EP1452207B1 - Racket for ball sports - Google Patents

Abstract

Racket (1) comprises a frame having a head region (3) for receiving strings and a grip section for holding the racket. The frame has in at least two segments (17) of the head region several reinforcing elements (15) running perpendicularly to the frame. An independent claim is also included for the production of the above ball game racket. Preferred Features: The reinforcing elements are provided in four segments arranged a distance apart. The racket has 3-5 reinforcing elements per segment. The reinforcing elements and the frame are made of the same or different material.

Description

The present invention relates to a racket for ball games, in particular a tennis racket, squash rackets, badminton rackets and racquetball rackets, with a frame having a head portion for receiving a string and a handle or handle portion. Such bats often have a subsequent to the club head and in the handle portion merging heart area or a fork.

In general, a beaten, d. H. a striking the clothing of the racket ball elastic deformation of the racket or an elastic displacement of the head portion from its longitudinal axis and leads to a deterioration of the accuracy. Such a deflection of the club head is responsible for the direction of the ball played. Even a slight deflection of the club head can cause a significant deviation of the actual target point of the ball from the desired in a ball played over the field length. After the ball has been deflected by the ball, the ball moves away from the bent racket. The club goes after the separation from the ball in its free damped oscillation (natural frequency) on.

Furthermore, a hit on the racket ball or a hit ball causes forces that are transmitted to the player via the racket. Such forces or vibrations or shocks are, at least in the long-term effect, responsible for the player's health problems such as the so-called tennis elbow occur.

Furthermore, a continuous compensation of the impact shock and the forces occurring during the game to a rapid fatigue of the player. Also, the control is over the club and thus the playing behavior influenced by excessive forces acting on the player.

If the player hits the ball at the so-called "sweet spot" or the "sweet area", the player only feels a weak impulse. However, even with balls played in this way, the actual trajectory of the ball can deviate from the desired one due to unfavorable deformation of the racket and health consequences, such as the already mentioned tennis elbow, occur, at least for repeated or frequent hits.

The US-A-5,462,274 discloses a tennis racket comprising longitudinal strings stretched in a longitudinal direction of the racket and transverse strings stretched in a transverse direction perpendicular to the longitudinal direction, the ratio of the tension of each longitudinal string to the tension of each transverse string being in the range of 2.5 / 1 to 4/1 so that a nodal line for second-order vibrations lies in the so-called sweet area, whereby the reaction of the tennis racket to an impulse by a tennis ball is to be reduced.

The US-A-4,997,186 discloses a racquet frame, eg for a tennis racket, having a head portion, a handle portion and a neck portion extending therebetween. The head portion encloses an open area and has a plurality of string holes for attaching a string to the head portion and over the open area. The heart region is in the form of a pair of legs and substantially V-shaped. In the racket frame, differing aspect ratios are provided to pre-determine the rigidity of the frame. A first aspect ratio refers to the location of the maximum cross-sectional height of the racket frame in a lower portion of the head portion to provide a double reverse tapered profile along the cross-sectional height of the racket frame. A second aspect ratio refers to providing a sudden transition in an inwardly facing surface of the head region of the racquet frame to provide a dual tapered conical profile along the transverse width of the head region of the racquet frame. A third aspect ratio relates to changing the cross-sectional height to the cross-sectional width along the heart area of the racquet frame to provide a larger heart area height and a larger heart area width near the handle section.

The US-A-5,310,179 describes a tennis racket construction having an oval header area frame defining a stringing surface, wherein the longitudinal size of the stringing surface is in the range of 320 to 390 mm and the transverse length thereof is in a range of 200 to 240 mm and the longitudinal compression stiffness of the head region is at a value is set in the range of 30 to 200 kgf / mm. The disclosed construction is intended to allow for the provision of greater head and cross string tensions, thereby achieving a higher degree of "spin" on shot balls.

The DE-A-199 53 626 describes an improved ball game racket in which a profile forming the frame at different frame positions according to the main types of stress occurring there have different cross-sectional shapes, the resistance moments adapted to the respective types of stress, wherein in the range between four and six o'clock and / or at the heart area of the racket at least one hump-like stiffening element can be provided.

