FR2627990A1 - Tennis racquet with vibration absorbing elements around strings - with elements fitting into holes in frame and having through which strings are threaded - Google Patents

Abstract

The frame (11) of the tennis racket has holes through which the strings (12) are threaded. Vibration absorbing elements (141-144) are fixed to the upper part of the frame and have holes (101-104) for the strings which are aligned with the holes in the frame. The strings are in contact with these elements. The holes in the frame, in its central longitudinal part and central lateral part, have their axes aligned with the direction of the strings. The vibration absorbing elements are made of an elastomer material or a visco-elastic material, such as silicone rubber or a synthetic resin. USE/ADVANTAGE - The tennis racket has elements to absorb the vibrations of the strings.

Description

(6 FRENCH REPUBLIC Publication no .: 2 627 990 (use only

  for NATIONAL INSTITUTE reproduction orders)

INDUSTRIAL PROPERTY

  D National registration number 89 028 1 5 PARIS

(Int CI4: A 63 B 49/00.

A1 PATENT APPLICATION

  Filing date: March 3, 1989. (Applicant (s): SUMITOMO RUBBER INDUSTRIES LTD.

- Jp.

  (Priority: JP, March 4, 1988, n 63-29395.

  (Inventor (s): Hiroyuki Banba Shuhei Nimura Ha-

ruyoshi Minamiguchi.

  Date of public availability of the

  application: BOPI "Patents" n 36 of September 8, 1989.

  (i References to other national documents appearing

rented: (r) Holder (s)

  (Agent (s): Cabinet Armengaud Aîné.

  4) Tennis racket with a vibration absorbing element.

  (5 Tennis racket which includes a frame provided with a plurality of holes for the passage of strings and an element 1 for absorbing vibrations, provided with an opening for 134 strings, the element absorbing vibrations being fixed to the frame 132 so that the axis of the opening for the cords of the vibration absorbing element 14 1 7 is aligned with that of the hole provided in the frame for the cord and that the absorbing element 13 31

  vibration comes into contact with a rope stretched over the frame, 132.

  this racket being characterized in that a determined number 13.3 142 min of holes 101. 104 for the strings, provided in a 133 y.1043l portion between a longitudinal central portion and a portion 133 1 4431 \ 44 l I lateral side of a front part 111 of the frame 11, fate made so that their respective axes are aligned 12 -12 O with a direction of tension of the strings 12 and in that the vibration absorption element 14 is fixed on a

  portion corresponding to said rope holes 10.

  IB D Sale of booklets at IMPRIMERIE NATIONALE, 27. rue de la Convention -75732 PARIS CEDEX 15

4/2627990

  The present invention relates to a tennis racket comprising a

  element absorbing the vibrations of the strings.

  We know that when a tennis player hits the ball with his racket, the impact of this ball on the racket causes a relatively large vibration of the strings of the racket. Due to such vibrations (especially high frequency vibrations) there may be physiological disturbances for the player such as in particular an injury or numbness of his arm. Therefore it is necessary to eliminate the

  vibrations on tennis rackets.

  10 The Japanese patent application published under number 168 473/1985 describes a tennis racket which is provided with a flexible vibration-absorbing band, made of an elastic or visco-elastic material wound around a plurality of taut strings. on the racket sieve. However, the vibration absorption band must be detached when replacing the strings. Consequently, there may be a loss of the strip when changing the string of the racket. Furthermore, such a vibration absorption band has the disadvantage of being subject to damage or loss by fall during repeated operations of placing and removing the

  racket, given its small thickness.

  In the application for a Japanese utility model published under number 183/1986, the present licensee described an equipped tennis racket. a vibration absorbing element comprising a plurality of openings for the passage of the cords. The vibration absorption element is fixed on the part

  inside the racket frame, the openings being aligned with the holes in.

  passing the strings through the racket so that the vibration-absorbing element can absorb the vibrations due to contact with the strings. Consequently, the invention described in this earlier publication eliminates the need to have to detach the vibration absorbing member and this

  the latter cannot be damaged.

