EP4154950B1 - Racquet for a ball game and method for producing the same - Google Patents

Description

Ball game rackets are available for a variety of sports and/or leisure activities, for example tennis, table tennis, badminton and squash. For each sport and/or leisure activity, there is a relatively wide selection of different ball game rackets, for example made of different materials, from which the respective user can choose.

The material used can influence the properties of the respective ball game racket, for example its rigidity. Relatively inexpensive ball game rackets are usually made at least mostly from plastic or metal, for example aluminum. For competitive sports, however, ball game rackets are often made at least partially from more sophisticated materials, for example from fiber composite materials using glass fibers, carbon fibers, aramid fibers, ceramic fibers or other high-performance fibers. By using such materials, the properties of the ball game racket can be positively influenced, for example to increase the performance of the ball game racket.

In addition, ball game rackets can have different designs, for example different shapes and/or dimensions, which can also influence the properties of the respective ball game racket, for example its rigidity and/or ball control. By choosing the material and/or the design of the ball game racket, specific properties of the ball game racket can be achieved in order to adapt the properties of the ball game racket to the playing style and/or performance of the respective user.

A relatively new sport that also uses ball rackets is the so-called padel tennis, also called paddle tennis or pädel, which is already widespread in some regions of the world, for example Spain, Italy, Central America and South America. The popularity of padel tennis is also increasing worldwide, for example in other European countries, such as Sweden.

In padel tennis, as in traditional tennis, a ball is hit over a net into the opponent's half of the court using a racket. In contrast to traditional tennis, the court has external walls that can also be used to hit the ball into the opponent's half of the court, similar to squash.

In contrast to conventional tennis rackets, squash rackets or other ball game rackets with strings, a padel tennis racket does not usually have a hitting surface made of taut strings. Instead, the padel tennis racket usually has a continuous plate, which is often also called the core. This plate usually defines the hitting surfaces of the respective padel tennis racket. The plate is often coated or planked with an additional material in order to influence or specifically change the stiffness and/or elasticity of the racket.

For example, the FR 3 042 124 A1 a ball game racket for padel tennis with a handle portion and a head portion. The head portion has a core and a first hollow tube extending partially around the core to reinforce the edge region of the head portion. The first hollow tube has a rounded portion on the periphery of the racket head and a flat side on a side facing the core which abuts the core as a wall. The ball game racket has a second hollow tube extending in the handle portion of the ball game racket. The first and second tubes are made of a composite material.

Furthermore, the FR 3 026 016 A1 a ball game racket for padel tennis or beach tennis. The ball game racket has a head section with a core. An outer wall of a racket frame running around the core is additionally reinforced. This means that the ball game racket can be made with a tubeless frame.

Due to the lack of a surrounding tube and thus the lack of an inner wall in the head section, which is defined by a side of the tube facing the core, such as This is the case, for example, in the FR 3 042 124 A1 As described, the ball game racket has less stiffening compared to previously known designs of padel tennis rackets with a tube running around the core, which can increase the playability of the ball game racket. This is why, at least for padel tennis, tubeless ball game rackets have largely prevailed over ball game rackets with a tube running around the core in recent years.

The document EP 3 225 288 A1 discloses a ball game racket having all the technical features set out in the preamble of claim 1.

However, the ball game rackets known from the state of the art that are suitable for padel tennis still have disadvantages. On the one hand, this is due to the relatively short existence of padel tennis as a sport compared to other ball game sports. On the other hand, padel tennis has so far only been practiced as a niche sport in certain regions of the world. Therefore, the development effort for such ball game rackets for padel tennis has so far been limited. Due to the increasing popularity of this sport, also in other regions of the world, there is a need to further develop the properties of ball game rackets for paddle tennis and at least partially improve the disadvantages of the ball game rackets known from the state of the art.

It is therefore an object of the present invention to provide a ball game racket with improved properties, especially with improved playability in paddle tennis. This object is achieved by the subject matter of the independent patent claims. Advantageous embodiments with expedient further developments of the invention are specified in the respective subclaims and in the following description.

A first aspect of the invention relates to a ball game racket with a handle section and a head section connected to the handle section. The head section has a frame and at least one core. The core defines at least partially two striking surfaces and at least one edge, preferably a peripheral edge, which connects the striking surfaces at least in some areas. A first tube extends at least in some areas through the frame at least along at least one area of the edge of the core. The The first tube is partially covered with a composite material such that at least a region of an outer side of the first tube facing the edge of the core is free of composite material.

The handle section can be designed to be gripped by at least one hand of a user, so that the ball game racket can be moved by the user and aimed at a game ball or similar target object. For this purpose, the handle section can have properties that can make it easier for the user to grip the handle section. For example, the handle section can have at least a slip-reducing surface that can prevent or at least reduce slipping of the handle section in the user's hand.

Preferably, the head section is at least partially designed to hit the ball or target object and to transfer a force to the ball or target object in order to accelerate the ball or target object and, if possible, play it into the opponent's playing field. For this purpose, the head section can have properties that can facilitate or improve the force transmission of the ball and/or the acceleration of the ball and/or the ball control and/or the comfort of the ball game racket in use.

The frame of the head section preferably defines at least in sections an outer circumference of the ball game racket. The core is preferably arranged at least partially within a space defined by the frame.

The handle section and the head section are preferably at least partially formed in one piece. For example, the handle section and the head section can have at least one common component that extends at least partially through the handle section and the head section. Alternatively, the handle section and the head section can be separate components that can then be connected to one another, for example by gluing, welding, or other joining methods.

The core of the head section is preferably made of a material with a relatively low Density to reduce the weight of the ball game racket and thus increase the handling and acceleration of the ball game racket. The core can be made at least partially, preferably completely, from a porous material, preferably a foam material. Preferably, the core is made from a foam material made of polyurethane (PU), ethylene vinyl acetate (EVA) or a thermoplastic elastomer (TPE-A). However, other foam materials or other alternative materials can also be used.

