Note: Descriptions are shown in the official language in which they were submitted.
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PERSONAL WATERCRAFT
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to recreational personal watercraft and more
particularly to water walkers (i.e. personal watercraft having two independent floats
which can be individually secured to a person's feet to allow the person to move over the
surface of a body of water with a striding motion).
2. Description of the Related Art
The goal of walking on water has attracted many inventors. The personal
watercraft known as water walking devices or "water walkers" generally have two
independent floats. A user can mount one of the floats to each foot. The user can then
travel across water using a motion similar to cross country skiing. A problem with water
walkers is that it is difficult to "grip" water. The prior art proposes various ways to make
floats which experience more drag when they are moved through the water in a rearward
direction than when they are moved through the water in a forward direction. Forexample, some prior art water walkers have one or more flaps or fins attached to the
lower surfaces of their floats. The flaps open and push against the water when the floats
are moved rearwardly. Examples of this type of water walker are shown in U.S. patent
No.5,236,381 to Keogh and U.S. patent No.5,060,621 to Nayes. Such water walkers are
not very efficient. There is significant backslipping and power is provided only by a
user's legs. It can also be difficult for users to maintain their balance with this type of
water walker.
Some known water walkers provide poles which a user can hold. The poles help
the user to stay in balance. The poles may be equipped with flotation devices or paddle
plates at their lower ends. U.S. patent No. 4,527,964 to Gilbert and U.S. patent No.
5,558,553 to Okano describe examples of such poles. The poles help a user to develop
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5 some additional forward thrust but such devices are still not very efficient. The float that
the user is pushing off from (the "non-striding float") still tends to slip backward through
the water.
What is needed is a personal watercraft of the water walker type that allows a user
10 to glide across the surface of a body of water more efficiently than prior art water
walkers.
SUMMARY OF THE INVENTION
This invention provides a water walker type of personal watercraft having an oarsupported in an oarlock coupled to each oftwo independent floats. The oars may be used
to help to propel the water walker and to counteract backslip of the non-striding float.
Accordingly, one aspect of the invention provides a personal watercraft. The
20 personal watercraft comprises left and right independently movable floats having left and
right foot platforms for respectively receiving left and right feet of a user; left and right
supports extending upwardly from said left and right floats respectively; and, left and
right oarlocks, each capable of receiving an oar, respectively mounted on said left and
right supports. The left and right oarlocks are respectively located forwardly, upwardly
25 and outwardly from the left and right foot platforms. In a preferred embodiment the left
and right foot platforms are in foot wells in the left and right floats respectively. The
floats may comprise a pair of longit~l(lin~lly extending keels separated by a channel. The
floats may also each comprise a main float body and a pontoon coupled in spaced apart
parallel relationship to the main float body. A user may place oars in the oarlocks and
30 may then use the oars to assist in propelling the watercraft. The water walker may
optionally comprise a cross member detachably affixable to each of said floats and a seat
on said cross member. When the cross member is affixed between the floats, the floats
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5 are supported in spaced apart parallel relationship in relation to one another. and the
water walker may then be rowed like a conventional row boat.
Another aspect of the invention provides a personal watercraft. The water craft
comprises first and second independent elongated floats, and an oarlock capable of
10 receiving an oar coupled to each of the floats by a support. Each of the floats has a hull,
a front end, a back end, and a means for securing a foot located near a center of buoyancy
of the float. Each of the supports holds one of the oarlocks at a position above an upper
surface of the float between the front of the float and the means for securing a foot. The
supports preferably each comprise a support member pivotally coupled to the float, and
15 a brace member having one end pivotally coupled to the float and a second end coupled
to the support member.
