[0001] The present invention concerns swim fins, and particularly concerns an open-heel
shoe swim fin.
[0002] Swim fins, which are made in a very wide variety of shapes and sizes, are divided,
among other things, into two main families, that is to say the one of full-foot fins,
in which the user's foot is completely inserted up to the heel into a suitable housing,
and the one of the open-heel fins, in which only the user's forefoot enters a cavity
suitably arranged in the fin, while the heel is surrounded by a strap connected to
the foot-pocket sides and provided with a portion or element, named heel element,
right suitable to accommodate the user's heel.
[0003] Clearly, the two different types of fins address to very different uses; full-foot
fins normally address to the user who practices snorkeling or underwater fishing,
where it is important to control the fin movement whereas it is not essential to have
the ability to wear dive boots to protect the feet from cold. On the other hand, this
last necessity becomes very important when practicing scuba diving to even considerable
depths, being therefore advisable to reduce as much as possible the heat loss from
the diver's body. However, the use of dive boots actually prevents the adoption of
full-foot fins, which are generally designed to best adapt to the shape of the naked
foot and would tend to slip away when another interposed material is present.
[0004] A problem with the use of open-heel shoe fins lies in the fact that, in this type
of fins, the sole portion of the shoe of the fin is made of a relatively more rigid
material and in one piece with the paddle portion of the fin, and this configuration
makes it so that the same sole portion moves away from and close to the diver's heel
during a finning cycle, thus creating a strong feeling of instability, thus losing
the functionality (thrust) and simultaneously increasing the load exerted by the strap,
i.e. by the heel element, on the heel of the user.
[0005] The strap that is used to hold the foot in the open-heel shoe is generally made of
elastomeric material, and is prone to cause discomfort to the user at the Achilles
tendon, due to the very shape of the ankle section. In this regard, the initial attempt
was to make straps having an enlarged central portion, so as to spread over a larger
area the tensile load exerted by the strap, then a removable heel element has been
inserted on the strap made of elastomeric material. This solution is mainly connected
to the possibility of choosing a more comfortable material for the heel element, and
at the same time of allowing the two parts to be replaced in distinguished ways.
[0006] At the state of the art, solutions such as the one reported in document
EP2433680, whose owner is the same applicant, are known. However, the heel element described
therein is a body of flexible material that is essentially flat and is adapted to
the user's heel by deformation. This solution tends on the one hand to wear out the
element itself, which is subjected to a considerable load, and on the other hand clearly
limits the comfort of the user, since in use the heel element will tend to naturally
slide towards the Achilles tendon and to apply its maximum load right in that region.
[0007] Moreover, open-heel fins are currently used exclusively in combination with dive
boots, as the existing straps and heel elements are not suitable to allow a comfortable
and continuous use without the buffering and cushioning effect of neoprene. Moreover,
the open-heel shoe fins are only developed for being used with dive boots, so the
material of the shoe itself is rather rigid (to improve the transmission of the force
from foot to fin), but this does not make it very comfortable without dive boots.
This way, dive boots or two kinds of different fins must be always available.
[0008] Object of the present invention is thus to provide an open-heel shoe swim fin wherein
it is possible to connect the heel element to the shoe of the fin in a more stable
way, so that to reduce and control the oscillation of the sole portion with respect
to the back portion of the foot of the user, and so that to distribute the load of
the connection more efficiently.
[0009] Moreover, a further object of the invention is to provide a heel member that is able
to overcome the problems highlighted above and to be coupled with a shoe of a sufficiently
soft material for being comfortable, thus ensuring greater fitting comfort to the
user and simultaneously greater stability and safety in the coupling with the shoe
of the fin by means of the strap and thus allowing a comfortable and continuous use
both in combination with dive boots and in the absence of dive boots on the feet of
the user.
[0010] Object of the present invention is thus an open-heel shoe swim fin comprising a paddle
portion and a shoe portion, said shoe portion comprising a sole portion made in one
piece with said paddle portion, first coupling means of the strap being arranged on
the sides of said shoe portion, the strap being connected to a heel member, said sole
portion of said shoe being provided, in proximity of the end opposite the one facing
said paddle portion, with second coupling means of the strap.
[0011] In a first embodiment, said strap is connected at an end of said heel member and
returned to the heel member itself by coupling the strap of the shoe of the fin with
said first and said second coupling means. In a variant, said strap is connected with
said heel member and returned to said heel member by coupling with said first coupling
means, and coupled with said second coupling means.
[0012] Said first and said second coupling means can comprise flaps radially projecting
from said shoe portion, which are substantially oriented in parallel to the sole plane
of the shoe, and provided with at least one through-slot for connecting with the strap.
In a preferred embodiment, the walls of the slot have an inclination so that to favor
the connection with the strap.
