Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The present invention herein consists of a handle
for sports rackets which offers an improvement of the
conventional octagonal tapered grip of conventional tennis
rackets which easily causes the growth of calluses (hardening
and thickened skin and/or medullary sheath) at points in the
palm where the conventional racket grip corners impact the
hypothenar eminence of the gripping hand. The invention
herein resembles the contours of a diamond and converts the
10 sides of a conventional tennis racket grip into a contiguous
series of gripping surfaces by increasing the total number of
surfaces and therefore avoids the aforesaid callus growth,
while also providing more comfort and affording a greater
number of gripping positions as the invention herein is
utilized during actual sports performance.
Most conventional tennis rackets have an octagonal
columnar gripping handle with eight planar surfaces. The
handle is tapered such that the butt and the horizontal
surfaces are wider than the forward section of the grip, while
20 otherwise remaining an octahedron in overall shape. When a
conventional tennis racket handle is gripped while striking
a tennis ball, the corners of the handle impact the hypothenar
eminence of the hand, often resulting in the development of
calluses (hardened and thickened skin and/or medullary sheath)
as well as other physical injuries occurring where the impact
of the struck ball is repeatedly transferred to the palm.
The main objectives of the invention herein are to
provide a kind of variation in the shape of conventional
sports racket handles, wherein the resultant shape is similar
30 to multi-faceted surface of a diamond, and thus converts the
overall shape of the gripped section of the handle into a
series of contiguous planar surfaces which form a virtual
single surface, in order to avoid callus development at the
hypothenar eminence of the palm, while also providing a more
comfortable gripping position for the palmer muscles.
According to the present invention, there is
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provided a handle for a tennis racket to improve the grip and
the grasping action at the hypothenar eminence of the palm,
the tennis racket having a head portion with a planar hitting
surface, the handle comprising:
a) a middle portion having a first polygonal cross-
section;
b) a butt end portion facing way from the head
portion and having a second polygonal cross-section, the
polygon of the butt portion cross-section being different in
10 shape from the polygon of the middle portion cross-section
wherein the polygon of the butt portion comprises opposite,
parallel sides extending obliquely to the plane of the hitting
surface; and
c) a transition zone connecting the middle portion
to the butt portion, a cross-section of the transition zone
comprising a polyhedron having a number of sides NT such that:
NT=(NM+NB)-Np
where:
NT=number of sides of transition zone cross-section;
NM=number of sides of polygon at middle portion;
NB=number of sides of polygon at butt portion; and
Np=number of sides of middle portion and butt
portion polygons that are parallel to each other in an octant.
According to the present invention, there is also
provided a handle for a tennis racket to improve the grip and
the grasping action at the hypothenar eminence of the palm,
the tennis racket having a head portion with a planar hitting
surface, the handle comprising:
a) a middle portion having a first polygonal cross-
section;
b) a butt end portion facing way from the head
portion and having a second polygonal cross-section, the
polygon of the butt portion cross-section being different in
shape from the polygon of the middle portion cross-section
wherein the minimum number of sides of the butt portion
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polygon extending parallel to the plane of the hitting surface
is zero; and
c) a transition zone connecting the middle portion
to the butt portion, a cross-section of the transition zone
comprising a polyhedron having a number of sides NT such that:
NT=(NM+Ng)~NP
where:
NT=number of sides of transition zone cross-section;
NM=number of sides of polygon at middle portion;
NB=number of sides of polygon at butt portion; and
Np=number of sides of middle portion and butt
portion polygons that are parallel to each other in an octant.
Preferred embodiments of the invention will now be
described as examples without limitative manner, having
reference the attached drawings, wherein:
Figure 1-A is an illustration of a hand grasping a
conventional sports racket handle;
Figure l-B is an illustration showing the angular
20 extent of the hypothenar eminence where callus growth is
likely to occur;
Figure 1-C is a cross-sectional drawing of the lower
end of ~ convention~l sports r~
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Figure 2 is an orthograpllic drawing of a conventional temlis racket
handle and face as viewed fiotn a bottom perspective.