The core can also have at least one opening, preferably a plurality of openings. The opening preferably extends, at least in a section of the core, along a longitudinal axis completely through the core. By providing at least one opening in the core, the weight of the core can be reduced. In addition, when the ball game racket is moved in use, air can flow through the respective opening in order to reduce the aerodynamic resistance of the ball game racket in use. In addition, the stiffness and/or elasticity and/or the recovery property of the ball game racket can be specifically controlled, i.e. reduced or increased, through the opening or openings. For example, the stiffness and/or elasticity of the ball game racket can be varied by choosing the relative arrangement, dimensions, shape and/or number of openings. The core preferably has a plurality of openings which are distributed in a pattern in the core. The openings are preferably arranged in a matrix-like manner, for example in one row or in several rows, preferably arranged next to one another. The ball game racket can additionally have a material applied to the core at least in some areas, for example a single or multi-layer coating. The opening or openings that can be provided in the core preferably also extend through the additional material applied to the core in this case.

The core can be formed in one piece. Alternatively, the core can be constructed in several parts. In a multi-part construction, a large number of core segments can be assembled to form the core. The individual core segments can be firmly connected to one another, for example by means of an adhesive and/or other joining agents. The Core segments can alternatively or additionally be connected to one another by an element extending at least partially over the core and/or around the core, for example a casing, a frame, a paneling, a coating or the like.

The core at least partially defines two striking surfaces and at least one edge, preferably a peripheral edge, which connects the striking surfaces at least in part. The striking surfaces can be designed to directly or indirectly transfer forces from the user, and via the ball game racket, to the game ball or similar target object.

Since the core defines the two striking surfaces, the interaction of the ball with the ball game racket, and thus the playability of the ball game racket, can be specifically controlled, in particular by developing the properties of the core, for example its rigidity, flexibility, recovery properties, etc. For example, by specifically selecting the properties of the core, the ball acceleration, ball control and/or the comfort of the ball game racket can be influenced and thus adapted to the user's playing style and performance. The properties of the core can be influenced or controlled, for example, by choosing the material(s) and/or the dimensions and/or the shape of the core. The core can be made at least partially, preferably completely, from a porous material, preferably a foam material. The core is preferably made from a foam material made of polyurethane (PU), ethylene vinyl acetate (EVA) or a thermoplastic elastomer (TPE-A). However, other foam materials or other alternative materials can also be used.

The striking surfaces are preferably each designed as a flat surface. The striking surfaces are preferably arranged substantially opposite one another. The striking surfaces preferably run substantially parallel to one another. Alternatively, the striking surfaces can run at an angle to one another, preferably in an angle range of 0.5° to 20°, more preferably from 0.5° to 15°, most preferably from 0.5° to 10°.

The edge preferably extends substantially perpendicular to one of the striking surfaces, preferably to both striking surfaces. Alternatively, the edge can extend at an angle that is greater or less than 90° to at least one of the two striking surfaces. For example, the edge can extend at an angle of 60° to 89.5°, preferably from 70° to 89.5°, more preferably from 75° to 89.5°, more preferably from 80° to 89.5°, most preferably from 85° to 89.5°, to at least one of the two striking surfaces.

The striking surfaces can be contact surfaces that come into direct contact with the ball or target object when the ball or target object hits the ball game racket. Alternatively, the core can be covered at least in some areas with a covering material, which can thereby come into direct contact with the ball or target object when the ball or target object hits the ball game racket. For example, the core can be coated at least in some areas, preferably completely, with at least one material layer, preferably a plurality of material layers, preferably made of a composite material. The striking surfaces are preferably completely coated with at least one material layer, preferably a plurality of material layers. The material layer preferably comprises a composite material. The choice of the covering material, for example its structure and/or composition, and/or the number of layers of the covering material can be used to control the stiffening and/or increased stability of the core caused by the covering material.

In areas of the core where the cover material is attached, the cover material can form a contact surface for direct contact with the ball or game object. However, the core preferably serves in each case as a receiving structure and/or transfer structure that can absorb forces from the ball and/or transfer forces to the ball.

A first tube extends at least partially through the frame at least along at least one area of the edge of the core. The first tube is preferably made of a plastic, preferably polyamide, co-polyamide, polyethylene, polypropylene or a similar material. Preferably, the plastic is stretched prior to incorporation of the tube into the ball game racket. The first tube preferably has a peripheral wall and a cavity defined within the peripheral wall. The cavity preferably extends over the entire length of the tube. The tube itself preferably has intrinsic flexibility and/or elastic deformability. Preferably, the tube extends along 30% to 100%, more preferably along 35% to 100%, more preferably along 40% to 100%, more preferably along 45% to 100%, more preferably along 50% to 100%, more preferably along 55% to 100%, more preferably along 60% to 100%, more preferably along 65% to 95%, most preferably along 65% to 90%, of a circumference of the edge of the core.

The first tube is partially covered with a composite material such that at least one area of an outer side of the first tube facing the edge of the core is free of composite material. The first tube can be wrapped with a composite material at least in some areas. The composite material can be selected from a variety of composite materials. In particular, the composite material can be selected according to the desired properties, for example the desired stiffness and/or damping properties of the ball game racket. The composite material preferably has a variety of synthetic fibers, preferably carbon fibers and/or glass fibers. Alternatively or additionally, the composite material can have a variety of natural fibers, for example flax and/or bamboo fibers. The fibers are preferably embedded in at least one matrix material.