US-A-6,293,878 describes a device for damping vibrations in a sports racquet with a first and a second elastic damping material connectable to the racket frame, and a mass accessory which is free to oscillate independently of the racket frame and has a clip arrangement.

EP 1 149 607 A2 discloses a sports racket according to the preamble of claim 1 with a handle and a frame. The frame includes an inner portion and an outer portion disposed substantially opposite to the inner portion. The inner portion of the frame has a plurality of waves that move toward and away from the clothing surface. These waves can be provided at different locations and have a variable wavelength or amplitude.

However, with the racquets known from the prior art, the optimum rigidity or the optimal damping behavior of a racquet is not met, so that accuracy, pulse absorption and handling or playability of these known racquets still leave much to be desired. With the known from the prior art rackets, the possibility of optimal, simple or fast and cost-effective production is still not met.

The present invention is based on the object, a further improved racket, in particular an improved tennis rackets and improved Squash racket to provide. Other objects of the invention are to provide a racket which overcomes the disadvantages of the prior art, which has improved stiffness or stiffness, which is simple and inexpensive to produce and / or which has improved playability. This object is achieved with the features of the claims.

The invention is based on the basic idea of providing a ball game racket with a frame which has a head area for receiving a clothing and a grip portion for holding the ball game racket, wherein the frame at the head area in at least two segments each have a plurality of clamps formed transversely to the frame. or rib-like stiffening elements.

In this context, transverse to the frame means approximately perpendicular to a longitudinal axis extending through the frame or through individual frame areas or infinitesimal frame elements. Figuratively speaking, such a longitudinal axis approximately follows the frame contour. In this case, the stiffening elements generally extend approximately radially to a circle formed by the head region, that is to say in the clothing plane, and / or perpendicular to the clothing plane. The stiffening elements surround or clasp the frame at least partially and / or completely.

The stiffening elements allow by an optimized change of the cross-sectional profile of the racket frame in the head area a change in the vibration or damping behavior along the frame, so that an optimized vibration or damping behavior is achieved. The stiffening elements cause an optimized mass distribution of the entire racket mass and an increase or change in the stiffness of the racket over the course of the racket. In this way, the playing behavior of the racket can be influenced. The player also feels subjectively a larger sweet spot.

The stiffening elements are arranged in at least two, preferably in four segments of the frame in the head region of the racket, each segment having a plurality of stiffening elements, preferably three to five stiffening elements. The Segments are preferably provided in the range of about 3:30 to 5 o'clock and 7 o'clock to 8 o'clock 30 or in the range of 1 o'clock to 2 o'clock 30 and 9 o'clock 30 to 11 o'clock.

The stiffening elements have different rib widths and / or different distances from one another within a segment, the width of the clamps of a segment being directed in the direction of a transverse axis extending approximately centrally through the head region of the racquet, i. in the direction of 3 o'clock or 9 o'clock, increases. Here, the width of one stiffening element relative to an adjacent stiffening element or the width of one group of stiffening elements increases with respect to an adjacent group of stiffening elements, wherein the width of the individual stiffening elements or of the individual stiffening elements of a group of stiffening elements is constant. According to the invention, a stiffening element has a greater width than a directly adjacent stiffening element and / or a smaller width than another directly adjacent stiffening element. Furthermore, two adjacent stiffening elements have an approximately equal or equal width, wherein they in turn have a greater and / or smaller width than an adjacent group of two stiffening elements. Preferably, such a width change along the racket profile takes place uniformly or symmetrically with respect to the racket.

The individual segments preferably have a width or length of about 60 to 90 mm and more preferably a width of about 70 to 80 mm along the frame or the racket contour. The width of the individual staples or ribs preferably ranges from about 2.5 to 12 mm, and more preferably from about 4.5 to 9 mm.

The brackets also have a distance surrounding the frame profile of about 0.25 to 1 mm, preferably about 0.5 mm. Preferably, the brackets have a thickness of about 0.25 to 1 mm, preferably about 0.5 mm, relative to the frame, ie, the surface of the brackets rises about 0.5 mm from the adjacent surface of the frame. The racket frame thus experiences in the region of a bracket a radius extension of about 0.25 to 1 mm, preferably of at least about 0.5 mm.