[0013] Moreover, further object of the present invention is a heel member for an open-heel
shoe fin, comprising a looped-shaped body with a substantially parabolic profile,
so that to form a cavity with a substantially parabolic profile inside it, the cavity
being adapted for housing the ankle of the user, which is provided in both of its
arms with at least one axial duct adapted for housing the strap for the coupling with
the shoe of the fin.
[0014] In an embodiment, at least one radial cavity communicating with said axial duct,
is provided on each of said arms, said cavity being suitable for the coupling with
an element intended to connect with an end of the strap. Advantageously, said arms
are each provided with a further axial duct parallel to the first duct, said radial
cavities being in communication with one of the two ducts. This way, the strap portion
runs along the entire overall length of said heel member from the one that is returned
by the coupling means coupling with the sides of the shoe of the fin.
[0015] Advantageously, said heel member is made in one piece of elastically yielding material,
and preferably of polymeric foam, and even more preferably closed-cell polymeric foam.
Polymeric foams suitable for making the aforesaid heel member comprise polyurethane
and polystyrene.
[0016] An embodiment variation provides that the heel element is made of thermoplastic rubber
or natural rubber or mixtures thereof.
[0017] In a further embodiment, the body of said member is provided with gripping means
on the outer wall of its vertex; these gripping means comprise a through opening made
near the vertex of said heel member.
[0018] Further advantages and characteristics of the swim fin according to the present invention
will become clearer in the following detailed description of some embodiments thereof,
made by way of example and without limitations, with reference to the accompanying
tables of drawings, in which:
figure 1 is a bottom perspective view of a first embodiment of the fin according to
the present invention;
figure 2 is a bottom perspective view of a second embodiment of the fin according
to the present invention;
figure 3 is a plan view of the heel member of figure 2, and
figure 4 is a perspective view of the heel member shown in figure 3.
[0019] A first embodiment of the fin according to the present invention is shown in figure
1; 1 denotes the shoe portion of said fin, which is provided with a paddle portion
2. The flap 211, provided with a slot 221 in which the strap 3 is inserted, the strap
being connected to an end of the heel member 4, while the other end crosses the slot
121 of the flap 111 projecting from the sole portion 101, before also connecting with
the heel member 4, is outwardly projecting on the side 201 of the shoe. Such heel
piece 4 provides two arms 104 wherein an axial duct 114 and a radial opening 124 are
formed. The heel piece 4, as will become clearer below, comprises an ogive-shaped
cavity 304 adapted for housing the heel of the user, between its two arms 104. At
the end facing outwardly, the heel member 4 has the grip 204 for favoring the fin
to be fitted.
[0020] A second embodiment of the fin according to the present invention is shown in figure
2; equal numerals correspond to equal parts. In this case, the strap 3 is returned
in the slot 221 of the flap 211 projecting backward from the side 201 of the shoe
1 towards the heel member 5, which has two coaxial ducts 115 and 125 on the arm 105,
and a radial opening 135 with respect to the same arm, through which the end of the
strap 3 is connected to the slot 321 formed in the flap 311 projecting from the sole
portion 301. Like in the case previously described, the heel member is provided with
the ogive 305 at the intersection of the two arms 105 and of the grip 205.
[0021] A plan view of the heel member of figure 2 is shown in figure 3; equal numerals correspond
to equal parts. The positioning of the axial ducts 115 and 125 formed in the two arms
105, which are parallel to one another, is highlighted in the figure. As is clear
in figure 4, which shows the same member from the opposite perspective with respect
to that of figure 3, the ducts 125 open onto the radial cavities 135 formed on the
side walls of each arm 105, while the ducts 115 open onto the wall facing the grip
205.
[0022] The operation of the fin according to the present invention will become clearer below.
As mentioned in the preamble, in the open-heel shoe fins known in the state of the
art, the strap, provided with a heel piece, is connected to a single point for each
side of the shoe. Consequently, this results in the fact that the sole portion near
the heel of the diver moves close to and away from the heel itself during the finning
cycle, thus making the finning not very comfortable and also less safe. The fin according
to the present invention is provided, as proved in both embodiments of figures 1 and
2, with further coupling means for coupling with the strap, which are arranged in
proximity of the heel of the user, and thus able to minimize the oscillation described
above and then globally improving the fitting of the fin and its use.
[0023] In the embodiment of figure 1, the two ends of the strap are connected to the heel
member 4 and returned through the slots of the flaps 211 and 111. The embodiment of
figure 2, which is functionally equivalent to that of figure 1, provides the advantage
of a more compact arrangement of the strap and thus more effective in preventing possible
contacts and tangling of the strap itself. The heel member 5 used in this embodiment
has two axial ducts overlapping inside the arm 105, and which allow the forth and
back travel of the strap 3 with respect to the slot 221 of the flap 211.
