U.S. patent application number 11/470217 was filed with the patent office on 2008-03-06 for buoyant safety paddle and method of manufacture thereof.
Invention is credited to Lyle Wilkinson.
Application Number | 20080057802 11/470217 |
Document ID | / |
Family ID | 39152270 |
Filed Date | 2008-03-06 |
United States Patent
Application |
20080057802 |
Kind Code |
A1 |
Wilkinson; Lyle |
March 6, 2008 |
BUOYANT SAFETY PADDLE AND METHOD OF MANUFACTURE THEREOF
Abstract
A buoyant safety paddle (11) for a kayak, a canoe or other small
boat facilitates kayak deep-water self-rescue reentries and
facilitates the movement of small boats over aqueous surfaces. Such
buoyant paddle displaces significant volume while minimizing weight
eliminating the need for post-capsize attached flotation. Each such
buoyant paddle's volume is predetermined and distributed to retain
paddling efficiency. Each such buoyant paddle has a handle (19)
which extends from one blade (12) or between two blades, and is
water tight, with a continuous strong rigid skin (41) and low
density core (42). This construction provides a buoyant, minimal
weight, stiff, high strength paddle which is economical to
manufacture.
Inventors: |
Wilkinson; Lyle; (Kahului,
HI) |
Correspondence
Address: |
Lyle Wilkinson
56 Kunihi Lane, #315
Kahului
HI
96732
US
|
Family ID: |
39152270 |
Appl. No.: |
11/470217 |
Filed: |
September 5, 2006 |
Current U.S.
Class: |
440/101 ;
416/70R |
Current CPC
Class: |
B63H 16/04 20130101;
B63C 9/28 20130101 |
Class at
Publication: |
440/101 ;
416/70.R |
International
Class: |
B63H 16/04 20060101
B63H016/04; B63H 16/10 20060101 B63H016/10 |
Claims
1-16. (canceled)
17. A buoyant paddle formed by (a) a rigid continuous seamless skin
over (b) a low density or hollow core shape with (c) thick paddle
blade(s) and (d) a handle to attain (e) a weight to volume ratio
which provides a minimum 15.5 pounds of inherent buoyancy, whereby
a human can do a deep-water self-rescue reentry and efficiently
propel a small boat.
18. The combination of claim 17 wherein said seamless skin is
formed at least in part of plastic reinforced with fiber such as
fiberglass, carbon fiber, or Kevlar.
19. The combination of claim 17 wherein said seamless skin is
formed at least in part of un-reinforced plastic such as
polypropylene or ABS (acrylonitrile butadiene styrene).
20. The combination of claim 17 wherein thickness of said seamless
skin is varied in proportion to stress loads, thick in the loom
where strength is needed most and thin in the blade where loads are
less and cross section is greater, whereby improving
strength/weight ratio over uniformly thick skin.
21. The combination of claim 17 wherein said core is hollow.
22. The combination of claim 17 wherein said core is low density
closed-cell foam.
23. The combination of claim 17 wherein the paddle's two blade
shape is (a) symmetric, similar to a Greenland paddle, and (b) has
wide blades a minimum of 1.5 inches thick.
24. The combination of claim 17 wherein the paddle's two blade
shape is (a) asymmetric, similar to a European or modern paddle,
and (b) has blades a minimum of 1.5 inches thick.
25. The combination of claim 17 wherein the single blade shape is
(a) similar to a canoe paddle shape and (b) has blades a minimum of
1.5 inches thick.
26. The combination of claim 17 wherein the paddle is manufactured
as a single continuous seamless rigid skin over a low density core
as means to eliminate joints between blade faces and between handle
and blade.
27. In a paddle for propelling and maneuvering a small boat, the
combination comprising: (a) one or two paddle blades and handle (b)
a continuous seamless rigid skin and a low density core (c) a
volume to weight ratio which provides the buoyancy of a Class III
PFD, whereby the safer paddle facilitates self-rescue, rolling and
bracing without compromising paddling efficiency.
28. In a method of manufacturing a paddle for use with a small
boat, the steps comprising: forming a closedcell foam blank,
wrapping said blank completely with a seamless reinforcing fabric
sleeve, wetting out the fabric with resin, curing, then finishing.
