employing
hydrofoil lift have been used or proposed for use. U.S. Pat. No.
3,105,249, discloses a device meeting the latter description. All
such devices suffer from the drawback that a motor boat must be
used to propel (pull) the device. The motor boat, like the PWCs
discussed above, is noisy, uses a planing hull which creates
substantial wakes, and pollutes the water.
[0010] Other watergoing vehicles have been proposed which employ
hydrofoils as part of the lift or control system of the craft.
Hydrofoils are usually utilized to permit operation of a water
craft in excess of speeds efficiently attainable with conventional
hull forms. Often, hydrofoils have been proposed for use with
hulled craft, whereby the craft will travel at low speeds using the
displacement of the hull, and, at higher speeds, lifted partially
or completely out of the water on a hydrofoil.
[0011] The high speeds attainable with hydrofoils are accomplished
in that a hydrofoil provides a more efficient means of providing
the lift necessary to float or ride on the water. Conventional
displacement hulls simply displace a volume of water equal to the
weight of the vehicle. Planing hulls displace water at lower
speeds, and, at higher speeds, provide a crude form of lift by
impacting the water downwardly, elevating the craft from the water
and permitting higher speeds.
[0012] There continues to exist a need for an efficiently operating
personal water craft (PWC) vehicle that avoids or minimizes the
environmental impacts resulting from the widespread use of planing
hulled craft. Further, efforts are ongoing to improve the
recreational experience of such craft, which, in the conventional,
planing hull PWC design, can largely be achieved only through
increasingly powerful engines to provide increased speed.
[0013] A principal object of the present invention is thus to
provide a PWC design which provides many, if not all, of the
benefits of existing PWC designs, but which eliminates or
significantly reduces the noise, water, air and wake pollution
associated with the operation of conventional PWCs, principally
through the elimination of the hull structure and the reliance on
the use of hydrofoil lift for the craft.
[0014] It is a further principal object of the present invention to
provide a PWC design that is more efficient in operation and has
much lower power requirements, for equivalent on-water performance,
as compared with conventional PWC designs.
[0015] It is an additional important object of the present
invention to provide a fast and dynamic vehicle that may operate
legally in waterways in which other, larger powered water craft
have been or may be restricted by laws or regulations limiting the
available motor power.
[0016] It is a further object of the present invention to provide a
PWC design which is convenient and enjoyable to use, and is easy to
maintain and transport.
SUMMARY OF THE INVENTION
[0017] The above and other objects of the present invention are
achieved by providing a water craft which uses a hydrofoil or a
plurality of hydrofoils as the sole means of suspending the craft
operator above the surface of the water, such that the craft or
vehicle can operate with dramatically less power than comparable
water craft, such as conventional PWCs. The hydrofoil-based
personal water craft of the present invention will thus operate
with considerably less air, water, and noise pollution, and will
generate far less wake than do hulled craft. The water craft
further employs an operator platform designed with a suitable
aspect ratio to provide hydrodynamic lift at startup, to aid in
transitioning the craft from its startup position to its running
position.
[0018] The hydrofoil craft of the present invention includes a main
hydrofoil subassembly including an operator platform on which the
operator will stand, sit, or kneel, and a hydrofoil extending from
below the platform. This subassembly is coupled to a propulsion
system which is disposed forwardly of the hydrofoil subassembly.
The hydrofoil craft is steered and/or controlled by a
handlebar-type assembly that extends rearwardly from a position
adjacent to the propulsion system, placing the handlebars in
position to be held by the operator when the operator is kneeling
or standing. The propulsion system itself may be either an axial
flow impeller type, or a ducted propeller type system, and the
handlebar controls for power and steering will be tailored to the
specific type of propulsion unit provided.
[0019] A strut assembly is used to couple the main foil assembly to
the propulsion and steering systems, and the craft thus has no
hull. Floatation devices may optionally be secured to the strut
assembly, and/or to the operator platform, to give the craft
sufficient buoyancy to prevent full submersion of the craft when
the craft is idle or stationary.
[0020] The operator platform is designed with a suitable aspect
ratio such that, at low speeds, it can function as a larger foil to
aid in lifting the platform out of the water to achieve running
configuration. After providing hydrodynamic lift, as the platform
emerges from the water with an increase in vehicle speed, the
platform will temporarily function as a planing surface, until it
clears the surface of the water and becomes completely
foil-borne.
[0021] The upper surface of the platform preferably includes a
non-slip surface, in order to provide increased traction for the
operator's feet, and also includes small toe and heel (front and
rear) cups or chocks to allow the operator to brace his or her feet
against the flow of water crossing the platform.
[0022] The forward-mounted propulsion system may incorporate one or
more hydrofoils, in order to provide lift to the propulsion system
when in operation. The forward portion of the craft, namely where
the forward end of the handlebar column is coupled to the
propulsion system, also includes hydrofoils to control the depth
of, or the elevation of, the front end and propulsion system while
operating at low speeds and at full speed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] These and other features, aspects and advantages of the
present invention will become better understood when the following
detailed description is read with reference to the accompanying
drawings, wherein:
[0024] FIG. 1 is a substantially schematic side elevation view of
the hydrofoil water craft in accordance with a preferred embodiment
of the present invention.
[0025] FIG. 2 is a substantially schematic top plan view of the
hydrofoil water craft in accordance with a preferred embodiment of
the present invention.
[0026] FIG. 3 is a substantially schematic front elevation view of
the hydrofoil water craft in accordance with a preferred embodiment
of the present invention.
