EP0223882A1 - Anordnungen zum Übertragen der Saitenspannung auf den Rahmen eines Sportschlägers - Google Patents
Anordnungen zum Übertragen der Saitenspannung auf den Rahmen eines Sportschlägers Download PDFInfo
- Publication number
- EP0223882A1 EP0223882A1 EP85201947A EP85201947A EP0223882A1 EP 0223882 A1 EP0223882 A1 EP 0223882A1 EP 85201947 A EP85201947 A EP 85201947A EP 85201947 A EP85201947 A EP 85201947A EP 0223882 A1 EP0223882 A1 EP 0223882A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- string
- racket
- head frame
- rocker
- opening
- 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.)
- Granted
Links
- 230000005540 biological transmission Effects 0.000 abstract description 3
- 230000003116 impacting effect Effects 0.000 abstract 1
- 239000000463 material Substances 0.000 description 7
- 230000000694 effects Effects 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 239000004952 Polyamide Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 238000004873 anchoring Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000000418 atomic force spectrum Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 235000009508 confectionery Nutrition 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
Images
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
- A63B49/14—Protection devices on the frame
-
- 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
- A63B49/022—String guides on frames, e.g. grommets
-
- 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
- A63B49/028—Means for achieving greater mobility of the string bed
Definitions
- This invention relates to transmission of tension among the various strings of a strung sports racket upon impact with a ball or other playing object.
- strings which are each effectively anchored as they pass across the head or face opening to the next string hole.
- String elasticity, static string tension, frame stiffness, strung area geometry, and balance are all factors known to affect power, control, comfort and equipment performance. Many shapes, sizes, material, string tension, weights, even grips have been tried to improve the various games.
- the present invention can be incorporated in any size or geometry sports racket made from any common material.
- an exemplary configuration is that of a mid-sized tennis racket, made from graphite fiber impregnated resin.
- the exemplary racket is shown at 10 in Fig. 1 of the drawings.
- the racket 10 includes an elongated handle 11 extending from a handgrip 12 along a shaft 13 to a throat 14.
- the throat 14 is secured or integral with a head frame 17.
- the head frame 17 is planar with the handle 11 and defines a string opening 18.
- a string 19 may be threaded through the head frame 17 in a crisscross fashion of individual string chords 20. This woven pattern defines a planar racket face for impact with a ball or other playing object. It is preferable that the string incorporated for use with the present invention be a single strand of gut or conventional synthetic string material. The string can be tied at opposed ends to the head frame in any conventional manner.
- the head frame includes an outer surface 21 that is oriented perpendicularly to the planar racket opening.
- An inner surface 22 of the frame 17 defines the opening configuration. String is threaded through the head frame between surfaces 21 and 22 through string holes 24.
- Conventional string holes are formed through the racket head frame in substantially radial orientations.
- the string is oriented in chord lengths that are preferably longitudinal and transverse with respect to the handle.
- the strings therefore are tightened against conventionally formed hole peripheries at vertices of angles formed between the radial holes and the transverse or longitudinal strings. This produces a binding or anchoring effect on the string chords.
- String holes 24 are arranged to be coaxial with the strings passing through them and are preferably arranged in two groups.
- a first or longitudinal group of string holes 24 are formed through the racket head frame along parallel longitudinal axes and spaced across the head frame to receive string portions forming the longitudinal chords.
- a second group of string holes are formed up the sides of the head frame between surfaces 21 and 22. The second group of holes are also parallel to one another and spaced along the head length in transverse orientation to the longitudinal string chords. The particular orientation of the string chords can vary.
- String holes 24 are preferably of sufficient size to loosely receive the string chords.
- the chord segments can thus be centered within the holes without touching or rubbing against the head frame material between the outer and inner surfaces 21 and 22.
- the string chords 20 are therefore loosely received rather than anchored in the holes 24.
- the head frame 17 may be provided with an annular channel 25 extending about its outer periphery.
- the base of channel 25 serves as the outwardly facing head frame surface 21 for purposes of this description.
- the surface 21 is advantageously situated between channel walls 26 as shown in Fig. 2.
- tension transmitting means 27 is intended to transmit tension from one string chord to an adjacent chord using a rocking action.
- a preferred rocker means 28 is shown in detail in Fig. 4. It includes a top surface 34 and bottom surface 35.
- the bottom surface is advantageously convex, preferably cylindrical.