Figure 3 is an isomeltic drawing of a conventional tennis rackel handle,
with tlle positional coordillates rela1ive to tlle center of the bult (Cl) indicated.
Figure 4 is an ot1hograF)llic dl~wing of Ihe invention herein, showitlg
the cross-sectional shape of the inven1iotl herein (in the foregroluld), overlaid
against the cross-sectional shape (itl the background), Or a conventional temlisracket llandle to contrast the variation itl overall cross-sectional shape.
Fi~ure 5 is anolller ort1logtaphic drawing oF tlle invention herein,
10 sllowing cross-sectional shal)e of the invention heleill against the cross-
sectional shape of a convenlional tennis racket handle, with both cross-
sectional shapes in tl~e sallle plane of view to contrast the variation.
Figure 6 is an ot1hogt~l-hic dt~wing Or lhe invention herein, ShOWillg
the cross-sectional shape of the invention hel-ein (in tlle foreground), againstthe cross-sectional shape (in the backgroun(l) of another kind of convelltional
tennis racket llandle to contrast the valiation in overall cross-sect;ional shape.
Figure7is an isometric drawing of the tennis racket handle of
the invention herein showing the transitional confluence of two dif-
ferent types of shapes to illustrate the multi-surface configuration
of the invention herein as a variation extending contiguously from an
octahedron.
Figure 8 is an iS~,~LLic drawing of the tennis racket handle
of the invention herein showing the transitional confluence of two
different polygons to
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illustrate the multi-surface configuration of the invention
herein as a variation extending contiguously from a
quadrihedron.
Figure 9 is an isometric drawing of the tennis
racket handle of the invention herein showing the transitional
confluence of two similar but incongruent polygons to
illustrate the multi-surface configuration of the invention
herein as variation extending contiguously from an octahedron.
Figure lo is a cross-sectional drawing of the multi-
lo surfaced tennis racket handle of the invention herein showingtwo vertically oriented trapezoids and three lines extending
from the center (O) of the aforesaid racket handle which
bisect the arcs of the secants formed by the outer sides (ab,
bc and ca) of trapezoid delineated by points a, b, c and d.
Figure 10-A is a cross-sectional drawing of the
multi-surfaced tennis racket handle of the invention herein
showing two vertically oriented trapezoids and the interior
arcs under sides a~, b'c' and C'd', and sides a~, bc and cd.
As indicated in Fig. 2 and Fig. 3, the octagonal
20 segments positions of a conventional octahedron tennis racket
handle are indicated by vertical (defined herein as the y-
axis) and horizontal (herein defined as the x-axis)
coordinates with the coordinates relative to the positions of
both the face and handle of a conventional tennis racket shown
in Fig. 2. As further indicated in Fig. 3, a transverse axis
(z) extends through the coordinate center point O of a
conventional tennis racket handle. As further indicated in
Fig. 2, the line passing through aforementioned center point
O and the conventional tennis racket face is the vertical axis
30 (y) and the line passing through the aforesaid vertical axis
and aforementioned center point 0 is the horizontal axis (x).