Description
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0001] (Not Applicable)
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to flotation devices for self-rescue
from a capsized kayak, and to paddles or oars for manually
propelling and maneuvering kayaks, canoes or other small boats.
BACKGROUND OF THE INVENTION
[0004] 2. Description of the Prior Art
[0005] Paddles and oars have evolved over thousands of years and
the most popular material for manufacture had long been wood.
During the 20th Century new materials were introduced. U.S. Pat.
No. 738,053 to Murdock (1903) and U.S. Pat. No. 2,527,040 to
Swenson (1950) incorporated using hollow metal oars. In 1977, U.S.
Pat. No. 4,061,106 to Ware elaborated on the importance of fiber
placement in building light, strong racing paddles. U.S. Pat. No.
4,303,402 to Gooding (1981) and U.S. Pat. No. 6,991,501 to Wilce
(2006) championed attaining low weight using combinations of
plastic and aluminum. U.S. Pat. No. 5,820,424 to Steinhour and
Addison (1998) purported that lightweight kayak paddles with bent
shafts are more ergonomic and can be oriented by touch alone.
[0006] Regardless of construction materials and method,
contemporary practice provides only just enough buoyancy to float
the paddle. Paddle manufacturing and paddle patents have focused on
use of the paddle as a means of manually propelling and maneuvering
kayaks, paddle weight, and on economy of production.
[0007] Small differences in weight can be of considerable
significance during the use of paddles. The paddle must be
repeatedly manipulated, often thousands of times during each use,
and weight has a cumulative effect on the effort that is demanded
of the user of the paddle. The current practice is to minimize
weight by any method including reducing volume.
[0008] It is also well known in the art that rigid skin on
low-density core construction is strong, rigid and durable.
Surfboard, sailboard and racing yacht manufacturers use
construction employing a low-density core material sandwiched
between strong, thin facings. The result is a lightweight, strong,
stiff composite structure which acts in the same manner as a
continuous beam with the skins taking bending stresses while the
core acts as the "web" to carry shear and compressive loads.
Surfboard manufacturers acquire roughly shaped closed-cell foam
blanks, shape the blanks, and then cover the blank with a
continuous skin of fiber reinforced plastic to create a
surfboard.
[0009] The Greenland style paddle evolved over thousands of years.
Many paddlers like the symmetry and claim it is a superior paddle
for endurance and heavy weather. Greenland style paddles are
predominantly carved from a single piece of wood and achieve
minimal weight through wood selection and removing volume.
[0010] The European or modern style paddle emerged in the 20.sup.th
century. This is the most prevalent style. Blade area is
concentrated far from the center of the paddle, increasing power.
Blade shapes and paddle lengths have evolved to fill niches as they
become popular. Sea kayaking paddles are at the long end of the
length continuum and whitewater paddles are at the short end. Sea
kayaking paddle blades are at the narrow end of the width continuum
and whitewater paddle blades are at the wide end. Power faces can
be flat, curved, spooned and/or have a dihedral from the center
line. The paddle blades are generally asymmetric with the up side
longer than the down side as a means of equalizing wet area on
either side of the paddle's longitudinal axis at the apex of the
stroke.
[0011] The European style paddle is constructed of various
materials to meet weight, low rotational mass, propulsion
efficiency, strength, durability, and price objectives. The least
expensive, least capable paddles are normally fabricated with
plastic blades and aluminum handles. The most expensive, most
specialized performance paddles are usually fabricated with carbon
fiber reinforced plastic.
