EP0727244B1 - Racket with a string tensioning device - Google Patents

Abstract

The racquet frame has lengthwise and crosswise strings, and a handle. Part of the frame (7) has a string-tensioning piece abutment (8) which has through bores (11) in the middle for the strings, distributed along a line running in the peripheral direction of the frame. A tension piece (9) rests beneath the abutment part and also has through bores (12) for strings in the middle. The two sets of through bores are flush with each other. The side parts of the tension part and abutment to one side of the row of bores have cooperating retainer grooves and protuberances. The side parts to the other side have support steps and surfaces.

Description

The invention relates to a racket for ball games, in particular tennis, Squash and badminton rackets, with a frame that is longitudinal and Cross strings comprehensive covering, with one with the frame connected handle and with a tensioning device for the strings, as well as a Method for adjusting the string tension of such ball game rackets.

A variety of string tensioning systems for tennis racquets are known. For example, DE 38 18 152 A1 discloses a tennis racket a string tensioner, which has a gas spring element on the racket handle is attached. The gas spring element causes the middle main strings of the racket even when a string is elongated by use have constant string tension. Such a tensioning device is, however, quite complex to construct, has one that should not be neglected Weight and a certain susceptibility to failure. It is questionable whether it is proven itself under the great stresses of gaming. Is also with this tensioning device can only implement a single constant string tension, which is determined by the spring force of the gas spring.

DE 38 13 872 C2 and DE 39 17 868 C2 are clamping devices known, the an increase in circumference of the racket frame, which in Area of the heart of the racket is divided. This jig causes a constant tensioning of all racket strings, however shows the racket frame compared to an undivided, one-piece Racket frame a reduced stability.

The object of the invention is to provide an apparatus and a method create that without loosening the covering an increase in the tension of the Racket strings allows without destabilizing interventions in the Racket frame and achieved without expensive and prone to failure aids becomes.

This object is achieved with respect to the device by characterizing features of claim 1 and with respect to the method by the characterizing features of claim 9 or claim 10 solved.

To adjust the string tension it is only necessary to use a tensioning device which consists of an abutment and a clamping part, on To arrange racket frames. Both parts of the jig are from extends through the racket strings, the racket strings around webs of the tensioning part are led around and the tensioning part fixed by the string tension is pressed against the abutment and the racket frame. Clamping part and Abutments point to one side of the row of openings for the Strings latch grooves or latch projections engaging in the latch grooves. On the other hand, the clamping part and abutment with support levels or Provide contact surfaces so that through the locking grooves and locking projections different locking positions of the clamping part with respect to the abutment can be realized in which the contact surface each on a other edition level. By resting on the contact surface different levels of support is caused that the clamping part with respect of the abutment is tilted and the distance between the areas in which the strings loop around the tension part, changed to the abutment part. Due to this change in distance, the tension of the clamping part protruding strings varied.

With this simple, inexpensive and light clamping device different locking positions, it is possible to reliably adjust the string tension to vary in discrete gradations. In a preferred one Embodiment of the invention are the locking throats and the support levels on the abutment and at least one locking projection and at least one Support surface arranged on the clamping part. The locking projection forms the lower longitudinal edge of the clamping part, and the bearing surface is that of the lower longitudinal edge opposite area of the lower surface of the clamping part educated. Of course, the edition levels or the Locking grooves can be arranged on the clamping part without affecting the mode of operation the clamping device changes significantly.

The abutment can be firmly integrated in the racket frame, e.g. if the frame is made of carbon fiber reinforced plastic. For use the tensioning device according to the invention on a conventional racket it is also possible to use the abutment as a separate part against the racket frame trainable. In this case, both parts of the jig held by the string tension on the racket frame.

Because the longest racket strings in play are also the largest absolute Are subject to stretching, it makes sense to place the tensioning device on this Let strings work. It is also advantageous to use the tensioning device not on an exposed area of the perimeter of the racket frame fasten, as this would result in a source of injury. That is why Tensioning device advantageously arranged within the heart of the racket, that is, within the range defined by the two V-shaped Struts and the lower frame section running between them and the connection between the racket frame and the racket handle forms. The tensioning part lies against the lower frame section mentioned on.

