Aquatic wheelchair

An aquatic wheelchair having a main flotation body of thermoplastic material of closed cell construction including a seat portion and an integral backrest portion. Flotation paddle wheels are connected to the seat portion and a flotation stabilizer wheel assembly is detachably connected to the backrest portion. The flotation paddle wheels are constructed and arranged to facilitate the grasping thereof by the user for manually propelling the wheelchair not only on soft terrain but also in water.

BACKGROUND OF THE INVENTION 
Many victims of injury to the brain or spinal cord are left paralyzed and 
in need of care so that they can continue to live active and productive 
lives. It was reported in 1988, that the National Institute on Disability 
and Rehabilitation Research estimated that in the United States alone, 
there were 300,000 wheelchair-bound paraplegics and quadriplegics; many of 
whom keep physically active by playing various sports; such as, tennis and 
basketball, while in their wheelchairs. 
In order that wheelchair-bound persons may expand their activity to aquatic 
recreation and aquatic sports, such as, water polo, after considerable 
research and experimentation, the aquatic wheelchair of the present 
invention has been devised which comprises, essentially, a main flotation 
body having a seat portion and a backrest portion, flotation paddle wheels 
are mounted on the seat portion on each side thereof, and a flotation 
stabilizer wheel is detachably connected to the backrest portion. The 
flotation paddle wheels are constructed and arranged to facilitate the 
convenient grasping of the top portions of the paddle portions of the 
paddle wheels by the user when seated for manually propelling the 
wheelchair not only on soft terrain, such as a sandy beach or grass areas, 
but also in water, such as a pool, lake, bay or ocean.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the drawings and more particularly to FIGS. 1 and 2, the 
aquatic wheelchair of the present invention comprises a main flotation 
body 1 having a seat portion 2 and an integral backrest portion 3. 
Flotation paddle wheels 4 are connected to the seat portion 2 on each side 
thereof, and a flotation stabilizer wheel assembly 5 is detachably 
connected to the backrest portion 3. The seat 2 and backrest 3 are formed 
of lightweight polystyrene or other suitable thermoplastic material of 
closed cell construction, and as will be seen in FIGS. 2 and 3, they are 
each curved or formed with a concave configuration to enhance the comfort 
of the occupant. 
Referring to FIG. 5, it will be seen that the paddle wheels 4 are rotatably 
mounted on a tubular axle 6 extending transversely of the seat and 
extending through depending hangers 2a integrally formed with the seat. 
The axle 6 is provided with suitable washers 7 positioned and secured on 
each side of the hangers 2a to reinforce the same and secure the axle 6 
thereto, and the outer washers act as spacers for the paddle wheels. The 
axle 6 is hollow with sealed ends and is therefore buoyant, and a washer 
and bolt assembly 8 on each end thereof maintains the paddle wheels 4 on 
the axle 6. 
The details of the construction of the paddle wheels 4 which are molded of 
plastics material are illustrated in FIGS. 5 and 6. Each paddle wheel 
comprises an inner hub portion 4a surrounding the axle 6 and forming the 
bearing for the wheel. An outer hub portion 4b is spaced radially 
outwardly from the hub portion 4a, and the inner and outer hub portions 4a 
and 4b are connected by end walls 4c, to thereby form an annular flotation 
chamber 4d. A plurality of circumferentially spaced, radially extending 
spokes 4e are formed integral with the outer hub portion 4b, the spokes 
being hollow with their outer ends being closed as at 4f and their sides 
being closed by end walls 4g. The inner ends of the spokes 4e communicate 
with the annular flotation chamber 4d, as at 4h, whereby the flotation of 
the wheel is enhanced. In order to reinforce the spokes 4e and to provide 
ground engaging surfaces in addition to those shown at 4f to facilitate 
propelling the wheelchair on terrain, incl. soft terrain, the outer ends 
of the spokes 4e are interconnected by a pair of laterally spaced tubular 
rings 4i. Experimentation has shown, for example, and not by way of 
limitation, that an efficiently operating paddle wheel providing the 
proper amount of buoyancy and thrust, can have a diameter of approximately 
two feet, a width of approximately eight inches, with the width of each of 
the ground engaging surfaces of the pair of laterally spaced tubular rings 
4i being approximately two inches. The diameter of the annular flotation 
chamber 4d in such a paddle wheel is approximately thirteen inches. It is 
preferred that each paddle wheel, for example, has eight spokes. With a 
wheel having the dimensions given by way of example, each paddle wheel 
will have approximately 304 square inches of thrusting surface. By way of 
comparison, a large canoe paddle has approximately 105 square inches of 
thrusting surface. The two paddle wheels will have more thrusting surface 
than six canoe paddles, so that the occupant of the chair can propel 
himself or herself forwardly in the water with ease. 