[0027] FIG. 4 is a substantially schematic front elevation view of
a main hydrofoil subassembly in accordance with a preferred
embodiment of the present invention.
[0028] FIG. 5 is a substantially schematic front elevation view of
a main hydrofoil subassembly in accordance with an alternative
preferred embodiment of the present invention.
[0029] FIG. 6 is a substantially schematic front elevation view of
a main hydrofoil subassembly in accordance with a further
alternative preferred embodiment of the present invention.
[0030] FIG. 7 is a substantially schematic view of a propulsion
system and the arrangement of the components thereof in accordance
with a preferred embodiment of the present invention.
[0031] FIG. 8 is a substantially schematic view of a propulsion
system and the arrangement of the components thereof in accordance
with another preferred embodiment of the present invention.
[0032] FIG. 9 is a substantially schematic view of a propulsion
system and the arrangement of the components thereof in accordance
with a further preferred embodiment of the present invention.
[0033] FIG. 10 is a substantially schematic side view of a forward
end of the hydrofoil water craft of the present invention, showing
details of a preferred forward depth control system for the
propulsion system.
[0034] FIG. 11 is a substantially schematic side elevation view of
the main hydrofoil subassembly illustrating details of a depth
control system for the hydrofoil subassembly.
[0035] FIG. 12 is a top plan view of a foil to be employed in the
main hydrofoil subassembly in accordance with a preferred
embodiment of the present invention.
[0036] FIGS. 13A-C are substantially schematic side elevation views
of the hydrofoil water craft of the present invention, illustrating
operational details of the pivoting propulsion subassembly.
[0037] FIGS. 14A-D are substantially schematic side elevation views
of the hydrofoil water craft of the present invention, illustrating
the position of the craft and the operator during a typical
take-off sequence.
[0038] FIG. 15 is a substantially schematic view of a propulsion
system and the arrangement of the components thereof in accordance
with an alternative preferred embodiment of the present
invention.
[0039] FIG. 16 is a substantially schematic view of a propulsion
system and the arrangement of the components thereof in accordance
with an alternative preferred embodiment of the present
invention.
[0040] FIG. 17 is a substantially schematic side elevation view of
the hydrofoil water craft in accordance with an alternative
preferred embodiment of the present invention.
[0041] FIG. 18 is a substantially schematic top plan view of the
hydrofoil water craft in accordance with an alternative preferred
embodiment of the present invention.
[0042] FIG. 19 is a substantially schematic front elevation view of
the hydrofoil water craft in accordance with an alternative
preferred embodiment of the present invention.
[0043] FIG. 20 is a substantially schematic view of a propulsion
system and an arrangement of the components thereof in accordance
with an alternative preferred embodiment of the present
invention.
[0044] FIG. 21 is a substantially schematic view of the propulsion
system of FIG. 20 illustrating the manner in which the system rocks
the propulsor.
[0045] FIG. 22 is a front elevation view of internal components of
the propulsion system illustrated in FIG. 20.
[0046] FIG. 23 is a substantially schematic front elevation view of
an alternative preferred embodiment of the operator platform in
accordance with the present invention.
[0047] FIG. 24 is a substantially schematic side view of the
operator platform of FIG. 23.
[0048] FIG. 25 is a substantially schematic front elevation view of
an alternative preferred embodiment of the operator platform in
accordance with the present invention.
[0049] FIG. 26 is a substantially schematic side view of the
operator platform of FIG. 25.
[0050] FIG. 27 is a substantially schematic side elevation view of
the hydrofoil water craft in accordance with a preferred embodiment
of the present invention.
[0051] FIG. 28 is a substantially schematic top plan view of the
hydrofoil water craft in accordance with a preferred embodiment of
the present invention.
[0052] FIG. 29 is a substantially schematic rear elevation view of
the hydrofoil water craft in accordance with a preferred embodiment
of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] Referring initially to FIGS. 1-3, a water craft 100
employing hydrofoil lift in accordance with a preferred embodiment
of the present invention is illustrated. Craft 100 includes a main
or rear hydrofoil subassembly 102, and a forward steering and
propulsion subassembly 104, and a strut assembly 106 connected to
and extending between the forward and rear subassemblies.
[0054] In accordance with the present invention, the water craft is
defined as being hull-less. The term hull-less water craft, as used
herein, means a craft having at least one normal operating position
for the rider in which an adult person, when in such operating
position, and while the craft is at rest in calm water, will
necessarily be in contact with the water.
[0055] The strut assembly illustrated in FIGS. 1-3 is a single
strut 108, preferably a hollow tube having a circular
cross-sectional shape. The strut may preferably be on the order of
four inches (4") in diameter, and made of aluminum or other
high-strength, lightweight material which is resistant to corrosion
in fresh water and in sea water. Plain carbon steel tubing with a
corrosion-resistant paint or coating could alternatively be
employed, as could a fiber-reinforced plastic or other engineering
thermoplastic.
[0056] The rear or main hydrofoil subassembly 102 includes an
operator platform 110 which is sized to accommodate the feet of the
operator (10, FIGS. 14B-D), and to permit the operator to kneel
comfortably thereon. The platform 110 preferably has a high
traction, non-slip surface 112, at least at the central portions
where the operator's feet will normally be placed, although the
entire upper surface could be made of a non-slip material, if
desired. Platform 110 preferably has front and back footing cleats
114, 116, respectively, secured thereto, with the front cleats 114
provided to break the flow of water to minimize the force of any
water flowing across the upper surface of the platform on the
operator's feet. The back cleats 116 are provided to aid in
preventing the operator's feet from slipping off the platform. The
cleats are illustrated in FIG. 1, but are omitted from FIG. 2, in
order to show, in FIG. 2, the non-slip surface 112.