The clamping part can be tilted by any suitable gripping device or Pliers can be effected. However, the clamping part advantageously has two at its ends arranged engagement holes into which two pins one Clamping levers can be inserted. The clamping part is also on the clamping lever low force can be tilted against the string tension.

So that the strings are not on the sharp edges of the openings be worn out and tear, it is advantageous to face each other Mouths of the openings of the clamping part and the Abutment part at least in the direction transverse to the circumferential direction of the Racket frame expand like a funnel and by this expansion remove sharp edges at the mouths.

Finally, the passage openings can be lined with plastic sleeves become. These plastic sleeves can also be made in one piece with the abutment part and be connected to the tensioning part. With a one-piece attachment the plastic sleeves on the abutment part take over these plastic sleeves the guidance of the abutment part on the racket frame. Thereby can additional guide elements, such as sidewalls of the Abutment part, omitted.

The device according to the invention can be used in two different processes used to adjust the string tension. For the recreational player it is sufficient to attach the tensioning part when applying the racket covering to be placed in the position of the lowest voltage, so that at a decrease in the string tension of the players by engaging the The desired part in the position of the next higher string tension String tension can adjust. For the professional player who during the game on an adjustment of the string tension to adjust the respective day form and game situation is interested, it makes sense the clamping device when covering the racket in the position of the medium tension so that the player during the game the string tension by tilting the tensioning part in one direction or the other can increase or decrease.

Fig. 1

einen Tennisschläger mit einer erfindungsgemäßen Spannvorrichtung,

Fig. 2

die Draufsicht auf eine Ausführungsform der erfindungsgemässen Spannvorrichtung in vergrößerter Darstellung,

Fig. 3

die Seitenansicht der Spannvorrichtung aus Fig. 2 im Schnitt mit gestrichelt dargestelltem Spannhebel,

Fig. 4a bis 4c

die Spannvorrichtung aus den Fig. 2 und 3 in drei unterschiedlichen Raststellungen,

Fig. 5

eine andere Ausführungsform der erfindungsgemäßen Spannvorrichtung in Draufsicht,

Fig. 6a bis 6c

die Seitenansicht der Spannvorrichtung aus Fig. 5 im Schnitt in drei unterschiedlichen Raststellungen,

Fig. 7

die Seitenansicht einer anderen Ausführungsform des Widerlagerteils der erfindungsgemäßen Spannvorrichtung in geschnittener Darstellung.

Further features of the invention result from the following description of the drawings. The drawings show in

Fig. 1

a tennis racket with a tensioning device according to the invention,

Fig. 2

the top view of an embodiment of the tensioning device according to the invention in an enlarged view,

Fig. 3

2 shows the side view of the tensioning device from FIG. 2 in section with the tensioning lever shown in broken lines,

4a to 4c

2 and 3 in three different locking positions,

Fig. 5

another embodiment of the tensioning device according to the invention in plan view,

6a to 6c

5 shows the side view of the tensioning device from FIG. 5 in section in three different locking positions,

Fig. 7

the side view of another embodiment of the abutment part of the tensioning device according to the invention in a sectional view.

The tennis racket shown in FIG. 1 consists of a racket handle 1 and a racket frame 2 which is covered with cross strings 3 and main strings 4 is provided. The racket handle 1 is with the racket frame 2 connected via two V-shaped struts 5,6. Between Points at which the struts 5, 6 merge into the racket frame 2, The lower frame section 7 runs against this lower frame section 7 is the tensioning device, which consists of an abutment part 8 and there is a clamping part 9. Both parts are from the middle main strings 4 through the racket string and through the string tension pulled against the lower frame section 7.