Ball game rackets that have a tube that partially extends through the respective frame are usually manufactured using a so-called tube blowing process. The ball game racket described here can also be manufactured using the tube blowing process. In the tube blowing process, the tube is usually either made from a composite material or at least rolled up with a composite material over the entire circumference of the tube and then placed in a heatable mold. Such a structure and a corresponding manufacturing process are described, for example, in the aforementioned FR 3 042 124 A1 described. The hose usually has openings at both ends that are fluidically connected to one another via the hollow space of the hose. At least one of the ends of the hose is usually connected to a source of compressed gas, preferably a source of compressed air. The mold can then be heated and the hollow space of the hose can be pressurized with compressed gas in order to heat the composite material and at the same time press it against the inner surfaces of the mold so that the ball game racket can assume the desired shape and/or geometry as optimally as possible.

When the hollow space of the hose is subjected to a pressurized gas, the composite-reinforced hose is expanded, whereby the hose presses against the core arranged at least partially within the hose and thereby at least partially tensions and/or compresses it. When the hose completely wrapped in composite material or made entirely of composite material hardens, the hose solidifies in this expanded position, whereby in previously known ball game rackets the core and the hose remain essentially in a tensioned and/or stiffened state even after the hose has ceased to be subjected to pressurized gas and after the ball game racket has been removed from the mold. The stiffening and/or compression of the core, particularly in the areas of the core close to the hose, by the hose can have a negative effect on the playability of the ball game racket. In particular, the relatively high stiffness of the core caused at least in some areas, especially in the areas of the core close to the tube, can have a negative effect on ball control in the stiffened areas and generally in the edge area of the ball game racket. In addition, the relatively high unevenness of the stiffness of the core caused by this, which can increase in particular due to the tension described above through the tube to the edge of the core, can impair the playability of the ball game racket.

By providing a composite-free region facing the edge of the core on the outside of the first hose, elastic deformability and/or elastic recovery of the hose in this composite-free region can be made possible even after the composite material has hardened. This allows the hose in the composite-free area, due to the intrinsic elastic recovery property of the hose, at least partially return from the expanded state caused by the pressurized gas exposure to the non-expanded state after the pressurized gas exposure of the hollow space of the hose has ended and the composite material has at least partially hardened. As a result, stiffening and/or tensioning of the core by the hose can be prevented or at least reduced in order to achieve a softer structure and/or greater elastic deformability, especially in the edge area of the ball game racket. As a result, the playability of the ball game racket, especially in the edge area of the ball game racket, can be improved.

Since the edge area of the ball game racket is a relatively large distance from the handle section compared to areas that are closer to the center of the respective hitting surface, an impact of the ball on the edge area of the ball game racket can transfer relatively large forces and/or moments to the hand and/or arm of the user, which can cause an increased risk of injury and/or a deterioration in the comfort of the ball game racket. These effects can be promoted by increased rigidity in the edge area of the ball game racket. A softer structure and/or greater elastic deformability in the edge area of the ball game racket can result in greater cushioning of the ball game racket, which can reduce the risk of injury and increase the comfort of the ball game racket.

The composite-free region of the first tube facing the edge of the core can, when the ball game racket is ready for use, at least partially rest against the edge of the core. Preferably, when the ball game racket is ready for use, a gap, preferably an air gap, is arranged at least partially between the edge of the core and the composite-free region of the first tube. In the region of the gap, a cavity is therefore arranged between the edge of the core and the composite-free region of the first tube, with neither part of the tube nor part of the core being arranged in this cavity. This allows the rigidity in the edge region of the ball game racket can be further reduced in order to further improve the playability of the ball game racket. Preferably, the entire composite-free area of the first tube and the edge of the core are non-contacting with each other.

As already explained at the beginning, at least for padel tennis, tubeless ball game rackets have largely prevailed over ball game rackets with a surrounding tube in recent years. However, the configuration of the ball game racket with a tube described here has advantages over tubeless ball game rackets, for example compared to the configuration mentioned at the beginning. FR 3 026 016 A1 described ball game rackets, surprisingly have advantages. For example, a smaller core can be used compared to tubeless ball game rackets, since the tube replaces part of the core in the edge area of the ball game racket. Due to the smaller solid material of a tube compared to the core, the weight of the ball game racket can be reduced compared to tubeless ball game rackets with the same or at least similar dimensions. The material weight saved as a result, especially in the edge area of the ball game racket, can be used or employed elsewhere. For example, the edge area of the ball game racket can be made more robust, for example by providing thicker material thicknesses and/or additional material. This can increase the robustness of the ball game racket, especially in the edge area of the same. In padel tennis in particular, the ball game rackets used can relatively frequently be exposed to high loads, for example due to the ball game rackets accidentally hitting wall structures that border the playing field in padel tennis. A robust design of the ball game racket, especially the edge area, can increase the service life of the ball game racket.

In addition, by providing a tube that serves to shape the ball game racket, as already described above, a more flexible and/or more precise design of the edge of the head section of the ball game racket can be made possible compared to tubeless ball game rackets. In particular, by varying the geometry and/or dimensioning of the heatable mold in which the frame is cured, the shape and/or geometry of the frame can be varied in a reliable, flexible and relatively simple manner. Designing the edge of the head section in tubeless ball game rackets, where the core extends essentially to the edge of the respective ball game racket, is much more complex and/or has less design freedom. For example, the edge of the core must be cut out relatively precisely in order to achieve the desired contour and/or geometry of the edge of the core.

Furthermore, the tube blowing process for producing a ball game racket equipped with a tube can achieve a higher quality and/or fatigue strength when using a composite material compared to the manufacturing process for a tubeless ball game racket. In particular, the individual layers of the composite material can be compressed more strongly when the tube is subjected to compressed gas than in the manufacturing process for a tubeless ball game racket. This can increase the quality and/or durability of the ball game racket.

The ball game racket described herein may be particularly suitable for padel tennis. However, the ball game racket may also be suitable for other sports and/or leisure activities in which a ball game racket is used.

Preferably, at least in the region of the first tube extending along at least one region of the edge of the core, substantially 10% to 50%, preferably 10% to 40%, more preferably 10% to 30%, most preferably 15% to 30%, of an outer circumference of the first tube is free of composite material. These value ranges can enable elastic deformation and/or elastic recovery of the tube in the composite material-free region in order to prevent or at least reduce stiffening and/or tensioning of the core by the tube. This can increase the playability of the ball game racket, particularly in the edge region of the ball game racket.