[0057] The platform 110 provides several important functions in
addition to providing a footing surface. The platform will have on
the order of thirty pounds (30 lbs.) of buoyancy, by virtue of its
displacement in the water, which serves to maintain the rear
hydrofoil assembly in a position close to the surface of the water
when the craft 100 is not being propelled through the water. Also,
due to the length A and width B of the platform, preferably on the
order of about 40 inches or less, and 18 inches or less,
respectively, and the thin cross-section thereof, the platform 110
will act as a hydrofoil, providing lift during the initial take-off
of the craft, as will be discussed in greater detail later.
[0058] The aspect ratio of the operator platform is desirably about
1 to 2 (1/2) or greater, in order that sufficient lift is generated
during take-off. Even more preferably, an aspect ratio of 1 (1 to
1) or greater is desired in order to aid in readily and quickly
lifting the operator platform to the surface of the water.
[0059] The hydrofoil subassembly further has a pair of foil struts
118 secured to the underside of the platform 110, and depending
downwardly therefrom. A main foil 120 is secured at the lower ends
of the foil struts. Rounded ends 119 of the foil struts extend a
short distance below the main foil 120, in order to reduce vehicle
drag when transporting the vehicle across land, and in order to
minimize the possibility that the foil will ground itself against
the bottom of the body of water.
[0060] The main foil 120 is preferably somewhat greater in length C
(on the order of 48 inches or less) and smaller in width D (on the
order of 4 inches or less) than platform 110, and the
cross-sectional shape thereof is designed to provide lift. The
length of the foil struts may preferably be on the order of thirty
inches (30"), thus spacing the main foil 120 from the operator
platform at that distance.
[0061] The operator platform 110, foil struts 118 and main foil
making up the rear foil subassembly may be made from aluminum, and,
in this instance the struts may be joined to the platform and to
the main foil by welding. Other materials can optionally be
employed, including composite materials, injection molded plastics,
rotomolded plastics, and even different materials may be employed
for the platform, foil struts, and main foil, i.e., materials
selection for the components is not seen as being critical to the
construction of a craft 100 in accordance with the invention. Where
other or dissimilar materials are used, other conventional joining
or fastening means, including, for example, riveting, threaded
connections, or adhesives, will be readily recognized as being
possible candidates for use.
[0062] The main or rear foil subassembly 102 is secured to strut
108, as by welding, if all aluminum components are employed, or by
other suitable connectors or fastening means. Strut 108 defines a
centerline of the craft 100, as it is connected to the platform 110
at a center line of the platform. Foil struts 118 are laterally
spaced equidistantly from strut 108, and the main foil 120 is
centered on the craft as well. The connection of the main foil
subassembly 102 to strut assembly 106 is reinforced by the
provision of a pair of angled support bars 122 rigidly fastened
between strut 108 and the foil struts 118.
[0063] FIGS. 4, 5 and 6 illustrate, in substantially schematic
form, alternative preferred configurations for the rear or main
hydrofoil subassembly 102. FIG. 4 shows the subassembly 102 in the
configuration shown in FIG. 1, with the operator platform 110,
front foot cleats 114, foil struts 118, main foil 120, and also
showing the rearward portion of strut assembly 106, strut 108 and
angled support bars 122.
[0064] FIG. 5 illustrates an alternative configuration in which the
only difference is that the main foil actually comprises a pair of
spaced apart foils 120a and 120b attached to foil struts 118. FIG.
6 illustrates a single foil construction, but with a centrally
disposed support bar 122' connected between strut 108 and the main
foil 120. As can readily be envisioned from viewing FIG. 6, the
centrally disposed support bar 122' may be used as a single foil
strut, which construction would eliminate the need for side foil
struts 118. These various embodiments are shown to illustrate that
the connections and supports between the main body strut 108 and
the main hydrofoil subassembly 102 are not seen as being critical
to proper operation of the craft 100, nor is the specific foil
configuration.
[0065] Returning to FIGS. 1-3, the strut assembly 106 has a
steering or control subassembly and a propulsion subassembly 104
disposed at the forward end of strut 108. While the illustrated
embodiments all depict the propulsion subassembly 104 being located
at or near the front end of the craft, it is to be recognized that
the propulsion may be provided at essentially any position along
the length of the craft. Thus, while it is presently believed that
providing both the propulsion subassembly and the steering or
control subassembly at the forward end of the craft should provide
the best overall performance, it is not seen as being critical that
the propulsion subassembly be so located. Certain advantages in
stability and maneuverability are obtained, however, by having the
steering or control subassembly at or near the forward end of the
craft.
[0066] Shown schematically in FIGS. 1-3 are a control column 124,
having a handlebar 126 at a distal end thereof, and being
operatively coupled to a control housing 128 at a proximal end
thereof. A motor housing 130 is disposed rearwardly of control
housing 128, and underneath control column 124, and is secured to
strut 108 by suitable mounting hardware or welding. A propulsor
housing 132 is disposed at a lower end of control housing 128.
Details of the construction and operation of, and the components
contained within, these housings will be discussed in greater
detail in the discussion of other drawing figures presented. An
anti-dive plate 134 is preferably provided on control housing 128,
which has a flat surface area oriented such that, when the forward
end of the craft begins to dive, the plate will impact the surface
of the water with a positive angle of attack, which will prevent or
greatly dampen any further diving motion.