The structure of the clamping device and how it works can be 2, 3, 4a - 4c. The lower frame section 7 is in the 2 and 3 indicated by thin lines. Against the lower frame section 7 is the abutment part 8, which has side cheeks 10, which laterally enclose the lower frame section 7 of the racket frame 2. The abutment part 8 and the clamping part 9 have through openings 11 and 12 for the strings 4 of the racket. These openings 11, 12 are essentially aligned with the passage openings 13 of the lower frame section 7. Between two adjacent passage openings 12 of the clamping part 9 there is a web 14 in order which the longitudinal strings 4 of the racket cover run around, so that Clamping part 9 and abutment part 8 firmly against the racket frame section 7 be pressed.

The operation of the tensioning device can be seen in FIGS. 4a-4c. On the right side, the abutment part 8 has three locking grooves 15 on, and the clamping part 9 is provided with three locking projections 16. One the locking projections 16 is through the lateral longitudinal edge of the clamping part 9 formed. Theoretically, only that would reliably lock into place lateral longitudinal edge of the clamping part 9 are sufficient as a locking projection 16. The additional locking projections 16 of this embodiment only serve an additional safeguard against unintentional adjustment of the tensioning device.

On the left side in the drawings the support levels 17 are closed recognize that with the bearing surface 18 by the side region of the Bottom surface of the clamping part 9 is formed, cooperate.

In the first position with the lowest voltage, that of FIG. 4a remove, the lower surface of the clamping part 9 is essentially flush against the surface of the abutment part 8. In the recognizable in Fig. 4b the first clamping position, the clamping part 9 is pivoted through an angle α and locked in this position. The outer edge of the clamping part 9, which forms the locking projection 16, engages in the central locking groove 15 on. The contact surface 18 of the clamping part 9 lies on the middle contact level 17 on. Characterized in that the clamping part 9 relative to the abutment part is tipped, the main string 4 is stretched, and it becomes its tension elevated.

4c the clamping device is shown in the outermost clamping position, wherein the locking projection 16 of the clamping part in the innermost locking groove 15 engages and the bearing surface 18 of the clamping part on the highest Edition level 17 of the abutment part rests. The clamping part 9 is around Angle β inclined to the abutment part 8.

By tilting the clamping part 9 relative to the abutment part 8 the main string 4 against the edge regions of the passage openings 11, 12 of the Abutment part 8 and the clamping part 9 moves. To prevent the Main strings 4 damaged by sharp edges of the through openings 11, 12 are the opposite mouths of the passage openings 11,12 provided with a funnel-like expansion 19.20.

To pivot the clamping part 9 with respect to the abutment part 8 points the clamping part 9 has an engagement hole 21 at each of its two ends. In these Engagement holes 21 are the side fork-like engagement pins Tension lever 22 - shown in dashed lines in Fig. 3 - insertable. With help the clamping lever 22, the clamping part 9 can be easily tilted by hand, by pressing the tension lever 22 with the force F. The engagement holes 21 for the clamping lever 22 do not necessarily have to be perpendicular to the Passages 12 run, but can also be parallel to this extend, wherein the engagement pin of the clamping lever 22 are angled.

5 shows an alternative embodiment of the tensioning device, in which the abutment part 8 to protect the main strings 4 with plastic sleeves 23 is provided. As a preferred embodiment of the tensioner is made of light metal, especially aluminum, prevent the plastic sleeves 23 excessive wear of the main strings 4 due to friction on the metallic edges. Of course you can also in the Clamping part 9 plastic sleeve provided for the passage openings 12 become. 6a-6c show the embodiment of the tensioning device 5 and correspond to the previously described FIGS. 4a-4c.

7 shows an alternative embodiment of the abutment part 8 ', which consists of glass or carbon fiber reinforced plastic and on which the plastic sleeves 23 'are formed. In this embodiment the plastic sleeves 23 'take over the guidance of the abutment part 8 'in the passage openings of the lower frame section 7 of the Racket so that the side cheeks at the abutment part 8 'can be omitted.

