Note: Descriptions are shown in the official language in which they were submitted.
CA 02266916 1999-03-24
-1-
INFLATABLE WATERCRAFT
BACKGROiJND OF THE INVENTION
This invention relates to a powered inflatable
watercraft, particularly for fishing.
Inflatable watercraft are popular among fishermen and
water enthusiasts as such watercraft are readily
transportable, light weight and relatively inexpensive.
Generally, such an inflatable watercraft comprises a
sleeve-like skin enclosing an air bladder which is
inflatable and deflatable. While these types of inflatable
watercraft are commonly circular in shape, they can also be
U-shaped or have interconnected straight parallel pontoon
configurations. Typically an operator manually powers such
a watercraft by kicking his legs, which is both slow and
tiring to the operator. To overcome this problem,
inflatable watercraft with powered drive units have been
developed.
United States Patent No. 4,938,722 issued to Rizley
discloses a fisherman's float propelling system. The
system includes a toric fishing float, a non-buoyant fabric
sling seat attached to the fishing float for supporting an
operator, a propulsion means attached to a leg of the
operator, and a battery for powering the propulsion means
supported by an auxiliary float. When the system is in
water, the operator sits on the fabric sling seat which
sags below the fishing float, thereby increasing the drag
on the watercraft. While seated, the operator's lower body
is submersed in the water and in order for the operator to
stay dry, he would have to wear watertight clothing.
Further, if the water temperature was cold, the operator
would have to wear insulated clothing to remain at a
comfortable temperature.
CA 02266916 1999-03-24
-2-
The propulsion means disclosed by Rizley is a trolling
motor having a propeller which is surrounded by a guard,
and forces generated by the propeller are resisted by the
operator's leg, which can be tiring. Also, if the guard
becomes detached from the propulsion means, the operator is
likely to be injured because the propeller would be exposed
directly to the operator's legs. When transporting the
system, the operator would need to deflate two separate
floats and take great care in disconnecting the floats and
the propulsion means.
United States Patent No. 4,911,094 issued to Akers
discloses a powered floater. The floater includes a
buoyant member, a non-buoyant webbed seat attached to the
buoyant member for supporting an operator, and a separate
float tube having a battery and an electric motor for
turning a propeller. The operator of the floater would
have his lower body submersed in the water, which leads to
the same problems as discussed in the Rizley patent above.
Further, as the buoyant member and float tube are separate,
the operator would need to spend time and effort deflating
and disconnecting the member and tube for transportation
purposes.
United States Patent No. 4,021,873 issued to Francois
discloses a circular watercraft. Francois addresses the
problems encountered by Akers and Rizley due to the
operator's lower body being submersed in water. In
Francois the watercraft includes a buoyant hull supporting
a rigid deck having an opening to receive a power means to
drive and steer the watercraft. The deck could include a
seat to support the operator or the operator could stand or
sit directly on the rigid deck. However Francois also
discloses a stabilizer assembly to lend horizontal and
vertical stability to the watercraft, which makes the
watercraft difficult to disassemble and transport.
CA 02266916 1999-03-24
-3-
The problems encountered by Akers and Rizley due to
the operator's lower body being submersed in water is also
addressed by United States Patent No. 5,643,031 issued to
Fenton et al. Fenton discloses an aquatic vehicle which
includes an egg-like configured support frame, a cover
attached to the perimeter of the frame and enclosing a
buoyant float, and a non-buoyant seat attached to the
support frame. In the water, an operator is supported by
the seat. Depending on the weight of the operator, the
support frame can be adjusted relative to the cover so that
the seat can be positioned above the water. However, the
position of the support frame relative to the cover can not
be adjusted once the operator is sitting on the seat and
this may cause difficulties in making the correct
adjustment for the person's weight. Further, Fenton does
not disclose a drive unit for powering the vehicle.
United States Patent No. 5,601,461 issued to Mills
discloses a float tube propulsion apparatus which can be
releasably connected to a float tube. An operator must
spend time and effort connecting the apparatus and the
float tube before using the apparatus. Further the
operator must spend time and effort disconnecting the
apparatus and the float tube so that the operator can
efficiently transport and store the apparatus and the float
tube.