Moreover, as further indicated in Fig. 2, the vertical
surfaces of a conventional tennis racket handle are
represented by bc and ~'c'; the horizontal surfaces of the
conventional tennis racket handle are represented by aa' and
bbT; and the oblique surfaces of the conventional tennis
A',~,
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racket handle are represented by a~, c-d, a-Tb~ and cTar. The
main objective of the invention herein is to improve a
particular shortcoming of conventional tennis racket handles,
which is specifically localized at the aforementioned vertical
surfaces of a conventional tennis racket handle that protrude
onto the hypothenar eminence of the palm and leads to the
development of calluses (hardened and thickened skin and/or
medullary sheath), by providing a firmer and more comfortable
gripping position relative to the palmer muscles when the
10 tennis racket handle is wielded during actual play. the
improvement offered by the invention herein is the conversion
of the aforementioned vertical surfaces into oblique surfaces,
wherein as indicated in Fig. 4, the vertical surfaces of a
conventional octagonal tennis racket handle are comprised of
eight surface segments conjoined at points a, b, c, d, d', c',
b' and a'. The invention herein attains the aforementioned
objective, as
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illustrated with reference t.o point b, wherein, since the vertical surface
represented by b c is shorl.ened close l:o a vallle of O with the conversion
centered on pointl7, l;he resl~lt is the catlcellation of roin1, ~> and the formation
of the oblique surface represent,ed by a p . MoIeover, based on the same
principle~ an identica.l conversion t,o produce an oblique surface from a
vertical surface can be conduct.ed with respect: to points h', c' and p'. As
indica.ted in FIC~J. 5, the aforementioned conversion operations illust.rat,ed, by
FIG. 4 may also be applied, wherein, the interior horizontal surfaces
represente<l by a7 and d d' are lengthened to become the exterior hori7,0lltal
l0 surfaces represented by e e' and ff ', respectively, by shortening the vertical
surface represented by h c close t,o a value of 0 and cent,ering the conversion
on pointp, following which, point b is canceled and the result is the formation
of t.he oblique surface represented by e p. sased on the same principle, an
identical conversion to produce an oblique surface from a vertical sur~ace can
be conduct,ed. with respect to points h', c' and p', as additionally indicat,ed in
FIG. 5. As indicated in FIC~. 6, the oc~agonal cross-sectional shape of a
conventional tennis racket handle are represen~ed by the eight planar segments
conjoined at points a, b, c, d, d', c', b' and. a', wherein the hoIizontal planar
surfaces represented. by a7 and d d' are both parallel t,o the horizontal axis
20 (x) and the planar surfaces represented by b c and b'c' are both parallel to the
vertical axis ~y~ . when the aforesaid holizontal planar surfaces represented
by aa' and dd' as well as the aforesaid vertical planar sulfaces represented
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by bc and brc~ are shortened to form the respective arc angles
of the horizontal axis (x) and of the vertical axis (y), then,
the aforementioned points a, b, c, d, d', c', b' and a'
conjoining the eight planar surface segments comprising the
octahedron shape of a conventional tennis racket handle are
cancelled to form four oblique planar surfaces. The tennis
racket handle of the invention herein utilizes more than the
aforementioned former and latter two different multi-surfaced
polyhedrons presented as examples to illustrate the
lo performance of integrated conversions into a polyhedron with
a different number of planar surfaces and thereby effectively
eliminating the extreme planar intersection protrusions
characterizing the columnar shape at the butt of tennis racket
handle by providing oblique wedge-like planar and more
comfortable grasping surfaces, with the overall columnar shape
remaining similar along the upper portion of the tennis racket
handle. Furthermore, the aforementioned similar columnar
shape is qualified by two fundamental conditions which are (1)
the opposite angles are similar and (2) the comparative length
20 of each opposite planar surface are also similar. Thus, based
on the aforementioned fundamental qualifications (1) and (2),
columnar shapes with more than two different planar surfaces
will not be congruent, or if the oblique planar surfaces are
greater than the planar surfaces parallel to the vertical (y)
axis, then the resulting columnar shape will be identical to
the octahedron handle of a conventional tennis racket, wherein
the oblique planar
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surfaces are snlaller than the vertical planar sur~aces parallel Wit}l ttle vertical
(y) axis and therefore incongruent in temls of polygonal similarity. Ihe obliqueplanar surfaces of the invention herein refer to sllrfaces oblique to the veItical
and horizontal axis centered on the cross-sectional view of a tennis racket
handle and, as further indicated in FIC~J. 2, within the same limits, the skewedline segrnents and continuous broken lines representing oblique planar
surfaces are not parallel to tlle vertical axis (y) nor parallel to the horizontal
axis (x). E~lrthermore, the orientation of the skewed line segments are subject
to a primary condition, wherein the skewed line segments representing
10 oblique planar surfaces mu~st applvach the end point of the vertical axis (y) for
a given period at an inclination t.owards the horizontal axis (x). In addition, the
direction of the skewed line segments are subject to a secondary condition,
wherein the skewed line segments representing oblique planar surfaces must
approach the end point of the horizolltal axis (x) for a given period at an
inclination towards the vel1-ical axis (y)- Moreover, tlle direction of the
skewed line segments are subject to a third condition, wherein the line
segments representing oblique planar su.rfaces must approach the end pOiIltS of
the holizontal axis (x) for a given period at an inclination t.owards the vertical
axis (y) . Finally, the direction of the skewed line segments are subject to à
20 fou.rth condition, wherein the skewed line segmellts representing oblique
planar surfaces IIMlSt approach the end point of the horiæont~l axis (x) are for a
given period at an inclinat:ion towards the veltical axis (y). As indicatecl in FIG.
