EP0763372A2 - Tennis racket frame - Google Patents

Tennis racket frame Download PDF

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Publication number
EP0763372A2
EP0763372A2 EP96118475A EP96118475A EP0763372A2 EP 0763372 A2 EP0763372 A2 EP 0763372A2 EP 96118475 A EP96118475 A EP 96118475A EP 96118475 A EP96118475 A EP 96118475A EP 0763372 A2 EP0763372 A2 EP 0763372A2
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EP
European Patent Office
Prior art keywords
thermoplastic
tennis racket
bridge
racket frame
frame according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP96118475A
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German (de)
French (fr)
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EP0763372A3 (en
Inventor
Giorgio Dr. Greening
Regina Laws
Peter Dr. Itteman
Philippe Saguet
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Cytec Technology Corp
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Cytec Technology Corp
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Publication date
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Publication of EP0763372A2 publication Critical patent/EP0763372A2/en
Publication of EP0763372A3 publication Critical patent/EP0763372A3/en
Ceased legal-status Critical Current

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    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B49/00—Stringed rackets, e.g. for tennis
    • A63B49/02—Frames
    • A63B49/03—Frames characterised by throat sections, i.e. sections or elements between the head and the shaft
    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B60/00—Details or accessories of golf clubs, bats, rackets or the like
    • A63B60/06—Handles
    • A63B60/08—Handles characterised by the material
    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B49/00—Stringed rackets, e.g. for tennis
    • A63B49/02—Frames
    • A63B49/10—Frames made of non-metallic materials, other than wood
    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B49/00—Stringed rackets, e.g. for tennis
    • A63B49/02—Frames
    • A63B49/10—Frames made of non-metallic materials, other than wood
    • A63B49/11—Frames made of non-metallic materials, other than wood with inflatable tubes, e.g. inflatable during fabrication
    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B2209/00—Characteristics of used materials
    • A63B2209/02—Characteristics of used materials with reinforcing fibres, e.g. carbon, polyamide fibres
    • A63B2209/023—Long, oriented fibres, e.g. wound filaments, woven fabrics, mats

