EP0788817A2 - Sportschläger mit einer ungeraden Zahl Längssaiten - Google Patents

Sportschläger mit einer ungeraden Zahl Längssaiten Download PDF

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Publication number
EP0788817A2
EP0788817A2 EP97300763A EP97300763A EP0788817A2 EP 0788817 A2 EP0788817 A2 EP 0788817A2 EP 97300763 A EP97300763 A EP 97300763A EP 97300763 A EP97300763 A EP 97300763A EP 0788817 A2 EP0788817 A2 EP 0788817A2
Authority
EP
European Patent Office
Prior art keywords
string
frame
racket
string segments
longitudinal
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.)
Withdrawn
Application number
EP97300763A
Other languages
English (en)
French (fr)
Other versions
EP0788817A3 (de
Inventor
Tsai Chen Soong
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of EP0788817A2 publication Critical patent/EP0788817A2/de
Publication of EP0788817A3 publication Critical patent/EP0788817A3/de
Withdrawn legal-status Critical Current

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Classifications

    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B51/00—Stringing tennis, badminton or like rackets; Strings therefor; Maintenance of racket strings

Definitions

  • the present invention is related to an innovative stringing and frame construction associated with stringing of sports rackets, such as tennis, racquetball, badminton squash, etc.
  • the conventional string network comprises a system of longitudinal string segments approximately parallel to the axis of the frame, having an even number of string segments, and a cross string system approximately perpendicular to the longitudinal string system.
  • the structure of the frame is symmetrical to the axis of the racket, there is customary 16 to 20 longitudinal string segments, evenly distributed on both sides of the longitudinal axis which is itself void of string.
  • a conventional racket is shown in Fig. 1 where the frame 10 comprising the head portion 1, side frame 2, a throat 3 opposite to the top, shanks 4, and the handle 5.
  • the string network 6 comprises a longitudinal string system 7 approximately parallel to the axis of the frame 8, and a cross string system 9.
  • strings are anchored around the frame by means of string holes drilled at the center plane of the frame which is shown as plane M in Figures 4 and 5. Since a string develops a reactive force component perpendicular to the center plane M of the string network to return a ball only when the string is depressed deep enough to produce a significant inclination angle with respect to the central plane. For strings such as 12 which is near the boundary of the frame, the normal deflection is always small and the string network in boundary zones is often weak in tension and is not effective.
  • a feature of the invention is shown in the tennis racket 20 of Fig. 2. where there is a longitudinal string segment 21 at the center line 8 of the frame and the rest of the longitudinal string segments are distributed and connected to each other as a mirror image on both sides of the central longitudinal string 21.
  • the cross string segments which are interwoven up and down with the corresponding longitudinal string segments, are also arranged as a mirror image with respect to said center line. Therefore, the string pattern and the stress on the frame is truly symmetric and balanced about the central axis of the racket. It is to be noted that this inventive departure from the traditional stringing pattern of sports racket improves the performance of the racket but makes it difficult to be strung properly.
  • Fig. 1 A prior art tennis racket frame.
  • Fig. 2 shows an embodiment of the invention.
  • Fig. 3 shows another embodiment of the invention.
  • Fig. 4 shows a cross sectional view of section 4-4 of Fig. 3.
  • Fig. 5 shows a cross sectional view of section 6-6 of Fig. 3.
  • Fig. 6 shows a stringing pattern by a one piece longitudinal string.
  • Fig. 7 shows a stringing pattern by two pieces of longitudinal strings.
  • the present invention applies to general sports racket having a string net work.
  • the tennis racket is shown as an example to illustrate the invention.
  • Figure 1 shows a prior art racket frame 10, with a string network.
  • Fig. 2 shows a feature of the invention where the frame 20 has a longitudinal string segment 21 coinciding with the longitudinal center line 8 of the frame, comprising an odd number of longitudinal string segments symmetrically distributed as a mirror image at opposite sides of the central string. Segment is defined as a portion of a string end to end within the boundary of a frame. Ends of segments are connected through loops such as 24, 25, to become a continuous length of a piece of string. Loops are the anchors of string segments on the frame. Cross string segment is supported by respective longitudinal strings. A merit of the mirror imaged pattern can be seen from Figures 1 and 2 in which a ball 17 hits the center line of the racket. In Fig.
  • the ball will be in contact with at most four longitudinal strings.
  • the inner pair, 15 and 14, and the outer pair, 13 and 16, are interwoven non-symmetrically with respect to the center line. Their resultant is inclined to the plane of the frame. Therefore, a ball hits the exact center line of the frame will not bounce back along the exact normal direction of the frame.
  • the playing public had long tolerated this inaccuracy as a fact inherited from the equipment. Better players learned to compensate for the error.
  • FIG. 3 Another merit of the invention is shown in Fig. 3 and its view along the cut section 4-4 shown in Fig. 4. It is suggested here that for a type of string pattern in which a multiples of strings are anchored to the frame at points some distance away from the central plane M of the frame, the resulting weaving pattern will be exactly symmetric, including the slanted portion of the length of the string segment near the boundary of the frame, with respect to the central axis. This not only improves the stress distribution, reduces frame distortions along the two lateral sides, but also makes handling of the racket easier, because then the structure and the string network is exactly balanced about the center line of the frame. Ends of the segments may wrap around the frame for anchor instead of through an elevated opening in the frame. In Figures 6 and 7, more will be said about frame distortion.
  • end point 41 of the central longitudinal string 21 anchors at the upper half L of the frame, and the end 42 of the adjacent string segment is at the opposite half H of the frame.
  • Anchor points in the same region, such as 41 and 43, are arranged along a line 44 approximately symmetric to plane M as shown in Fig. 4 with respect to end points at the opposite region.
  • end points of cross string segments may be located away from the central plane of the frame.
  • the line 44 of end point trajectory may be a curved line, a straight line, or a composite line comprising line elements and arc elements.
  • Fig. 5 shows the cross section 6-6 of Fig. 3. It shows the cross string segment 61 anchors at side 2 of the frame. This cross string weaves up and down through longitudinal strings with all odd numbering strings, 21, 63, etc., on lower half L and even numbering string segments like 62, on the upper half H.
  • the cross string adjacent to 61 is 64 which is inclined oppositely at an angle with respect to the M plane. This inclination tightens the string and increases the string tension when a ball hits. With the string segment symmetrically wraps over the frame at the sides, control is improved.
  • Fig. 5 shows graphically the so-called mirror image arrangement. If the player rolls the racket about the handle 180 degrees, the string pattern remains symmetric to the center line 8. In a conventional racket, the sloping of the opposite ends is anti-symmetric: if the left end points upward, the right end points downward. This is not a desirable feature.
  • Fig. 6 shows a string pattern of the Fig. 2 frame in which a single piece of string 81 strings the whole longitudinal string system.
  • the segments within the frame's boundary is a mirror image with respect to the axis 8, however, the whole string pattern, including the loops 66, 67, are not symmetric to the axis 8.
  • Fig. 7 shows that the same frame in Fig. 2 is strung by two pieces of string: the first piece 84 and the second piece 85.
  • the second end d of 84 is anchored at the frame. Or, it may be tied to an adjacent string.
  • the fork 86 may be located at the head portion instead of at the throat.
  • a string may be made specifically for the invention and the two pieces are threaded together at 86 to form a fork instead of being joined by a tie as shown.
  • Other ways are possible to combine two pieces into a single one, All these practical arrangements will be named as a fork device in the specification. For the Fig.
  • the two end force 87 and 88 are parallel forces and are pulling towards the same axial direction. This is a significant improvement over the Fig. 6 one piece string arrangement. It is to be noted the fork device enables the loops such as 68, 69 to be a mirror image to the axis 8.
  • a truly mirror imaged stringing pattern improves greatly vibration and control. Without the centrally placed string and an odd number of symmetrical, mirror imaged longitudinal string pattern, and a two-piece, fork device of the longitudinal string arrangement, these improvements can not be achieved.