Yet another aspect of the invention provides a method for moving across the
surface of a body of water. The method comprises the steps of providing a personal
20 watercraft comprising first and second independent narrow and elongated floats and first
and second oarlocks mounted respectively on first and second supports connected
respectively to said first and second floats; providing first and second oars engaged
respectively with said first and second oarlocks; standing with one foot on each of said
first and second floats; and then alternating between moving said second float forwardly
25 relative to said first float while simultaneously pushing forwardly on a handle of said first
oar to drive a blade of said first oar rearwardly through the water and moving said first
float forwardly relative to said second float while simultaneously pushing forwardly on
a handle of said second oar to drive a blade of said second oar rearwardly through the
water.
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BRIEF DESCRIPTION OF THE DRAWINGS
In drawings which illustrate specific embodiments of the invention, but which
should not be construed as restricting the spirit or scope of the invention in any way:
Figure 1 is a top plan view of a personal watercraft according to a preferred
embodiment of the invention;
Figure 2 is a side view thereof;
Figure 3 is a sectional front view, along section line 3-3, thereof;
Figures 4A and 4B are detailed views of an oarlock for use in the invention;
Figure 5 is a top plan view of an outrigger style float according to an alternative
embodiment of the invention;
Figure 6 is a front view thereof;
Figure 7 is a top plan view of an embodiment of the invention which may be
converted to a rowing boat;
Figure 8 is a side plan view thereof;
Figure 9 is a sectional front view, along section line 9-9, thereof; and,
Figures 10A, 10B and 10C demonstrate a sequence of steps in the use of the
invention to glide across a body of water.
DETAILED DESCRIPTION
As shown in Figures 1, 2 and 3 a personal watercraft (or "water walker") 10
according to the invention comprises two floats 20L and 20R. In this disclosure the
letters "R" and "L" are used to identify parts on the right and left sides of the watercraft
respectively. For example, the reference numeral 20R refers to the right hand one of
floats 20 and the reference numeral 20L refers to the left hand float 20. Each float 20 has
a foot platform 22 for supporting one of a user's feet. Each float 20 has an oarlock 24
supported on a support 30 which extends upwardly from the float. Oarlocks 24 receive
oars 25 which a user can use, as described below, to propel watercraft 10 across the
surface of a body of water.
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Supports 30 support oarlocks 24 forwardly, upwardly and outwardly from foot
platforms 22. When a user is standing with his or her left and right feet respectively on
foot platforms 22L and 22R, oarlocks 24 are preferably located approximately 25 cm (10
inches) in front of the user's body, about 70 cm (28 inches) above foot platforms 22 and
about 25 cm (10 inches) outwardly from a longitudinal axis 98 passing through the center
ofthe respective one of footplatforms 22R,22L. These dimensions are only informative.
Supports 30 are preferably adjustable to allow the positions of oarlocks 24 to be varied
to suit an individual user.
Supports 30 preferably each comprise an elongated first member 32 pivotally
mounted to the respective float 20 at a point well forward from foot platform 22. A
second brace member 34 has one end pivotally mounted to float 20 and a second end
coupled to first member 32. The point of connection of first member 32 and bracemember 34 is preferably adjustable so that the elevation of oarlock 24 above float 20 may
be adjusted by changing the angle ~ of inclination of first member 32. This may be
accomplished, for example, by forming first member 32 from a pair of spaced apart arms
32A and 32B. Brace member 34 passes between arms 32A and 32B of support member
32 and is fixed in place by a pin 36 which passes through apertures 37 in arms 32A and
32B of support member 32 and brace member 34. A series of spaced apart apertures 37
may be provided in each of support member 32 and brace member 34 to enable the point
of connection of support member 32 and brace member 34 to be varied.
Support member 32 is preferably adjustable in length. This may be accomplished,
for example, by mounting oarlock 24 to a member 40 which is secured between arms32A and 32B by bolts 38. The distance L by which member 40 projects past arms 32A,
32B can be adjusted by removing bolts 38, altering the insertion length of member 40
between arms 32A and 32B and replacing bolts 38. It can be appreciated that this design
provides supports 30 which can securely, and reasonably rigidly, support oarlocks 24 and
yet allow the locations of oarlocks 24 to be adjusted both in elevation and in position fore
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and aft relative to float 20 to suit the physique and preferences of a user. A support 30
as described above may be collapsed to a compact storage configuration by removing pin
36. The dimensions of support member 32 and brace member 34 and the locations atwhich these members are attached to floats 20 are most preferably selected so that ~ is
in the range of about 30 degrees to about 60 degrees when support 30 is in use.