[0067] It can further be seen in FIG. 1 that the control housing
128 is angled toward the rear of the craft, and that the control
housing 128 and the propulsor housing present a swept-back, rounded
nose at the lower extent of the forward end of the craft. This
design aids in preventing the craft from becoming grounded in
shallow water and aids in transporting the craft over land.
[0068] The invention described thus far is a hull-less water craft
which is capable of floating in a partially submerged condition
when not in motion, and which, in operation, is lifted in the water
by a hydrofoil assembly disposed underneath an operator platform,
wherein the hydrofoil assembly bears the weight of the operator and
the rear portion of the craft. The propulsion subassembly propels
the hydrofoil, platform and operator through the water, and the
craft is controlled by the operator by a handlebar control
extending rearwardly toward the operator platform from the forward
control subassembly. Overall, the craft operates as a self
propelled sled.
[0069] FIG. 7 illustrates, in substantially schematic form, a
preferred arrangement or embodiment of a propulsion subassembly 134
and other associated components. The illustrated subassembly is
referred to as a split propulsion system, in that certain
components are housed in motor housing 130, and other components
are housed in propulsor housing 132. A split system has the
advantage of reducing the size of the housing (propulsor housing
132) that will remain submersed at full operating speed. This
yields a lower cross-section presented to the water, thus lowering
the form and wetted area drag of the propulsion system.
[0070] The selection of which components are positioned in the
motor housing 130 and in the propulsor housing 132 generally
follows a logical division of the components required to be
submersed in operation, and those that are not. In FIG. 7, the
motor housing 130, which will travel above the water surface at
operating speeds, has a reciprocating motor 136, a generator 138
driven by the reciprocating motor, and a fuel tank 140 supplying to
the reciprocating motor, disposed therein.
[0071] The motor housing optionally has an induction fan 142 in
fluid communication with the outside environment, which is used to
maintain a positive pressure in the motor housing 130. It may also
be desirable to fluidly couple the propulsor housing 132 to the
motor housing 130, in order to maintain a positive pressure
throughout both housings. Maintaining this positive pressure will
provide a moderate boost in engine performance and will make the
propulsion system less susceptible to small leaks, and provides a
means of continuously draining sump 166 through valve 168.
[0072] Mounting the reciprocating motor 136 in an upper motor
housing 130 positioned above (as illustrated) or alongside (not
shown) the strut assembly 106 desirably allows the interior of
strut 108 to house an exhaust system 144, which can include an
exhaust resonator 146, a muffler 148, and tubing runs 150
connecting the motor exhaust chamber or manifold to the exhaust
resonator and connecting the resonator to the muffler. In this
preferred embodiment, the strut 108 is left open at the rear end
109 thereof, as well as at its front end, such that the strut 108
is free flooding, and so that the exhaust gases will advantageously
exit the vehicle at the rear thereof. It is estimated that, due to
the ability to provide a long, linear muffler 148 in the strut 108,
the above-water exhaust system would achieve approximately the same
level of noise reduction as would a submerged exhaust port. When
the strut 108 is used to house the exhaust system, the motor
housing 130 and the strut 108 will be joined such that a passage or
opening is provided between the two components to allow the
connection of the tubing run 150 between the motor 136 and exhaust
resonator 146.
[0073] Generator 138 is electrically connected by cable or wiring
152 to a controller 154, which controls operation of electric drive
motor 156, and the distribution of power to the motor 156 and
battery 158. In this way, the generator supplies power to the motor
156 through controller 154, and also supplies power to battery 158.
Battery 158 provides the charge for ignition, and may also be
employed to intermittently provide power in initial takeoff and
acceleration modes. The controller 154, battery 158 and drive motor
156 are housed within propulsor housing 132 in the FIG. 7
embodiment.
[0074] Drive motor 156 has an output shaft 160 which extends
through the rear of the propulsor housing, and the shaft 160 is
operatively coupled to a propulsor means 162, shown schematically
in FIG. 7. The propulsor means 162 is preferably a ducted propeller
or an axial flow impeller, both of which are available in the
market, and both of which are relatively safe and efficient for use
in this particular service.
[0075] Drive motor 156 may be jacketed so as to be conduction
cooled. Small openings 164 are provided in a lower portion of
control housing 128 to function as a water inlet, which water is to
be collected and directed to the reciprocating motor 136 and to
exhaust system 144 (through the open front end of strut 108), for
cooling those components while the craft is foil-borne.
[0076] Propulsor housing 132 may preferably be provided with a sump
166 at the lower extent of the housing, with a popette valve or
another selectively openable means. The sump will collect water
that enters the housing, and the water may be drained or forced out
through valve 168.
[0077] As shown in this FIG. 7 embodiment, the propulsor housing is
coupled to the craft by a plate 170 that is secured to a lower end
of a control rod 172. Control rod 172 is mounted inside control
housing 128 and is rotatable about its longitudinal axis. Control
rod 172 is itself coupled by a universal joint (shown schematically
at reference numeral 174), to a steering bar 176 extending within
control column 124. Steering bar 176 is coupled to handlebar 126 in
a manner such that, when the handle bar is pivoted, the steering
bar will rotate about its longitudinal axis, and, through universal
joint 174, will cause control rod 172 and plate 170 to rotate.
Steering is thus effected in this embodiment by rotating the
handlebar 126, which, through the described linkage, rotates
propulsor housing 132 to a desired angle relative to the
longitudinal axis of the craft.