A common problem with inflatable watercraft relates to
controlling inflation pressure within air chambers of the
watercraft due to temperature variations or possible slow
leakage of air due to porosity or small openings in the
walls of the air chamber. In hot weather, bodies of water
are normally much colder than air temperature and thus a
watercraft that has been inflated on the shore to a
suitable pressure is chilled by cold water and the pressure
in the chambers is reduced, losing rigidity and floatation.
In these circumstances, with extreme pressure loss, the
CA 02266916 1999-03-24
-4-
person is forced to return to shore to apply additional
pressure. Also, it is not unusual for a watercraft to be
accidentally punctured during use, and this also can cause
deflation of the vessel, forcing the operator to return to
shore.
What would be desirable therefore is a powered
inflatable watercraft which does not require an operator's
lower body to be submersed in water during operation, does
not require assembly before use, does not require
disassembly before transportation and storage, and is not
hazardous to the operator's legs. Also, it would be
advantageous to reduce drag by providing a seat with
adequate floatation and support to prevent the operator's
lower torso from projecting into the water. In addition,
it would be an advantage to be able to control inflation
pressure of air chambers of the watercraft when the
watercraft is remote from the shore and normal on-shore
inflation apparatus is not available to overcome pressure
loss due to cooling of air within the air chambers, which
disturbs rigidity and trim of the watercraft.
BRIEF SUNIIKARY OF THE INVENTION
The present invention addresses the above problems by
providing a simple, light weight powered inflatable
watercraft which does not require an operator's lower torso
to be submersed in water during operation, does not require
assembly before use, does not require disassembly before
transportation and storage, and is not hazardous to the
operator's legs. The invention has a separately inflatable
seat, which in combination with other structure, supports
the operator's lower torso to prevent excessive projection
into the water with a corresponding decrease in drag. In
addition, the present invention provides a means for
controlling inflation pressure of separate chambers of the
watercraft, thus enabling pressure to be increased within
CA 02266916 2008-04-07
-
particular chambers as required to compensate for
cooling, and also to permit accurate trim of the
watercraft.
5 In accordance with one aspect of the invention, there is
provided a watercraft comprising: a generally U-shaped
floatation member having two laterally spaced apart side
portions each having a forward end, a rearward end and a
top surface; and a front end portion extending between
said forward ends; a seat member disposed between said
side portions and said front end portion, said seat
member having a front seat surface adjacent the front
end portion and a generally unobstructed, transversely
extending rear seat surface disposed oppositely from
said front seat surface; a rigid hull member located
beneath said seat member and having a lower surface
bulging downwardly below said floatation member; and a
drive unit for propelling said watercraft secured
beneath said rigid hull member adjacent to a central
longitudinal axis of said rigid hull member and
generally adjacent a vertical axis passing through a
centre of gravity of the loaded watercraft.
Preferably, the seat member has a bottom seat surface
and two side seat surfaces, each being complementary to
and adjacent one of the side portions. The front seat
surface is complementary with the front end portion and
the rear seat surface is disposed forwardly of the
rearward ends of the floatation member.
CA 02266916 2008-04-07
- 5a -
Preferably, the rigid hull member has a forward edge
connected to the front end portion, and two side edges
each connected to one of the side portions.
Preferably, the drive unit includes an electric motor
and a propeller rotatable about a generally horizontal
axis. The drive unit further
CA 02266916 1999-03-24
-6-
includes a battery holder located on the floatation member,
a manual control unit located within reach of an operator,
and electrical conduits extending from the battery holder
to the control unit and from the control unit to the drive
unit to permit control of electrical power supplied to the
drive unit.
Preferably, the watercraft has a back support member
extending upwardly above the front end portion.
Preferably, the watercraft has an air compressor unit
having a discharge, and air conduits extending from the
discharge to each of the floatation member, seat member and
back support member. Each of the air conduits have a
respective control valve allowing the floatation member,
seat member and back support member to be independently
inflated and deflated. The watercraft also has electrical
conduits extending from the compressor to the control unit
to permit control of the compressor.