Referring to FIG. 1, it will be noted that the construction and arrangement 
of the paddle wheels 4 relative to the seat portion 2 and backrest portion 
3 are such that the wheels 4 are mounted forwardly of the seat and 
backrest portions, for example, by approximately sixteen inches, to 
thereby position them for ease of grasping by the occupant of the chair, 
and by determining the center of gravity, so that the main flotation body 
1 will remain in a stabilized position while in the water, the seat 
portion 2 is inclined upwardly in a direction from the back of the chair 
toward the front. With the paddle wheels positioned in this manner, the 
tops of the wheels can become armrests for the occupant when the chair is 
at rest. The tops of the wheels are at the proper height, so that for 
propelling the chair forwardly, when floating in the water, the occupant 
grasps the closed outer ends 4f, that is the top portions, of the spokes 
4e with the hands, with the heel portion of the palms bearing against one 
surface of the spokes and the fingers extending around the closed ends 4f, 
and by pushing forwardly with the arms the paddle wheels are rotated 
toward the front of the chair. An occupant who has use of his arms, but 
not of his fingers, can also propel the chair forwardly, and maneuver the 
chair in the water, such as by rotating only one wheel for turning the 
chair. 
In order that the wheelchair will be stabilized while being propelled on 
the ground, the stabilizer flotation wheel assembly 5 is provided, the 
details of which are illustrated in FIGS. 1, 4 and 7. The wheel assembly 5 
comprises, a leg or pedestal 5a having a hollow balloon-type wheel 5b 
rotatably mounted on its lower end. The pedestal 5a, preferably formed 
from thermoplastic material of closed cell construction, is centered on 
the longitudinal axis of the seat portion 2 and extends upwardly through 
an opening 2b provided in the rear of the seat portion 2, and into a 
communicating passage 3b provided in a curved backrest flotation extension 
3a connected to the rear of the backrest 3 and the seat portion 2 behind 
the backrest 3 to provide additional flotation. The backrest flotation 
extension 3a is also formed from thermoplastic material of closed cell 
construction. The upper end of the pedestal 5a is terminated by a tongue 
5c which is slidably mounted in a groove 3c provided in the back wall of 
the backrest 3. The tongue connector 5 c and groove 3c may be 
correspondingly tapered to removably retain pedestal 5a in connection with 
the backrest 3. As an alternative, a removable pin, not shown, can be used 
to removably retain the wheel assembly 5 on the chair. The removable pin, 
for example, could extend through the rear edge of seat portion 2, into 
the opening 2b, and into the pedestal 5a. By this construction and 
arrangement, the wheel assembly 5 can be detachably connected to the main 
flotation body for purposes of storage or transportation. 
While the embodiment of the wheelchair as shown in FIGS. 1 to 6 employs a 
hollow, tubular axle 6 which enhances the overall flotation 
characteristics of the aquatic wheelchair, FIG. 8 illustrates another 
embodiment of an axle assembly wherein the paddle wheels 4 are rotatably 
mounted on stub shafts 9 secured to the hangers 2a. To maintain the 
lateral stability of the chair, a plastic coated multi-strand tension 
cable 10 of steel or the like is provided. The end portions of the cable 
extend through a pair of apertured end caps 11 threadably mounted on the 
receptive threaded end 12 of the stub shaft 9, the ends of the cable 10 
being enlarged as at 10a to prevent their removal from the apertured caps. 
By reducing the dimensions of the axle assembly, the flow resistance of 
the chair while being propelled in water is also reduced. Additional 
tensioning of the cable is provided by threading end caps 11 further onto 
the threaded ends 12 of the stub shafts. 
From the above description it will be readily apparent that the aquatic 
wheelchair of the present invention provides an improved aquatic vehicle, 
whereby wheelchair bound persons may expand their activity to aquatic 
sports and aquatic recreation, incl. fishing. The flotation of the 
wheelchair is enhanced by the lightweight buoyant material of the main 
flotation body 1, including seat portion 2, backrest 3 and backrest 
flotation extension 3a; and the pedestal 5a, together with the hollow 
stabilizer wheel 5b and the various hollow portions of the paddle wheels 
4. 
The terms and expressions which have been employed herein are used as terms 
of description and not of limitation, and there is no intention in the use 
of such terms and expressions, of excluding any equivalents of the 
features shown and described, or portions thereof, but it is recognized 
that various modifications are possible within the scope of the invention 
claimed.