- Surfaces 34 and 35 extend between smoothly curved ends 36.
- a groove or recess 37 may be formed along the top surface 34 to receive and orient a string in perpendicular orientation to the preferably cylindrical configuration of the bottom surface 35.
- Convex side walls 38 may extend between the bottom surface 35 and top surface 34, as best shown in Figs. 2 and 4.
- the lengths of the individual rockers are such that string cords draped over the top surfaces 34 and guided over ends 36 through adjacent string holes 24 can be centered precisely within the string holes 24. Contact is made with the racket frame only by way of rockers 28. This effectively eliminates frictional contact between the string cords and the frame head.
- the actual length dimension between rocker ends 36 is less than the distance between centers of adjacent parallel string holes 24 by approximately the diameter of the string being used.
- each rocker is arranged to be received with its longitudinal axis perpendicular to the racket opening or face.
- Contact between the rocker surfaces and the outer head frame surface exists along approximately parallel tangential lines of contact perpendicular to the planer face of the racket.
- the tangential lines of contact provide rolling or rocking motion thus reducing friction between the two surfaces to a mimimum, even with considerable tension being applied to one or both of the two adjacent string chords.
- the tangential line contact versus point contact, enables the rockers to withstand the high Hertzian stresses developed at the contact interface.
- the lines of contact are preferably oriented perpendicular to the planer string opening to provide high frictional resistance against sliding when the racket is impacted by a ball or other object. If rockers 28 slide along the lines of contact then one of the convex side walls 38 of rockers 28 will come into contact with an adjacent channel wall 26. Convex walls 38 are preferably semi-spherical and contact the channel wall at only a single tangential point. Such contact will prevent further sliding motion of the rocker with mimimal effect upon the rocking capability of the rockers.
- Figs. 1 and 3 indicate the preferred use of a plurality of rockers positioned between the string and outer head frame surface 21 at all string holes about the racket head frame. This arrangement supports all string chords in a tension transmitting and substantially friction free manner.
- the individual rockers be formed of a substantially rigid material such as aluminum or other lightweight, yet high strength, material.
- High strength plastic such as graphite-filled polyamide may also be used, as can any material which provides the necessary rigidity and can withstand the high Hertizan stresses developed along the contact surfaces.
- rockers between adjacent string segments to provide the roll tension transmitting capability.
- the rockers would function especially well in conjunction with a racket having oversized string holes or holes redrilled to loosely receive the strings coaxially therein.
- Rackets according to this invention are preferably strung with relatively long, continuous strings which are passed through the frame and over tension transmitting means 27.
- the relatively long continuous strings supported by the tensioning means allows the string tension to be uniformly distributed over a relatively large or entire area of the racket. This greater distribution of strain energy reduces localized high stresses which otherwise occur in conventional string rackets. The total amount of elongation or strain developed in the strings is accordingly increased because of the longer effective string length over which the tension is distributed. This provides several very beneficial advantages.
- One advantage is the higher initial tension which can be used to string the racket.
- This higher static string tension can be used with less risk of string breakage because of the more even distribution of tension throughout the racket face.
- the overall deflection of the racket face will also be greater than with conventional rackets wherein only a relatively small percentage of the strings share the peak loading at impact.
- the even distribution of strain and increased overall deflection of the string face provide a smaller restoring angle for impacts occurring near the racket frame thus providing increased velocity. This increases the preferred hitting area or "sweet zone" of the racket.
- the relative change in tension during impact is also less, thus reducing the apparent difference in control between hard and soft hits, and giving the player a wider range of available hits.
- Greater deflection also provides an overall longer dwell time during impact which improves control and power transmission to the ball.
- the ball also sees a more evenly balanced force profile when hit, especially near the frame of the racket. This improves control considerably when compared to conventional rackets which exprience abnormally high string tensions near the frame due to the relatively shorter string lengths.
- the invention also allows more energy to be transmitted to the ball thus reducing the levels of shock and vibration experience by the player.
- the invention is also advantageous in reducing friction and wear. Wear at the crisscross string intersections is reduced because the tension forcing the overlapping strings together is substantially reduced thus decreasing the frictional forces proportionately. This lower friction at the string intersections complements the minimal friction associated with the tension transmitting action of rockers 28.
- Stringing of the racket may be accomplished in substantially the usual manner, with rockers 28 inserted as stringing progresses.