Definitions

  • the invention relates to tennis racket frames made of tubular fiber composite material based on thermoplastic fiber / carbon fiber hybrid yarn, hybrid yarns in which thermoplastic fibers and reinforcing fibers are intimately mixed have been used increasingly in recent years for the production of high-performance composite materials.
  • the hybrid yarns as well as fabrics made therefrom, e.g. Braids are very flexible and can therefore be deformed as required. If they are consolidated by pressing at temperatures above the softening point of the thermoplastic, it melts and forms a matrix in which the reinforcing fibers are embedded in the preferred direction.
  • Tennis racket frames are also made from such hybrid yarn braids.
  • the starting point is a tubular braid into which an inflatable tube is inserted.
  • the braid is folded in the form of a tennis racket.
  • This structure is placed in a metal mold, the tube is inflated, and the tool is heated so that the braid is consolidated into a fiber-reinforced tube.
  • the invention was therefore based on the object of finding a better solution to the problem mentioned.
  • This object is achieved in that granules or a strand of blowing agent-containing thermoplastic material is filled into the hybrid yarn braid, which is to form the bridge.
  • the plastic containing foaming agent foams up and, depending on the amount of blowing agent, a sufficiently high internal pressure forms in the bridge.
  • the invention accordingly relates to a tennis racket frame made of a curved, hollow tube, the ends of which converge and form the handle, the wall of the tube consisting of consolidated thermoplastic fiber / carbon fiber hybrid yarn, and the bridge between the legs of the handle also a tube made of consolidated thermoplastic fiber / Carbon fiber hybrid yarn, which is filled with a foamed thermoplastic material with a density between 20 and 400 g / l.
  • Figure 1 shows a sketch of the finished tennis racket frame, with (1) the handle, (2) the two legs and (3) the bridge.
  • Hybrid yarn made of carbon fibers and thermoplastic fibers as well as a preferred process for its production and processing into composite materials are described in EP-B 156 599. It is also mentioned there that the hybrid yarn can be used to produce fabrics which can be made into composite bodies, e.g. Can handle tennis racket frames.
  • thermoplastics for the thermoplastic fibers are, for example, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polysulfones, polyether sulfones and polyether ketones; polyamides, such as polyamide-6 and polyamide-6,6, are particularly suitable.
  • thermoplastic materials for the plastic foam can in principle be the same thermoplastics as those from which the fibers are made.
  • the softening points should be of the same order of magnitude or slightly lower.
  • the thermoplastics should be selected so that the softening temperature of the thermoplastic plastic containing blowing agent is somewhat lower than the temperature at which the hybrid yarn is consolidated.
  • Polyamides, polyesters and polyetherimides as well as polysulfones and polyether sulfones are preferred.
  • the granules or the strand of thermoplastic plastic containing blowing agent can, e.g. described in DE-A 39 25 740, can be produced by extruding granules containing blowing agent.
  • Low-boiling liquids which preferably do not dissolve the thermoplastic, but at most swell, are preferred as blowing agents, preferably in amounts of 1 to 20, in particular 2 to 10,% by weight.
  • Suitable blowing agents are e.g. halogenated hydrocarbons such as dichloromethane and chlorobenzene, ketones such as acetone and methyl ethyl ketone, ethers, alcohols, water and mixtures thereof.
  • chemical blowing agents such as azo compounds and carbonates can also be used.
  • a tubular braid is first formed from the hybrid yarn.
  • the diameter of the cane depends on how thick the frame should be at each point; the tube is generally thicker on the handle than on the oval ring.
  • the wall thickness of the braid is of the order of 1 to 2 mm.
  • a flexible, thin-walled (0.05 to 2.0 mm) inflatable tube preferably made of a rubber or a high-melting plastic film, is then inserted into the tubular braid, after which the tubular braid is folded together in the form of a tennis racket frame.
  • a tubular hybrid yarn braid is again formed, which is approximately the length of the future bridge and has two tongue-shaped segments at each end.
  • Thermoplastic granulate or thermoplastic strand containing blowing agent is introduced into this mesh, expediently in a flat, flexible, thin-walled hose, preferably made of the same thermoplastic material as the thermoplastic fibers or a higher melting plastic.
  • the amount of granules filled in and the amount of blowing agent contained therein determine the density of the foam that forms when heated and the internal pressure that is to be built up in the process.
  • the density should be between 20 and 400 g / l, in particular between 50 and 200 g / l; the internal pressure in the order of 5 to 10 bar.
  • This piece of tubular hybrid braid is then placed as a bridge between the legs of the frame so that the two legs are encompassed by the tongue-shaped segments at the end of the braid. This state is shown in Figure 2.
  • the structure is then placed in a multi-part, preferably two-part metal mold, the inner surfaces of which correspond to the desired shape of the finished tennis racket frame.
  • the mold is closed and the tube is inflated to an internal pressure of the order of 5 to 10 bar, whereby the hybrid yarn braid is pressed against the mold wall.
  • the tool is then heated to a temperature above the melting point of the thermoplastic fibers and held at this temperature for about 3 to 30 minutes.
  • the tube can also be inflated simultaneously with or after the tool has been heated. If polyamide fibers are used, the tool temperature is around 300 ° C. The fibers fuse to form a consolidated plastic matrix in which the carbon fibers are embedded.
  • the two ends of the tube connect and form the handle of the racket, furthermore the tongue-shaped segments of the bridge connect with the legs, so that the bridge is firmly integrated into the frame.
  • the mold temperature is sufficiently high, the thermoplastic granules also melt in the bridge, gaseous blowing agent is released and presses the walls of the braid forming the bridge firmly against the mold wall, so that this hybrid yarn braid is also consolidated.
  • the tool is then cooled, the finished frame is demolded and, if necessary, reworked.
  • the flexible hose can be pulled out or left in the frame.
  • Another aspect of the invention relates to a tennis racket frame made of a curved, hollow tube, the ends of which converge and form the handle, the wall of the tube consisting of consolidated thermoplastic fiber / carbon fiber hybrid yarn and the bridge (3) between the legs (2) of the handle (1) is also a tube made of consolidated thermoplastic fiber / carbon fiber hybrid yarn, which is filled with a foamed thermoplastic material with a density between 20 and 400 g / l.
  • thermoplastic fibers consist of a polyamide and / or that the plastic foam consists of a polyamide, a polysulfone or a polyether sulfone.
  • the granules containing blowing agent can be contained in a flexible, thin-walled, inflatable tube which has been introduced into the hybrid yarn braid of the bridge (3).

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  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Physical Education & Sports Medicine (AREA)
  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Pulmonology (AREA)
  • Laminated Bodies (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)
  • Moulding By Coating Moulds (AREA)
  • Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
  • Molding Of Porous Articles (AREA)

Abstract

The bridge (3) between the arms (2) of the grip (1) is also a tube of consolidated thermoplastic fibre/carbon fibre-hybrid yarn, which is filled with a foamed thermoplastic with a density between 20 and 400 g/l. The thermoplastic fibres comprise a polyamide and the plastic foam is a polyamide, a polysulphone or a polyether sulphone. To make the racquet frame, a tubular network of thermoplastic/carbon fibre/hybrid yarn is formed, into which is introduced a flexible, thin-walled, inflatable hose. The tubular network is formed into the shape of a racquet frame, and a piece of tubular hybrid yarn network is laid as bridge (3) between the arms (2) of the frame so that the two arms are encompassed by two tongue-shaped segments of the bridge. The frame is placed in a metal mould which is then closed. The hose is then inflated exerting a pressure on the hybrid yarn network which by subsequent heating is consolidated to form a fibre-reinforced tube.

