Note: Descriptions are shown in the official language in which they were submitted.
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SWIM FIN AND BINDING FOR IMPROVED PROPULSION AND
REDUCED ANKLE STRAIN
FIELD OF THE INVENTION
The present invention relates to a swimming aid apparatus and more
specifically to
a foot-mounted swim fin, such as those used by scuba divers, snorkelers, and
the
like. In particular, the invention relates to an improved foot-mounted swim
fin with
a lower leg binding that provides greater thrust whilst lowering the strain
imposed
upon the ankle joint.
BACKGROUND OF THE INVENTION
The present invention is an improvement over Canadian Patent Application No.
2,665,278, filed April 29, 2009 wherein a swim fin and binding for improved
propulsion and reduced ankle strain is disclosed. Further developments have
been
revealed that outline the need for the production of an upgraded swim fin and
binding. For a ready understanding of the current state of the swim fin and
binding
the reader is directed to Canadian Patent Application No. 2,665,278.
Scuba diving and snorkelling are two popular activities where foot-mounted
swim
fins are used as a means to increase the propelling force through the water.
Typically, a foot-mounted swim fin comprises a fin blade or webbing and a
means
to affix a swimmers foot to the fin blade or webbing. The fin blade or webbing
increases the volume of water displaced during a kicking motion, which results
in
the scuba diver, snorkeler, or the like having an increased acceleration and
propulsion through the water.
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Traditional foot-mounted swim fins have been designed having the fin blade or
webbing rigidly affixed to a foot receiving portion or boot and being secured
to the
foot via a strapping means around the back of the heel. To achieve the maximum
propelling force from the foot-mounted swim fin and to reduce drag it is
desired to
have the fin blade or webbing and the foot receiving portion or boot
substantially
parallel or in-line with the swimmers tibia, this increases the force of the
kicking
motion and reduces drag during coasting. To achieve this effect with
traditional
foot-mounted swim fins great strain is imposed upon the ankle during the
kicking
motion. Thus it would be desirable to have a foot-mounted swim fin that
reduces
the stress imposed on the ankle while lowering drag and still allowing the
same or
greater propelling force. More recent developments of foot-mounted swim fins
have not adequately provided solutions to this problem.
United States Patent No. 4,017,925 issued April 19, 1977 to Shamlian describes
a
swim fin with members provided for maintaining a swimmers foot in a
predetermined angular relationship with respect to the swimmers leg. The ankle
movement restrictor attachment for the swim fin uses a shin brace with straps
or
tubular assembly pivoted to the rear of the fin and the restrictor can be
positioned
to fit around the back of the leg.
United States Patent Application publication No. 2007/0032148 published
February 8, 2007 to McCarthy describes an improved adjustable heel strap
having
an adjustable instep strap connected to the heel strap adjacent the heel
portion of a
swimmer foot. A method is also provided for a multi-dimensional heel strap
adjustability around the ankle and instep to reduce ankle strain, increase
ankle
support and distribute load and stress points.
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United States Patent No. 5,632,662 issued May 27, 1997 to Cadorette describes
a
swim fin that comprises a boot portion, a web portion and a pair of side
members.
A pivot means connects the side members to the boot portion and permits the
side
members and the web portion to rotate about the boot portion such that when a
legging strap is attached the web portion is pivoted to a position
approximately
parallel to the swimmer lower leg.
Some problems encountered in such prior art foot-mounted swim fins include the
fin blade or webbing not being substantially parallel or in-line to the
swimmers
tibia, the foot receiving portion or boot not being optimally positioned to
reduce
drag, the fin blade or webbing not being optimally positioned to reduce drag
and a
lack of substantive ankle support. These problems result in a greatly reduced
swimming efficiency and in some cases causing pain in and around the ankle
area.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention is to provide a foot-
mounted swim
fin and binding.
A purpose of this foot-mounted swim fin and binding is to provide a superior
way
to achieve comfort, thrust and speed for a swimmer. The foot-mounted swim fin
and binding accomplishes this by binding it to the body, such as for example,
to the
lower leg, so as to reduce chafing and/or blistering to the foot area, such
as, for
example, to the heel, by reducing and/or eliminating ankle strain and by
reducing
drag. The foot-mounted swim fin and binding also increases thrust potential by
optimizing the blade position.