[0012] Kayaking in rough waters carries with it the risk of
capsizing. After a capsize in cold waters, life threatening issues
of hypothermia or drowning are of immediate concern. Methods exist
for righting and reentering overturned kayaks. Skilled kayakers
frequently execute a kayak roll to "right" an inverted kayak. If
the capsize leads to egress from the cockpit, the skilled paddler
may reenter the cockpit upside down and underwater before executing
the roll. However, rough seas, skill level, strength, and
hypothermia sometimes combine to make it impossible to successfully
complete such a skilled maneuver. Accordingly, there exists in the
prior art several devices to assist kayakers in righting and/or
reentering capsized kayaks
[0013] Among such devices, U.S. Pat. No. 5,279,248 to Blachford and
Alistari M. (1994) describes a device having a rapidly
self-inflating means for flotation with a minimum volume of one
cubic foot of gas. It is adapted for positioning to one side of the
kayak, spaced from the kayak for movement in an arc of at least 90
degrees about the kayak by means of force applied to the handle of
the device. After capsize, the handle of the flotation device is
grasped and the device inflated. Force is then applied to the
handle to rotate the kayak and paddler to an upright position. This
kayak righting apparatus is a separate piece of equipment to
maintain and stow. After capsize such kayak righting apparatus must
be located, inflated and used as a source of buoyancy to right the
kayak. This procedure requires skill and removing at least one hand
from the paddle. Rolling the kayak upright must wait for automatic
inflation to provided adequate buoyancy. After the kayak is righted
such kayak righting apparatus needs to be deflated and stored to
get the paddle and the kayak back under control. Once self
inflating cartridges are spent, utility is gone as it is impossible
to orally inflate after capsizing, with the paddler's head
underwater.
[0014] It is well known in the art to use a post-capsize attached
flotation device to assist in self-rescue or solo reentry into a
capsized kayak. The most commonly used device is an inflatable or
foam sheath, jacket, collar or cuff. The sheath fits over one of
the kayak paddle blades so that one end of the paddle becomes
significantly buoyant. The paddle may then be deployed as an
outrigger to assist in the self-rescue effort.
[0015] Contemporary inflatable flotation devices comprise an
envelope having an internal cavity or sleeve that fits over the
kayak paddle blade. The technique for using this kind of
post-capsize attached flotation device in kayak deep-water
self-rescue typically involves the following steps: [0016] (1)
turning the capsized kayak into the upright position and hanging
onto the kayak; [0017] (2) selecting a side for reentry and taking
a position beside the cockpit [0018] (3) finding and removing
post-capsize attached flotation device from its storage place;
[0019] (4) attaching a post-capsize attached flotation device to
one blade; [0020] (5) inflating the flotation device until it is
secure on the blade and sufficiently full to provide buoyancy;
[0021] (6) slipping other paddle blade under rear deck rigging at a
right angle to the gunwale, with the inflated flotation device
extended as an outrigger; [0022] (7) kicking the legs to the water
surface and simultaneously pulling with both arms to squirm up on
rear deck, [0023] (8) sliding stomach down, head to stern until
feet can slip into cockpit; [0024] (9) twisting over to slide feet
into cockpit; [0025] (10) lowering butt onto seat; [0026] (11)
slipping paddle out from rear deck rigging; [0027] (12) removing
post-capsize attached flotation device; [0028] (13) deflating
post-capsize attached flotation device; [0029] (14) stowing
post-capsize attached flotation device; [0030] (15) paddling to
regain control of kayak.
[0031] The deep-water self-rescue reentry takes some dexterity and
can be difficult in rough water. Difficulty increases as the time
in cold water increases. Once righted the paddler still must deal
with the unwieldiness of Paddling with a float on one blade.
Usually the environment that created the need to do a reentry still
exists after reentry, so it is important to get the kayak under
control quickly.
[0032] Foam post-capsize attached flotation devices eliminate the
inflation and deflation steps, but take up more storage space.
[0033] The added buoyancy of a post-capsize attached flotation can
be helpful when learning to kayak roll. The float makes rolling
easier allowing concentration on different parts of the roll
without doing a wet exit. However, the kayak is difficult to
maneuver with a float on one blade during the time between roll
attempts.
[0034] Another method of kayak self-rescue is based on the
post-capsize attached flotation's aid to rolling. This method is
suitable for rough sea conditions when the kayak is inverted and
requires that the kayaker have at least some understanding of and
proficiency with reentry and roll techniques. It is significantly
easier to execute than a kayak roll without a post-capsize attached
flotation device. The technique includes the following steps:
[0035] (1) taking a position alongside the inverted kayak; [0036]
(2) placing the post-capsize attached flotation device onto the
paddle blade and inflating; [0037] (3) taking a position beside the
cockpit and facing stern; [0038] (4) grasping the paddle handle
along its length (with the longer, float end toward the bow), and
holding it against the near coaming; [0039] (5) reaching across the
cockpit and grasping the opposite coaming; [0040] (6) taking a deep
breath and quickly leaning back; [0041] (7) employing a backward
somersault, thrusting both legs into the cockpit and taking a
position securely inside, upside down and underwater; [0042] (8)
positioning the paddle parallel to the kayak side in preparation
for a kayak roll; [0043] (9) sweeping outwardly with the float end,
then flicking hip and pulling briskly downward so as to come to a
full upright position;
[0044] Brace strokes are used to prevent a kayak or canoe from
capsizing. The paddle blade is slapped on the water or sculled
through the water to generate force to keep the kayak upright.
