CA2079370C - Reshaping conversion process for tennis racket handles - Google Patents
Reshaping conversion process for tennis racket handlesInfo
- Publication number
- CA2079370C CA2079370C CA 2079370 CA2079370A CA2079370C CA 2079370 C CA2079370 C CA 2079370C CA 2079370 CA2079370 CA 2079370 CA 2079370 A CA2079370 A CA 2079370A CA 2079370 C CA2079370 C CA 2079370C
- Authority
- CA
- Canada
- Prior art keywords
- polygon
- tennis racket
- handle
- butt
- racket handle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B49/00—Stringed rackets, e.g. for tennis
- A63B49/02—Frames
- A63B49/08—Frames with special construction of the handle
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B60/00—Details or accessories of golf clubs, bats, rackets or the like
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B60/00—Details or accessories of golf clubs, bats, rackets or the like
- A63B60/06—Handles
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B60/00—Details or accessories of golf clubs, bats, rackets or the like
- A63B60/06—Handles
- A63B60/08—Handles characterised by the material
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B60/00—Details or accessories of golf clubs, bats, rackets or the like
- A63B60/06—Handles
- A63B60/10—Handles with means for indicating correct holding positions
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B60/00—Details or accessories of golf clubs, bats, rackets or the like
- A63B60/06—Handles
- A63B60/12—Handles contoured according to the anatomy of the user's hand
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B60/00—Details or accessories of golf clubs, bats, rackets or the like
- A63B60/06—Handles
- A63B60/16—Caps; Ferrules
Abstract
The invention herein relates to a handle for sports rackets which offers an improvement of the conventional eight-surface octagonal tapered grip of conventional tennis rackets which have the shortcoming of causing calluses (hardened and thickened skin and/or medullary sheath) where the grip corners impact the hypothenar eminence of the gripping palm. The aforesaid improved tapered grip consists of the modification of the conventional octagonal grip shape comprised of opposed horizontal surfaces into a polyhedral diamond shape, thus converting the conventional octahedral grip into a shape with multiple facets and more planar surfaces which thus minimize the number of corners impacting the gripping palm and, moreover, provides more comfort and a greater number of solid gripping positions.
Description
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 .,, ~
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 ,., 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~
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 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',~, , ~
- 207q370 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 .~
"~
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 ~. ~
- 207q370 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 ~_/
~.
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 . ,~
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 `- - 2079370 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 .~
(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 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 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~
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 .,, ~
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 ,., 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~
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 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',~, , ~
- 207q370 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 .~
"~
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 ~. ~
- 207q370 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 ~_/
~.
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 . ,~
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 `- - 2079370 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 .~
(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 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 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~
Claims (27)
1. 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 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+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.
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 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+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.
2. The tennis racket handle of claim 1, wherein the opposite oblique sides of the butt portion polygon are substantially equal in length.
3. The tennis racket handle of claim 1, wherein the lengths of the oblique sides of the butt portion polygon are greater than lengths of the sides of the butt portion polygon which extend parallel to the plane of the hitting surface.
4. The tennis racket handle of claim 1, wherein the cross-section of the middle portion is located within 12 cm of the butt end of the handle.
5. The tennis racket handle of claim 1, wherein the area of the butt portion polygon is greater than the area of the polygon of the middle portion.
6. The tennis racket handle of claim 1, wherein the butt portion polygon is a symmetrical polygon.
7. The tennis racket handle of claim 1, wherein the minimum number of sides of the butt portion polygon extending parallel to the plane of the hitting surface is zero.
8. The tennis racket handle of claim 1, wherein the polygon of the middle portion is an octagon.
9. The tennis racket handle of claim 8, wherein the butt portion polygon is a hexagon.
10. The tennis racket handle of claim 8, wherein the butt portion polygon is a tetragon.
11. The tennis racket handle of claim 8, wherein the butt portion polygon comprises an octagon dissimilar to the octagon of the middle portion.
12. The tennis racket handle of claim 8, wherein the butt portion polygon is a decagon.
13. The tennis racket handle of claim 1, wherein the polygon of the middle portion is a tetragon.
14. The tennis racket handle of claim 13, wherein the butt portion polygon is a hexagon.
15. The tennis racket handle of claim 13, wherein the butt portion polygon is a decagon.
16. 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 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+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.
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 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+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.
17. The tennis racket handle of claim 16, wherein the polygon of the butt portion comprises opposite, parallel sides extending obliquely to the plane of the hitting surface and wherein the opposite oblique sides of the butt portion polygon are substantially equal in length.
18. The tennis racket handle of claim 16, wherein the cross-section of the middle portion is located within 12 cm of the butt end of the handle.
19. The tennis racket handle of claim 16, wherein the area of the butt portion polygon is greater than the area of the polygon of the middle portion.
20. The tennis racket handle of claim 16, wherein the butt portion polygon is a symmetrical polygon.
21. The tennis racket handle of claim 16, wherein the polygon of the middle portion is an octagon.
22. The tennis racket handle of claim 21, wherein the butt portion polygon is a hexagon.
23. The tennis racket handle of claim 21, wherein the butt portion polygon is a tetragon.
24. The tennis racket handle of claim 21, wherein the butt portion polygon is a decagon.
25. The tennis racket handle of claim 16, wherein the polygon of the middle portion is a tetragon.
26. The tennis racket handle of claim 25, wherein the butt portion polygon is a hexagon.
27. The tennis racket handle of claim 25, wherein the butt portion polygon is a decagon.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2079370 CA2079370C (en) | 1992-09-29 | 1992-09-29 | Reshaping conversion process for tennis racket handles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2079370 CA2079370C (en) | 1992-09-29 | 1992-09-29 | Reshaping conversion process for tennis racket handles |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2079370A1 CA2079370A1 (en) | 1994-03-30 |
| CA2079370C true CA2079370C (en) | 1996-05-28 |
Family
ID=4150471
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2079370 Expired - Fee Related CA2079370C (en) | 1992-09-29 | 1992-09-29 | Reshaping conversion process for tennis racket handles |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2079370C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102006004862B3 (en) * | 2006-02-02 | 2007-10-11 | Head Technology Gmbh | Grasp band for ball games racket, has conical or trapezoid shape square base in longitudinal direction, where grasp band has length and width, where width varies over substantial part of length |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ATE438447T1 (en) | 2006-02-02 | 2009-08-15 | Head Technology Gmbh | GRIP AND HANDLE FOR BALL GAME RACKETS |
-
1992
- 1992-09-29 CA CA 2079370 patent/CA2079370C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102006004862B3 (en) * | 2006-02-02 | 2007-10-11 | Head Technology Gmbh | Grasp band for ball games racket, has conical or trapezoid shape square base in longitudinal direction, where grasp band has length and width, where width varies over substantial part of length |
Also Published As
| Publication number | Publication date |
|---|---|
| CA2079370A1 (en) | 1994-03-30 |
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