In a preferred embodiment of the invention, the clip-like stiffening elements are formed integrally with the racket. Here, the brackets are preferably formed by the radius expansion of the racket frame discussed above. The changes in diameter are chosen so that they do not adversely affect the transition of the frame profile to the respective clip, since if the changes are too great, the risk of breakage increases due to the deflection of the fibers contained in the frame, especially if the clamps or edges and transitions of the clips are relative are sharp-edged. The edges of the cross-sectional profile of the stiffening elements are therefore preferably rounded.

By providing the described stiffening elements in defined segments along the racket contour of the head area, among other things an increased strength or an increase and change in the stiffness of the racket along the frame course in the head area is effected, which in turn leads to an improved play behavior of the racket. Furthermore, the stiffening elements formed integrally with the racket permit simple and cost-effective production while at the same time optimizing the racket properties and the mass distribution.

Fig. 1

eine Vorderansicht eines Ballspielschlägers entsprechend dem Stand der Technik;

Fig. 2

eine Seitenansicht des Ballspielschlägers entsprechend Figur 1;

Fig. 3

eine Teilansicht eines Ballspielschlägers gemäß einer bevorzugten erfindungsgemäßen Ausführungsform;

Fig. 4a

eine Detailansicht eines Segments eines erfindungsgemäßen Schlägers in Draufsicht bzw. Vorderansicht; und

Fig. 4b

eine Detailansicht eines Segments eines erfindungsgemäßen Schlägers in Seitenansicht.

Hereinafter, a club according to the present invention will be described in detail with reference to a preferred embodiment with reference to the drawings. Show it:

Fig. 1

a front view of a ball game racket according to the prior art;

Fig. 2

a side view of the ball game racket accordingly FIG. 1 ;

Fig. 3

a partial view of a ball game racket according to a preferred embodiment of the invention;

Fig. 4a

a detailed view of a segment of a racket according to the invention in plan view and front view; and

Fig. 4b

a detailed view of a segment of a racket according to the invention in side view.

Figures 1 and 2 show a conventional ball game racket 2 in front and side view. The ball game racket 2 has a substantially oval club head 4, a heart area 6 and a grip portion 8. In the head region 4 of the racket 2 is usually a recess 10 for receiving a wear frame or headband, not shown, is provided. The heart area 6 of the racket 2 is arranged substantially between the head area 4 and the handle section 8 and represents the connection area between them. The heart area 6 has, for example, as in FIG FIG. 1 shown, an opening 12. However, this opening is not mandatory. However, when the opening 12 is formed, it is generally formed by two side portions 14 and 16 and a connecting portion or bridge 18 located in the head area 4 of the racket. Further, between the two side regions 14 and 16 of the heart region 6, a second connecting element 20, for example, for reasons of strength, be provided.

The in the Figures 1 and 2 illustrated conventional tennis racket 2 is formed from a molded profile with substantially constant dimensions, except for the recess 10. The cross-sectional shape or the cross-sectional dimensions of the profile forming the racquet frame are substantially constant from the side region 14 of the heart region 6 around the head region 4 and to the side region 16 and are substantially oval or rectangular. Only in the transition region between the heart region 6 and head region 4 or in the receiving region of the connecting element 18 does the racquet 2 have reinforced cross-sectional dimensions. As discussed above, there are other types of rackets in which the cross-sectional shapes or the cross-sectional dimensions of the profile forming the racket can undergo the cross-sectional changes described above.

For better orientation and for the simplified determination of certain areas along the frame profile in the head area 4 of a racket 2, the markings of a conventional dial of a clock are drawn in the head area 4. Thus, the features according to the invention and a racket according to the invention can be described below be described with reference to the respective circumferential position along the head portion 4 of the racket on the basis of the corresponding time. Here, the position to be designated along the circumference of the head portion 4 of the racket corresponds to the position of the "big hand" at the time mentioned. Thus, for example, "twelve o'clock" corresponds to an outermost head end 22 of FIG FIG. 1 shown racket 2.

