The present invention relates to the field of rackets, and more precisely
5 to the field of racket handles.
A particularly advantageous application of the present invention lies in
racket sports such as badminton; a badminton racket including a handle of
the present invention provides performance and properties that are highly
appreciated by players of badminton, and in particular by high level players.
10 Naturally, in the context of the present invention it is possible to
envisage other advantageous applications for other racket sports, in particular
sports such as tennis or squash.
The Applicant is of the opinion that the subject matter of the present
invention may also find advantageous applications in other sports, such as
15 golf.
So-called "traditional" handles for badminton rackets are known that
are octagonal in shape, being regular and straight.
With such a configuration, the size and the shape of the handle are the
same along the entire length of said handle.
20 Such handles are often based on wood having a grip wound thereon,
where the grip is made of a polyurethane type material.
The Applicant is of the opinion that with a traditional handle of that
type, players, and in particular high level players, lose power and accuracy
when they make plays such as a smash,
25 The Applicant is also of the opinion that that type of handle does not
provide best responsiveness and accuracy for flat play or for net play.
To mitigate those drawbacks, several known solutions are already in
existence: several documents in the state of the art have been found and
they tend to solve the above-mentioned problems of responsiveness and
3 o power, at least in part.
These documents include in particular Document CN 1 555 899, which
proposes a solution in which the handle is made of a material that, once
heated, retains the shape of the hand for better grip. The handle can thus be
said to be "thermoformed", where such a solution is also known for improving
5 the comfort of ski boots.
Document KR 200388042 proposes a solution in which the racket
handle includes encrustations for the fingers in order to improve a user's grip
on the racket.
There is also Document WO 96f19266, which discloses a handle for the
10 shafts of sports articles such as golf clubs or tennis rackets. The handle in
that document is constituted by a tubular body made of an elastomer material
having a recess with parallel edges for receiving the shaft, and having an
outside surface that is shaped to simulate a helically-wound adhesive strip.
In the documents in the state of the art, there is also Document
1.5 FR 2 665 097, which discloses an ergonomic handle for sports articles that
serves to increase the forces exerted by the hand in transverse movements
and to reduce slipping, while also removing sweat.
In any event, the various solutions proposed in the above-mentioned
documents are not satisfactory in terms of performance, in particular for
20 playing badminton at a good or even a high level. The Applicant is of the
opinion specifically that the various solutions envisaged in the state of the art
do not provide good grip and good responsiveness for a sport such as
badminton.
The Applicant finds a manifest shortcoming in racket handles and in
2s particular handles for badminton rackets: the state of the art does not
propose a satisfactory industrial solution providing good responsiveness,
accuracy, and power, together with comfort and grip that are appropriate for
pfaying badminton, and in particular badminton at a high level.
The object of the present invention is to provide a simple and effective
30 solution to the above-mentioned problems, among others, where problems
associated with cost and fabrication are naturally taken into consideration in
the context of the present invention.
One of the technical problems solved by the present invention thus
consists in proposing a solution concerning the design and the fabrication of a
5 racket handle that serves in particular to provide good grip while offering
good hitting power and good accuracy.
To this end, the present invention relates to a racket handle such as a
handle for a badminton racket, for example. Naturally, as mentioned above,
the present invention may also be considered for other rackets, such as, for
1.0 example: a tennis racket, a squash racket, or indeed a golf club.
In the present invention, the handle is substantially in the form of a
truncated cone in which each cross-section presents a shape that is
substantially elliptical.
According to the present invention, the handle for a racket, e.g. of the
rs badminton racket type, comprises a central core and a covering layer
covering the central core at least in part, the covering zone defined by the
covering of the covering layer around the central core being a grip zone in
which each cross-section is substantially elliptical in shape, and the grip zone
has a first end and a second end opposite from the first end, said second end
20 having provision for being connected to a rigid shaft of the racket, and the
grip zone presents the shape of a truncated cone extending over a length
greater than half the length of the handle, and the truncated cone is shaped
in such a manner that the cross-section of the first end corresponds to the
large base of the truncated cone, while the cross-section of the second end
25 corresponds to the small base of the truncated cone.