- One rocker is placed between the string and outer head frame surface 21 at each wrap where the string passes through one hole and extends over the outer surface to be received through the next adjacent hole.
- An important advantage of the present invention over other rackets employing pulley systems or saddle string mounts is the basic simplicity of the structure. It further allows the weight of the racket head to be maintained at a relatively low value. Prior art apparatus added to a conventional racket head significantly increase the head weight and adversely affect racket valance and performance. Other advantages are the small size and external positioning of the tension transmitting means so that there is no interference or intrusion into the string opening 18. This is a important since anything extending into the opening 18 will effectively diminish the opening size or decrease the effective string length.
Landscapes
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Physical Education & Sports Medicine (AREA)
- Golf Clubs (AREA)
- Footwear And Its Accessory, Manufacturing Method And Apparatuses (AREA)
- Vibration Dampers (AREA)
- Professional, Industrial, Or Sporting Protective Garments (AREA)
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/670,402 US4591165A (en) | 1984-11-14 | 1984-11-14 | Racket having strings which pass over rockable tension transmitting means |
AT85201947T ATE52419T1 (de) | 1985-11-22 | 1985-11-22 | Anordnungen zum uebertragen der saitenspannung auf den rahmen eines sportschlaegers. |
DE8585201947T DE3577512D1 (de) | 1985-11-22 | 1985-11-22 | Anordnungen zum uebertragen der saitenspannung auf den rahmen eines sportschlaegers. |
EP85201947A EP0223882B1 (de) | 1985-11-22 | 1985-11-22 | Anordnungen zum Übertragen der Saitenspannung auf den Rahmen eines Sportschlägers |
BE0/215901A BE903697A (nl) | 1984-11-14 | 1985-11-22 | Snaarsportracket met een snaarspanning overbrengende inrichting. |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP85201947A EP0223882B1 (de) | 1985-11-22 | 1985-11-22 | Anordnungen zum Übertragen der Saitenspannung auf den Rahmen eines Sportschlägers |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0223882A1 true EP0223882A1 (de) | 1987-06-03 |
EP0223882B1 EP0223882B1 (de) | 1990-05-09 |
Family
ID=8194087
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP85201947A Expired - Lifetime EP0223882B1 (de) | 1984-11-14 | 1985-11-22 | Anordnungen zum Übertragen der Saitenspannung auf den Rahmen eines Sportschlägers |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0223882B1 (de) |
AT (1) | ATE52419T1 (de) |
DE (1) | DE3577512D1 (de) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5100136A (en) * | 1990-11-23 | 1992-03-31 | Chen Dennis C S | Structure of racket |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1542177A (en) * | 1923-09-12 | 1925-06-16 | Rose Robert | Tennis racket and the like |
US3567225A (en) * | 1968-03-26 | 1971-03-02 | Brancroft Racket Co | Racket including string engaging elastomeric bushings and pads |
DE2611970A1 (de) * | 1976-03-20 | 1977-09-29 | Helmut Bausch | Tennisschlaeger |
US4462592A (en) * | 1981-07-22 | 1984-07-31 | Roberto Legger | Metallic frame for tennis rackets |
-
1985
- 1985-11-22 AT AT85201947T patent/ATE52419T1/de not_active IP Right Cessation
- 1985-11-22 EP EP85201947A patent/EP0223882B1/de not_active Expired - Lifetime
- 1985-11-22 DE DE8585201947T patent/DE3577512D1/de not_active Expired - Fee Related
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1542177A (en) * | 1923-09-12 | 1925-06-16 | Rose Robert | Tennis racket and the like |
US3567225A (en) * | 1968-03-26 | 1971-03-02 | Brancroft Racket Co | Racket including string engaging elastomeric bushings and pads |
DE2611970A1 (de) * | 1976-03-20 | 1977-09-29 | Helmut Bausch | Tennisschlaeger |
US4462592A (en) * | 1981-07-22 | 1984-07-31 | Roberto Legger | Metallic frame for tennis rackets |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5100136A (en) * | 1990-11-23 | 1992-03-31 | Chen Dennis C S | Structure of racket |
Also Published As
Publication number | Publication date |
---|---|
DE3577512D1 (de) | 1990-06-13 |
EP0223882B1 (de) | 1990-05-09 |
ATE52419T1 (de) | 1990-05-15 |
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