A preferred embodiment of a ball game racket 1 according to the invention is in the Figures 3 and 4 shown. The racket 1 according to the invention essentially corresponds in its basic structure to a conventional ball game racket, as described above with reference to FIGS Figures 1 and 2 has been described. Accordingly, the racket 1 according to the invention comprises a head area 3, a heart area 5 and a grip portion (not shown). As already described at the beginning, the heart area 5 of the racket according to the invention is essentially the connecting area between the head area 3 and the grip section and has, for example, an opening 7. The opening 7 is formed by two side sections 9 and 11 and a connecting section or a bridge 13 in the head region 3 of the racket 1. The heart region 5 of the racquet 1 according to the invention can also be counter to that in FIG FIG. 3 illustrated embodiment without the opening 7 may be formed, that is, the handle portion may extend closed to the head portion 3. Also, the connecting element or the bridge 13 is optional. Consequently, the heart region 5 may be formed only from the extensions 9 and 11 of the head portion extending toward the grip portion. Furthermore, the heart region 5, as already described above with reference to the beater 2 of the prior art, a second connecting element (not shown).

As already explained above, the racket 1 according to the invention is based on the idea at certain points along the frame of the head area 3 of the racket 1, in particular on those segments where particularly high loads, eg in the form of static or dynamic forces and torsional or bending moments occur, provide stiffening elements in the form of ribs or brackets 15, which allow depending on the design and arrangement of a targeted influencing the strength and rigidity of the racket 1.

The brackets 15 are provided in the illustrated preferred embodiment in the segments 17 at about 3 o'clock 30 to 5 o'clock and 7 o'clock to 8 o'clock 30 or in the range of 1 o'clock to 2 o'clock 30 and 9 o'clock 30 to 11 o'clock. In a particularly preferred embodiment of the invention, the brackets in the segments 17 are arranged at about 2 o'clock, 4 o'clock, 8 o'clock and 10 o'clock. The segments 17 each preferably have a width of about 60 to 90 mm and more preferably a width of about 70 to 80 mm. The width of the segments 17 can also be described as a length along the circumference of the frame in the head area 3 of the racket 1. Furthermore, the width of the individual brackets is about 2.5 to 11 mm and more preferably 4.5 to 9 mm. According to the invention, the width of the brackets in the individual segments increases in the direction of 3 o'clock and 9 o'clock, respectively.

The distance between the clamps 15 to each other in a preferred embodiment of the invention between 2 and 11 mm, preferably between 4 and 9 mm. In a preferred embodiment of the invention, the brackets have different, i. Within a segment increasing and / or decreasing distances, preferably also in the direction of the increasing clip width. In this case, the width and / or spacing of the individual stiffening elements or of the individual stiffening elements or of the groups of stiffening elements within one or more segments is preferably designed as described above with respect to the stiffening elements within a segment.

Preferably, the width and / or spacing of the stiffening elements, i. the individual stiffening elements or a group of stiffening elements with respect to adjacent and / or directly adjacent individual and / or groups of stiffening elements, wherein the width of and / or the distance between the individual stiffening elements or the individual stiffening elements of a group remains the same, to or from ,

Two corresponding preferred embodiments of the invention are in FIGS. 4a and 4b shown, where FIG. 4a a detail view of a segment in plan view and front view, and shows FIG. 4b a detail view of another segment in side view shows. The illustrations clearly show that the distance 23 the stiffening elements 15 to each other in the direction of the arrow C increases. From the FIGS. 4a and 4b Furthermore, a widening of the width 21 of the individual brackets within a segment 17 in the direction of the arrow C emerges. According to the direction of the arrow C corresponds to the direction to 3 o'clock or 9 o'clock.