Preferably, the composite material extends, at least in the region of the first tube extending along at least a region of the edge of the core, over 50% to 90%, preferably 60% to 90%, more preferably 70% to 90%, most preferably 70% to 85%, of an outer circumference of the first tube.

Preferably, a gap extends at least in some areas along the first tube between the edge of the core and the outside of the first tube. This allows the stiffness in the edge area of the ball game racket, i.e. in the area of the gap and the area of the tube, to be further reduced in order to further improve the playability of the ball game racket.

Preferably, the gap has a gap width extending from the core to the outside of the first tube of from 0.5 mm to 10 mm, preferably from 0.5 mm to 8 mm, more preferably from 0.5 mm to 6 mm, more preferably from 0.5 mm to 5 mm, more preferably from 0.5 mm to 4 mm, more preferably from 0.5 mm to 3 mm, more preferably from 0.5 mm to 2 mm, more preferably from 0.5 mm to 1.5 mm, most preferably from 0.5 mm to 1 mm.

Preferably, the first tube extends at least partially through the frame and the handle section. Preferably, the first tube is only partially covered with a composite material along its entire extension through the frame and the handle section. Alternatively, only the section of the tube that extends through the frame can be partially covered with a composite material such that at least a region of an outer side of the first tube facing the edge of the core is free of composite material. The section of the tube that extends through the handle section can be completely covered with a composite material. As a result, the composite material can have a higher stiffening effect in the handle section than in the frame.

Preferably, the first tube in the head section extends around the entire edge of the core. This allows essentially the entire contour of the striking surfaces to be formed by the tube, thereby increasing the stability of the core and the striking surfaces can be increased. Preferably, the entire section of the tube which extends around the edge of the core is partially covered with a composite material such that at least a region of an outer side of the first tube facing the edge of the core is free of composite material.

Preferably, at least in the region of the first tube extending along at least one region of the edge of the core, the entire region of the outside of the first tube facing the edge of the core is free of composite material. As a result, the tension and/or compression of the core over its entire edge by the tube can be reduced or even completely eliminated.

The ball game racket preferably has at least one additional hose that extends at least partially through the head section and/or through the handle section. By providing an additional hose, different areas of the ball game racket can each be individually equipped with a hose. For example, different hoses, for example made of different materials and/or with different geometries, can be used. Alternatively or additionally, the hoses can be individually pressurized with a respective gas pressure. For example, the hoses can be pressurized with different gas pressures and/or with different courses and/or different profiles of the pressurized gas application. In this way, areas of the ball game racket can be individually designed, for example with different stiffnesses and/or different elastic deformabilities and/or different elastic recovery properties.

Preferably, the additional hose extends at least partially through the handle section and from the handle section only partially into the head section and ends there. This allows the extension of the additional hose into the head section to be limited so that the additional hose can have a predetermined, preferably only minimal, influence on the stiffness in the head section. This allows the additional hose to be completely covered or wrapped with a composite material over its circumference, for example, in order to achieve a to achieve relatively high rigidity in the handle section and a comparatively lower rigidity in the head section.

Preferably, the ball game racket has at least two additional tubes, each of which extends at least partially through the head section and/or through the handle section.

Preferably, the two additional hoses each extend at least partially through the handle section and from the handle section only partially into the head section and each end there. Preferably, the two additional hoses extend in different directions from the handle section into the head section.

Preferably, the core is made at least partially, preferably completely, from a foam.

Preferably, the composite material is a fiber-plastic composite, preferably a carbon fiber-reinforced and/or glass fiber-reinforced plastic.

The ball game racket preferably also has at least one coating which extends at least partially over the core, preferably at least over the striking surfaces, and at least partially over the first tube. The coating preferably connects the core and the first tube to one another. When the ball or target object hits the ball game racket, the coating can come into direct contact with the ball or target object. The coating preferably comprises a composite material. The stiffening and/or increased stability of the core caused by the coating can be controlled by the choice of coating material, for example its structure and/or composition, and/or the number of layers of the coating.

Preferably, the coating has at least one layer made of a composite material, preferably of a fiber-plastic composite, preferably of a carbon fiber-reinforced and/or glass fiber-reinforced plastic.

Preferably, the handle section and/or the head section, preferably in a fork region of the ball game racket, has an expandable material, preferably an expanded polystyrene (EPS), which is designed to expand by activation, preferably by supplying heat. The expandable material can additionally cause a pressing and/or compaction of composite materials by the expandable material expanding in a targeted manner during the manufacture of the ball game racket and pressing the composite material against the corresponding heatable mold during the tube blow molding process. This can increase the stability and durability of the ball game racket.

1. a) Bereitstellen mindestens eines ersten verformbaren Schlauchs mit einem Hohlraum;
2. b) Beschichten eines Teils einer Außenseite des ersten Schlauchs mit einem ersten Verbundwerkstoff derart, dass ein Bereich der Außenseite des ersten Schlauchs frei von Verbundwerkstoff bleibt;
3. c) Bereitstellen eines Kerns, der zumindest teilweise zwei Schlagflächen und zumindest einen zumindest bereichsweise die Schlagflächen verbindenden, vorzugsweise umlaufenden, Rand definiert;
4. d) Anordnen des ersten Schlauchs entlang zumindest eines Bereichs des Rands des Kerns zumindest teilweise um den Kern herum derart, dass der verbundwerkstofffreie Bereich der Außenseite des ersten Schlauchs zumindest teilweise dem Rand des Kerns zugewandt ist;
5. e) Aufbringen mindestens einer Lage aus einem zweiten Verbundwerkstoff zumindest bereichsweise auf den Kern und den ersten Schlauch;
6. f) Beaufschlagen des Hohlraums des ersten Schlauchs mit einem Überdruck; und
7. g) Aushärten des Verbundwerkstoffes.