The invention has been described using the example of a tennis racket. However, it goes without saying that they are also on squash rackets or racket for other types of ball games.

Reference symbol list:

1

Racket grip

2nd

Racket frame

3rd

Cross string

4th

Main string

5

strut

6

strut

7

Lower frame section

8.8 '

Abutment part

9

Clamping part

10th

Sidewalls

11

Passage opening of the abutment part

12th

Passage opening of the clamping part

13

Passage opening of the racket frame

14

web

15

Snap throat

16

Locking projection

17th

Edition level

18th

Contact surface

19th

Widening

20th

Widening

21

Engagement hole

22

Tension lever

23.23 '

Plastic sleeve

24th

Bat heart

Claims (10)

1. A racquet for ball games, in particular a tennis, squash or badminton racquet, having a frame (2), which is strung with longitudinal (4) and transverse (3) strings, a handle (1) connected with the frame (2) and a tensioning device for the strings,
   characterised in that a frame portion (7) comprises an abutment piece (8, 8') of the tensioning device, which abutment piece comprises passage openings (11) for the strings (4) in its central area and distributed along a line extending in the circumferential direction of the frame (2) and in that a tensioning piece (9) lies against the abutment piece (8, 8") under the tensile stress of the strings (4), which tensioning piece (9) likewise comprises passage openings (12) for the strings (4) in its central area, which passage openings (12) are substantially aligned with the passage openings (11) in the abutment piece (8, 8"), the lateral areas of the tensioning piece (9) and the abutment piece (8, 8") located to one side of the row of passage openings (11, 12) comprising locking grooves (15) and locking tabs (16) interacting with one another and the lateral areas located to the other side comprising mutually interacting bearing steps (17) and bearing surfaces (18).
2. A racquet according to claim 1, characterised in that the locking grooves (15) and the bearing steps (17) are arranged on the abutment piece (8, 8') and in that at least one locking tab (16) and at least one bearing surface (18) are arranged on the tensioning piece (9), the locking tab (16) being formed of the lower longitudinal edge and the bearing surface (18) being formed of the lower lateral area of the lower face of the tensioning piece (9).
3. A racquet according to claim 1 or claim 2, characterised in that the abutment piece is formed of an abutment piece (8, 8") adjoining the racquet frame.
4. A racquet according to at least one of the preceding claims, characterised in that the tensioning device is arranged inside the racquet throat (24) and acts on the central longitudinal strings (4) of the racquet.
5. A racquet according to at least one of the preceding claims, characterised in that the tensioning piece (9) comprises an engagement hole (21) at each of its two ends for the insertion of two pegs of a tension lever (22).
6. A racquet according to at least one of the preceding claims, characterised in that the mutually opposing mouths of the passage openings (11, 12) of the abutment piece (8, 8") and the tensioning piece (9) widen in the manner of a funnel at least perpendicularly to the circumferential direction of the racquet frame (2).
7. A racquet according to at least one of the preceding claims, characterised in that at least the passage openings (11) for the strings (4) formed in the abutment piece (8, 8') are lined with plastics sleeves (23).
8. A racquet according to claim 7, characterised in that the plastics sleeves (23') are connected in one piece with the abutment piece (8').
9. A method of adjusting the string tension of a racquet for ball games, in particular a tennis, squash or badminton racquet, characterised in that a tensioning device consisting of an abutment piece and a tensioning piece, through which tensioning device some of the strings project and which may be locked in various positions of increasing string tension, is arranged in the position of least tension during stringing of the racquet and locked in the position of next-higher string tension during slackening of the string tension.
10. A method for adjusting the string tension of a racquet for ball games, in particular a tennis, squash or badminton racquet, characterised in that a tensioning device consisting of an abutment piece and a tensioning piece, through which tensioning device some of the strings project and which may be locked in various positions of increasing string tension, is arranged in the position of medium tension during stringing of the racquet and locked in a position of lower or higher string tension if the established tension is too high or too low.

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