Water sports airfoil

A water sports device adapted for carrying a rider airborne completely above the surface of the water upon being towed by a tow device. The water sports device comprises an elongated airfoil having a top portion and a bottom portion substantially opposite the top portion, the top portion being adapted for supporting the rider thereon. At least one tow connector is attached to the elongated airfoil, and the elongated airfoil is of a shape which causes it to receive an upward lift reaction from an airstream moving relative thereto upon being towed by the tow device. An elongated spar is provided within the airfoil to which the tow connector is attached. The interior support of the airfoil is, in one embodiment, polystyrene, such as Styrofoam.RTM. and the exterior surface is fiberglass. Alternate embodiments include the provision of pontoons under the elongated airfoil, and the attaching of at least one operable aileron, rudder, and/or at least one downwardly extending fin to the elongated airfoil.

BACKGROUND OF THE INVENTION 
This invention relates generally to a water sports device having an airfoil 
on which the user rides as he or she is towed by a tow device such as a 
boat. 
Water sports devices such as water skis, para-sails, kneeboards, jet skis, 
etc., enjoy continued popularity with water sports enthusiasts. Devices 
such as motorboats and jet skis carry their own propulsion means, while 
products such as water skis, knee boards, para-sails, etc., rely on a boat 
or some other towing device during use. These towed devices are typically 
of relatively simple design and allow the skier or rider to enjoy freedom 
in moving about the water while being towed. In the instance of a 
para-sail, the rider is actually pulled at a speed sufficient to give the 
para-sail enough lift to raise the rider out of the water. 
While the para-sail allows the rider to leave the water and become 
airborne, maneuverability of the para-sail, once airborne, may not be as 
rapid or extensive as desired. Further, the para-sail is inherently 
somewhat cumbersome in its handling and use, due to the size and 
characteristics of the sail itself and its accompanying lines, ropes, 
and/or cords. 
Accordingly, it will be desirable to have a relatively simple device which 
would allow the rider to become airborne and to enjoy a more rapid 
response to maneuvering inputs by the rider. 
Water sports devices have been patented on which a rider is carried and 
which is towed by a towing device such as a motorboat. For example, U.S. 
Pat. No. 3,105,249, issued to Palmore, discloses a hydrofoil apparatus for 
being drawn through the surface of the water and which includes a seat and 
handlebars for the rider. U.S. Pat. No. 2,815,518, issued to Kuehn, 
discloses a water vehicle having hydrofoils and a portion for supporting a 
rider, together with a steering system. 
U.S. Pat. No. 3,320,625, issued to Schlueter, discloses a winged surfboard 
having a wing and stabilizers. 
Italian Patent Document Nos. 592,466 and 618,588 disclose hydro-wing 
devices having winged portions which are pulled through the water. U.S. 
Pat. No. 3,604,031, issued to Cahail discloses a hydrofoil board having a 
seat portion connected to inclined foils which glide through the water. 
SUMMARY OF THE INVENTION 
It is, therefore, the principal object of this invention to provide a water 
sports device capable of being towed by a tow device and carrying a rider. 
Another object of the present invention is to provide a water sports device 
for carrying a rider above the surface of the water. 
Yet another object of the present invention is to provide a water sports 
device capable of being steered in the water by the rider. 
Still another object of the present invention is to provide a water sports 
device having flight control surfaces capable of controlling flight of the 
device above the surface of the water. 
A further object of the present invention is to provide a water sports 
device on which the rider can stand, kneel, sit or lie prone during use. 
A still further object of the present invention is to provide a method of 
causing a rider of a water sports device to become airborne. 
Generally, the present invention includes a water sports device adapted for 
carrying a rider and for being towed by a tow device. The water sports 
device comprises an elongated wing, or airfoil, having a top portion and a 
bottom portion substantially opposite the top portion, the top portion 
being adapted for supporting the rider thereon. At least one tow connector 
is attached to the elongated airfoil, and the elongated airfoil is of a 
shape which causes it to receive an upward lift reaction from an air 
stream moving relative thereto upon being towed by the tow device. 