A second aspect of the invention relates to a method for producing a ball game racket with a handle portion and a head portion connected to the handle portion, which has a frame. The method comprises the following steps:

1. a) providing at least a first deformable tube having a cavity;
2. b) coating a portion of an exterior of the first tube with a first composite material such that a region of the exterior of the first tube remains free of composite material;
3. c) providing a core which at least partially defines two striking surfaces and at least one, preferably circumferential, edge which connects the striking surfaces at least in regions;
4. d) arranging the first tube along at least a portion of the edge of the core at least partially around the core such that the composite-free region of the outside of the first tube at least partially faces the edge of the core;
5. e) applying at least one layer of a second composite material at least partially to the core and the first tube;
6. f) applying an excess pressure to the cavity of the first hose; and
7. g) Curing of the composite material.

The embodiments and/or advantages described above for the ball game racket apply analogously to the method.

By providing a composite-free region facing the edge of the core on the outside of the first tube, elastic deformability and/or elastic recovery of the tube in this composite-free region can be made possible even after the composite material has hardened. As a result, the tube in the composite-free region can at least partially return from the expanded state caused by the pressurized gas exposure to the non-expanded state due to the intrinsic elastic recovery force of the tube after the pressurized gas exposure of the hollow space of the tube has at least partially ended when the composite-reinforced tube has hardened. As a result, stiffening and/or bracing of the core by the tube can be prevented or at least reduced in order to achieve a softer structure and/or greater elastic deformability, especially in the edge region, of the ball game racket. As a result, the playability of the ball game racket, especially in the edge region of the ball game racket, can be improved.

Preferably, at least the tube coated with composite material is placed at least before step f) in a heatable mold in which at least steps f) and g) can be carried out at least partially.

Preferably, after step f), a plurality of openings can be introduced at least through the core and the second composite material. The openings are preferably designed as continuous openings that extend completely through the ball game racket. The openings preferably extend perpendicularly to at least one striking surface, preferably to both striking surfaces, through the ball game racket.

Preferably, in step b), the outside of the first tube is partially coated with a composite material such that substantially 10% to 50%, preferably 10% to 40%, more preferably 10% to 30%, most preferably 15% to 30%, of an outer circumference of the first tube is free of composite material.

Preferably, in step b), the outside of the first tube is partially coated with a composite material such that the composite material extends over 50% to 90%, preferably 60% to 90%, more preferably 70% to 90%, most preferably 70% to 85%, of an outer circumference of the first tube.

Preferably, after step f), the application of excess pressure to the cavity of the first tube is stopped. Subsequently, preferably at least in some areas along the first tube, a gap forms between the edge of the core and the outside of the first tube.

Preferably, the gap has a gap width extending from the core to the outside of the first tube of from 0.5 mm to 10 mm, preferably from 0.5 mm to 8 mm, more preferably from 0.5 mm to 6 mm, more preferably from 0.5 mm to 5 mm, more preferably from 0.5 mm to 4 mm, more preferably from 0.5 mm to 3 mm, more preferably from 0.5 mm to 2 mm, more preferably from 0.5 mm to 1.5 mm, most preferably from 0.5 mm to 1 mm.

Preferably, in step d), the first tube is arranged such that the first tube extends at least partially along at least a portion of the edge of the core, around the core and at least partially through the handle portion of the ball game racket.

Preferably, in step d), the first tube is arranged such that the first tube in the head portion extends around the entire edge of the core.

Preferably, at least before step e), at least one additional hose is arranged in the head portion and/or in the handle portion.

Preferably, the additional hose is arranged in the head section and/or in the handle section such that it extends at least partially through the handle section and from the handle section only partially into the head section of the ball game racket and ends there.

Preferably, at least before step e), at least two additional tubes are arranged in the head portion and/or in the handle portion, respectively.

Preferably, the two additional hoses are arranged in the head section and/or in the handle section such that the two additional hoses each extend at least partially through the handle section and from the handle section only partially into the head section and each end there. Preferably, the two additional hoses extend in different directions into the head section.

Preferably, in step b), the outside of the first tube is partially coated with a composite material such that the entire area of the outside of the tube facing the core is free of composite material.

Preferably, the core is made at least partially, preferably completely, from a foam.

Preferably, the first composite material and/or the second composite material is a fiber-plastic composite, preferably a carbon fiber-reinforced and/or glass fiber-reinforced plastic.

Preferably, at least before step g), an expandable material, preferably an expanded polystyrene (EPS), is arranged in the handle section and/or the head section of the ball game racket, preferably in a fork region of the ball game racket. Preferably, the expandable material is designed to expand by activation, preferably by supplying heat.

Preferably, in step f), the cavity of the first hose is subjected to an overpressure of 2 bar to 10 bar, preferably 2 bar to 5 bar. The term "overpressure" in the sense of the present disclosure is to be understood as an absolute pressure that is higher than the respective ambient pressure prevailing at the production site. With the value ranges specified above for pressurizing the first hose, a relatively high compression and/or shaping of the composite material used can be achieved. Preferably, in step f), the cavity of the first hose is subjected to a variable overpressure. For example, the hose can be subjected to different gas pressures and/or different courses and/or profiles of the pressurized gas application over a continuous or discontinuous time course. This makes it possible to optimize the properties of the ball game racket, for example its rigidity and/or elastic deformability and/or elastic resilience. The variation of the overpressure can, for example, also be carried out simultaneously and/or at different times together with variable heat generation in a heatable mold into which the hose can be inserted at least before step f). At least steps f) and g) can be carried out at least partially in the heatable mold.