g
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7, t:he t,ennis racket handle of the invention hetein is derived from the
geometric confluence of two dirferent polyhedlvlls to form a new columnar
solid. This is illust.rated in FI{J. 7~ wherein the octahedral handle of a
conventional t,ennis racket is d,epictRd in a cross-sectional view, with the
octagonal surface segmenls conjoine(~ at pointæ Cl~ h, c, d, d', c', h' and a', wilh
the hexagonal surface segments conjoined at points e, J~ g, g', f and e', thus
forming a diamond-shaped handle with a new su.rface conl,ours . AS viewed
from the croæs-sectional clrawing of the tennis racket handle, iIl add.ition to
being projected on the hexagon in the foregroull~l, the centered. coordinates are
10 also projected relative to an invisible line drawing of an octagon. in the
background, t,he reptesented su.rfaces of which serve t,o illuætrate the
incongruent polyhedral confluellce of dissimilar planar surfaces along the
length of the depicted temlis racket handle and thereby emphasizes the
distinction between the aforesaid planar surfaces which are in parallel
juxtaposition and the aforesaid planar su,rraces which are not in parallel
ju.xtaposition. with filrther regard to the conditions of parallel planar
juxt~l-osition7 the confluence of two dis~itnilar polyhedlolls are characterizedseven relationships: (1) two planes in parallel, such as the three parallel planes
of a hexahedron and the four parallel 'planes o.f a conventional octahedron (this
20 aspect i s filtt.her elaborated below); (2) three planes in parallel, such as in a
hexahedron and a decahedron; (3) four planes in parallel~ such as in a
rhombohedron; (4) five planes in parallel, such as in a decalledron; (5) six
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planeæ in parallel, such as in a dodecahedron; (~) seven planes in parallel, such
as iII a septilateral solid.; (7) eight planes in parallel, such as in an octahedron
and a decahedron, thus yiekling the deduction lllat the parallel planes of an
octahedron offers virhlally ~mlimited possibilit.ies in terms of merging with the
parallel planes of the aforementioned polyhedrons. However, a polyhedron of
ten or less planar surfaces is relatively Inore suilable for utili7~tion as a tennis
racket handle. In other words, when all of the oblique planar su.rfaces are not
in parallel, then the octahedron and other multi-planar polyhedrons have an
a.hsolute maximum of four planar surfaces which are in a parallel relationship"
10 ItIUS, if parallel line segments are project.ed froln a given pOiIlt in a single
plane, then being pa.rallel lines iII space, l:wo parallel line segments constitute
a plane and if from the same given point in a single plane two non-parallel
line segments are projected~ there are three points available which can
constitute a plane, so although the aforesaid two non-parallel line segments do
not necessarily constitute a plane within l:he original plane of the
aforementioned two parallel lines, the four end points of the aforementioned
two non-parallel line segments form lwo lliangular sloping planes. AS a result
the two different planes become integrated. through a nulllber of planar
surfaces consisting of connected 1:riangular planes. AS shown in the
20 polyhedron depicted in FIG. 7, the aforesaid trianglllar planes formed OII the
aforesaid. polyhed.ron appear as interconnected wedge-like shapes beveled like
the facets of a diamond. AS fUlther indicated iTI ~IG. 7, it can be known that
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(1) point b on the protnlding surrace of a convent;onal octagonal t:emlis rackethandle is converted to a planar su.rface, (2) the octahedral tennis racket handle
and the hexahedral tennis racket handle have incongruent cross-sectional
polygons and, moleover, the aforesaid hexahedral teImis racket handle
comprises a new type of columnar tennis racket handle shape, (3) the
aforesaid columnar tennis racket hanclle consists of mutually interconnected
wedge-shaped planar surfaces resembling the facets of a diamond, (4) as
illust.rated in the cross-sectional projection the aforementioned tennis racket
handle, the line segments representing the pairs of opposite planar surfaces are10 parallel to the holizontal axis (.r), while the four oblique planar surfaces are
not parallel to the horizontal axis (x), (5) the slopes of the hexahedral planarsu.rfaces are parallel to the vert:ical axis (y) and t.he planar su.rfaces parallel to
the vertical axis (y) approach the value Or o. ~ indicated in FIC~. 8, an
alternative version of the invention herein is depicted which illu.strates the
conversion from a quadri}ledron to a hexahedron and, as previously described
itl FIG. 7, also geometrically details the formation of wedge-shaped planes.