Success depends on sea conditions and kayaker skill. When the
paddle blade angle is wrong, instead of providing lift it dives
accelerating capsize. The leading edge of the blade must be held so
it is always rising, creating lift. When the leading edge is diving
it pulls the blade toward the bottom.
[0045] The present invention is directed to making paddling safer
by overcoming one or more of the problems discussed above.
BRIEF SUMMARY OF THE INVENTION
[0046] The paddle combines the utility of a paddle with the utility
of a post-capsize attached flotation device. This buoyant paddle
for propelling and maneuvering a boat includes one or two blade(s)
and a handle portion. This paddle has large displacement and
minimal weight adding significant buoyancy to combine the function
of such paddle and the function of a post-capsize attached
flotation device. This paddle facilitates the movement of small
boats over aqueous surfaces and is deployable as an outrigger to
assist in deep-water self-rescue reentry to a capsized kayak. This
invention relates to methods for manufacturing paddles with
buoyancy, strength, efficiency, minimal weight, durability and
economy.
Objects and Advantages
[0047] The goal of this buoyant paddle is to provide a safer paddle
than is currently available, while maintaining acceptable paddling
efficiency.
[0048] Accordingly, it is an object of this paddle to aid kayak
reentry. When used in a deep-water kayak self-rescue reentry it
eliminates six steps, reducing the reentry technique to these
steps: [0049] (1) turning the capsized kayak into the upright
position and hanging onto the kayak; [0050] (2) selecting a side
for reentry and taking a position beside the cockpit [0051] (3)
slipping one blade under rear deck rigging at a right angle to the
gunwale, with the other blade extended as an outrigger; [0052] (4)
kicking the legs to the water surface and simultaneously pulling
with both arms to squirm up on rear deck, [0053] (5) sliding
stomach down, head to stern until feet are over cockpit; [0054] (6)
twisting over to slide feet into cockpit; [0055] (7) lowering butt
onto seat; [0056] (8) slipping paddle out from rear deck rigging;
[0057] (9) paddling to regain control of kayak. A faster reentry is
a safer reentry. Especially in cold water, boaters need to minimize
wet time.
[0058] Another object is to improve kayak roll reliability. The
kayak roll is used to right an overturned kayak without doing a wet
exit and a reentry. The invention's buoyancy is a built in
flotation device always at the ready. Both clockwise and
counter-clockwise rolls are assisted as buoyancy is built into both
blades. A more reliable roll makes it less likely a kayaker will
need to do a deep-water self-rescue reentry. A more reliable roll
makes a safer kayaker. The built in flotation makes it easier to do
reentry and roll recovery without needing to attach a float to the
paddle or predetermine whether the roll will be clockwise or
counter-clockwise.
[0059] A further object is to improve support stroke effectiveness.
Brace strokes are used to prevent a kayak or canoe from capsizing.
This buoyant paddle increases support provided by brace strokes and
reduces the likelihood a paddle will dive on the brace stroke.
Better brace strokes reduce the need for kayak rolling or
deep-water self-rescue reentry. Better brace strokes make a safer
kayaker.
[0060] A still further object is to provide a buoyant paddle of
such construction and design so as to provide lightweight, low
rotational mass, propulsion efficiency, strength, durability and
economical manufacture. Lightweight, low rotational mass and
propulsion efficiency can be safety issues when distance to safe
harbor tests time and energy available. Strength and durability
become safety issues if the primary paddle fails and the spare is
less capable or missing. Economy becomes a safety factor if the
price is beyond the means of the paddler.
[0061] The construction of this invention varies rigid skin
thickness to increase strength where greatest torque will occur and
to reduce rotational mass. The skin is thickest in the handle and
thinnest in the fattest section of the blade.