Landscapes

  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Physical Education & Sports Medicine (AREA)
  • Braiding, Manufacturing Of Bobbin-Net Or Lace, And Manufacturing Of Nets By Knotting (AREA)
  • Professional, Industrial, Or Sporting Protective Garments (AREA)
  • Steering Devices For Bicycles And Motorcycles (AREA)
EP97300763A 1996-02-12 1997-02-06 Sportschläger mit einer ungeraden Zahl Längssaiten Withdrawn EP0788817A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US60019796A 1996-02-12 1996-02-12
US600197 1996-02-12

Publications (2)

Publication Number Publication Date
EP0788817A2 true EP0788817A2 (de) 1997-08-13
EP0788817A3 EP0788817A3 (de) 1999-08-18

Family

ID=24402681

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97300763A Withdrawn EP0788817A3 (de) 1996-02-12 1997-02-06 Sportschläger mit einer ungeraden Zahl Längssaiten

Country Status (2)

Country Link
EP (1) EP0788817A3 (de)
JP (1) JPH09215781A (de)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4033582A (en) * 1974-02-28 1977-07-05 Linden Gaylord C Method of stringing rackets
WO1981003431A1 (en) * 1980-06-02 1981-12-10 M Mcmahon Racquet strings and racquets
DE3805920A1 (de) * 1988-02-25 1989-09-07 Gebhard Dischinger Verfahren zum herstellen eines geflechts, insbesondere fuer die besaitung eines ballschlaeger-rahmens und danach hergestelltes geflecht, sowie rahmen und hilfsmittel fuer die erstellung eines solchen geflechts
WO1990001974A1 (en) * 1988-08-18 1990-03-08 Rodney Svoma Sports racket
EP0542461A2 (de) * 1991-11-12 1993-05-19 Dunlop Limited Ballschläger
DE29504602U1 (de) * 1995-03-13 1995-06-08 Schade, Siegfried, 40822 Mettmann Tennisschläger

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4033582A (en) * 1974-02-28 1977-07-05 Linden Gaylord C Method of stringing rackets
WO1981003431A1 (en) * 1980-06-02 1981-12-10 M Mcmahon Racquet strings and racquets
DE3805920A1 (de) * 1988-02-25 1989-09-07 Gebhard Dischinger Verfahren zum herstellen eines geflechts, insbesondere fuer die besaitung eines ballschlaeger-rahmens und danach hergestelltes geflecht, sowie rahmen und hilfsmittel fuer die erstellung eines solchen geflechts
WO1990001974A1 (en) * 1988-08-18 1990-03-08 Rodney Svoma Sports racket
EP0542461A2 (de) * 1991-11-12 1993-05-19 Dunlop Limited Ballschläger
DE29504602U1 (de) * 1995-03-13 1995-06-08 Schade, Siegfried, 40822 Mettmann Tennisschläger

Also Published As

Publication number Publication date
JPH09215781A (ja) 1997-08-19
EP0788817A3 (de) 1999-08-18

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