  The licensee also proposed two other embodiments of tennis racket. One is described in the Japanese utility model application published under number 81 439/1987 and shown in Figure 7 of this publication. In such a racket the vibration absorbing element 93 is made of rubber, synthetic resin or the like, so as to reduce the weight of this vibration absorbing element, the latter being introduced into the holes 92 of the lower part 911 of frame 91 of the racket so as to constitute a protective element for the strings. The other embodiment of this tennis racket is described in the Japanese utility model published under the number 53 938/1987 and shown in Figure 8 of this publication. In this prior system, a determined number of vibration absorption elements 95 are provided which take their place on parts projecting inwards from a protection element for the strings 94 placed in the holes: 92 provided for the passage some ropes. It will be noted that in such a system the vibration absorption elements 93 and 95 both have openings 931 and 951 for the passage of the strings which correspond to the openings 92 provided in the frame of the racket for the passage of the strings so as to come in contact

  ropes through these openings 931 and 951. -

  The technical problem not resolved by the above-mentioned earlier publications and the manner in which the

  The present invention has solved such a technical problem.

  In the Japanese utility models published under the numbers 81 439/1987 and 53 938/1987, mentioned above, the vibration-absorbing element 93 or 95 is fixed to the frame of the racket 91 so that the axes of the openings 931 or 951 provided for the passage of the cords in the absorbent element the vibrations 93 or 95 are aligned with the holes 92 provided in the frame 91 for the passage

some ropes.

  Similarly, it is conventional to orient the axes of the holes 92 so that they are substantially perpendicular to the circumference of the frame of the racket 91, which makes it possible to reduce the length of the holes 92 provided in the frame for the passage of the strings (figure 11 of these publications). Furthermore, the strings 96 are always stretched in longitudinal and lateral directions on the frame 91 of the racket. Consequently, the directions of the holes 92 and those of the taut strings 96 are aligned only in the parts

  upper and lower and on the opposite side parts of the frame of the -

  racket 91, and they cannot be aligned with the other parts (which

  will be defined below as the oblique parts).

  Therefore, in the case of a vibration absorbing member 9? produced in the form of a string protection element, which is fixed in the holes 92 provided for the passage of the strings in an oblique portion as shown in FIG. 9, or in the case where the vibration absorption element 95 is placed on a protection element for the strings 98, fixed on an oblique portion as shown in FIG. 10 a tensile force F of the 3 strings is applied to the anterior ends of the absorption elements these vibrations 97 and 95 in directions different from those of the axes of the holes 92 provided for the passage of the cords. This results in a risk of damage to these elements. Particularly, in a racket in which the vibration absorbing element 97 is used as a string protection element as illustrated in FIG. 7, the traction force mentioned above, causes an application of the vibration absorbing element 97 (element protecting the ropes) - on the inner wall of the hole 92 provided for the passage of the ropes in the frame 91, and in a racket as shown in FIG. 10 of the publications mentioned above, the rope 96 is directly applied against the inner circumferential surface of the string protection element 9 &. Consequently, the vibration absorption effect of the absorption device is reduced. It follows from the above statement that, in tennis rackets according to the prior art, the parts provided for fixing the absorption elements vibrations 93 and 95 are limited to the central, lateral and longitudinal parts of the racket frame, that is to say to the upper part, to the lower part and to the opposite lateral parts. The other parts of the racket frame are not suitable for such attachment. Consequently, rackets according to the prior art cannot effectively absorb vibrations when a ball strikes other portions of the racket sieve than the central part - (i.e. the less taut part ). Likewise, it is well known that vibrations occur which generate a gene for the player when the ball hits a part of the sieve situated slightly outside the central part, these vibrations being much greater than when the ball hits this part. central, I1 is therefore particularly interesting to design a racket especially for beginners, capable of absorbing vibrations when the ball

  strikes part of the racket sieve outside the central part.

  The present invention proposes to provide such a racket.

  Consequently, this invention relates to a tennis racket which comprises a frame provided with a plurality of holes for the passage of the strings and with an element for absorbing vibrations, provided with an opening for the strings, the vibration absorbing element being fixed to the frame so that the axis of the opening for the cords of the vibration absorbing member is aligned with that of the hole provided in the frame for the rope and the vibration absorbing member comes into contact with a rope stretched over the frame, this racket

  being characterized in that a determined number of holes for the strings.

  provided in a portion between a longitudinal central portion and a lateral central portion of a front part of the frame, are made so that their respective axes are aligned with a direction of tension of the strings and in that the absorption element of the vibration is fixed on a portion corresponding to said rope holes, According to a preferred embodiment of the present invention there is provided another vibration absorbing element which can be fixed either to the upper part of the racket or to the lower part or on the parts

  - opposite sides of the racket frame.