Preferably, in step f), the cavity of the first tube is subjected to a pulsating overpressure. This allows the properties of the ball game racket, for example its rigidity and/or elastic deformability and/or elastic recovery capacity, to be optimized or specifically changed. Desired and/or predefined properties of the ball game racket can be achieved in particular via the pulse strength, pulse duration and/or pulse frequency. The pulsing of the overpressure can be coordinated, for example, with a variation in the heat generation in a heatable mold into which the tube can be inserted at least before step f).

Preferably, in step f), the cavity of the first tube is subjected to a, preferably predetermined, profile of an at least temporarily inconstant pressure curve over a pressurization time.

Preferably, in step f), the cavity of the first hose is subjected to a first overpressure and the cavity of the one additional hose or the cavities of the at least two additional hoses are each subjected to a second overpressure. The first overpressure and the second overpressure are preferably different. By individually subjecting the hoses, preferably with different overpressures and/or overpressure profiles and/or overpressure curves, areas of the ball game racket can be individually designed, for example with different stiffnesses and/or different elastic deformabilities and/or different elastic recovery properties. This allows the properties of the ball game racket, or more precisely the properties of different areas of the ball game racket, to be optimized and/or adapted to the wishes and/or needs of the user.

Preferably, in step f), the cavity of the first hose is subjected to a first overpressure of 2 bar to 5 bar and the cavity of the one additional hose or the cavities of the two additional hoses are subjected to a second overpressure of 2 bar to 10 bar. Preferably, the additional hoses are subjected to a higher overpressure than the first hose. This allows a relatively high rigidity to be achieved in the handle section, while the rigidity and a pressing force caused by the expansion of the first hose in the head section, at least around the core, can be limited or reduced.

Preferably, the cavity of the one additional hose or the cavities of the two additional hoses are subjected to the second overpressure and the cavity of the first hose is subjected to the first overpressure at least partially at different times. This also makes it possible to optimize the properties of the ball game racket, or more precisely the properties of different areas of the ball game racket, and/or to adapt them to the wishes and/or needs of the user. The first hose and the two additional hoses can be arranged in the ball game racket in such a way that at least two of the hoses extend through the ball game racket, partially overlapping or at least substantially adjacent to one another. By applying the two additional hoses and the first hose at different times, increased compression and/or pressing due to simultaneous expansion of the two additional hoses and the first hose can be prevented or at least reduced.

Fig. 1

zeigt in einer Draufsicht einen erfindungsgemäßen Ballspielschläger gemäß einer ersten Ausführungsform;

Fig. 2

zeigt eine Querschnittsansicht des Ballspielschlägers aus Fig. 1 entlang der Schnittlinie A-A;

Fig. 3

zeigt in einer Draufsicht einen erfindungsgemäßen Ballspielschläger gemäß einer weiteren Ausführungsform;

Fig. 4

zeigt in einer Draufsicht einen erfindungsgemäßen Ballspielschläger gemäß einer weiteren Ausführungsform;

Fig. 5

zeigt in einer Draufsicht einen erfindungsgemäßen Ballspielschläger gemäß einer weiteren Ausführungsform.

Preferably, the start of the application of the second overpressure to the cavity of the one additional hose or the cavities of the two additional hoses takes place with a time delay, preferably by 2 to 30 seconds, after the start of the application the cavity of the first hose with the first overpressure. Further advantages, features and details of the invention emerge from the following description of a preferred embodiment and from the drawings. The features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of the figures and/or shown alone in the figures can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the invention, the scope of the invention being defined by the appended claims.

Fig.1

shows a plan view of a ball game racket according to the invention according to a first embodiment;

Fig.2

shows a cross-sectional view of the ball game racket from Fig.1 along the section line AA;

Fig.3

shows a plan view of a ball game racket according to the invention according to a further embodiment;

Fig.4

shows a plan view of a ball game racket according to the invention according to a further embodiment;

Fig.5

shows a plan view of a ball game racket according to the invention according to a further embodiment.

Fig.1 shows a ball game racket 10 according to the invention in accordance with a first embodiment. The ball game racket 10 has a handle section 12 and a head section 14 connected to the handle section 12. The head section 14 has a frame 16 and a core 18. The core 18 defines two striking surfaces 20. Due to the Fig.1 The perspective shown is only a striking surface 20 in Fig.1 Both striking surfaces 20 are in the Fig.2 The second striking surface 20 can be substantially parallel to the Fig.1 shown striking surface 20. Preferably, the two striking surfaces 20 are substantially opposite each other The core 18 also defines a peripheral edge 22 connecting the striking surfaces 20.

Furthermore, the ball game racket 10 has a transition area 23 that connects the handle section 12 to the head section 14. The transition area 23 has an opening 25. The transition area 23 is often also referred to as the "heart" or "throat".

The ball game racket 10 also has a first tube 24 which extends through the frame 16 along a portion of the edge 22 of the core 18. The tube 24 is only shown schematically as a solid line in Fig.1 shown. In Fig.2 the hose 24 is shown in more detail.

The first tube 24 has a circumferential wall 26 and a cavity 28 defined within the circumferential wall 26. The cavity 28 preferably extends over the entire length of the tube 24.

The hose 24 has, as shown in Fig.2 a substantially square cross-sectional shape. However, other cross-sectional shapes are also conceivable, for example a round, an elliptical, a triangular or a polygonal cross-sectional shape. The cross-sectional shape of the hose 24 formed in the ball game racket 10 depends essentially on the geometry of a mold in which the ball game racket 10 is pressed and cured in a hose blow molding process. The hose blow molding process is described in more detail below.

The tube 24 is partially covered with a composite material 30 such that at least a region 32 of an outer side of the tube 24 facing the edge 22 of the core 18 is free of composite material.

A gap 36 extends between the edge 22 of the core 18 and an outer side of the first tube 24.

The ball game racket 10 can additionally have a coating 34 which extends at least over the core 18 and the first tube 24. The coating 34 can come into direct contact with the ball or target object when the ball or target object hits the ball game racket 10. The coating 34 preferably comprises a composite material. For the sake of clarity, the coating 34 is shown in Fig.1 not shown.