It can be understood that the second end is close to the head of the
racket, while the first end, opposite to the second end, is remote from said
head. The truncated cone is advantageousIy shaped in such a manner that
its cross-section is greater at the first end than at the second end. In other
3 o words, the large base of the truncated cone is arranged at the first end, while
the small base of the truncated cone is arranged at the second end.
4
Furthermore, the term "cross-section" as used in the present invention
should be understood throughout the description below as designating a
section on a plane perpendicular to the axis of revolution of the cone.
Thus, the handle of the present invention presents a specific
5 configuration that is characteristic of the present invention.
The Applicant has observed that this specific configuration presents the
following advantages in particular:
the thick portion of the cone, at the bottom end of the handle or "end
cap" provides good grip; this good grip ensures that it can be held securely so
1.0 as to increase power for a volley shot, in particular a smash; and
the fine portion of the cone, at the top portion of the handle or "top
cap", makes the racket responsive for flat play and net play.
Thus, by means of this specific configuration as proposed above, the
player has a racket with a handle that is highly appreciated for being
15 ergonomic and comfortable, being very responsive in the high portion of the
handle and providing good power in the low portion of the handle, while
maintaining irreproachable comfort because of the conical shape.
Advantageously, the handle of the present invention has a central core
and a covering layer covering the central core at least in part. The covering
20 zone that is defined by the covering of the covering layer around the central
core is referred to as a grip zone.
In an advantageous variant embodiment of the present invention, the
covering layer comprises a material such as a foam, and this foam is
preferably a polyurethane foam. Alternatively, in another variant
2s embodiment, the covering layer comprises a material such as an injected
plastics material, with this plastics material preferably being a material of the
styrene ethylene butadiene styrene (SEBS) type.
In an advantageous embodiment, the central core of the present
invention comprises an elongate element having a bottom portion and a top
30 portion; the element has cross-sections, each presenting a shape that is
substantially polygonal over at least a portion of the length of said elongate
5
element, and in particular over the length of the bottom portion of said
elongate element. The top portion of the elongate element preferably
presents, all along its length, cross-sections, each presenting a shape that is
substantially oval.
s Under such circumstances, the covering layer is configured to fit
around the polygonal elongate element in such a manner that the handle
presents substantially the form of a truncated cone with cross-sections, each
presenting a shape that is substantially elliptical.
The bottom portion may also include cross-sections, each presenting a
10 shape that is oval, elliptical, or round.
Under such circumstances, and preferably, the handle of the present
invention includes:
a) at the first end, a cross-section in the shape of a first ellipse with a
first major axis and a first minor axis; and
15 b) at the second end, a cross-section in the shape of a second ellipse
with a second major axis and a second minor axis.
Advantageously, the area of the first ellipse is greater than the area of
the second ellipse.
Advantageously, the taper ratio between the first and second major
20 axes lies substantially in the range 1.05 to 1.2, approximately.
Advantageously, the taper ratio between the first and second minor
axes lies substantially in the range 1.2 to 1.5, approximately.
In an advantageous variant embodiment of the present invention, the
central core is made at least in part out of wood.
2s Advantageously, the central core indudes an opening in its top portion,
which opening is configured to enable a rigid shaft to be inserted therein so
as to enable the handle to be assembled with the racket.
In an advantageous variant embodiment of the present invention that
may naturally be combined with the other variants described above, the grip
30 zone is covered at least in part by an overgrip.
The present invention also provides a racket, e.g, of the badminton
racket type, including a handle as described above.
Correspondingly, the present invention also provides a method of
fabricating a handle for a racket, such as a badminton racket, for example,
5 said handle including an elongate central core.
Advantageously, the fabrication method of the present invention
comprises:
a positioning step consisting in positioning the central core inside a
mold having molding means in the form of a truncated cone in which each
1 o cross-section presents a shape that is su bstantialty elliptical; and
a molding step consisting in pouring a foamable liquid into said mold
or alternatively consisting in injecting a liquid plastics material into said mold.
The fabrication method as described above has characteristic steps
that make it possible to obtain the configuration and the geometry of the
1s handle of the present invention.
Advantageously, the elongate central core presents a cross-section that
is polygonal.