Preferably, the watercraft has two forwardly facing mirrors
located adjacent respective side portions of the floatation
member.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
In drawings which illustrate embodiments of the invention,
Figure 1 is a perspective view according to a first
embodiment of the invention;
Figure 2 is a top plan view according to the first
embodiment of the invention;
Figure 3 is a rear view according to the first embodiment
of the invention;
CA 02266916 1999-03-24
-7-
Figure 4 is a bottom view according to the first
embodiment of the invention;
Figure 5 is a side view according to the first embodiment
of the invention, shown with an operator, in
broken outline, sitting in the invention; and
Figure 6 is a longitudinal cross-section view taken along
line 6-6 of Figure 2.
DETAILED DESCRIPTION OF THE INVENTION
Referring to mainly to Figure 1, an apparatus according to
a first embodiment of the invention is shown generally at
10.
The apparatus 10 includes a generally U-shaped floatation
member 12 having two laterally spaced apart side portions
14 and 16 having respective forward ends 18 and 20,
rearward ends 22 and 24, and top surfaces 26 and 28. The
floatation member 12 also has a front end portion 30
extending between said forward ends 18 and 20. The
portions 14, 16 and 30 are generally coplanar, and have
generally circular cross-sections shown in Figures 3 and 6,
and typically are about 15 inches in diameter.
The apparatus 10 further includes a seat member 32 disposed
between said side portions 14 and 16 and said front end
portion 30. The seat member 32 has a curved front seat
surface 34, shown in Figure 6, which is complementary to
and located adjacent the front end portion 30. The seat
member 32 has two side seat surfaces 36 and 38, shown in
Figure 3, which are complementary to and adjacent
respective side portions 14 and 16. The seat member 32
also has a transversely extending rear seat surface 40
disposed oppositely from said front seat surface and
forwardly of said rearward ends 22 and 24. Further, the
CA 02266916 1999-03-24
-8-
seat member 32 has a seating surface 42 upon which an
operator sits and a bottom seat surface 44. The operator
faces rearwardly (see Figure 5), and the rear seat surface
40 is generally unobstructed to permit relatively easy
access for the operator. This contrasts with many prior
art watercraft where the operator's feet, sometimes wearing
swim fins, must pass through a narrow gap between a rear
edge of the seat and a rear portion of the watercraft. The
apparatus further includes a back support member 46 which
is complementary to and extends upwardly above the front
end portion 30.
The floatation member 12, the seat member 32 and the back
support member 46, have a respective floatation cover 100,
seat cover 102, and back support cover 104. The floatation
cover 100 has a bottom half 106 made of a heavy canvas
which can withstand abrasion caused by the watercraft
running up on a beach or the force of the watercraft
hitting a submerged obstacle in the water, and a top half
108 made of a heavy duty nylon. The seat cover 102 and the
back support cover 104 are also made of a heavy duty nylon.
Each of the covers 100, 102 and 104 enclose a respective
floatation bladder, seat bladder, and back support bladder
which are made of a flexible airtight material to provide
respective air chambers which are separately inflatable and
deflatable, as will be described.
The apparatus further includes a rigid hull member 47,
shown in Figure 4, which is made of a light weight yet
relatively stiff material, such as sheet metal, eg.
aluminum, or a plastic. The rigid hull member 47 has a
curved forward edge 48 connected to said front end portion
30 and two straight side edges 50 and 52, each side edge
being connected to one of said side portions 14 and 16
respectively. The three edges 48, 50 and 52 of the hull
member 47 are securely connected in a releasable manner to
the floatation member 12 to permit easy removal of the hull
CA 02266916 1999-03-24
-9-
member 47 for servicing. As seen in Figure 3, the rigid
hull member 47 also has two obliquely inclined planar side
surfaces 54 and 56, each sloping downwardly from the side
edges 50 and 52 respectively to merge into a generally
triangular planar centre surface 58. The centre surface 58
slopes downwardly and rearwardly about 2 - 3 degrees when
viewed transversely in Figure 6, and thus it can be seen
that the member 47 has a lower surface bulging downwardly
below the floatation member. The bottom seat surface 44 is
generally complementary to the shape of the hull member 47
to be supported thereon.
The apparatus 10 further includes a drive unit 60, shown in
Figure 6, extending downwardly from the hull member 47.