[0078] FIG. 8 depicts another preferred arrangement for the
propulsion subassembly. This arrangement resembles, to some extent,
the configuration of an outboard motor. This embodiment may
preferably employ the same exhaust system 144 as in the FIG. 7
embodiment.
[0079] In this embodiment, the pressurized motor housing 130
encloses a fuel tank 140 and a motor 136. The output of the motor
136 powers a drive shaft assembly 180, which drives the propeller
162 or other propulsor means. A swept-back, rounded, drive shaft
housing 182 encloses a majority of the submersed portion of the
drive shaft assembly, and the housing 182 is pivotably or rotatably
coupled at the underside of the control housing 128.
[0080] Control rod 172 in this embodiment is coupled to a rotatable
motor mount 184, by a steering coupling 186, illustrated as a pair
of pulleys 188, 190 and a belt 192 extending between the pulleys.
Steering is effected by rotating the handlebar 126, as in the FIG.
7 embodiment, which causes control rod 172, and pulley 188
connected thereto, to rotate. Through belt 192, the second pulley
190 is rotated, which rotates the drive shaft housing 182, drive
shaft assembly 180 and propeller 162.
[0081] A further preferred propulsion subassembly configuration is
illustrated in FIG. 9. This configuration replaces the rigid,
geared drive shaft assembly 180 shown in FIG. 8 with a flexible
drive cable or shaft 196. The use of the flexible drive shaft 196
enables the use of the simpler steering system shown in FIG. 7. In
this embodiment, drive shaft housing 182 is coupled to a control
rod 172 at a lower plate 170 attached thereto. Rotation of the
drive shaft housing 182 and propeller 162 to effect steering takes
place in a manner similar to the manner in which propulsor housing
132 is rotated in the FIG. 7 embodiment.
[0082] FIG. 10 illustrates a preferred embodiment of a forward end
propulsion system depth control system 200. The depth control
system 200 employs one or more pivotable foils 202 (one shown)
extending laterally from opposite sides of control housing 128. The
foil or foils 202 are preferably pivoted at their center of lift,
and the pivot means can be a pin or pins extending from the foils
202 through the walls of control housing 128. The angle of attack
of the foils 202 is controlled by sensor 204, which includes a
large, inclined sensor plate 206 attached to an arm 208 pivotably
secured to control housing 128. Arm 208 is connected to one or both
of the foils 202.
[0083] As shown, in a preferred embodiment, the plate 206 and arm
208, and the foils 202, are in a substantially neutral position,
i.e., substantially parallel to the surface of the water, when the
propulsor housing and the front of the craft are traveling stably
at approximately the desired depth. Plate 206 is designed such that
it will substantially skim the surface of the water. Thus, as the
front end of the vehicle begins rising farther out of the water,
plate 206 will descend, pushing downwardly on the front of the
foils 202, by action of the pivoting arm 208, to position the foils
to have a negative angle of attack. The foils thus impart a
downward force on propulsor housing 132, substantially preventing
it from rising any higher in the water. The ability to generate the
negative angle of attack is an important and significant feature,
in that the operator on platform 110 may have a tendency to lean
back and/or pull back on handlebars 126, both of which will tend to
cause the craft to attempt to raise the front end thereof. The
depth control system will, in all conceivable instances, be capable
of retaining the front end in the water.
[0084] When the front end of the vehicle begins to descend past the
desired neutral position, plate 206 pivots upwardly, causing arm
208 to pull upwardly on the front of foils 202, thus providing a
desired positive angle of attack to substantially prevent further
descent of the front end, and to urge the front end back to the
neutral position.
[0085] A damper foil 212 and arm 214 may preferably be secured to
arm 208 at the side of pivot point 210 to which plate 206 is
attached. The damper foil 210 will be positioned to remain
submerged during normal operation, and will damp or stiffen the
sensor 204, making it less sensitive to wave action or other water
surface level transients.
[0086] FIGS. 11 and 12 illustrate features that may advantageously
be included on the rear foil subassembly 102, in order to provide
depth control for the foil and rear portion of the craft. More
specifically, these figures show the use of ventilation means
provided to reduce the lift of the foil, and thus to regulate the
minimum depth (maximum height) attained by the foil in
operation.
[0087] In FIG. 11, a ventilation tube 220 is shown extending
upwardly from the upper surface 121 of foil 120, alongside foil
strut 118. An identical ventilation tube would be similarly
positioned on the second foil strut (not shown). The low pressure
region present on the top of the lifting foil 120 is used by tube
220 to induct air from above the surface of the water to the top of
the foil. This air induction, also referred to as ventilation, has
the effect of dramatically reducing the lift generated by the
foil.
[0088] Thus, in the present invention, the ventilation tube 220,
when fully submerged, has no substantial ventilating effect, and
the lift provided by the foil will raise the foil 120 and the
operator platform 110. The length of the ventilation tube 220 is
selected such that an upper end 222 thereof breaks the surface of
the water when the foil 120 reaches a predetermined level below the
surface of the water corresponding to the desired closest distance
of approach of the foil to the surface of the water, and the
desired elevation of the platform 110 in operation.
[0089] When the upper end of the tube breaks the surface,
ventilation commences, thereby dramatically reducing lift. As a
result, the foil will remain substantially at that level in the
water. At this position, the top of the tube will spend a portion
of time exposed to the air and a portion of the time submerged, due
to the natural action of crossing even small waves or wakes. This
has the effect of providing a smooth transition from the normal to
the ventilated condition. The ventilation system becomes more
effective at higher craft speeds, due to the increased tendency of
the vehicle to climb, with even the minimal lift provided by the
ventilated foil.