Thus, by virtue of its configuration and its specific properties, and also
by virtue of the technical fabrication steps that are performed, the present
20 invention makes it possible to design and fabricate a racket handle that is
ergonomic, providing good grip, good hitting power, and that is very
responsive for various types of play such as smashes, flat play, or indeed net
play-
Other characteristics and advantages of the present invention appear
25 from the following description made with reference to accompanying
Figures 1A-1B to 5 which show two limiting embodiments, and in which:
Figures I A and I B are respective diagrammatic longitudinal section
views of a handle in a first advantageous embodiment of the present
invention;
3 o ' Figures 2A to 2C are respective diagrammatic cross-section views of a
handle in the embodiment of Figures 1A and 1B;
7
Figures 3A and 3B are respective diagrammatic longitudinal section
views of a handle in a second advantageous embodiment of the present
invention;
Figures 4A to 4C are respective diagrammatic cross-section views of a
5 handle of the embodiment of Figures 3A and 30; and
Figure 5 shows an embodiment of a racket including a handle in
accordance with either of the embodiments of Figures 1A and 10 or 3A and
3B.
With reference to Figures 1A-1B to 5 taken together, there follows a
10 description of a racket handle in two advantageous embodiments of the
present invention, and also of the associated method of fabrication.
An object of the present invention is to enable a racket handle to be
designed and fabricated that is responsive and ergonomic and that provides
good power and accuracy, in particular for smash type play, for flat play, and
15 for net play.
To this end, and as shown in Figure 5, the present invention relates to
a handle 100 for a racket R, e.g. of the badminton racket type, the racket
comprising a head with stringing, and a shaft.
As mentioned above, the handle 100 of the present invention may
20 equally well be adapted to any type of racket such as, for example, a racket
of the tennis racket type or of the squash racket type.
In the two embodiments described herein, and as shown in particular
in Figures 1A-1B and 3A-30, the handle 100 of the present invention
comprises:
25 a central core 10 made at least in part out of wood; and
- a covering layer 20 covering the central core 10 at least in part; the
covering zone Z as defined by the covering of the covering layer 20 around
the central core 10 is referred to as a grip zone Z.
In the presently-described example, the covering layer 20 is made of
3 o pofyurethane foam. Naturally, any other equivaient material could be
envisaged in the context of the present invention.
8
As mentioned above, the material used may equally well be an injected
plastics material of the SEBS type. Under such circumstances, there is no
need to provide any overgrip.
In order to solve the above-specified technical problem, the subject
s matter of the present invention has the following characteristics:
In the two presently-described embodiments, and as shown in
Figures 18-IB and 3A-30, the grip zone Z of the handle 100 is in the form of
a truncated cone.
The term "truncated cone" is used herein to mean a cone for which the
l o apex portion is not present.
In this example, the truncated cone extends over the entire length of
the grip zone Z and over a length greater than half the length of the handle
100.
The truncated cone preferably extends over a length that is greater
15 than two-thirds the length of the handle 100. The truncated cone is shaped
in such a manner that the cross-section of the first end E l or El' corresponds
to the large base of the truncated cone, whereas the cross-section of the
second end E2 or E2' corresponds to the small base.
In this example, the cross-section decreases continuously from the first
20 end E l or El' to the second end E2 or E2', thereby enabling it to provide
excellent grip.
In both of the presently-described embodiments, and as shown in
Figures 2A to 2C and 4A to 4C, each cross-section Sl, S2, 53 and Sl', SZ', S3'
is substantially elliptical in shape. This ergonomic shape also provides a grip
2 5 that is comfortable,
More precisely, in the two presently-described embodiments, and as
shown in Figures 18-16, 2A-ZC, 3A-3B, and 48-4C, the grip zone Z has a first
end El or E l ' and a second end E2 or E2'. The second end, opposite from
the first end, is designed to be connected directly to the shaft, and the handle
30 100 presents:
a) at the first end El or El', a cross-section S1 or Sl' in the shape of a
first ellipse e l or el', this first ellipse presenting a first major axis L1 or L1'
and a first minor axis C l or (1'; and
b) at the second end E2 or EZ', a cross-section S2 or 52' in the shape
5 of a second ellipse e2 or e2', this second ellipse presenting a second major
axis L2 or L2' and a second minor axis 12 or e2'.