[0062] Reduced rotational mass and buoyancy increase paddling
efficiency. Reducing rotational mass puts more paddler energy into
propelling the boat through the water by reducing the energy needed
just to move the paddle. Increasing blade buoyancy lets the paddle
pop out of the water at the end of the stroke reducing the energy
absorbed by pulling the paddle up out of the water. The method of
construction of this invention has the flexibility to produce
paddle blade shapes tuned for efficiency in different applications
and for different paddler preferences.
[0063] The method of construction of this invention has the
flexibility to produce paddles for different price points. The
rigid skin low density combination can be fabricated with various
materials ranging from cheap to expensive. The rigid skin material
pricing would increase from entry level polypropylene, through ABS
(acrylonitrile butadiene styrene) and FRP (fiberglass reinforced
plastic), to expensive carbon fiber/Kevlar reinforced plastic. The
low density core material pricing would increase from free hollow,
through EPS (expanded polystyrene) to expensive, rigid, tough, SAN
(styreneacrylonitrile) or PVC (polyvinyl chloride) closed-cell
foams.
BRIEF DESCRIPTION OF THE DRAWINGS
[0064] In the accompanying drawings:
[0065] FIG. 1 is a perspective view of the Greenland style
embodiment of the invention.
[0066] FIG. 2 is a perspective view of the European style
embodiment of the invention.
[0067] FIG. 3 is a perspective view of the canoe style embodiment
of the invention.
[0068] FIG. 4 is a cross section of the handle portion of the
paddle showing the rigid skin and low density core.
[0069] FIG. 5 is a cross section of the blade portion of the paddle
showing the rigid skin and low density core.
[0070] FIG. 6 is a cross section along the longitudinal axis of the
paddle showing the single continuous rigid skin encapsulating the
low density core of the blades and the handle.
[0071] FIG. 7 is a cross section of the handle portion of a paddle
fabricated by joining two rigid skin low density core halves along
the longitudinal centerline of such paddle.
[0072] FIG. 8 is a perspective view of a modular paddle.
TABLE-US-00001 Reference Numerals in Drawings 11 Buoyant Safety
Paddle 12 blade 13 major surface (blade face) 14 opposite major
surface 15 side 16 opposite side 17 first end of blade 18 second
end of blade 19 handle 41 rigid skin 42 low density core 81 four
piece blade 1 82 four piece handle 1 83 four piece handle 2 84 four
piece blade 2 85 three piece blade 1 86 three piece handle 87 three
piece blade 2 88 two piece blade/handle 1 89 two piece blade/handle
2 91 extension
DETAILED DESCRIPTION OF THE INVENTION
[0073] Referring to FIGS. 1, 2, and 3 of the drawings, a paddle 11
in accordance with these embodiments of the invention have a paddle
blade 12 with opposite facing major surfaces 13 and 14, and sides
15 and 16, extending between first and second ends 17 and 18 of the
blade. A handle 19 extends from the first end 16 of the blade 12 to
enable grasping and maneuvering of the paddle 11. The blade 12 may
have any of the outlines that are customary in paddles for small
watercraft such as canoes and kayaks. The handle portion 19 has a
length that is dependent on the type of watercraft. Canoe paddles,
for example, are proportioned to be gripped at the distal end by
one hand of the user while the other hand grips the handle at a
location which is relatively close to the blade 12. Kayak paddles
are longer and have blades 12 at each end of the handle 19 which
blades may be immersed in the water, alternately, at opposite sides
of the hull of the kayak. The present invention is adaptable to
paddles offerings of all differing types. The blade(s) 12 and
handle 19 are encapsulated by a common rigid skin eliminating
bulky, dense blade handle joints.
[0074] The blade 12 of these examples is thick enough to provide
buoyancy. The dimensions of sides 15 and 16, in combination with
dimensions of the paddle faces 13 and 14 are determined by buoyancy
requirement. Increasing thickness increases volume. Increasing
volume while minimizing weight increases buoyancy. The buoyancy
required to perform a kayak reentry can vary with weather, kayak
design, paddler physique and paddler skill level.
[0075] Referring to FIG. 1 of the drawings, a paddle in the
Greenland style is symmetric with four power faces and a short
rectangular handle between long blades. The Greenland style is the
preferred embodiment of the buoyant safety paddle as in addition to
symmetry and the short rectangular handle it has a better volume to
skin ratio.