Description

Die Erfindung betrifft Tennisschlägerrahmen aus rohrförmigen Faserverbundwerkstoff auf Basis von Thermoplastfaser/Kohlenstoffaser-Hybridgarn, Hybridgarne, in denen Thermoplastfasern und Verstärkungsfasern innig vermischt sind, werden in den letzten Jahren in zunehmendem Maße zur Herstellung von Hochleistungsverbundwerkstoffen verwendet. Die Hybridgarne sowie daraus hergestellte Flächengebilde, z.B. Geflechte, sind sehr flexibel und deshalb beliebig verformbar. Wenn man sie durch Verpressen bei Temperaturen oberhalb des Erweichungspunktes des Thermoplasten konsolidiert, schmilzt dieser und bildet eine Matrix, in der die Verstärkungsfasern in Vorzugsrichtung orientiert eingelagert sind.The invention relates to tennis racket frames made of tubular fiber composite material based on thermoplastic fiber / carbon fiber hybrid yarn, hybrid yarns in which thermoplastic fibers and reinforcing fibers are intimately mixed have been used increasingly in recent years for the production of high-performance composite materials. The hybrid yarns as well as fabrics made therefrom, e.g. Braids are very flexible and can therefore be deformed as required. If they are consolidated by pressing at temperatures above the softening point of the thermoplastic, it melts and forms a matrix in which the reinforcing fibers are embedded in the preferred direction.

Aus derartigen Hybridgarngeflechten werden auch Tennisschlägerrahmen hergestellt. Man geht dabei von einem rohrförmigen Geflecht aus, in das man einen aufblasbaren Schlauch einführt. Das Geflecht wird in Form eines Tennisschlägers zusammengelegt. Dieses Gebilde wird in eine Metallform eingelegt, der Schlauch wird aufgeblasen, und das Werkzeug wird erhitzt, so daß das Geflecht zu einem faserverstärkten Rohr konsolidiert. Probleme bereitet dabei der Aufbau der "Brücke" zwischen den beiden Schenkeln des Griffes, welche zur Stabilisierung des Schlägers notwendig ist.Tennis racket frames are also made from such hybrid yarn braids. The starting point is a tubular braid into which an inflatable tube is inserted. The braid is folded in the form of a tennis racket. This structure is placed in a metal mold, the tube is inflated, and the tool is heated so that the braid is consolidated into a fiber-reinforced tube. The construction of the "bridge" between the two legs of the handle, which is necessary to stabilize the racket, presents problems.

Es ist nicht möglich, den aufblasbaren Schlauch, der im äußeren Rahmen des Tennisschlägers liegt, auch in die Brücke zu verlegen, um damit die Brücke an das Rohr, aus dem der Rahmen geformt wird, direkt anzubinden und beide gemeinsam unter Druck zu setzen. Man hat deshalb schon versucht, ein brückenförmiges Gebilde aus duroplastichem Polyurethanschaum mit Hybridgarngeflecht zu überziehen, dieses Gebilde zwischen die Schenkel des Rahmens einzulegen und zusammen mit dem Rahmen zu konsolidieren. Dabei entsteht aber kein genügender Innendruck in der Brücke, so daß hier das Hybridgarngeflecht nicht ausreichend konsolidiert wird. Dies führt zu porösen Schwachstellen, welche bei den hohen Torsions- und Zugbelastungen, welchen gerade die Brücke des Tennisschlägers ausgesetzt ist, Anlaß zu Bruch geben kann.It is not possible to lay the inflatable tube that is in the outer frame of the tennis racket in the bridge in order to directly connect the bridge to the tube from which the frame is formed and to pressurize both together. Attempts have therefore already been made to cover a bridge-shaped structure made of thermosetting polyurethane foam with a hybrid yarn braid, to insert this structure between the legs of the frame and to consolidate it together with the frame. However, there is no sufficient internal pressure in the bridge, so that the hybrid yarn braid is not sufficiently consolidated here. This leads to porous weak points, which are the high torsional and Tensile loads, which the tennis racket's bridge is exposed to, can give rise to breakage.

Der Erfindung lag also die Aufgabe zugrunde, eine bessere Lösung für das genannte Problem zu finden.The invention was therefore based on the object of finding a better solution to the problem mentioned.

Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß man Granulat oder einen Strang aus treibmittelhaltigem thermoplastischem Kunststoff in das Hybridgarngeflecht, welches die Brücke bilden soll, einfüllt. Beim Erhitzen des Werkzeugs schäumt der treibmittelhaltige Kunststoff auf und je nach Menge des Treibmittels bildet sich in der Brücke ein genügend hoher Innendruck aus.This object is achieved in that granules or a strand of blowing agent-containing thermoplastic material is filled into the hybrid yarn braid, which is to form the bridge. When the tool is heated, the plastic containing foaming agent foams up and, depending on the amount of blowing agent, a sufficiently high internal pressure forms in the bridge.

Gegenstand der Erfindung ist demzufolge ein Tennisschlägerrahmen aus einem gebogenen, hohlen Rohr, dessen Enden zusammenlaufen und den Griff bilden, wobei die Wand des Rohres aus konsolidiertem Thermoplastfaser/Kohlenstoffaser-Hybridgarn besteht, und die Brücke zwischen den Schenkeln des Griffes ebenfalls ein Rohr aus konsolidiertem Thermoplastfaser/ Kohlenstoffaser-Hybridgarn ist, welches aber mit einem geschäumten thermoplastischen Kunststoff einer Dichte zwischen 20 und 400 g/l gefüllt ist.The invention accordingly relates to a tennis racket frame made of a curved, hollow tube, the ends of which converge and form the handle, the wall of the tube consisting of consolidated thermoplastic fiber / carbon fiber hybrid yarn, and the bridge between the legs of the handle also a tube made of consolidated thermoplastic fiber / Carbon fiber hybrid yarn, which is filled with a foamed thermoplastic material with a density between 20 and 400 g / l.

Abbildung 1 zeigt eine Skizze des fertigen Tennisschlägerrahmens, wobei mit (1) der Griff, mit (2) die beiden Schenkel und mit (3) die Brücke bezeichnet sind.Figure 1 shows a sketch of the finished tennis racket frame, with (1) the handle, (2) the two legs and (3) the bridge.

Hybridgarn aus Kohlenstoffasern und Thermoplastfasern sowie ein bevorzugtes Verfahren zu seiner Herstellung und die Verarbeitung zu Verbundwerkstoffen sind in EP-B 156 599 beschrieben. Dort wird auch erwähnt, daß aus dem Hybridgarn Gewebe hergestellt werden kann, das man zu Verbundkörpern, z.B. Tennisschlägerrahmen verarbeiten kann.Hybrid yarn made of carbon fibers and thermoplastic fibers as well as a preferred process for its production and processing into composite materials are described in EP-B 156 599. It is also mentioned there that the hybrid yarn can be used to produce fabrics which can be made into composite bodies, e.g. Can handle tennis racket frames.

Bevorzugte thermoplastische Kunststoffe für die Thermoplastfasern sind z.B. Polypropylen, Polyethylenterephthalat, Polybutylenterephthalat, Polyphenylensulfid, Polysulfone, Polyethersulfone und Polyetherketone; besonders geeignet sind Polyamide, wie Polyamid-6 und Polyamid-6,6.Preferred thermoplastics for the thermoplastic fibers are, for example, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polysulfones, polyether sulfones and polyether ketones; polyamides, such as polyamide-6 and polyamide-6,6, are particularly suitable.

Die thermoplastischen Kunststoffe für den Kunststoffschaum können grundsätzlich die gleichen Thermoplasten sein, wie die, aus denen die Fasern bestehen. Die Erweichungspunkte sollen in der gleichen Größenordnung oder etwas niedriger liegen. Grundsätzlich sollen die Thermoplaste so gewählt werden, daß die Erweichungstemperatur des treibmittelhaltigen thermoplastischen Kunststoffs etwas niedriger liegt als die Temperatur, bei der das Hybridgarn konsolidiert wird. Bevorzugt sind Polyamide, Polyester und Polyetherimide sowie Polysulfone und Polyethersulfone.The thermoplastic materials for the plastic foam can in principle be the same thermoplastics as those from which the fibers are made. The softening points should be of the same order of magnitude or slightly lower. In principle, the thermoplastics should be selected so that the softening temperature of the thermoplastic plastic containing blowing agent is somewhat lower than the temperature at which the hybrid yarn is consolidated. Polyamides, polyesters and polyetherimides as well as polysulfones and polyether sulfones are preferred.