Accordingly, as an aspect of the present invention, there is provided a foot-
mounted swim fin and binding. The binding comprises a rigid curved leg
engaging
means, at least one strapping means for affixing the rigid curved leg engaging
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means to the lower portion of a swimmers leg and a pair of side members. Each
of
the pair of side members comprise an upper and a lower member which are
pivotably connected and the upper member of each of the side members are
rigidly
affixed to each side of the rigid curved leg engaging means. The foot-mounted
swim fin comprises a fin blade or webbing and a foot receiving portion and the
lower member of each of the pair of side members are operably rigidly affixed
to
the sides of the foot receiving portion.
As another aspect of the present invention, there is provided a foot-mounted
swim
fin and binding. The foot-mounted swim fin and binding comprises a shin
engaging means extending in a longitudinal direction having a pivot slot
formed
longitudinally therein and at least one strapping means for affixing the swim
fin
and binding to the lower portion of a swimmers leg. A rigid shin member
extending longitudinally having an upper and a lower portion and having at
least
one pivot member in the upper portion adapted to engage with the pivot slot of
the
shin engaging means for allowing the rigid shin member to pivot and slide in
the
same plane relative to the shin engaging means. A fin blade or webbing for
increasing a propelling force of a swimmer having a foot receiving portion
with a
top portion formed therein. A hinge mechanism is rigidly affixed to the lower
portion of the rigid shin member and removably affixed to the top portion of
the
foot receiving portion having a pivot axis that is parallel to the plantar
flexion axis
of rotation of the swimmers ankle joint for allowing the fin blade or webbing
to
pivot relative to the rigid shin member.
The foot-mounted swim fin and binding comprises a fin blade or webbing having
a
foot receiving portion formed thereon. A hinge mechanism is removably affixed
to
the fin blade or webbing and foot receiving portion for allowing the fin blade
or
webbing to rotate relative to a shin engaging means.
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The pair of side members or the hinge mechanism of the present invention
preferably have a maximum predetermined allowable angle, which is defined as
the angle whereby the foot is maximally extended (i.e. pointed out),
preventing
hyperextension of the swimmers ankle joint.
The pair of side members of the present invention that are pivotably connected
preferably have an axis of rotation that is substantially equal to the plantar
flexion
(i.e. the movement which increases the angle between the foot and the leg)
axis of
rotation of the swimmers ankle joint. The hinge mechanism of the present
invention preferably has axis of rotation that is substantially parallel to
the plantar
flexion axis of rotation of the swimmers ankle joint.
The upper and lower members of the present invention are preferably pivotably
connected via a single pivotable means, such as, for example, a hinge or
rivet, and
even more preferably pivotably connected via a plurality of inter-connecting
members each of which are connected via a pivotable means.
The hinge mechanism of the present invention may be replaced with the
plurality
of inter-connecting members each of which are connected via a pivotable means
as
described herein.
The fin blade or webbing of the present invention is preferably at an angle
with
respect to the foot receiving portion such that when the foot is maximally
extended
the fin blade or webbing is substantially parallel or in-line with the
swimmers tibia.
The rigid curved leg engaging means of the present invention is preferably
made
from a durable waterproof material or any combination thereof, such as, for
example, stainless steel or plastic, and even more preferably made from a
lightweight waterproof material or any combination thereof, such as, for
example,
fibreglass or carbon fibre.
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The fin blade or webbing and the foot receiving portion of the present
invention
are preferably formed as two pieces and are operably rigidly affixed together,
and
even more preferably formed as a single piece.
The fin blade or webbing and the foot receiving portion of the present
invention
are made from a flexible material, such as, for example, rubber, and it is
preferable
that the fin blade or webbing is made more rigid than the foot receiving
portion.
The rigid curved leg engaging means or shin engaging means of the present
invention preferably has a gel padding, a foam padding or the like affixed to
the
inside, allowing for greater comfort during use.
The upper and lower members of each of the pair of side members of the present
invention preferably have an a adjusting means, allowing for fine tuning of
the axis
of rotation of the upper and lower members to be substantially equal to the
plantar
flexion axis of rotation of the swimmers ankle joint.