More specifically, the present invention also includes an elongated spar 
within the airfoil to which the tow connector is attached. The interior 
support of the airfoil is, in one embodiment, polystyrene, such as 
Styrofoam.RTM. and the exterior surface is fiberglass. 
Additionally, other embodiments of the present invention include the 
provision of at least one pontoon under the elongated airfoil, and 
attaching at least one operable aileron, rudder, and/or at least one 
downwardly extending fin to the elongated airfoil. 
The airfoil of the present invention also includes a portion on which the 
rider may sit, kneel, or stand, as well as at least one handle for the 
rider to hold onto during use. Once the rider is onboard the airfoil, and 
the airfoil connected to a tow device such as a motorboat, tow cable from 
a wench, land-based vehicle, etc., and towing is begun, the airfoil will 
experience lift forces. Because the airfoil is of a cross-sectional 
aerodynamic profile, aerodynamic forces cause a lift force to be applied 
to the bottom of the wing, causing it to become airborne upon an 
appropriate tow speed being achieved. The user can influence when 
"takeoff" of the airfoil occurs, by shifting his or her body weight to 
increase the angle of attack of the airfoil. Likewise, the user may, by 
shifting his or her body weight, lessen the angle of attack to cause the 
airfoil to dive or, perhaps, stay in the water and not become airborne at 
all. 
Once airborne, the user, again, by shifting his or her body weight, can 
cause the airfoil to bank from side to side, turn, climb, dive, and 
perhaps, even roll. 
In one embodiment, at least one operable aileron is provided which can be 
actuated by the user to further enhance flight control of the airfoil. 
Additional flight control surfaces, such as flaps, elevators, etc., could 
also be provided, as well as a V-shaped wing profile instead of the 
longitudinally, relatively straight, profile illustrated herein. 
Furthermore, the airfoil of the present invention could include at least 
one downwardly extending stabilizer fin for enhancing control of the 
airfoil while both in the water and in flight, and additionally, at least 
one rudder could be provided which could be operated by the rider to 
enhance control of the airfoil while it is both waterborne and airborne. 
Moreover, at least one transversely mounted pontoon could be provided on 
the airfoil which would cause the airfoil to sit up higher, or perhaps 
completely out of, the surface of the water in order to enhance airflow 
beneath the wing, and, accordingly, lift of the airfoil while being towed 
by the tow device.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The accompanying drawings and the description which follows set forth this 
invention in its preferred embodiment. However, it is contemplated that 
persons generally familiar with water sports devices and airfoils will be 
able to apply the novel characteristics of the structures illustrated and 
described herein in other contexts by modification of certain details. 
Accordingly, the drawings and description are not to be taken as 
restrictive on the scope of this invention, but are to be understood as 
broad and general teachings. 
Referring now to the drawings in detail, wherein like reference characters 
represent like elements or features throughout the various views, the 
water sports device of the present invention is indicated generally in the 
figures by reference character 10. 
Turning to FIG. 1, airfoil 10 is illustrated having a rider R standing 
thereon. Airfoil 10 is connected to a tow device, generally T, by tow 
ropes, or lines, generally L. Tow device T is illustrated as being a 
motorboat 12 having an upwardly extending tow bar 14, having a tow ring, 
generally 16 connected thereto. In the FIG. 1 illustration, airfoil 10 is 
being towed by towboat 12 at a speed sufficient for it to become airborne 
above the height of the surface of the water, generally W. 
In the embodiment of the present invention shown in FIG. 1, tow connectors, 
generally 18, are provided on airfoil 10, and can include eyebolts 20 
having ringed portions 22 to which tow lines L are connected. 
Extending substantially the length of airfoil 10 is an elongated spar 24. 
In one preferred embodiment, spar 24 is a polyvinyl chloride (PVC) pipe to 
which threaded ends of eyebolts 20 are received, with bolts 26 retaining 
eyebolts to spar 24. 