  Consequently, with a racket according to the present invention in which a vibration-absorbing element is fixed on a part of the frame of the racket other than the upper part, the lower part and the opposite lateral parts of the frame, the axes of the holes. provided for the passage of the strings being aligned with the directions of tension of the strings, it is possible to effectively and efficiently absorb the vibrations caused by the impact of a ball on the strings and more particularly the vibrations which are caused when the ball hits a part of the racket sieve

  -20 other than the central part of the latter.

  According to a variant of this invention, a vibration absorption element is fixed on the upper part, the lower part and / or the side parts of the frame of the racket in addition to an oblique part of the latter which allows absorb vibrations over a large part of the surface of the

racket sieve.

  Other features and advantages of the present invention

  will emerge from the description given below with reference to the accompanying drawings

  which illustrate various embodiments thereof without any limiting character. In the drawings: - Figure 1 is a schematic plan view of a vibration absorption element according to a first embodiment of the invention; Figure 2 is a perspective view of a string protection element to be fixed to the frame of the racket according to this first embodiment; Figure 3 is a sectional view of a main part of this first embodiment; - Figure 4 is a plan view showing the main part of this first embodiment before the attachment of a string protection element and a vibration absorbing element; - Figure 5 is a sectional view of a main part of a second embodiment of the present invention - Figure 6 is a sectional view of a vibration absorbing element provided in this second embodiment of the racket according to the invention; - Figures 7 and 8 are plan views illustrating the essential parts of tennis rackets according to the prior art; - Figures 9 and 10 are sectional views showing vibration absorbing elements according to the present invention mounted on an oblique part of rackets according to the prior art and; - Figure 11 shows schematically in plan a racket according to the

prior art.

  We now refer to Figures 1 to 4 which represent a first

  example of embodiment of a racket according to the invention.

  The frame 11 of the rag shown in the figures is produced from a material such as light metal or plastics reinforced with fibers. A face 111 of the frame has a plurality of holes 10 provided for the passage of the cords and which extend through the frame 11. The face 111 is provided with a protection element for the cords 13 which comprises cylindrical systems protecting the cords 131 and a base 132 produced in the form of a strip which corresponds to the face 111 of the frame there as shown in FIG. 2. The protective element of strings 13 is fixed to the frame 11 by introducing the protective systems 131 into the corresponding holes 10. Consequently, the internal wall of a hole 10 is covered by a protective system 131. Each string protective system 131 of the protective element 13 has an opening or bore 133 for the passage of a cord. The '12 strings are stretched longitudinally and laterally on the racket frame by

  - passing through openings 133 one after the other.

  Basically, the holes 10 provided for the passage of the cords are formed so that their axes are aligned with directions substantially perpendicular to the circumference of the frame 11, respectively as shown t1. in FIG. 1. However 8 holes 101-104 for longitudinal strings provided on suronit in portions of the frame situated between an upper portion of this frame (that is to say an upper portion looking at FIG. 1 or a central portion longitudinal) and the opposite lateral portions (that is to say the lateral portions located on the right and left of the racket by looking at FIG. 1 or the central lateral portion), These holes 101-104 have axes which are aligned with the directions in which the strings 12 are stretched on the frame] 1 (that is to say the longitudinal direction in Figure 1). A vibration absorbing element 14, produced in the form of a protection element for

  strings, is fixed in holes 101-104 as shown in Figures 3 and 4.

  The vibration absorbing element 14 is preferably made from an elastic or visco-elastic material such as silicone rubber or a synthetic resin. In the same way as the string protection element 13 mentioned above, the vibration-absorbing element 14 comprises cylindrical string protection systems 141-144 each comprising an opening or bore 146 for the passage of the strings and a base 145 connecting the

protective systems 141-] 44.

  The vibration absorbing member 14 is. fixed to frame 11 by introducing the protective systems for ropes 141-144 into the holes 101--104 provided respectively in frame 11 for the passage of the ropes, this introduction being carried out from the outside so that the ends of the Protective string systems protrude from the inner peripheral surface 112 of the face 111 of the frame. The vibration absorbing element 14 is also covered by the base 132 of the string protective element 13 so as to ensure protection. The base 132 is provided with openings or bores 134 which correspond to the respective openings or bores 146 provided for the passage of the cords. Each string 12 is introduced through the openings 134 and 146. It will be noted that the vibration-absorbing element '14 is fixed to the face 111 of the frame 11 of the racket so that the axes of the openings 146 provided for the passage of the strings are practically aligned with the axes of the holes 101-104 provided in frame 1.1 for the passage of the strings, so that the axes of the openings 146 are aligned with the direction in which the strings 12 are stretched on the frame 11. Furthermore, the diameter of each opening 146 is chosen so as to be substantially equal to that of the cord 12 (generally of the order of 1.2 to 1.4 mm) or smaller, so that the stretched cord 12 can come to contact of

  the vibration absorbing element 14.