As already explained above, the Fig.1 and 2 The ball game racket 10 shown is manufactured using a so-called hose blowing process. In conventional hose blowing processes, the hose is usually either made from a composite material or at least rolled with a composite material over the entire circumference of the hose and then placed in a heatable mold. Such a structure and a corresponding manufacturing process are described, for example, in the aforementioned FR 3 042 124 A1 described. The hose usually has openings at both ends that are fluidically connected to one another via the hollow space of the hose. At least one of the ends of the hose is usually connected to a source of compressed gas, preferably a source of compressed air. The mold can then be heated and the hollow space of the hose can be pressurized with compressed gas in order to heat the composite material and at the same time press it against the inner surfaces of the mold so that the ball game racket can assume the desired shape and/or geometry as optimally as possible.

When the hollow space of the hose is subjected to a pressurized gas, the composite-reinforced hose is expanded, whereby the hose presses against the core arranged at least partially within the hose and thereby at least partially tensions and/or compresses it. When the hose completely wrapped with composite material or made entirely of composite material hardens, the hose solidifies in this expanded position, whereby in previously known ball game rackets the core and the hose remain essentially in a tensioned and/or stiffened state even after the hose has been subjected to pressurized gas and after the ball game racket has been removed from the mold. The stiffening and/or compression of the core, in particular in the areas of the core close to the tube, can have a negative impact on the playability of the ball game racket. In particular, the relatively high stiffness of the core caused at least in some areas, particularly in the areas of the core close to the tube, can have a negative impact on ball control in the stiffened areas and generally in the edge area of the ball game racket. In addition, the relatively high unevenness of the stiffness of the core caused by this, which can increase in particular due to the tension caused by the tube to the edge of the core as described above, can impair the playability of the ball game racket.

By providing the composite material-free region 32 facing the edge 22 of the core 18 on the outside of the first tube 24, an elastic deformability and/or elastic recovery movement of the tube 24 in this composite material-free region 32 can be made possible even after the curing of the composite material 30, 34. As a result, the tube 24 in the composite material-free region 32 can at least partially return from the expanded state caused by the pressurized gas exposure to the non-expanded state due to the intrinsic elastic recovery force of the tube 24 after the pressurized gas exposure of the cavity 28 of the tube 24 has ended and the composite material 30, 34 has at least partially cured. As a result, stiffening and/or tensioning of the core 18 by the tube 24 can be prevented or at least reduced in order to achieve a softer structure and/or a higher elastic deformability, especially in the edge region, of the ball game racket 10. As a result, the playability of the ball game racket 10, especially in the edge region of the ball game racket 10, can be improved.

Fig.3 shows a ball game racket 110 according to the invention according to a further embodiment. The ball game racket 110 can essentially be designed like the ball game racket 10 from the Fig.1 and 2 In contrast to the ball game bat 10 from the Fig.1 and 2 , the ball game racket 110 has, according to the Fig.3 shown embodiment has two additional hoses 125, which each extend through the handle section 12 and from the handle section 12 only partially into the head section 14 and each end there. The two additional hoses 125 extend in different directions from the handle portion 12 into the head portion 14.

By providing a plurality of hoses 24, 125, different areas of the ball game racket 110 can each be individually equipped with their own hose. For example, different hoses 24, 125, for example made of different materials and/or with different geometries, can be used. Alternatively or additionally, the hoses 24, 125 can be individually pressurized with a respective gas pressure during the hose blowing process. For example, the hoses 24, 125 can be pressurized with different gas pressures and/or with different pressurized gas exposure courses and/or different pressurized gas exposure profiles. Alternatively or additionally, the hoses 24, 125 can be pressurized with pressurized gas at least partially one after the other, i.e. staggered in time. For example, the cavity 28 of the first hose 24 can begin to be pressurized with the first overpressure. Subsequently, i.e., with a time delay after the start of the application of pressure to the cavity 28 of the first hose 24, preferably by 2 to 30 seconds, the cavity 28 of at least one of the additional hoses 125 can be subjected to the second overpressure. In this way, regions of the ball game racket 110 can be individually designed, for example with different stiffnesses and/or different elastic deformabilities and/or different elastic recovery properties.

The additional hoses 125 are only shown schematically as solid lines in Fig.3 The additional hoses 125 may have substantially the same, or at least a similar, construction as the hose 24 of the Fig.1 and 2 In particular, the additional tubes 125 can each have a circumferential wall 26 and a cavity 28 defined within the circumferential wall 26. The cavity 28 preferably extends over the entire length of the respective tube 125.

In contrast to the hose 24, the additional hoses 125 can be completely covered or wrapped with a composite material 30, especially since the additional hoses 125 only partially extend into the head section 14. As a result, the additional hoses 125 have no or at least only a small influence on the Rigidity in the head section 14. Thus, the additional tubes 125 can be completely covered or wrapped with composite material 30 over its circumference in order to bring about a relatively high rigidity in the handle section 12 and a comparatively lower rigidity in the head section 14 through the additional tubes 125. Alternatively, the additional tubes 125 can also be only partially covered or wrapped with composite material 30.

Fig.4 shows a ball game racket 210 according to the invention according to a further embodiment. The ball game racket 210 can essentially be designed like the ball game racket 10 from the Fig.1 and 2 In contrast to the ball game bat 10 from the Fig.1 and 2 , the ball game racket 210 has, according to the Fig.4 The embodiment shown in FIG. 1 has a tube 124 which extends around the entire edge 22 of the core 18 and thereby forms a loop which surrounds the core 18. In contrast to the embodiment shown in FIG. Fig.4 shown embodiment, the area in Fig.1 shown tube 24 only around a portion of the edge 22 of the core 18.