Encircling spar 24 is the airfoil support structure, generally S. Support 
structure S, in the preferred embodiment, is polystyrene, commonly known 
as Styrofoam.RTM.. Support structure S forms the basic aerodynamic profile 
of airfoil 10 and is preferably covered along its surfaces with a 
fiberglass skin 28. However, other materials, such as fabric, neoprene, 
plastic and/or rubber or vinyl coatings could also be used if desired. 
Further, support structure S, if constructed of a rigid material such as 
polystyrene, could be used without any skin 28 at all, if desired. 
It is to be noted that support structure S, although preferably constructed 
of a buoyant material such as polystyrene, could also be air, if airfoil 
10 was made of airtight construction, such as blow molded plastic. 
Further, airfoil 10 could be constructed of vinyl, plastic, rubber, or 
some other material such that it could be inflated for use, and then 
deflated for transport and/or storage. 
Connected to airfoil 10 are attachment rings 30 to which handle ropes, 
generally 32, are attached. Handle ropes 32 are also provided with 
handles, generally 34, which are grasped by the rider R during use. 
Although handles 34 have been shown as being connected to airfoil 10 by 
ropes 32, it is to be understood that handles 34 could be of a variety of 
configurations, and could be flexibly or rigidly attached to airfoil 10 by 
other means such as by plastic piping, plastic coated cables, etc. 
Airfoil 10 defines a platform, generally P, on which rider R is shown 
standing in FIG. 1. Rider R could also sit, kneel, or even lie down on 
platform P during use, if desired. 
An alternate embodiment of the present invention is illustrated in FIG. 2. 
In the FIG. 2 embodiment, lines L are not fixedly tied to tow connectors 
18, but are instead allowed to freely pass therethrough. Rider R, through 
grasping of handles 34, and through his or her attachment to platform P of 
airfoil 10 by a releasable strap 40, effectively connects airfoil 10 to 
the tow device. Strap 40 could include a hook and fastener system, such as 
Velcro.RTM., or could use snaps, buckles, clips or the like in order to 
fasten airfoil 10 to Rider R. 
Also provided on airfoil 10 is at least one pontoon, two pontoons, 42, 44 
being illustrated in the FIG. 2 embodiment. Pontoons 42, 44 are connected 
to the underside of airfoil 10 by pylons 46, 48, respectively. Pontoons 
42, 44 pylons 46, 48 could be material such as polystyrene, fiberglass, 
rigid plastic, aluminum, etc. or some other suitable material. 
Pontoons 42, 44 can be used to raise airfoil 10 such that airfoil 10 is 
only partially, or entirely spaced above the surface of the water W. This 
allows a greater airflow beneath airfoil 10, once airfoil 10 is towed. By 
allowing a greater airflow under airfoil 10, airfoil 10 should experience 
lifting forces at lower tow speeds than perhaps would be expected without 
pylons 42, 44. Pylons 42, 44 could be configured such that they stayed 
with airfoil 10 during flight, or pylons 42, 44 could be configured such 
that they can be jettisoned from airfoil 10, when airfoil 10 becomes 
airborne, or when otherwise desired. 
In the FIG. 2 embodiment, rider R will actually experience the towing force 
from the towing device T, since lines L are not secured to tow connectors 
18, but are instead held by the rider R. However, rider R will also be 
able to manipulate lines 52 independently of one another, if desired, to 
in effect turn air foil 10, or otherwise maneuver it during flight. Rider 
R could also extend his arms forward, while leaning back and holding lines 
50, 52, and perhaps increase the angle of attack of airfoil 10 by raising 
the leading edge 54 thereof with respect to trailing edge 56. Rider R 
could also do the reverse, in order to lower leading edge 54 of airfoil 10 
if he desired to cause airfoil 10 to enter a dive. 
FIG. 3 illustrates a further embodiment of the airfoil of the present 
invention, and is designated generally as 10A. Airfoil 10A includes at 
least one downwardly extending stabilizer fin, generally F, and in FIG. 3, 
two stabilizer fins 58, 60 are shown, each of fins 58, 60 extending 
downwardly from a respective end 62, 64 of airfoil 10A. Elongated slots 66 
are provided within each fin F to allow for adjustment of the length by 
which the end 68 of a fin 58, 60 extends below airfoil 10A. Enlarged head 
pins or screws 70 are provided in the ends 62, 64 of airfoil 10A for 
receipt in slots 66 of fins 58, 60 and allow for the fixing of a fin in 
the desired position after adjustment. 