The drive unit 60 is connected adjacent to a central
longitudinal axis of the rigid hull 47. The drive unit has
a tubular strut 61 with a screw-threaded upper end 63 which
extends through an opening in the centre surface 58 and is
secured thereto by lower and upper nuts 65 and 69. When
the nuts 65 and 69 are tightened on the strut 61 to secure
the strut 61 rigidly to the rigid hull member 47, the strut
61 is disposed generally perpendicularly to the centre
surface 58 of the rigid hull member 47. The strut 61 also
has a lower end 67 connected to a motor housing 64
containing an electric motor which drives a conventional
propeller 62 about an axis which is also approximately 2 to
3 degrees inclined to the horizontal when the apparatus is
correctly trimmed due to the slope of the surface 58. The
drive unit 60 also has a cap-type marine fitting 59 which
is located at the upper end 63 of the strut 61 to permit
"breathing" of the housing as will be explained.
The apparatus further includes a manual control unit 66
located in a rigid container adjacent the top surface 26
near the rearward end 22. The apparatus further includes
a first set of electrical conduits 68 extending from the
control unit 66 to a battery holder 70 located in an
CA 02266916 1999-03-24
-10-
opening 72 at the top of the back support member 46. The
battery holder 70 is generally adjacent a central
longitudinal axis of the apparatus. There are also a
second set of electrical and air conduits 74 extending from
the control unit 66 to the marine fitting 59 and down the
strut 61 to the electric motor in the motor housing 64.
The air conduit is routed with the electrical conduit for
convenience, and communicates with the housing 64 to permit
breathing thereof while preventing ingress of water. The
control unit 66 has a motor speed control to vary speed of
the motor. The battery holder 70 is a rigid moulded
plastic box which is set into the back support bladder and
adapted to hold a small, lightweight, high capacity,
sealed, on-board battery (not shown), similar to the type
of battery used to power an electric wheel chair.
The apparatus further includes two side storage
compartments 76 and 78 extending upwardly above said top
surfaces 26 and 28 and having releasable top covers, eg.
securable with zip fasteners. The apparatus also includes
an on-board air compressor 80 with a discharge, and an air
tube 81 with a first end releasably connected to the
discharge and a second end connected to an air distribution
manifold 82, the compressor and manifold being located in
the storage compartment 76. Undesignated electrical
conduits extend between the control unit 66 to the air
compressor 80 for supplying power thereto. The compressor
draws little current and generates a small pressure
increase sufficient to inflate the bladders to one or two
psi above atmospheric pressure. A suitable compressor that
is commonly used to provide air pressure for bladders
located in automobile seat backs to help correct an user's
posture can be selected for the present invention. There
are three air conduits 84, 86 and 88 extending from the
manifold 82 to the floatation bladder, seat bladder and
back support bladder, respectively. Each of the air
conduits 84, 86 and 88 have a respective control valve 85,
-- ----------
CA 02266916 1999-03-24
-11-
87 and 89 for independently inflating and deflating the
floatation bladder, seat bladder, and back support bladder
respectively. Each valve has an open position to permit
inflation and deflation and a closed position to hold the
pressure of the bladders. The valves 85, 87 and 89 are
manually actuated by the operator and accessible through
the releasable cover of the compartment 76.
In summary, it can be seen that the apparatus 10 has a
control unit which can control the speed of the electric
motor and the actuation of the air compressor 80. The
three control valves permit control of pressure in each of
the separate bladders, permitting accurate control of trim
of the watercraft, thus reducing drag when the vessel is
required to cover relatively large distances across a body
of water. The operator can adjust inflation pressure of
the three bladders while the operator is sitting on the
seat and is remote from the shore, thus compensating for
pressure loss due to cooling from the cold water. The use
of the compressor and control valves also permits addition
of air to one or more bladders which may have been
accidentally punctured by contact with underwater
obstructions thus enabling the operator to return to shore
safely, assuming that output from the compressor can
accommodate loss of air pressure due to the puncture.
Thus, independent remote control of the inflation of the
three bladders of the vessel permit efficient inflation of
the chambers, as well as providing a degree of safety not
found in prior art apparatus.