Das Granulat bzw. der Strang aus treibmittelhaltigem thermoplastischem Kunststoff kann, wie z.B. in DE-A 39 25 740 beschrieben, durch Extrudieren von treibmittelhaltigem Granulat hergestellt werden. Als Treibmittel kommen bevorzugt niedrig siedende Flüssigkeiten in Frage, die den Thermoplasten nicht lösen, sondern höchstens quellen, vorzugsweise in Mengen von 1 bis 20, insbesondere von 2 bis 10 Gew.-%. Geeignete Treibmittel sind z.B. halogenierte Kohlenwasserstoffe, wie Dichlormethan und Chlorbenzol, Ketone, wie Aceton und Methylethylketon, Ether, Alkohole, Wasser und Gemische davon. Grundsätzlich können auch chemische Treibmittel, wie Azoverbindungen und Carbonate verwendet werden.The granules or the strand of thermoplastic plastic containing blowing agent can, e.g. described in DE-A 39 25 740, can be produced by extruding granules containing blowing agent. Low-boiling liquids which preferably do not dissolve the thermoplastic, but at most swell, are preferred as blowing agents, preferably in amounts of 1 to 20, in particular 2 to 10,% by weight. Suitable blowing agents are e.g. halogenated hydrocarbons such as dichloromethane and chlorobenzene, ketones such as acetone and methyl ethyl ketone, ethers, alcohols, water and mixtures thereof. In principle, chemical blowing agents such as azo compounds and carbonates can also be used.

Zur Herstellung des erfindungsgemäßen Tennisschlägerrahmens wird zunächst ein rohrförmiges Geflecht aus dem Hybridgarn gebildet. Der Durchmesser des Rohrgeflechts richtet sich danach, wie dick der Rahmen an der jeweiligen Stelle sein soll; am Griff ist das Rohr im allgemeinen dicker als am ovalen Ring. Die Wanddicke des Geflechts legt in der Größenordnung von 1 bis 2 mm. Man führt dann einen flexiblen, dünnwandigen (0,05 bis 2,0 mm) aufblasbaren Schlauch, vorzugsweise aus einem Kautschuk oder aus einer hochschmelzenden Kunststoffolie, in das rohrförmige Geflecht ein, anschließend wird das rohrförmge Geflecht in Form eines Tennisschlägerrahmens zusammengelegt.To manufacture the tennis racket frame according to the invention, a tubular braid is first formed from the hybrid yarn. The diameter of the cane depends on how thick the frame should be at each point; the tube is generally thicker on the handle than on the oval ring. The wall thickness of the braid is of the order of 1 to 2 mm. A flexible, thin-walled (0.05 to 2.0 mm) inflatable tube, preferably made of a rubber or a high-melting plastic film, is then inserted into the tubular braid, after which the tubular braid is folded together in the form of a tennis racket frame.

Nun wird die Brücke gebildet. Dazu formt man wieder ein rohrförmiges Hybridgarngeflecht, welches etwa die Länge der späteren Brücke hat und an beiden Enden jeweils zwei zungenförmige Segmente aufweist. In dieses Geflecht wird treibmittelhaltiges Thermoplast-Granulat bzw. Thermoplast-Strang eingegeben, zweckmäßigerweise in einem flachgelegten, flexiblen, dünnwandigen Schlauch, vorzugsweise aus dem gleichen thermoplastischen Kunststoff wie die Thermoplastfasern oder einem höherschmelzenden Kunststoff. Die Menge des eingefüllten Granulats sowie die Menge des darin enthaltenen Treibmittels bestimmen die Dichte des Schaums, der sich beim Erhitzen bildet, sowie den Innendruck, der dabei aufgebaut werden soll. Die Dichte soll zwischen 20 und 400 g/l, insbesondere zwischen 50 und 200 g/l liegen; der Innendruck in der Größenordnung von 5 bis 10 bar. Dieses Stück rohrförmigen Hybridgeflechts wird dann als Brücke so zwischen die Schenkel des Rahmens gelegt, daß die beiden Schenkel von den zungenförmigen Segmenten an den Endes des Geflechts umfaßt werden. Dieser Zustand ist in Abbildung 2 dargestellt.Now the bridge is built. To do this, a tubular hybrid yarn braid is again formed, which is approximately the length of the future bridge and has two tongue-shaped segments at each end. Thermoplastic granulate or thermoplastic strand containing blowing agent is introduced into this mesh, expediently in a flat, flexible, thin-walled hose, preferably made of the same thermoplastic material as the thermoplastic fibers or a higher melting plastic. The amount of granules filled in and the amount of blowing agent contained therein determine the density of the foam that forms when heated and the internal pressure that is to be built up in the process. The density should be between 20 and 400 g / l, in particular between 50 and 200 g / l; the internal pressure in the order of 5 to 10 bar. This piece of tubular hybrid braid is then placed as a bridge between the legs of the frame so that the two legs are encompassed by the tongue-shaped segments at the end of the braid. This state is shown in Figure 2.