In Figures 1A-QB, 2A to 2C, 3A-38, and 4A to 4C, it can also be seen
that the cross-section S1 or S1' in the shape of a first ellipse e l or el'
presents an area that is greater than the area of the cross-section S2 or S2' in
l o the shape of a second ellipse e2 or e2'.
More particularly, the first major axis L l or Ll' and the first minor axis
41 or &ofI th'e first ellipse e l or el' have values that are greater respectively
than the second major axis 12 or L2' and the second minor axis e2 or a2' of
the second ellipse e2 or e2'.
15 It can thus be understood that in the two presently-described
embodiments, the taper ratio between the first and second major axes L1 and
L2 (or L1' and L2') lies substantially in the range 1.05 to 1.2 approximately,
and the taper ratio between the first and second minor axes f1 and t2 (or (?I'
and r2') lies substantially in the range 1,2 to 1.5 approximately.
20 Because of this specific shape, and these specified proportions, the
player has a racket with a handle that is highly appreciated for being
ergonomic and comfortable and that is very responsive over the top portion
of the handle, with good power over the bottom portion of the handle, while
retaining irreproachable comfort because of the conical shape.
25 In each of the presently-described embodiments, the handle 100, and
more precisely the grip zone Z, is covered at least in part in an overgrip 30,
the overgrip 30 improving user comfort. As mentioned above, in alternative
manner, the material for the covering layer may be injected plastics material
of the SEBS type. Under such circumstances, there is no need to provide an
overgrip. It is also possible to make provision for using a foam that is softer
than a polyurethane foam.
In the two presently-described embodiments, and as shown in
particular in Figures 2A to 2C and 4A to 4C, the central core 10 comprises an
5 elongate element:
a) of cross-sections that are each substantially polygonal in shape
along the length of the bottom portion of the elongate element, i.e. the
portion lying substantially between the sections S1 and S3 or Sl' and S3'; and
b) of cross-sections that are each substantially oval in shape over the
1.0 length of the top portion of the elongate element, i.e. the portion lying
substantially between the sections 52 and 53 or S2' and 53'.
In both of the presently-described embodiments, the covering layer 20
is configured to be shaped around the central core 10 so that the handle 100
is substantially in the form of a truncated cone in which each cross-section
a5 S1, S2, 53 or Sl', S2', 53' is substantially elliptical.
In order to obtain such a shape, the present invention provides a
specific fabrication method (not shown herein), but that presents the
following steps in particular:
a positioning step consisting in positioning the central core 10 inside
20 a specific mold (not shown) presenting molding means in the form of a
truncated cone in which each cross-section presents a shape that is
substantially elliptical and presents the characteristics as described above;
and
a molding step consisting in pouring a foamable liquid into the mold.
25 In the presently-described example, the foamable liquid is poured in at
a temperature of about 4S°C, this liquid being designed to set and become a
foam at a temperature lying in the range 40°C to -S°C, with this happening
when said liquid is allowed to cool for a duration of about 4 minutes.
The foam is a polyurethane foam with hardness of about 25 on the
30 Shorescale.
Alternatively, this molding step may consist in injecting a liquid plastics
material into the mold, the liquid being suitable for setting over time as a
result of cooling.
By means of such a method, it is possible to obtain a specific
5 configuration with a central core made of wood and a covering layer made of
foam, this layer covering the core so as to obtain the expected shape.
In the embodiment described with reference to Figures 3A-36, the
central core I0 has an opening 0 in its top portion configured to enable the
rigid shaft T of the head to be inserted therein in order to assemble the
10 handle 100 with the racket R. Thus, in this example, it is possible to make
handles 100 independently of the remainder of the racket R, the head of the
racket being assembled with the racket handle via the shaft T which is
inserted in the hole 0. In the presently-described embodiment, this shaft T is
adhesively bonded inside the handle over a depth of about 7 centimeters,
15 By virtue of these various technical characteristics, and in particular
because of the shape and the specific proportions, it has been found that the
racket provides very good performance for playing badminton: the handle of
the present invention is very responsive, it provides very good grip, with good
comfort, while enabling good power and good accuracy for plays such as a
20 smash, or good accuracy and good responsiveness for plays such as flat play
or net play.