[0090] The opening at the lower end 224 of the tube is preferably
positioned immediately adjacent the upper surface of the foil, and
may preferably face laterally toward the side of the craft, or
rearwardly, away from the flow of water. This will ensure a
reliable low pressure coupling of the opening to the foil.
[0091] FIG. 12 illustrates a further preferred embodiment of the
ventilator system. In this figure the ventilator tubes 220 are
positioned inside, or are made integral with, foil struts 118. In
addition, a ventilator extension tube 226 extends laterally within
the interior of foil 120, and has a plurality of orifices 228
extending through the upper surface 121 of the foil, which will
bleed air inducted through ventilator tubes 220 to the upper
surface of the foil. This configuration is expected to increase the
effectiveness of the ventilation.
[0092] The two ventilator tubes 220 could communicate with the
entire ventilator extension tube, or, preferably, the ventilator
extension tube will comprise two separate tubes 230, 232 and each
ventilator tube 220 may be in fluid communication with only the
portion of the extension tube 226 on the side of the craft on which
the respective ventilator tube 220 is disposed. This arrangement
can provide a limited amount of roll control, in addition to or as
an enhancement to the depth control, in that, if one side of the
craft is raised higher, for example, with the operator leaning
considerably to one side, the ventilator on that raised side will
operate to decrease lift on the foil on the raised side thereby
tending to right the craft, while the ventilator on the lower side
will not be significantly decreasing lift on the opposite side.
[0093] FIGS. 13A-C illustrate a further feature of the propulsion
and steering system in accordance with a preferred embodiment of
the present invention. In these figures, the propulsion and
steering system is assembled to the main strut subassembly 106 such
that the propulsor housing and propeller can pivot or rock relative
to the strut 108, and such that the longitudinal axes of these
components will not always be in parallel.
[0094] The main object of providing a rocking propulsion
subassembly is to facilitate the initial take-off of the vehicle,
as will be discussed in greater detail below. Referring now to
FIGS. 14A-D, a typical take-off sequence is illustrated
schematically. With no operator onboard, the vehicle or craft 100
is partially buoyant, with portions of the craft extending above
and below the surface of the water, as seen in FIG. 14A. The
operator 10 mounts or boards the craft 100 preferably by kneeling
or crouching on the operator platform 110, as shown in FIG. 14B. In
this position, the forward end of the craft remains near the
surface of the water, while the operator platform 110 lowers under
the weight of the operator.
[0095] The operator 10, using the controls disposed on handlebar
126, starts the craft moving in the water, whereupon the rear foil
subassembly and the lift provided by the operator platform 110
cause the rear portion of the craft to rise such that the operator
platform breaks the surface of the water, as seen in FIG. 14C.
Further increases in craft speed result in a further raising of the
operator platform due to the lift provided by foil 120. In full
operation (FIG. 14D), the operator platform 110, motor housing 130,
and strut assembly 106 travel above the surface of the water, due
primarily to the lift provided by main foil 120, with lift also
contributed by foils 202 attached to the propulsor housing 132.
[0096] Returning now to FIGS. 13 A-C, the components enabling the
propulsor housing 132 to be rocked during take-off will be
described. Control column 124 is pivotably connected to control
housing 128 by a suitable hinged connection 230 (see also FIG. 7)
or other means. This pivotable connection is desired even when the
rocking propulsor housing is not employed, so that the handlebar
126 can travel between a lowered position and a raised position, to
enable the handlebars to be held comfortably when the operator is
kneeling or standing, and to accommodate a range of operator
heights.
[0097] Where a rocking propulsor is used, the propulsor housing 132
is hingedly connected to the steering mechanism (plate 170 in FIG.
7) by hinge means 232. This connection is made at the rear portion
(aft of center) of the propulsor housing. A rod or cable 234, shown
schematically in FIG. 13A, is secured to the control column 124 at
a point which will pivot upwardly when the handlebar at the end of
the control column is pivoted downwardly, or is at a lowered
position (FIG. 13B). The opposite end of rod or cable 234 is
secured to the propulsor housing 132 at a point rearward of the
hinged connection. Thus, when the handlebar is lowered, the rod or
cable pulls the rear portion of the propulsor housing upwardly,
and, when the handlebar 126 is raised, the propulsor housing is
able to pivot back into its normal orientation or position. The
propulsor housing preferably would have a biasing means to retain
it in contact with plate 170 in the absence of a substantial
downward force being applied to the handlebar 126 and control
column 124.
[0098] The rocking propulsor housing facilitates an easier and
potentially quicker take-off for the craft. In the at-rest position
(FIG. 13B), the vehicle, with an operator or rider 10 in place, is
pitched upwardly. While this has the benefit of angling the foils
to better generate lift, the propulsor housing 132, if not
pivotable, would also be similarly upwardly pitched. This would
cause the propulsor subassembly to have a tendency to broach the
surface of the water, which can cause the propeller 162 to
ventilate with air, and thereby lose thrust and efficiency.