Oarlocks 24 are mounted to the upper ends of members 40. As best shown in
Figures 4A and 4B, each oarlock 24 comprises a clevis 44 pivotally secured to its
member 40 for rotation about axis 45 which is preferably inclined outwardly at an angle
~ in the range of about 40 degrees to about 80 degrees, and most preferably about 60
degrees (Fig 3.). Oar 25 may then be pivotally mounted to each clevis 44. For example
shaft 50 of each oar 25 may be received within tube 54 which is, in turn, pivotally
secured to clevis 44. Those skilled in the art will realize that there are many possible
designs of oarlocks 24 and oars 25 which may suitably be used in the invention. For
example, each oar 25 may simply be received between the arms of clevis 44. What is
needed is that oarlock 24 acts as a fulcrum supported by a support 30 for an oar 25 to be
worked against. Oarlocks 24 are preferably ofthe universal joint type so that oars 25 can
be smoothly pivoted about two perpendicular axes 45, 49. This permits a user to swing
oars 25 out of the water on their return strokes, as discussed below.
Oars 25 typically resemble paddles. Preferably each oar 25 comprises a shaft 50,which can be slidably received in tube 54 of an oarlock 24. A hand grip 82 is provided
at one end of shaft 50. A blade 84, preferably having a wide, flat shape is located at the
other end of shaft 50. Oars 25 are preferably just long enough so that blades 84 are
immersed in water when a user is standing on floats 20 with grips 82 at shoulder level
and shafts 50 engaged in oarlocks 24.
Most preferably, oars 25 are retained in oarlocks 24 so that oars 25 will not be lost
if a user lets go of them momentarily. Those skilled in the art will realize that there are
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numerous ways to retain an oar 25 in an oarlock 24. For example, a grooved sleeve 85
may be inserted into each tube 54 creating a key hole shaped aperture 86. Grips 82 of
oars 25 may be shaped to pass through aperture 86 only when aligned properly with
aperture 86. Oars 25 may be held in place in oarlocks 24 by inserting them through
sleeves 85 and then rotating them.
Each float 20 is typically about 210 cm to 240 cm (7 feet to 8 feet) long and about
30 cm (1 foot) wide. These dimensions can vary considerably without departing from the
scope of the invention. The preferred dimensions for floats 20 depend on the intended
user's size, weight and skills. In general, longer and narrower floats 20 are capable of
developing higher speeds while shorter and wider floats 20 provide better stability. The
volume and weight of each float 20 must be sufficient so that the combined buoyancy of
floats 20R and 20L is sufficient to support the weight of a user without sinking.
Preferably each float 20 has enough buoyancy to support the weight of a user.
Floats 20 may have various forms. In one preferred embodiment, as shown best
in Figure 3, the lower surface 60 of each float 20 comprises a pair of longit~1~1in~11y
extending keels 62 separated by a channel 64. The bottom 60 of each float 20 in channel
64 is preferably about 7.5 cm (3") above the lowest point of keels 62. The bottom 60 of
each float 20 is preferably ramped upwardly at both the front and rear ends of floats 20.
Each float 20 is pointed at its front end. This design tends to improve the stability of
floats 20. Preferably keels 62 are sufficiently buoyant that when a user has shifted his or
her weight to the other float 20 in preparation for thrusting float 20 forward the portion
61 of lower surface 60 in channel 64 is above the water surface. This tends to reduce
drag on float 20.
An alternative float configuration is illustrated by floats 120 of Figures 5 and 6.