The clamps are formed by a change in diameter, in particular a diameter extension relative to the frame profile of preferably 0.25 to 1.0 mm, in particular about 0.5 mm. In a particularly preferred embodiment according to the invention, the peripheral profile of the clamps corresponds to the racket profile at the corresponding positions, wherein the clamps have a radius extension of approximately 0.5 mm circumferentially relative to the respective frame profile. In a further embodiment according to the invention, the clips circulate the frame profile at least partially. In a further preferred embodiment according to the invention, in which the racket according to the invention has a recess corresponding to recess 10, as in FIG. 2 described, the brackets 15 are correspondingly recessed at the points of the recess 10, that is, they include the racquet profile only partially. In a further preferred embodiment of the invention, which comprises the racquet profile partially comprising brackets 15, these have no abrupt or sudden beginning and no abrupt or sudden end, but are flowing into the respective cross-sectional profile over. In a further preferred embodiment according to the invention, the clamps completely revolve around the racket profile, ie extend endlessly around the frame profile.

In this context show Figure 4a and Figure 4b the circumferential radius extension 19 of the brackets or stiffening elements 15 relative to the respective frame profile. FIG. 4a further shows a detailed view of a racket, which has a recess 10, wherein the stiffening elements 15 are recessed at the locations of the recess 10 accordingly. In a preferred embodiment according to the invention, the radius extension 19 formed by stiffening elements 15 decreases in the direction of the recess 10, so that the radius extension 19 is less than that over the remaining circumference of the frame profile when the stiffening element 15 passes into the recess 10 trained radius extension and in a particularly preferred embodiment of the invention is approximately 0.

The in FIG. 3 illustrated ball game racket according to the invention has in the segments 17 at about 2 o'clock, 4 o'clock, 8 o'clock and 10 o'clock in each case five brackets 15, the brackets 15 in each of the segments in each case in the direction of 3 or 9 clock wider (see FIGS. 4a and 4b ). In a preferred embodiment according to the invention, the brackets widen by the same value and in a further preferred embodiment according to the invention each by a corresponding ratio. Accordingly, the brackets of an embodiment according to the invention widen by, for example, in each case half a millimeter and in accordance with a further embodiment according to the invention by in each case 10 to 30% of the width of the preceding bracket. In a further preferred embodiment of the invention, the brackets within a range only a total of a broadening, but not each clip undergoes widening compared to an adjacent clip.

In a further embodiment according to the invention, a ball game racket according to the invention has three brackets 15 per segment and, according to a further preferred embodiment, four brackets 15. Preferably ball game racket according to the invention, which are designed as tennis rackets, five brackets 15 per segment 17, while inventive ball game rackets, which are designed as squash rackets, preferably three brackets 15 per segment 17 have.

According to a preferred embodiment of the invention, the brackets are integrally formed with the frame of the racket. Alternatively, however, the brackets may also have different materials, for example, to achieve additional stiffening effects. If the racket made of fiber composites, there is a limitation on the size of the diameter or radius change in the brackets, as they may be relatively sharp due to their general size and dimensional ratios and thus the risk of breakage due to the fiber deflection increases. In a preferred embodiment of the invention, the edges and transitions of the brackets 15 are preferably rounded, so that dangerous voltage spikes in the frame can be avoided.

The racket 1 according to the invention as well as the arrangement and design of the clamps is also preferably substantially symmetrical with respect to a longitudinal central axis A, so that the above-described clamp segments in the region around 7 or 8 and 10 or 11 o'clock are also symmetrical to corresponding ones Positions are provided between 1 or 2 and 4 or 5 o'clock. In a further preferred embodiment according to the invention, the racket 1 according to the invention and the arrangement and design of the clamps are furthermore preferably substantially symmetrical with respect to a transverse central axis B, so that the above-described clamp segments in the range of approximately one or two and ten or 11 clock are also provided symmetrically at corresponding locations between 4 or 5 and 7 or 8 clock.

As material for the racket 1 according to the invention all known materials for tennis, squash, badminton and other rackets for ball sports are suitable. In particular, the racket 1 according to the invention is made of wood, metal, metal alloys, plastic, carbon fiber composite material, fiber materials, composites and combinations thereof.

Furthermore, the invention provides a method of manufacturing a ball game racket having a head portion along which the brackets are disposed in discrete segments, and more particularly a ball game racket in accordance with the preferred embodiments described above.