The rigid curved leg engaging means of the present invention is preferably
made
from a durable waterproof material or any combination thereof, such as, for
example, stainless steel or plastic, and even more preferably made from a
lightweight waterproof material or any combination thereof, such as, for
example,
fibreglass or carbon fibre.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will be further described, by way of
example, with reference to the accompanying drawings, in which:
Figures 1(a) and (b) are 3-dimensional perspective views of the foot mounted
swim
fin and binding of an embodiment of the present invention;
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Figures 2(a) and (b) are side views of the foot mounted swim fin and binding
of an
embodiment of the present invention illustrating the maximum allowable angle;
Figures 3(a) and 3(b) is a perspective view of a preferred pivotable
connection
between the upper and lower members of the pair of side members of an
embodiment of the present invention;
Figure 4 is a perspective side view of the fin blade or webbing at an angle
with
respect to the foot receiving portion of an embodiment of the present
invention;
Figure 5 is a 3-dimensional perspective view of the foot mounted swim fin and
binding of another embodiment of the present invention;
Figure 6(a) and (b) are front and side views of the shin engaging means of the
foot
mounted swim fin and binding of another embodiment of the present invention;
Figure 7 is a 3-dimentional perspective view of the rigid shin member of the
foot
mounted swim fin and binding of another embodiment of the present invention;
Figure 8 is a front view of the shin engaging means and rigid shin member of
the
foot mounted swim fin and binding of another embodiment of the present
invention; and
Figure 9 is a side view of the shin engaging means and rigid shin member of
the
swim fin and binding of another embodiment of the present invention showing
the
relative pivoting and sliding movements.
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will now be described with reference to
Figures 1 to 4.
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Figures 1(a) and 1(b) are 3-dimensional perspective views of the foot mounted
swim fin and binding (20) of an embodiment of the present invention. The
binding
(1) comprises a rigid curved leg engaging means (2), at least one strapping
means
(3) and a pair of side members (4). The rigid curved leg engaging means (2) is
formed to fit around the back of the calf of the lower leg of a swimmer. The
at least
one strapping means (3) are used to rigidly affix the rigid curved leg
engaging
means (2) to the calf of the swimmer lower leg when being worn. Each of the
pair
of side members (4) comprise an upper (5) and a lower (6) member which are
pivotably connected and the upper member (5) of each of the side members are
rigidly affixed to each side of the rigid curved leg engaging means (2). The
foot-
mounted swim fin comprises a fin blade or webbing (8) and a foot receiving
portion (9) and the lower member (6) of each of the pair of side members (4)
are
operably rigidly affixed to the sides of the foot receiving portion (9).
The pair of side members (4) which are pivotably connected has an axis of
rotation
(A) that is substantially equal to the plantar flexion axis of rotation of the
swimmer
ankle joint, which is being rigidly held in place by the leg engaging means
(2) and
the at least one strapping means (3). To fine tune the position of the axis of
rotation
(A), preferably there is provided on each of the upper (5) and lower (6)
members
of the pair of side members (4) an adjusting means (not shown) to lengthen
and/or
shorten the upper (5) and lower (6) members of each of the pair of side
members
(4). The adjusting means may be any means that is known in the art; preferably
the
adjusting means are a slot and bolt mechanism.
The axis of rotation (A) preferably has a maximum predetermined allowable
angle
(0 = 02 - 01), which is defined as the angle between when the foot is rotated
as
much as possible toward the shin (01) (i.e. the lower leg and foot form the
smallest
acute angle possible) and when the foot is maximally extended (02) (i.e.
pointed
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out) without the ankle joint being hyper-extended, as illustrated in figures
2(a) and
2(b), respectively. The maximum predetermined allowable angle (0) allows the
swimmer achieve the maximum propelling force from the foot-mounted swim fin
(20) by having the fin blade or webbing (8) and the foot receiving portion (9)
substantially parallel or in-line with the swimmers tibia.