Floats 120 comprise a main float body 70 and a narrow stabilizing outrigger pontoon 72
connected to main float body 70 by cross members 74. Outrigger pontoon 72 is on the
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outside of main float body 70. For example, on left float 120L, outrigger pontoon 72L
is on the left hand side of main float body 70L. Support 30 is preferably mounted to
pontoon 72. This embodiment has the advantage of being more stable for the user
without producing excessive drag. This embodiment also provides a stable platform for
a user without forcing the user to adopt an unn~tllrally wide spacing between his or her
feet. In a float 120 foot platform 22 is preferably offset slightly in main float body 70
toward pontoon 72.
Floats 20 or 120 may be made with any suitable construction. Each float 20 or 120
may, for example, be in the form of a shell of a composite material or plastic defining a
hollow hull, a member made of closed cell foam or the like.
Watercraft 10 preferably includes some means for securing a user's foot to each
foot platform 22. Most preferably, each foot platform 22 is located in a foot well 80
dimensioned to receive a user's foot and lower leg. Each foot platform 22 is preferably
located low in its float 20 for stability. Foot wells 80 conform closely enough to a user's
feet to allow the user to smoothly move floats 20 through the water. In the alternative,
one or more straps may be provided to hold a user's foot in place on foot platform 22.
The means used to keep a user's foot on foot platform 22 should be very easily releasable
to enable a user to quickly and surely remove his or her foot from floats 20 in case of
capsize.
Figures 7, 8 and 9 show a watercraft 110 according to an alternative embodiment
of the invention. Watercraft 110 includes one or more detachable cross members 112
which may be used to secure a pair of floats 20 together in a fixed parallel relationship.
When floats 20 are secured by cross member 112 then personal watercraft 110 may be
used as a c~t~m~ran style rowing boat. A seat 114 is located between floats 20 on cross
members 112. Cross members 112 preferably comprise elongated pins 102 at either end.
Pins 102 are slidingly and fairly snugly received in corresponding shafts 104 in floats 20.
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Cross members 112 preferably support floats 20 approximately 60 cm (2 feet) apart and
parallel to each other. The height and positions of oarlocks 24 may be adjusted by
adjusting supports 30 to fit the new rowing style. With cross members 112 in place,
watercraft 110 may be rowed in a conventional manner. Watercraft 110 may be converted
back into a water walker by simply removing cross members 112.
Now that the basic construction of a personal watercraft according to the invention
has been described, a method of use thereof will be explained with reference to Figures
10A, 10B and 10C. As shown in Fig. 10A, a user U begins by standing facing forward
on floats 20 with his left foot on foot platform 22L and his right foot on foot platform
22R. The user shifts his weight onto one float (for example float 20L) and thrusts the
other float 20R forwardly. At the same time, the user will push handgrip 82L forwardly
to sweep blade 84L of oar 25L through the water. The thrust provided by oar 25L
prevents float 20L from backsliding. Blade 84R may be held out of the water by moving
its hand grip 82R downwardly. Blade 84R may be moved into position for the next
skoke by moving its handgrip 82R rearwardly.
Next, as shown in Figure 1 OB, the user U continues to glide forwardly and begins
to shift his weight toward float 20R. Oar 25R is in position for a stroke. Oar 25L is
leaving the water at the end of its stroke. As shown in figure 10C, when most of the
user's weight is on float 20R the user thrusts float 20L forwardly. At the same time, the
user pushes forward on hand grip 82R to sweep blade 84R through the water and pulls
back on hand grip 82L to move blade 84L into position for another stroke. Those
f~mili~r with cross country skiing will appreciate that the method of walking across water
using a water walker 10 is very similar to cross country skiing and will provide exercise
to a users legs and arms.
As will be apparent to those skilled in the art in the light of the foregoing
disclosure, many alterations and modifications are possible in the practice of this
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-10-
5 invention without departing from the spirit or scope thereof. Accordingly, the scope of
the invention is to be construed in accordance with the substance defined by thefollowing claims.