[0099] Maintaining the handlebar 126 and control column in the
lowered position will raise the back end (and lower the front end)
of the propulsor housing, as seen in FIG. 13B. This will decrease
the relative pitch of the propulsion system to the surface of the
water, and will direct the thrust generated by the propeller
directly at the underside of the operator platform 110. In the
takeoff sequence, operator platform 110 provides lift while
emerging from the water, and the propulsion thrust thus boosts the
lifting forces acting on the platform. This results in the operator
and platforms being more easily lifted prior to the craft's
achieving higher speeds. Since less of the operator will be in the
water creating drag, the vehicle can be propelled forward with less
power. Finally, the thrust of the propeller will be more closely in
line with the desired direction of motion, thereby maximizing the
use of the thrust to propel the craft forward.
[0100] The propulsor section would preferably be able to pivot on
the order of about 10-20 degrees from its normal position, but this
can be varied to accommodate specific geometries of the craft.
[0101] FIGS. 15 and 16 illustrate two alternative preferred
arrangements of a fully submersed propulsion subassembly, which
could be employed in place of the partially submersed or split
systems illustrated in FIGS. 7-9. The principal differences between
the two embodiments in FIGS. 15 and 16 are the type of drive motor
and auxiliary equipment employed.
[0102] In FIG. 15, a pressurized propulsion enclosure 300 is
provided. In this configuration, an electric motor 302 is used to
power a ducted propulsor 304. Electric motor 302 is, in turn,
powered by a gas-powered motor/generator combination 305, 306. The
motor 305 has an exhaust port 307 extending through the wall of the
enclosure. The generator output can drive the electric motor
directly and/or can be stored in battery 308 under the control of
charge controller 310. Fuel for the gas-powered motor is stored in
fuel cell 312.
[0103] The use of this power plant configuration provides high
efficiency, lower gas motor power requirements, allowing use of a
smaller gas motor, and a built-in thrust reverse capability. The
craft may also be operated on battery power alone intermittently,
allowing extremely quiet operation, and limited "get home"
operation in the event of a gas motor failure.
[0104] The propulsion enclosure 300 may also be provided with a
snorkel tube 314 to allow air to be inducted into the enclosure by
the motor, thereby allowing the enclosure to operate as a
compressed air plenum for supercharging the gas motor. Enclosure
300 may be mounted to the underside of the strut subassembly by a
pair of propulsion support struts 316, 318.
[0105] The FIG. 16 embodiment is a gas engine powered system.
Propulsion enclosure 400 contains a gas engine/motor 402, a fuel
cell 404, a starter motor 406 and battery 408 used to power the
starter motor. The motor output is used to power the propulsor 410.
As in the FIG. 15 embodiment, the propulsion enclosure has a
snorkel tube 412, and an engine exhaust port 414. While this
configuration may be somewhat less efficient than that illustrated
in FIG. 15, it may be less expensive to construct. Overall,
submersing the entire propulsion system in either of these
arrangements offers the benefits of better sound isolation, lower
foil lift requirements, and greater inherent stability.
[0106] FIGS. 17-19 illustrate an alternative preferred
configuration of the personal water craft 500 of the present
invention. The principal difference between this embodiment and the
embodiment illustrated in FIGS. 1-3 is the construction of the
strut subassembly 506. In this embodiment, the craft still has a
forward propulsor housing 532, a control housing 528, control
column 524, handlebar 526, rear operator platform 510 and rear foil
assembly 502, including main foil 520.
[0107] Strut subassembly 506 in this embodiment comprises a pair of
laterally spaced struts 508L, 508R (FIGS. 18, 19) that connect the
propulsor subassembly 104 to the foil subassembly 102. Each of
struts 508L and 508R is made up of strut sections, a forward
section 550L,R which connects to the control housing 528, and
branches to the left or right, respectively, a middle longitudinal
section 552L,R, connected to and extending from the forward
sections to rear sections 554L,R. Rear sections 554L,R connect to
the rearward end of middle sections 552L,R, and to the underside of
operator platform 510, at the point where foil struts 518 connect.
Auxiliary foil struts 522 also connect to the rearward end of
middle sections 552L,R, and to a lower end of foil struts 518.
[0108] The craft of the present invention is on the order of ten
(10) feet in overall length, and the height from the main foil 120
to the operator platform 110 may be on the order of about 30 inches
or less. The span of the main foil 120 is preferably 48 inches or
less, with the operator platform preferably being several inches
less in span than the main foil. The craft thus is of a manageable
size for a single user, and can readily be trailered in a manner
similar to the current trailering of the hulled personal water
craft now on the market.
[0109] FIGS. 20 and 21 illustrate a further preferred embodiment of
the propulsion subassembly of the present invention. FIG. 22 is a
front elevation view of certain internal components of the
propulsion subassembly.
[0110] This propulsor subassembly 600 includes a control housing or
strut 602 and a propulsor housing or gear housing 604 which is
positioned below the control housing. Control housing or strut 602
is secured to the forward end of the craft (not shown in FIGS. 20,
21) and depends downwardly therefrom.
[0111] Extending through control housing 602 is a drive shaft 606,
coupled at its upper end to an output of a motor. Drive shaft 606
is operatively coupled to ducted propulsor 608 by a bevel gear pair
609, which comprises drive gear 610 and driven gear 612. Drive
shaft 606 may include a universal joint or a flexible coupling
(shown schematically in FIG. 22 at reference numeral 611)
connecting it to bevel gear 610, so that the drive shaft can
continue to drive the gear pair when the propulsor housing is
rocked or pitched, relative to the drive shaft. The driven gear 612
of the gear pair is connected to the propulsor 608 by a driven gear
shaft 614, which is connected to driven gear 612 and extends from
the interior to the exterior of propulsor housing 604.