[0076] The symmetry of the Greenland style paddle lends itself to
safety. The paddle can be held in any of four positions as all four
faces are power faces. No matter how the buoyant safety paddle is
grabbed, if the blade face is perpendicular to the water's surface
paddling can start. The short rectangular handle allows a paddler
to orient the buoyant safety paddle by touch alone. The combination
of symmetry and short rectangular handle make it unnecessary to
flip the paddle around its lateral axis or roll the paddle around
its longitudinal axis to get the power face pulling. The
combination of symmetry, short rectangular handle, and blade
buoyancy encourages a powerful vertical stroke close to the side of
the kayak. The rectangular handle provides good control of the
paddle eliminating blade flutter and allowing efficient power
strokes.
[0077] For a given paddle length and blade width a Greenland style
buoyant safety paddle has more of its length in the fat cross
section blade than in the narrow cross section of the handle. One
inch, of 5 by 2 inch blade, has 14 square inches of skin and
includes 10 cubic inches of volume for a volume-to-skin ratio of 1
to 0.71. Whereas 1 inch, of 1.5 by 1.2 inch handle, has 5.4 square
inches of skin and includes 1.8 cubic inches of volume for a
volume-to-skin ratio of just 1 to 0.33. Having less skin for a
given volume means predetermined buoyancy can be achieved with a
stronger, lighter paddle.
[0078] Referring to FIG. 2 of the drawings, a paddle in the
European or modern style has blade area concentrated far from the
center of the paddle handle. Such paddles' blades can be symmetric
or asymmetric. Such paddles blades' Power faces can be flat,
curved, spooned and/or have a dihedral from the center line.
[0079] Referring to FIG. 3 of the drawings, a canoe paddle is
symmetric. The handle is generally "T" shaped.
[0080] Referring to FIGS. 4, 5, and 6 of the drawings, a paddle in
accordance with these embodiments of the invention have a rigid
skin 41 and a low density core 42. Such rigid skin and such low
density core combine to provide paddle rigidity and strength. Such
rigid skin and such low density core combine to provide increasing
volume without a proportionate increase in weight. The present
invention's buoyant paddles have more volume than common paddles
while weighing approximately the same.
[0081] Referring to FIG. 7 of the drawings, a paddle in accordance
with these embodiments of the invention has halves 71 and 72 joined
with a longitudinal centerline seam 73. Such centerline seam can be
a simple glue line or reinforced as means to increase rigidity and
strength perpendicular to the power face.
[0082] Referring to FIG. 8 of the drawings, a paddle in accordance
with these embodiments of the invention have a plurality of parts
81, 82, 83, 84, 85, 86, 87, 88, 89, and 91 that join together. The
blade 81, handle 82, handle 83, and blade 84 join to form a
four-piece paddle. The blade 85, handle 86, and blade 87 join to
form a three-piece paddle. The blade/handle 88 and blade/handle 89
join to form a two-piece paddle. The extension 91 fits between
handles 82 and 83 or between blade/handles 88 and 89 to increase
the length of such four or such two-piece paddle. Each of said
parts is constructed of a rigid skin over a low density core.
[0083] The rigid skin over low density core is manufactured by
various methods. The most basic process involves carving a
closed-cell foam blank, wrapping blank with fiberglass, wetting out
with resin, curing, then finishing. A lighter stronger buoyant
paddle can be produced by applying pressure with vacuum bagging to
increase uniformity of resin saturation and to remove excess resin.
The lightest and strongest buoyant paddle requires SAN closed-cell
foam, carbon fiber fabric sleeves, heat-set epoxies, and heated
presses. The foam is cut large, the carbon fiber sleeve is slipped
over the core, the fiber is wetted out with epoxy, the wet paddle
is slipped into the mold, pressure is applied squeezing the skin
between mold and foam, and temperature is elevated to set the
epoxy. Kevlar or other reinforcing fiber materials are used to add
characteristics such as durability. Metal, polypropylene, or ABS
rigid skins are made hollow and filled with pour foam to prevent
buoyancy loss when rigid skin is punctured. After the two parts of
the pour foam are mixed and poured, the foam expands and sets. To
prevent paddle rupture, the pour foam parts are precisely measured
and an escape route for excess foam is provided.
* * * * *