  When using the racket described above for playing tennis, the vibrations caused by the impact of a ball on the strings 12l soni absorbed by the vibration absorbing element. 14 which is in contact with the strings 12. Consequently the user does not feel any unpleasant sensation resulting from the vibrations. Thus this tennis racket effectively and efficiently absorbs vibrations, especially when a ball hits a part of the racket sieve located outside the center of the latter, which is particularly useful for beginners, this advantage resulting from the fact that the vibration absorbing element 14 is fixed on a part which is offset with respect to the longitudinal and lateral central portions of the frame 11. Furthermore, the axes of the holes 101-104 provided in the frame 11 for the passage of the cords are aligned with the direction in which the strings 12 are stretched over the frame 11 and the vibration-absorbing element 14 is fixed in these holes 101-104, which causes the axes of the * openings 146 provided in the element to coincide absorbing vibrations 14 for the passage of the ropes with the direction of the stretched ropes 12. Consequently, unlike the systems according to the prior art shown in the figure igure 9, no intolerable force is applied to the anterior ends. protective rope systems 141-144 and you can easily get a good

vibration absorption effect.

  The vibration absorbing element 14, which includes the protective systems for cords 141-144 to be inserted in the holes 101-104 of the frame 11 and a relatively thin base 145 ensuring the connection of these protective systems, can be made of fluorosilicone ( that is to say a silicone of fluorine) or similar which makes it possible to reduce its weight and results in a weak influence on the weight and the balance of the tennis racket. In addition, the presence of the vibration-absorbing element 14 has no influence and is not visible since the only parts visible from the outside are formed by the ends of the protective rope systems 141-144

  which project from the internal surface 112 of the frame 11.

  We now refer to Figures 5 and 6 which illustrate a second

  exemplary embodiment of the invention.

  In this embodiment, an oblique portion of a face 111 of the frame II of the racket is provided with holes 101-104 for the passage of the strings, the axes of these holes being aligned with the direction in which the strings are stretched. In addition, these string protection systems 231 forming part of a string protection element 23 are introduced into respective holes 10

  provided for the passage of the strings through the frame 11 and in the holes 101-

  104. In other words, the protective element for strings 23 is made so as to comprise a certain number of protective systems 231 which are introduced into the holes 101-104 and which are oriented in the direction of the taut strings. Next, vibration absorbing elements 24, which are made of the same material as the vibration absorbing element 14 described above, are attached to the protruding ends of the string protective systems 231

inserted in holes 101-104.

  As can be seen in FIG. 6, the vibration absorbing element 24 has a cylindrical portion 241 and a conical portion 242. The cylindrical portion 241 is provided with a rectilinear connection opening 243 having a diameter smaller than the diameter outside of the protective rope system 231. The conical portion 242 is provided with a tapered opening 244 for the passage of the rope, this opening having a larger diameter identical to the diameter of the connecting opening 243 and a smaller diameter smaller than

that of the rope.

  The connection opening 243 fits on the projecting part of the string protection system 231 so that the vibration-absorbing element 24 can adapt to it and be fixed to it (for example by gluing if necessary). The rope 12 is introduced through the opening 244 provided for this purpose in the vibration-absorbing element 24 in order to tension the rope. In this nonlimiting exemplary embodiment, the vibration absorbing element 24 is at the coetact of the cord 12. Consequently, any vibration is certainly absorbed by the element 24. Likewise, as in the first exemplary embodiment described above, the axis * of the opening 244 provided in the vibration absorption element 24 for the passage of the rope is aligned with the direction in which the rope 12 is stretched. Consequently, a vibration absorption effect can be obtained without difficulty. Furthermore the vibration absorbing element 24 in this second embodiment of the invention is so small that it has only a negligible influence on the weight and the balancing

a tennis racket.

  Note that the number of holes provided in frame 11 of the racket for fixing the vibration absorbing element 14 or 24 is not limited

  a 8 and it can be changed if necessary. Similarly, in the description which

  precedes an exemplary embodiment has been described in which the openings 146 e% 244 provided in the vibration absorption elements 14 and 24 for the passage of the cords have diameters which are smaller than that of the cords. It will be noted however that, even in the case where the diameter of the openings 146 and 244 is greater than that of a rope, similar effects can be obtained by shifting the axes of the openings 146 and 244 outside the axes of the strings so that '' a lateral surface of the rope comes into contact with the walls

internal of openings 146 and 244.