F~rthennore, since the slope of c d is skewed with respect the vertical
axis ~y), point a, which demarks the u~pper right corner of the aforementioned
quadrihedron is cancelecl, reslllting in the formation of sloped planar surfaces20 as represented by ~cd.As indicated in FIG. 9, the convergence of two
dissimilar octahedrons in the formation of a tennis racket handle is detailed
which~ furthermore, illustrates that although the opposite pairs of planar
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surfaces remain in par~.llel? lhe resllltant conto~lrs are different due to a
conversion applied to the overall shape, wherein reselnblance to the columnar
shape of a conventional t,ennis rackel, han(lle is generally emulated~ bu.t the
slopes of the obli(lue planar surfaces have an increased inclination towards thevertical axis (y). sased on the aForementioned descriptions and d.rawings of
the invention herein, what has been explained, is the process undertaken while
merging the cross-sectional polygonal surfaces of different polyhedrons,
wherein a conver~ion in the t,otal nulllbe1- of planar surfaces occllr which
yield~ a new colllmnar shape an(l. I`ul1hermore, demotlstra1,es that such a
10 confluence of two dirferent polyhe(l.l(ltls afrects the resultant number of
opposite planar surfaces remaining in a pa,rallel relationship and, therefore,
determines the qualitative changes in final polyhedral shape. Thus, the
conversion offered by the invention herein is a mathematical process wherein
a new mlmber of planar surfaces can be effectively derived from an existent
polyhedron, wherein, as in<licat,ed in FIG. 7, since there are two opposit,e
planes of the hexahedron and two oppoæite planes of the octahedron which are
parallel t,o the horizontal axis (x), t,hen a total of 12 new planar su.rfaces can be
produced (based on t,he calculation: 8+~2=12).T11en, as further indicated in
FIG. 9, since there are two octahedrons with each having eight planes in
20 parallel with the holizontal axis (x)~ then a total of eight new planar surfaces
can be prod.uced (based on tlle calculation: X+8-8=8). As indicat,ed in FIC~. 10
and FIG. 10-A, in the cross-sectional drawings of an octahedral tennis racket
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handle, two vertical line segments are drawn between points a and d, and.
similarly between points d' and a', thus the aforesaid line segments are in
para.llel and form a rectangle occl~ying the center portion of the octagon
delineated by points a, d, d' and a', as well as one trapezoid contiguous to
each lengthwise component ~ad and d'a') of the aforementioned rectangle.
F(l.rthermore, exterior arcs and interior arcs can be projected relative to the
sides ab, bc and cd as well as relative l:o the sides d'c', c'b' and b'a' of
aforesaid trapezoids, with the aforesaid interior and exterior arcs serving as
folmative parameters in ~he derivalion of additional planar surfaces suitable to1 () the design of d.ifferently shaped telmis racket handles~
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