[0024] The flaps 211, 111 and 311 projecting from the shoe portion of the fin according
to the invention are preferably made in one piece with said shoe portion of the fin,
usually made of thermoplastic material.
[0025] In order to implement these solutions, a heel member that allows to easily and stably
connect the strap to two points for each side of the shoe was advantageously designed.
Such member was designed so that to solve the problems encountered in the open-heel
shoe fins known in the state of the art.
[0026] The shape of the body of the heel member according to the present invention ensures
a housing that better meets the comfort needs of the anatomical part concerned with
respect to that which is provided in the state of the art. In fact, as shown in figure
3, the substantially parabolic profile of the cavity comprised between the two arms
105 allows a better distribution of the load exerted by the strap. Then, the fact
that the heel member body is made of an elastically yielding material allows the Achilles
tendon of the user to rest more "softly" at the vertex of the cavity on one hand and
allows the ends of the arms 105 to converge towards the heel of the user on the other,
thus enveloping it and thus evenly distributing the load exerted by the strap.
[0027] In particular, the ogive 305 intended to house the heel of the user is adherent to
the morphology of the anatomic part in question, and its shape allows the positioning
of the Achilles tendon. The geometry is so that, in theory, the tendon itself is unstressed,
i.e. the heel piece rests on the sides adjacent to the tendon.
[0028] Once properly connected to the shoe, according to one of the modes described above,
the heel member can simply be used by the user who, at the fitting time, will introduce
his foot by using the grip provided at the end of the vertex end of the body of the
aforesaid member.
[0029] The device according to the present invention thus provides an effective solution
to the problems highlighted at the state of the art, thus ensuring a comfortable fit
and further contributing to the rationalization and simplification of the connection
with the open-heel shoe of the fin.
[0030] The body of the heel member is made of elastically yielding material, and preferably
of closed-cell polymeric foam, which better adapts to the conditions of high environmental
stress to which the device is subjected; preferable polymeric foams are polyurethane
foams and polystyrene foams.
1. Open-heel shoe swim fin comprising a paddle portion (2) and a shoe portion (1), said
shoe portion (1) comprising a sole portion (101; 301) made in one piece with said
paddle portion (2), first coupling means (211, 221) of the strap (3) being arranged
on the sides (201) of said shoe portion (1), the strap being connected to a heel member
(4;5), said sole portion (101;301) of said shoe being provided, in proximity of the
end opposite the one facing said paddle portion, with second coupling means (111,
121; 311, 321) of the strap (3).
2. Swim fin according to claim 1, wherein said strap (3) is connected at an end of said
heel member (4) and returned to the heel member (4) itself by coupling the strap (3)
of the shoe (1) of the swim fin with said first (211, 221) and said second (111, 121)
coupling means.
3. Swim fin according to claim 1, wherein said strap (3) is connected with said heel
member (5) and returned to said heel member (5) by coupling with said first coupling
means (211, 221), and coupled with said second coupling means (311, 321).
4. Swim fin according to any one of preceding claims 1 to 3, wherein said first (211,
221) and said second (111, 121; 311, 321) coupling means comprise flaps radially projecting
from said shoe portion (1), which are substantially oriented in parallel to the sole
plane (101; 301) of the shoe and provided with at least one through-slot (221, 121;
321) for connecting with the strap.
5. Swim fin according to claim 4, wherein the walls of the slot (221, 121; 321) have
an inclination so that to favor the connection with the strap (3).
6. Heel member for an open-heel shoe swim fin, comprising a looped-shaped body (4; 5)
with a substantially parabolic profile, so that to form a cavity with a substantially
parabolic profile inside it, the cavity being adapted for housing the ankle of the
user, which is provided in both of its arms with at least one axial duct (114; 115,
125) adapted for housing the strap (3) for the coupling with the shoe of the swim
fin.
7. Heel member according to claim 6, wherein each of said arms (104; 105) is provided
with at least one radial cavity (124; 135), communicating with said at least one axial
duct (114; 115; 125).
8. Heel member according to claim 7, wherein said arms (105) are each provided with a
further axial duct (125) parallel to the first duct (115), said radial cavities (135)
being in communication with one of the two ducts.
9. Heel member according to any one of claims 6 to 8, wherein said heel member is made
in one piece of an elastically yielding material, and preferably of expanded polymeric
material, and even more preferably of expanded closed cell polymeric material.
10. Heel member according to any one of preceding claims 6 to 8, wherein the body of said
member is made in one piece of thermoplastic rubber or natural rubber or mixtures
of these rubbers.
11. Heel member according to any one of preceding claims 6 to 10, wherein the body (4;
5) of said member is provided, on the outer wall of its vertex, with gripping means
(204; 205).
12. Open-heel shoe swim fin according to any one of preceding claims 1 to 5, wherein said
heel member (4; 5) is made according to one or more of preceding claims 6 to 11.