The upper (5) and lower (6) members are preferably pivotably connected via a
single pivotable means, and even more preferably pivotably connected via a
plurality of inter-connecting members (10) each of which are connected via a
pivotable means. Figures 3(a) and 3(b) shows a preferred embodiment of the
pivotably connected upper (5) and lower (6) members. The ends of the upper (5)
and lower (6) members are tapered on one side, two of the inter-connecting
members (10) are substantially oval in shape while the middle inter-connecting
member (10) is substantially triangular in shape, and each of which are
connected
via a pivotable means. The shape of the ends of the upper (5) and lower (6)
members in conjunction with the shape of the middle inter-connecting member
(10) allow the side members (4) to pivot in the direction of the tapers and
prevent
the side members (4) to pivot opposite the direction of the tapers. This
embodiment
contains three inter-connecting members, the upper (5) and lower (6) members
may be connected via more or less inter-connecting members (10) without
departing from the spirit of the invention.
The pivotable means may be any means that is known in the art; preferably the
pivotable means are, for example, hinges or rivets.
The fin blade or webbing (8) of the present invention is preferably at an
angle with
respect to the foot receiving portion (9) such that when the foot is maximally
extended the fin blade or webbing (8) is substantially parallel or in-line
with the
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swimmers tibia as depicted in Figure 4(a) and 4(b). The angle between the fin
blade or webbing (8) and the foot receiving portion (9) is typically about 200
to
300. This angle allows the fin blade or webbing (8) to be substantially
parallel or
in-line with the swimmers tibia.
To provide further comfort and to aid in the reduction of chaffing the rigid
curved
leg engaging means (2) preferably has a gel padding, a foam padding or the
like
(not shown) affixed to the inside.
The fin blade or webbing (8) and the foot receiving portion (9) of the present
invention may be permanently rigidly affixed to the binding (1) or optionally
it
may be removable, allowing for customizability.
The fin blade or webbing (8) and the foot receiving portion (9) of the present
invention are preferably formed as two separate pieces and are operably
rigidly
affixed together, and even more preferably formed as a single piece.
Another embodiment of the present invention will now be described with
reference
to Figures 5 to 9.
Figure 5 is a 3-dimensional perspective view of the foot mounted swim fin and
binding (40) of another embodiment of the present invention. The foot mounted
swim fin and binding (40) comprises a fin blade or webbing (41) having a foot
receiving portion (42) formed thereon. Preferably, the fin blade (41) would be
rigid
with a width that is larger than its length. Preferably, the fin blade (41)
would be
substantially parallel with the tibia when a swimmer's foot is maximally
extended
(02).
Affixed to the fin blade (41) or formed as one unit is a foot receiving
portion (42)
to fully enclose and secure the foot. The foot receiving portion (42) may also
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be formed to partially enclose the foot and have a strapping means (not shown)
around the heel or ankle to ensure a secure and tight fit so the swimmer's
foot is
held in position in relation to the foot receiving portion (42) and fin blade
(41).
A hinge mechanism (44) is either formed into the fin blade (41) and foot
receiving
portion (42) as one unit or formed in such a way so as to allow the fin blade
(41)
and foot receiving portion (42) to detach from the hinge mechanism (44) and
allow
for example an interchange of fin blade (41) and foot receiving portion (42)
styles.
The hinge mechanism (44) may be formed onto the top of the foot receiving
portion (42) so as to provide comfort and be located to keep it in line with a
shin
engaging means (45). The shin engaging means (45) is preferably positioned on
the
front side of the lower leg over the shin bone area. Preferably, the shin
engaging
means (45) extends from a position just below the knee cap down to the ankle
area
and does not interfere with the hinge mechanism (44) on top of the foot when
the
foot is rotated as much as possible toward the shin (81).
The underside of the shin engaging means (45) is formed to fit the shin area.
The
profile of the shin engaging means (45) is shaped so as to minimize drag in
the
water. The hinge mechanism (44) is preferably positioned at the top of the
foot as
close to the ankle as possible in such a way that the hinge mechanism does not
interfere with the swimmer's ankle, foot, lower leg or of the shin engaging
means
(45) when the swimmer's foot is rotated as much as possible toward the shin
(91)
or when the swimmer's foot is maximally extended (02). This range of motion of
the swimmer's foot, i.e. repeatedly moved from a maximally extended position
(02)
to being rotated as much as possible toward the shin .(81), is necessary for
swimming with this type of fin and a traditional swim fin for that matter.