Das Gebilde wird dann in eine mehrteilige, vorzugsweise zweiteilige Metallform gelegt, deren Innenflächen der gewünschten Form des fertigen Tennisschlägerrahmens entsprechen. Die Form wird geschlossen und der Schlauch wird zu einem Innendruck in der Größenordnung von 5 bis 10 bar aufgeblasen, wodurch das Hybridgarngeflecht gegen die Formwand gepreßt wird. Das Werkzeug wird dann auf eine Temperatur oberhalb des Schmelzpunktes der Thermoplastfasern erhitzt und etwa 3 bis 30 min bei dieser Temperatur gehalten. Das Aufblasen des Schlauchs kann auch gleichzeitig mit oder nach dem Erhitzen des Werkzeugs vorgenommen werden. Im Fall der Verwendung von Polyamidfasern liegt die Werkzeugtemperatur bei etwa 300°C. Dabei verschmelzen die Fasern zu einer konsolidierten Kunststoffmatrix, in der die Kohlenstoffasern orientiert eingelagert sind. Dabei verbinden sich auch die beiden Enden des Rohres und bilden den Griff des Schlägers, ferner verbinden sich die zungenförmigen Segmente der Brücke mit den Schenkeln, so daß die Brücke fest in den Rahmen eingebunden wird. Bei ausreichend hoher Werkzeugtemperatur schmilzt auch das Thermoplastgranulat in der Brücke auf, gasförmiges Treibmittel wird freigesetzt und preßt die Wände des die Brücke bildenden Geflechts fest an die Formwand, so daß auch dieses Hybridgarngeflecht konsolidiert. Das Werkzeug wird dann abgekühlt, der fertige Rahmen entformt und gegebenefalls nachbearbeitet. Der flexible Schlauch kann herausgezogen oder im Rahmen belassen werden.The structure is then placed in a multi-part, preferably two-part metal mold, the inner surfaces of which correspond to the desired shape of the finished tennis racket frame. The mold is closed and the tube is inflated to an internal pressure of the order of 5 to 10 bar, whereby the hybrid yarn braid is pressed against the mold wall. The tool is then heated to a temperature above the melting point of the thermoplastic fibers and held at this temperature for about 3 to 30 minutes. The tube can also be inflated simultaneously with or after the tool has been heated. If polyamide fibers are used, the tool temperature is around 300 ° C. The fibers fuse to form a consolidated plastic matrix in which the carbon fibers are embedded. The two ends of the tube connect and form the handle of the racket, furthermore the tongue-shaped segments of the bridge connect with the legs, so that the bridge is firmly integrated into the frame. If the mold temperature is sufficiently high, the thermoplastic granules also melt in the bridge, gaseous blowing agent is released and presses the walls of the braid forming the bridge firmly against the mold wall, so that this hybrid yarn braid is also consolidated. The tool is then cooled, the finished frame is demolded and, if necessary, reworked. The flexible hose can be pulled out or left in the frame.

Ein weiterer Aspekt der Erfindung betrifft einen Tennisschlägerrahmen aus einem gebogenen, hohlen Rohr, dessen Enden zusammenlaufen und den Griff bilden, wobei die Wand des Rohres aus konsolidiertem Thermoplastfaser/Kohlenstoffaser-Hybridgarn besteht und die Brücke (3) zwischen den Schenkeln (2) des Griffes (1) ebenfalls ein Rohr aus konsolidiertem Thermoplastfaser/Kohlenstoffaser-Hybridgarn ist, welches mit einem geschäumten thermoplastischen Kunststoff einer Dichte zwischen 20 und 400 g/l gefüllt ist.Another aspect of the invention relates to a tennis racket frame made of a curved, hollow tube, the ends of which converge and form the handle, the wall of the tube consisting of consolidated thermoplastic fiber / carbon fiber hybrid yarn and the bridge (3) between the legs (2) of the handle (1) is also a tube made of consolidated thermoplastic fiber / carbon fiber hybrid yarn, which is filled with a foamed thermoplastic material with a density between 20 and 400 g / l.

Es ist bevorzugt, daß die Thermoplastfasern aus einem Polyamid bestehen, und/oder daß der Kunststoffschaum aus einem Polyamid, einem Polysulfon oder einem Polyethersulfon besteht.It is preferred that the thermoplastic fibers consist of a polyamide and / or that the plastic foam consists of a polyamide, a polysulfone or a polyether sulfone.