[0112] The propulsor housing or gear housing 604 is coupled to the
control housing or strut 602 by means of a control disc 620
captured in a channel 622 of a bracket 624, the bracket being
secured to an upper inner wall of the propulsor or gear housing
604. Control disc 620 is circular (actually, a short cylinder), and
has a pair of spaced fork members 626 extending perpendicularly
upwardly from an upper surface 628 of the disc. The fork members
626 are connected by pins 630 to the control housing 602, which
allows the fork members to pivot relative to the control housing,
thereby pivotably securing the propulsor or gear housing 604
thereto.
[0113] A rocking control cable 632, illustrated as a sleeved
control cable, is connected to the control disc 620 at a point to
the aft of the fork members 626. The rocking control cable can be
operated by push/pull control rods or arms (not shown), and can
move the propulsor or gear housing from a normal, non-rotated axial
orientation (FIG. 20) to a rotated orientation (FIG. 21), by
pulling upwardly on the rear of the control disc 620. The control
disc 620, in turn, rotates bracket 624 in which it is captured,
thereby rotating the propulsor or gear housing 604 and propulsor
608. It is expected that it will be undesirable to allow the
propulsor housing to be rocked or rotated in the opposite
direction, i.e., with the propulsor 608 oriented to provide upward
thrust, and, in that case, a stop element 634 may be mounted to the
inner wall of control housing 602 as schematically illustrated in
FIGS. 20 and 21, with the stop 634 preventing the fork members 626
from moving rearwardly past the upright or vertical
orientation.
[0114] This propulsor subassembly also provides for steering
control, by providing a tang or flange 636 projecting upwardly from
the upper surface 628 of the control disc 620. A steering control
cable 638 may preferably be attached to tang 636, and, when the
cable is manipulated by the rider, the tang is pushed or pulled,
thereby causing the control disc 620 and propulsor or gear housing
604 to rotate from side to side.
[0115] The controls for the rocking and steering of the propulsor
or gear housing need not be sleeved cables of the push/pull type,
but instead may comprise hydraulic controls or other suitable
control means.
[0116] FIGS. 23 and 24 are front and side views, respectively, of
an operator platform in accordance with an alternative preferred
embodiment of the present invention. In this embodiment, platform
110 is equipped with a saddle-type seat 300, made up of two side
panels 302 and an upper, contoured seat panel 304. In this
embodiment, an operator would have the option of standing,
crouching, or being seated while operating the craft.
[0117] The saddle-type seat in the illustrated embodiment has a
channel 306 extending therethrough to permit water to pass through
when the platform 110 is not completely elevated out of the
water.
[0118] FIGS. 25 and 26 are front and side views, respectively, of
an operator platform in accordance with another alternative
preferred embodiment of the present invention. In this embodiment,
platform 110 is equipped with a bicycle seat 310 elevated above
platform 110 and supported by seat strut 312. Both the saddle-type
seat and the bicycle seat configurations are perceived as being
desirable primarily as a function of customer preference, and the
addition of either seat to the operator platform is not seen as
having any dramatic impact on the operation of the craft.
[0119] FIGS. 27-29 are side, top and rear views of a further
preferred embodiment of the craft of the present invention. In this
embodiment, the operator platform 410 is not entirely substantially
planar, but rather has two wing sections 412, 414, and a raised
central saddle section 416.
[0120] As can be seen by comparing this embodiment to the FIG. 23
embodiment, which adds a saddle seat to the planar operator
platform 110, the embodiment shown in FIGS. 27-29 simply forms the
footing elements (wing sections 412, 414) integrally with the
saddle portion (saddle section 416). In making this a unitary
component, it can be seen, in FIG. 29, that a central planar
portion of the operator platform 110 may be omitted, and the
operator platform 410 may be secured to strut 108 by one more
platform struts 418 (two shown).
[0121] It can be seen in FIG. 28 that the operator platform 410 is
provided with several areas of non-skid surfaces, including footing
surfaces 420, seating surface 422, and crouching surfaces 424. The
crouching surfaces are positioned to engage the inside of the knee,
thigh and/or calf, of the rider. The non-skid surfaces provide
traction and increased stability for the rider, in the available
operating positions, which primarily include standing, sitting and
crouching/kneeling. A saddle-type operator platform will allow the
rider to closely conform his or her body to the operator platform
(see FIG. 27), thereby streamlining the body and reducing drag
during the takeoff sequence.
[0122] As noted previously, the operator platform of the present
invention preferably has an aspect ratio of at least about 1/2, and
more preferably at least about one (1). In measuring the aspect
ratio of platform 110, for example, the overall dimensions of the
platform would be used in determining the aspect ratio. For a
nonuniformly shaped platform, such as platform 410, the aspect
ratio of either the entire platform 410, or of the wing sections
412, 414, should be at least about 1/2.
[0123] It is to be understood that the foregoing description of the
preferred embodiments of the present invention is for illustrative
purposes, and many variations or modifications may become apparent,
upon reading this disclosure, to those of ordinary skill in the
art. In particular, while the strut assembly, the operator
platform, the main foil assembly, the control subassembly and the
propulsion subassembly have been described as separate units that
are joined together, it is envisioned that any two or more of these
subassemblies or components, and even the entire craft, may be
formed as an integral or unitary assembly. Such embodiments are
regarded as being within the spirit and scope of the present
invention. Those and other such variations and modifications are
intended to fall within the spirit and scope of the present
invention, and the scope of the invention is to be determined by
reference to the appended claims.
* * * * *