It should be observed that the present detailed description relates to
particular embodiments of the present invention, but that the description can
under no circumstances be considered as limiting on the subject matter of the
2 5 invention.
We Claim
1. A handle (100) for a racket (R), e.g. of the badminton racket (R) type, the
handle comprising a central core (10) and a covering layer (20) covering the
central core (10) at least in part, the covering zone (Z) defined by the
5 covering of the covering layer (20) around the central core (10) being a "grip"
zone (Z) in which each cross-section (Sl, 52, S3, Sl', SZ', S3') is substantially
elliptical in shape, the handle being characterized in that the grip zone (Z) has
a first end (El, El') and a second end (E2, E2') opposite from the first end,
said second end (E2, E2') having provision for being connected to a rigid shaft
1.0 (T) of the racket (R), in that the grip zone (Z) presents the shape of a
truncated cone extending over a length greater than half the length of the
handle (IOO), and in that the truncated cone is shaped in such a manner that
the cross-section of the first end corresponds to the large base of the
truncated cone, while the cross-section of the second end corresponds to the
1s small base of the truncated cone,
2. A handle (100) according to claim 1, characterized in that the covering
layer (20) comprises a material such as a foam, preferably a polyurethane
foam, or a material such as an injected plastics material, preferably an
20 injected plastics material of the SEBS type.
3. A handle (100) according to claim 1 or claim 2, characterized in that the
central core (10) comprises an elongate element of cross-sections that each
present a shape that is substantially polygonal over the entire length of a
as bottom portion of the elongate element and of cross-sections, each
presenting a shape that is substantially oval over the entire length of a top
portion of the elongate element, and in that the covering layer (20) is
configured to be shaped around the polygonal elongate element in such a
manner that the handle (100) is substantially in the form of a truncated cone
30 in which each cross-section (Sl, 52, S3, Sl', SZ', S3') is substantially elliptical
in shape,
13
4. A handle (100) according to any one of claims 1 to 3, characterized in that
said handle (100) presents: a) at the first end (El, El'), a cross-section (Sl,
S1') in the shape of a first ellipse (el, el') with a first major axis (Ll, L2) and
5 a first minor axis (el, tl'); and b) at the second end (E2, EZ'), a cross-section
in the shape of a second ellipse (E2, EZ') with a second major axis (L2, L2')
and a second minor axis (C2, 62'), in that the taper ratio between the first and
second major axes (LI, Ll' and L2, L2') lies substantially in the range 1.05 to
1.2; and in that the taper ratio between the first and second minor axes ([I,
l o el' and !2, a2') lies substantially in the range 1.2 to 1.5.
5. A handle (900) according to any one of claims 1 to 4, characterized in that
the central core (10) is made at least in part out of wood.
15 6. A handle (100) according to any one of claims 1 to 5, characterized in that
the central core (10) includes an opening (0) in its top portion, which opening
is configured to enable the shaft (T) of the racket to be inserted in order to
enable the handle (100) to be assembled with the stringing of the racket (R).
20 7. A handle (100) according to any one of claims 1 to 6, characterized in that
the handle (100) and preferably the grip zone (Z), is covered at least in part
in an overgrip (301,
8. A badminton racket (R) including a handle (100) according to any one of
25 claims 1 to 7.
9. A racket according to claim 8, characterized in that it includes a head, in
that the frustoconical grip zone (2) presents a first end (El, El') and a second
end (E2, E2') remote from the first end, which second end is connected by a
shaft to the head, and in that the cross-section of the first end is greater than
the cross-section of the second end.
10. A method of fabricating a racket handfe (100) according to any one of
5 claims 1 to 7, such as for example a badminton racket, said handle (100)
having an elongate central core (lo), the method being characterized in that
it comprises:
a positioning step consisting in positioning the central core (10) inside
a maid having molding means in the form of a truncated cone in which each
1.0 cross-section presents a shape that is substantially elliptical; and
a molding step consisting in pouring a foamabte liquid into said mold
or consisting in injecting a liquid plastics material into said mold,
11. A method according to claim 10 for fabricating a handle (100) for a racket
15 (R), the method being characterized in that the elongate central core (10)
presents a cross-section that is polygonal.