Außerdem betrifft die Erfindung ein verfahren zur Herstellung des Tennisschlägerrahmens umfassend folgende Verfahrensschritte:

  • man bildet ein rohrförmiges Geflecht aus Thermoplastfaser/Kohlenstoffaser-Hybridgarn,
  • man führt einen flexiblen, dünnwandigen, aufblasbaren Schlauch in das rohrförmige Geflecht ein,
  • man legt das rohrförmige Geflecht in Form eines Tennisschlägerrahmens zusammen,
  • man legt ein Stück rohrförmiges Hybridgarngeflecht als Brücke (3) so zwischen die Schenkel (2) des Rahmens, daß die beiden Schenkel von jeweils zwei zungenförmigen Segmenten des die Brücke bildenden Hybridgarngeflechts umfaßt werden,
  • man legt das Gebilde in eine mehrteilige Metallform ein und schließt diese,
  • man bläst den Schlauch auf, so daß er auf das Hybridgarn-Geflecht einen Druck ausübt und dieses gegen die Formwand preßt,
  • man erhitzt das Werkzeug auf eine Temperatur oberhalb des Schmelzpunktes der Thermoplastfasern, wobei das Hybridgarngeflecht zu einem faserverstärkten Rohr konsolidiert,
  • man kühlt das Werkzeug ab und entformt,
wobei das Hybridgarngeflecht, welches die Brücke (3) bildet, teilweise mit Granulat oder einem Strang aus einem treibmittelhaltigen thermoplastischen Kunststoff gefüllt ist, welches beim Erhitzen des Werkzeugs aufschäumt und dadurch einen Druck auf das Hybridgarngeflecht ausübt, welcher dieses gegen die Formwand preßt.The invention also relates to a method for producing the tennis racket frame comprising the following method steps:
  • a tubular braid made of thermoplastic fiber / carbon fiber hybrid yarn is formed,
  • a flexible, thin-walled, inflatable tube is inserted into the tubular braid,
  • you put the tubular braid together in the form of a tennis racket frame,
  • a piece of tubular hybrid yarn braid is placed as a bridge (3) between the legs (2) of the frame such that the two legs are each surrounded by two tongue-shaped segments of the hybrid yarn braid forming the bridge,
  • you place the structure in a multi-part metal mold and close it,
  • the tube is inflated so that it exerts pressure on the hybrid yarn braid and presses it against the mold wall,
  • the tool is heated to a temperature above the melting point of the thermoplastic fibers, the hybrid yarn braid being consolidated into a fiber-reinforced tube,
  • you cool the mold and demold it,
wherein the hybrid yarn braid, which forms the bridge (3), is partially filled with granules or a strand of a blowing agent-containing thermoplastic, which foams when the tool is heated and thereby exerts pressure on the hybrid yarn braid, which presses it against the mold wall.

Das treibmittelhaltige Granulat kann in einem flexiblen, dünnwandigen, aufblasbaren Schlauch enthalten sein, welcher in das Hybridgarngeflecht der Brücke (3) eingeführt wurde.The granules containing blowing agent can be contained in a flexible, thin-walled, inflatable tube which has been introduced into the hybrid yarn braid of the bridge (3).

Claims (15)