  The attachment portion of the vibration absorbing element is not limited to the areas located near the upper part of the frame 11 of the racket or to parts of this frame located between the upper part and the opposite sides of the frame. It will be noted that a vibration absorption element can be fixed at any location situated between a longitudinal central portion of the frame 11 (that is to say the upper part of the frame or its lower part in the form of a collar ) and a central lateral portion of this frame, that is to say lateral portions). For example, a vibration absorption element can be located between the opposite lateral portions and the lower collar-shaped portion of the frame 11 or only on one of the lateral portions located on the right or on the left of this frame 11 In addition, in all these examples of elements for absorbing vibrations are fixed in holes 101-104 ensuring longitudinal guidance of the strings, however it will be noted that these elements can be fixed in holes providing guidance.

lateral of the strings.

  It should be noted that the present invention is not limited to an application to a tennis racket in which a vibration absorption element is fixed only on an oblique portion of the frame of the racket. This invention requires that the vibration absorbing member be attached at least to an oblique portion of the frame. Consequently, a vibration absorption element can be fixed on the upper part, on the lower part in the form of a collar or on a lateral portion of the frame 11, the axes of the holes 10 provided for the passage of the cords corresponding to the direction. according to which the strings are stretched, these elements of absorption of vibrations being added to that provided on the oblique portion of the frame of the racket which makes it possible to increase the effect of absorption of vibrations. Similarly, it is possible to envisage a variant in which a vibration absorption element for an upper portion of the frame, for a lower portion of this frame or for a lateral portion, and a vibration absorption element for their neighboring oblique portion respective, are made so as to constitute a single body. Of course, the present invention is not limited to the various examples of embodiment or application mentioned and described here, but it encompasses

all variants.

  li REVEDiGATIONS 1. Tennis racket which includes a frame provided with a plurality of holes for the passage of the strings and an element for absorbing vibrations, provided with an opening for the strings, the vibration-absorbing element being fixed to the frame so that the axis of the opening for the cords of the vibration absorbing element is aligned with that of the hole provided in the frame for the rope and the vibration absorbing element comes into contact with a string stretched over the frame, this racket being characterized in that a determined number of holes 1iO !, 104) for the strings, provided in a portion between a longitudinal central portion and a central lateral portion of a front portion (111) of the frame (11), are made so that their respective axes are aligned with a tension direction of the strings (12) and in that the vibration absorption element (14) is fixed on a portion corresponding to said

rope holes (10).

  2. Tennis racket according to claim 1. characterized in that said vibration absorbing element (14) is made of a material

  elastomer and a visco-elastic material.

  3. Tennis racket according to claim 1 characterized in that the vibration absorbing element (14) is fixed to a portion located between a

  upper part and a lateral part of the frame (11). 4. Tennis racket according to claim 1 characterized in that

  the vibration absorbing element is fixed on a part situated between a

  collar part and a side part of the frame (11).

  5. Tennis racket according to claim 1 characterized in that the vibration absorbing element comprises a plurality of protective string systems (131), each comprising an opening for the strings (133) and introduced from the outside into openings for frame strings, and a

  base connecting the protective ropes.

  6. Tennis racket according to claim 1 characterized in that it comprises a string protection element (23, 231) fixed to the surface of the frame, and in that said vibration absorbing element (24) is placed on a

  end protruding towards the inside of the string protection element.

  7. Tennis racket according to claim 6 characterized in that said vibration absorbing element comprises a straight connection opening (243) and a tapered opening (244) for the strings, the straight connection opening being engaged with the end projecting inward from

  the string protection element (231).

  8. Tennis racket according to claim 1 characterized in that the opening (146) for the strings of said vibration absorbing element preserves

  substantially the same diameter as the strings (12).

  9, tennis racket according to claim 1 characterized in that the opening (146) for the strings of said vibration absorbing member has

  a smaller diameter than that of the strings (12).

  10. Tennis racket according to claim 1 characterized in that the opening (146) for the strings of said vibration absorbing element has a larger diameter than that of the strings (12) and, the axis of the opening of the strings is offset from the axis of the stretched rope (12), -AC 0 o I '! * t -_ _; . O NL :) t LC, ^ EL; ^ .. 'f, i O

FIG. 2

133 131 133

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FIG. 5

101,232 232,233,233

FIG. 6

241 243

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FIG. 9

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