A preferred method has the following steps: First, the layers of a plurality of layers of a material to form the frame of the racket takes place. Furthermore, the multilayer structure thus created is set in a mold having recesses or depressions at positions corresponding to the brackets of the racket, and then formed and solidified. Thereafter, the removal of the ball game racket from the mold. If the brackets are to have different material, this can additionally be introduced at the appropriate places in the mold.

In another preferred method of the invention, the layers of the frame and staple forming material comprise carbon fiber composite material which is molded and consolidated under elevated temperature and / or pressure. In another method according to the invention, shaping and solidification take place in a press.

An inventive ball game racket guarantees a comparison with the known in the art rackets improved vibration or damping behavior and improved stiffness. An inventive racket thus allows influencing the playing behavior. Subjectively, the player feels a bigger sweet spot. By adapting the design and / or the arrangement of the staples according to the invention as well as the described clip segments, the specific characteristics and characteristics of the ball game racket can be adjusted according to the requirements. The optimized mass distribution also makes it possible to provide a racket that has excellent stiffness and dynamic behavior at low overall weight.

Claims (18)

1. A ball game racket including a frame comprising a head region (3) for receiving a stringing and a handle portion for holding the ball game racket, wherein in the head region the frame comprises in any one of at least two segments (17) a plurality of stiffening elements (15) extending transversely with respect to the frame, characterized in that the stiffening elements (15) formed in one segment (17) all widen in the direction towards three o'clock and nine o'clock.
2. The ball game racket according to claim 1, wherein the stiffening elements (15) are provided in four segments (17).
3. The ball game racket according to any one of claims 1 or 2, wherein the segments (17) are spaced apart from each other.
4. The ball game racket according to any one of claims 1 to 3, wherein the segments (17) and/or the stiffening elements (15) are arranged substantially symmetrically with respect to each other.
5. The ball game racket according to any one of the preceding claims, wherein stiffening elements (15) are arranged in the racket head (3) in the areas of about half past three o'clock to five o'clock and seven o'clock to half past eight o'clock or in the areas of one o'clock to half past two o'clock and half past nine o'clock and eleven o'clock.
6. The ball game racket according to any one of the preceding claims, wherein the segments (17) each have a width of about 60 to 90 mm along the racket contour.
7. The ball game racket according to any one of the preceding claims, wherein the stiffening elements (15) form a circumferential projection (19) on the racket contour of about 0.25 to 1 mm.
8. The ball game racket according to any one of the preceding claims, wherein the stiffening elements have a width (21) in the range of about 2.5 to 11 mm.
9. The ball game racket according to any one of the preceding claims, wherein the stiffening elements are spaced from each other by a distance (23) of about 2 mm to about 11 mm.
10. The ball game racket according to any one of the preceding claims, wherein the distance (23) between the stiffening elements (15) formed in one segment increases in the direction towards three o'clock and nine o'clock.
11. The ball game racket according to any one of the preceding claims, wherein the racket comprises three to five stiffening elements (15) per segment (17).
12. The ball game racket according to any one of the preceding claims, wherein each segment (17) comprises five stiffening elements (15) in case the ball game racket is a tennis racket, and wherein each segment (17) comprises three stiffening elements (15) in case the ball game racket is a squash racket.
13. The ball game racket according to any one of the preceding claims, wherein the stiffening elements (15) and the frame are made of the same material.
14. The ball game racket according to any one of the preceding claims, wherein the stiffening elements (15) and the frame are made of different materials.
15. The ball game racket according to any one of the preceding claims, wherein the stiffening elements (15) are shaped as ribs and/or brackets.
16. A process for producing a ball game racket according to any one of claims 1 to 15 including a frame comprising a head region (3) and a handle portion, comprising the following steps:

    (a) stacking a plurality of layers of a material for forming the frame of the racket,

    (b) placing the multi-layer structure into a mold and subsequently molding and hardening the structure, wherein in the head region (3) of the racket stiffening elements (15) extending transversely with respect to the frame are formed in at least two segments (17); and

    (c) removing the ball game racket from the mold.
17. The process according to claim 16, wherein the layers of the material forming the frame comprise a carbon fiber compound material which is molded and hardened under an increased temperature and/or increased pressure.
18. The process according to any one of claims 16 to 17, wherein the molding and hardening takes place in a press.

Images