Fig.5 shows a ball game racket 310 according to the invention according to a further embodiment. The ball game racket 310 is essentially like the ball game racket 210 from Fig.4 In contrast to the ball game bat 210 made of Fig.4 the ball game racket 310 has, according to the Fig.5 The embodiment shown has two additional hoses 125, which each extend through the handle section 12 and from the handle section 12 only partially into the head section 14 and each end there. The two additional hoses 125 extend in different directions from the handle section 12 into the head section 14.

In contrast to the hose 124, the additional hoses 125 can be completely covered or wrapped with a composite material 30, especially since the additional hoses 125 only partially extend into the head section 14. Therefore, the additional hoses 125 have no or at least only a small influence on the rigidity in the head section 14. Thus, the additional hoses 125 can be completely covered or wrapped with composite material 30 over its circumference in order to additional tubes 125 to achieve a relatively high rigidity in the handle section 12 and a comparatively lower rigidity in the head section 14. Alternatively, the additional tubes 125 can also be only partially covered or wrapped with composite material 30.

Claims (15)

1. A ball game racquet (10; 110; 210; 310) with a handle portion (12) and a head portion (14) connected with the handle portion (12),

   wherein the head portion (14) comprises a frame (16) and at least one core (18),

   wherein the core (18) at least partially defines two striking surfaces (20) and at least one, preferably circumferentially extending, edge (22) which connects the striking surfaces at least partially,

   wherein at least one first tube (24; 124) extends at least partially through the frame (16) along at least a portion of the edge (22) of the core (18),

   characterized in that

   the first tube (24; 124) is partially covered with a composite material (30) in such a way that at least one portion (32) of an outer side of the first tube (24; 124) facing the edge (22) of the core (18) is free of composite material.
2. The ball game racquet (10; 110; 210; 310) according to claim 1, wherein, at least in the portion of the first tube (24; 124) extending along at least a portion of the edge (22) of the core (18), substantially 10% to 50%, preferably 10% to 40%, more preferably 10% to 30%, most preferably 15% to 30%, of an outer circumference of the first tube (24; 124) is free of composite material.
3. The ball game racquet (10; 110; 210; 310) according to any one of the preceding claims, wherein a gap (36) extends at least partially along the first tube (24; 124) between the edge (22) of the core (18) and the outer side of the first tube (24; 124).
4. The ball game racquet (10; 110; 210; 310) according to any one of the preceding claims, comprising at least one additional tube (125) which extends at least partially through the head portion (14) and/or through the handle portion (12).
5. The ball game racquet (10; 110; 210; 310) according to claim 4, wherein the additional tube (125) extends at least partially through the handle portion (12) and extends only partially from the handle portion (12) into the head portion (14) and ends there.
6. The ball game racquet (10; 110; 210; 310) according to any one of the preceding claims, comprising at least two additional tubes, each of which extending at least partially through the head portion and/or through the handle portion , wherein each of the two additional tubes (125) extends at least partially through the handle portion (12) and extends only partially from the handle portion (12) into the head portion (14) and ends there, wherein the two additional tubes (125) extend from the handle portion (12) into the head portion (14) in different directions.
7. A method for producing a ball game racquet (10; 110; 210; 310) with a handle portion (12) and a head portion (14) connected with the handle portion (12), the head portion comprising a frame (16), the method comprising the following steps:

   a) providing at least one first deformable tube (24, 124) with a cavity (28);

   b) coating a portion of an outer side of the first tube (24; 124) with a first composite material (30) in such a way that a portion (32) of the outer side of the first tube (24; 124) remains free of composite material;

   c) providing a core (18) at least partially defining two striking surfaces (20) and at least one, preferably circumferentially extending, edge (22) which connects the striking surfaces (20) at least partially;

   d) arranging the first tube (24; 124) along at least a portion of the edge (22) of the core (18) at least partially around the core (18) in such a way that the portion (32) of the outer side of the first tube (24; 124), which is free of composite material, at least partially faces the edge (22) of the core (18);

   e) applying at least one layer of a second composite material (34) at least partially to the core (18) and the first tube (24; 124);

   f) applying an overpressure to the cavity (28) of the first tube (24; 124); and

   g) curing the composite material (30, 34).
8. The method according to claim 7, wherein, at least prior to step e), at least one additional tube (125) is arranged in the head portion (14) and/or in the handle portion (12).
9. The method according to claim 8, wherein the additional tube (125) is arranged in the head portion (14) and/or in the handle portion (12) in such a way that it extends at least partially through the handle portion (12) and only partially from the handle portion (12) into the head portion (14) of the ball game racquet (110; 310) and ends there.
10. The method according to any one of claims 7 to 9, wherein, in step f), a variable overpressure is applied to the cavity (28) of the first tube (24; 124).
11. The method according to any one of claims 7 to 10, wherein, in step f), a, preferably predetermined, profile of an at least temporarily inconstant pressure profile over a pressurization time is applied to the cavity (28) of the first tube (24; 124).
12. The method according to claim 8 or 9, or according to claim 10 or 11 when dependent from claim 8 or 9, wherein, in step f), a first overpressure is applied to the cavity (28) of the first tube (24; 124) and a second overpressure is applied to the cavity (28) of the at least one additional tube (125), wherein the first overpressure and the second overpressure are different.
13. The method according to claim 8, 9 or 12, or according to claim 10 or 11 when dependent from claim 8 or 9, wherein, in step f), a first overpressure of 2 bar to 5 bar is applied to the cavity (28) of the first tube (24; 124) and a second overpressure of 2 bar to 10 bar is applied to the cavity (28) of the at least one additional tube (125).
14. The method according to claim 12 or 13, wherein the applying the second overpressure to the cavity (28) of the at least one additional tube (125) and the applying the first overpressure to the cavity (28) of the first tube (24; 124) are at least partially staggered in time.
15. The method according to claim 14, wherein a start of the applying the second overpressure to the cavity (28) of the at least one additional tube (125) is delayed in time, preferably by 2 to 30 seconds, after a start of the applying the first overpressure to the cavity (28) of the first tube (24; 124).

Images