The apparatus is also provided with two retractable
forwardly facing mirrors 92 and 94, shown in retracted and
extended positions respectively. Each mirror is connected
by a respective axially aligned swivel to one of the side
storage compartments 76 and 78. When both the mirrors are
extended by rotating outwardly, the operator can see
forwardly more easily than in prior art craft. Also, seat
CA 02266916 1999-03-24
-12-
belt portions 96 are provided adjacent the seat surface to
enable the operator to strap himself to the seat for safety
in rough water conditions.
Operation
To prepare the watercraft for use, the operator disconnects
the air tube 81 from the discharge of the on-board air
compressor 80 and connects the air tube 81 to a larger on-
shore air compressor (not shown) which eliminates the need
to use the smaller compressor 80, thus saving time and use
of the on-board battery. The on-shore air compressor is
used to inflate the floatation bladder to a pressure
sufficient to provide buoyancy to the apparatus 10 and
stiffness to the floatation member 12. The seat bladder is
independently inflated to a pressure sufficient to provide
additional buoyancy to the apparatus 10, to provide
stiffness in the seat member 32 to support the operator so
that the operator's lower torso is not submersed in the
water, and to push the bottom seat surface 44 to a position
adjacent the rigid hull member 47. The back support
bladder is also independently inflated to a pressure
sufficient to provide stiffness in the back support member
46 to support the operator's back and to prevent the
collapse of the seat member 32. Once the bladders are
filled using the on-shore air compressor, the air tube 81
is disconnected from the on-shore air compressor and re-
connected to the on-board air compressor 80. The operator,
shown in dotted outline in Figure 5, sits on the seat
member 32 and can operate the manual control unit 66 and
the control valves 85, 87 and 89 to independently control
the pressure in bladders while the watercraft is in
operation. After several hours of operation on the water,
it may be necessary for the operator to adjust the pressure
in the floatation bladder and the seat bladder to provide
sufficient buoyancy so that the watercraft obtains optimum
CA 02266916 1999-03-24
-13-
trim to reduce drag and keep the operator's torso out of
the water, and also to reduce operator fatigue.
The operator can also operate the manual control unit 66 to
control the speed of the electric motor. As the drive unit
60 is fixed, it cannot contribute materially to steering of
the watercraft. Steering is accomplished by the swim fins
provided on the operator's feet and, when the operator's
legs are extended, the fins act as rudders to steer the
craft when powered by the propeller, thus reducing operator
fatigue. Clearly, if the battery looses power due to
excessive use, low temperature or other situation, the
operator can propel himself back to the shore and safety by
using his swim fins as in the prior art. When the
watercraft is to be transported or stored, each of said
bladders is fully deflated to provide the apparatus with a
compact shape for ease of transportation and storage.
It can be seen that the drive unit 60 is located directly
beneath a forward half of the seat member 32, and thus is
located essentially immediately vertically beneath the
torso of the operator. Thus, the drive unit 60 is mounted
closely adjacent the centre of gravity of the watercraft
when loaded and as such generates a propulsion force
through a vertical axis of the centre of gravity, thus
reducing a swivelling effect that could otherwise occur if
the line of action of the propulsion force were displaced
longitudinally or laterally from the vertical axis of the
centre of gravity. This contributes to enhanced stability
of the vessel when operated at cruising speed in relatively
rough water and/or in strong winds. In addition, the drive
unit 60 is located sufficiently forwardly to essentially
eliminate accidental contact with the operator's legs or
feet.
At cruising speed the operator generally leans backwardly,
ie. towards the forward end of the watercraft, so as to
CA 02266916 1999-03-24
-14-
partially lower the forward end, thus shifting the axis of
rotation of the propeller 62 towards a generally horizontal
position. When the operator is fishing, the operator would
generally lean forwardly, ie. towards the rear of the
watercraft. The downwardly and rearwardly inclination of
the hull member 47 and the downwards bulging thereof
provides additional volume adjacent the rear seat surface
40 for the seat member to expand into. This additional
volume increases water displacement when the operator leans
forwardly, thus reducing any tendency of the seat member to
slope downwardly into the water, and thus reducing the
chance of the operator slipping off the seat member and
into the water. Care is taken to ensure that the bottom
seat surface 44 is protected from possible damage from the
strut 61 and the marine fitting 59.
While a specific embodiment of the invention has been
described and illustrated, such embodiment should be
considered illustrative of the invention only and not as
limiting the invention as construed in accordance with the
accompanying claims.