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Affixed to the hinge mechanism (44) on top of the swimmer's foot is a rigid
shin
member (46) that is substantially positioned in front of and parallel to the
swimmers shin. Preferably, the rigid shin member (46) will have a hydrodynamic
profile that causes the least amount of drag while the swimmer's lower leg is
moving during a scissor-kick, or the like. The other end of the rigid shin
member
(46) is adapted with pivot members (47) to engage with corresponding
longitudinal
slot(s) (48) of the shin engaging means (45) so as to be able to pivot and
slide. The
leg engaging means (45) is also adapted with another longitudinal slot (49)
that is
adapted to receive the rigid shin member (46). The shin engaging means (45)
has a
longitudinal slot (48) along the upper portion that is adapted to receive the
pivot
members (47) of the rigid shin member (46). The longitudinal slots (48, 49)
and
pivot members (47) combination allows the shin engaging means (45) to slide
and
pivot in relation to the rigid shin member (46) for easily allowing the
swimmer's
foot to repeatedly moved from a maximally extended position (02) to being
rotated
as much as possible toward the shin (01) when swimming.
The rigid shin member (46) may be made of materials such as, for example,
aluminum, stainless steel, carbon fiber, or any other material suitable to
sustaining
the forces experienced when swimming.
The rigid shin member (46) may also be replaced with the upper (5) and lower
(6)
members being pivotably connected via a plurality of inter-connecting members
as
described above in the other embodiment.
The leg engaging means (45) is affixed to the lower leg of the swimmer,
preferably
at the narrowest part of the ankle and below the knee cap, i.e. at the top of
the calf
muscle on back of leg. Leg engaging strapping means (50) affixes the leg
engaging
means (45) to the lower leg of the swimmer. Preferably, for this embodiment a
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fabric sheath (not shown), having for example a zipper, that extends the
entire
length of the leg engaging means (45) and around the back of the lower leg.
Additionally, any other configuration that rigidly holds the leg engaging
means
(45) tightly in place may be used.
The rigid shin member (46) and its pivot members (47) are able to slide and
pivot
in their respective longitudinal slots (48, 49). The portion of the rigid shin
member
(47) nearest to the swimmer's foot can protrude from its longitudinal slot
(49) as
needed to allow the swimmer's foot to rotate in the direction toward the lower
leg,
i.e. from 62 to 81. When the swimmer's foot rotates in the opposite direction,
i.e.
from 0 1 to 02, and becomes maximally extended, the pivot members (47) of the
rigid shin member (46) stop against the lower portion of the longitudinal slot
(48)
on the leg engaging means (45). The rigid shin member (46) is also stopped at
a
predetermined point in the leg engaging means (45) at the portion nearest to
the
ankle. At the same time the rigid shin member (46) prevents the hinge
mechanism
(44) on top of the swimmer's foot from rotating past a maximum predetermined
allowable angle, which is similar to the maximum predetermined allowable angle
as described above in the other embodiment. Both of the stops described above
prevent hyper-extension of the ankle joint and distributes the forces
generated by
the fin blade or webbing (41) while swimming away from ankle joint over the
length of the lower leg via the leg engaging means (45). The forces are
transferred
through the hinge mechanism (44) through the rigid shin member (46) through
the
leg engaging means (45) and finally onto the lower leg of the swimmer.
Chafing and blistering of the heel is essentially eliminated. Substantially
more
force from the swimmer's upper leg while scissor-kicking can be transferred to
the
fin blade or webbing (41). All critical components could consist of any
suitable
metals, plastics, composites, carbon fiber, etc. or any combination -of these.
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Padding may be added in certain areas where contact is made with the swimmer's
body. Various adjusting mechanisms may be added to allow for adjustability to
the
stop point positions on the foot mounted swim fin and binding (40). The leg
engaging strapping means (50) may be made of any material that conforms to the
leg, for example, fabric and zipper or straps and buckles or any -other
suitable
material. Preferably the fin blade or webbing (41) would ideally approximate a
dolphin's tail.
The foregoing are exemplary embodiments of the present invention and a person
skilled in the art would appreciate that modifications to these embodiments
may be
made without departing from the scope and spirit of the invention.
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