Airfoil 10A also includes at least one operable aileron, generally A. In 
the FIG. 3 embodiment, ailerons 72, 74 are illustrated adjacent trailing 
edge 56A of airfoil 10A. Ailerons 72, 74 can be connected by ropes or 
cords 76, 78, which pass downwardly through holes 80 through airfoil 10A, 
and then upwardly through holes 82 and extend outwardly therefrom. During 
use, rider R could pull up on cords 76, 78 simultaneously, or 
independently of one another, to operate ailerons 72, 74. Further, 
spoilers 84, 86 are provided on forward portions of airfoil 10A and are 
similarly operable by cords 88, 90 to further enhance the maneuverability 
of airfoil 10A during use. 
Turning to FIG. 4, a further embodiment of the present invention is shown. 
This embodiment, illustrated generally by reference numeral 10B, includes 
at least one rudder generally 92 to allow for steerage of airfoil 10B 
while in the water and in flight. In FIG. 4, airfoil 10B is shown having 
two rudders, 94, 96. The rudder system in FIG. 4 is shown in simplified 
form, and includes idler arms 98, 100 being fixedly connected to the 
respective upper ends 102, 104 of rudders 94, 96, respectively. Tie rods 
106, 108 are connected to idler arms 98, 100, respectively, such that 
movement of tie rods 106, 108 causes respective movement of idler arms 98, 
100, and in turn, rudders 94, 96, respectively. An arm, such as a pitman 
arm 110, is connected to both tie rods 106, 108, and a crank arm 112 is 
connected to pitman arm 110, with an upstanding handle 114 connected to 
pitman arm 112. Handle 114 is moveable in the direction shown by arrows a 
and b in order to cause corresponding pivoting of rudders 94, 96. Thus, 
the rider can cause airfoil 10B to be steered to the left and to the right 
while being towed in the water, and also while airborne. 
FIGS. 5A and B are sectional views of variations of airfoil 10, the 
difference between the views being the thickness of airfoil 10. The 
thickness t.sub.1 of the airfoil in FIG. 5A being less than the thickness 
t.sub.2 of the airfoil profile illustrated in FIG. 5B. It should be noted 
that the profile of the airfoil of the present invention could be any 
number of a varieties of known aerodynamic profiles. For example, the 
chord length CL of the airfoils of the present invention could be between 
3 and 4 feet and the length of the airfoils AL (FIG. 4) is preferably 
between 8 and 12 feet, although both the dimensions of the CL and the AL 
could be greater than or less than these lengths, depending on the 
application desired, the desired aerodynamic effects, costs, age and/or 
weight of the rider, the level of skill of the rider, etc. 
In one preferred embodiment, the maximum airfoil thickness is between 6% 
and 18% of the length of CL at a distance of between 20% to 40% of the 
length of CL aft of leading edge 54. Further, in general and to a limit, 
the more blunt leading edge 54 is, and the thickness of the airfoil, the 
greater lift, but also, correspondingly, the greater the drag. Conversely, 
a thinner profile would typically yield less drag, but also, accordingly, 
less lift. 
From the foregoing, it can be seen that the present invention includes a 
water sports airfoil capable of a variety of configurations and 
variations. The airfoil could be of very simple, basic construction, such 
as shown in FIG. 1, or could be much more elaborate and could include in a 
single embodiment, the pontoons, rudders, ailerons, spoilers, and fins, if 
desired, or, the present airfoil could have any combination of those 
features, if desired. 
While preferred embodiments of the invention have been described using 
specific terms, such description is for present illustrative purposes 
only, and it is to be understood that changes and variations to such 
embodiments, including but not limited to the substitution of equivalent 
features or parts, and the reversal of various features thereof, may be 
practiced by those of ordinary skill in the art without departing from the 
spirit or scope of the following claims.