Tennisschlägerrahmen mit a. einem ersten rohrförmigen Geflecht, das zwei Enden aufweist, die zusammenlaufen und somit einen Griff bilden, wobei das erste rohrförmige Geflecht aus einem konsolidierten Thermoplastfaser/Kohlenstoffaser-Hybridgarn besteht; und b. einem zweiten rohrförmigen Geflecht, das als Brücke.(3) zwischen den Schenkeln (2) von dem ersten rohrförmigen Geflecht angeordnet ist, wobei das zweite rohrförmige Geflecht ein konsolidiertes Thermoplastfaser/Kohlenstoffaser-Hybridgarn ist und wobei das zweite rohrförmige Geflecht einen geschäumten thermoplastischen Kunststoff in solch einer Menge enthält, daß die Dichte des geschäumten Kunststoffs im Bereich zwischen 20 und 400 g/l liegt. Tennis racket frame with a. a first tubular braid which has two ends which converge and thus form a handle, the first tubular braid consisting of a consolidated thermoplastic fiber / carbon fiber hybrid yarn; and b. a second tubular braid, which is arranged as a bridge. (3) between the legs (2) of the first tubular braid, the second tubular braid being a consolidated thermoplastic fiber / carbon fiber hybrid yarn and the second tubular braid being a foamed thermoplastic in contains such an amount that the density of the foamed plastic is in the range between 20 and 400 g / l. Tennisschlägerrahmen nach Anspruch 1, dadurch gekenzeichnet, daß das erste rohrförmige Geflecht einen flexiblen, dünnwandigen, aufblasbaren Schlauch enthält.Tennis racket frame according to claim 1, characterized in that the first tubular braid contains a flexible, thin-walled, inflatable tube. Tennisschlägerrahmen nach Anspruch 1 oder 2, dadurch gekenzeichnet, daß die Thermoplastfasern aus einem Polyamid bestehen.Tennis racket frame according to claim 1 or 2, characterized in that the thermoplastic fibers consist of a polyamide. Tennisschlägerrahmen nach Anspruch 1 oder 2, dadurch gekenzeichnet, daß der geschäumte, thermoplastische Kunststoff aus einem Polyamid, einem Polysulfon oder einem Polyethersulfon besteht.Tennis racket frame according to claim 1 or 2, characterized in that the foamed thermoplastic consists of a polyamide, a polysulfone or a polyethersulfone. Tennisschlägerrahmen nach Anspruch 1 oder 2, dadurch gekenzeichnet, daß der geschäumte, thermoplastische Kunststoff in dem zweiten rohrförmigen Geflecht in einem flexiblen, dünnwandigen Schlauch vorgesehen ist, der aus dem gleichen thermoplastischen Kunststoff besteht wie die thermoplastischen Fasern des rohrförmigen Geflechts oder eines höherschmelzenden Kunststoffs.Tennis racket frame according to claim 1 or 2, characterized in that the foamed, thermoplastic material is provided in the second tubular braid in a flexible, thin-walled tube, which consists of the same thermoplastic material as the thermoplastic fibers of the tubular braid or a higher-melting plastic. Tennisschlägerrahmen nach Anspruch 1 oder 2, dadurch gekenzeichnet, daß das
zweite rohrförmige Geflecht an jedem Ende ein zungenförmiges Segement aufweist und daß das zweite rohrförmige Geflecht als Brücke zwischen den Schenkeln des ersten rohrförmigen Geflechts angeordnet ist, derart, daß die Enden von den zungenförmigen Segmenten umfaßt werden.Tennis racket frame according to claim 1 or 2, characterized in that the
the second tubular braid has a tongue-shaped segment at each end and the second tubular braid is arranged as a bridge between the legs of the first tubular braid, such that the ends are encompassed by the tongue-shaped segments. Tennisschlägerrahmen, der durch ein Verfahren mit folgenden Schritten erhältlich ist: a. Bildung eines aus Schenkeln bestehenden Rahmens, der aus einem rohrförmigen Geflecht aus Thermoplastfaser/Kohlenstoffaser-Hybridgarn gebildet wird, in welches ein flexibler, dünnwandiger, aufblasbarer Schlauch eingeführt wird; b. Einfügen einer Brücke aus rohrförmigem Hybridgarngeflecht zwischen die Schenkel; c. Einlegen des Rahmens und der Brücke in eine mehrteilige, verschließbare Metallform; d. Aufblasen des Schlauchs; und e. Erhitzen der geschlossenen Metallform auf eine Temperatur oberhalb des Schmelzpunktes der Thermoplastfasern, dadurch gekennzeichnet, daß f. die Brücke vor dem Erhitzen der Metallform mit Granulat oder einem Strang aus einem treibmittelhaltigen thermoplastischen Kunststoff gefüllt wird. Tennis racket frame, which is obtainable by a process comprising the following steps: a. Forming a thigh-shaped frame formed from a tubular braid of thermoplastic fiber / carbon fiber hybrid yarn into which a flexible, thin-walled, inflatable tube is inserted; b. Inserting a bridge of tubular hybrid yarn between the legs; c. Inserting the frame and the bridge into a multi-part, lockable metal mold; d. Inflating the tube; and e. Heating the closed metal mold to a temperature above the melting point of the thermoplastic fibers, characterized in that f. before the metal mold is heated, the bridge is filled with granules or a strand of a thermoplastic containing blowing agent. Tennisschlägerrahmen nach Anspruch 7, dadurch gekenzeichnet, daß die Brücke an den Enden zwei zungenförmige Segmente aufweist, die die Schenkel umfassen.Tennis racket frame according to claim 7, characterized in that the bridge has at the ends two tongue-shaped segments which enclose the legs. Tennisschlägerrahmen nach Anspruch 7, dadurch gekenzeichnet, daß das Aufblasen des Schlauchs gleichzeitig mit oder nach dem Erhitzen der Metallform erfolgt.Tennis racket frame according to claim 7, characterized in that the tube is inflated simultaneously with or after the metal mold has been heated. Tennisschlägerrahmen nach Anspruch 7, dadurch gekenzeichnet, daß der treibmittelhaltige thermoplastische Kunststoff eine Schmelztemperatur hat, die unterhalb einer Temperatur liegt, bei der das Hybridgarn konsolidiert ist.Tennis racket frame according to claim 7, characterized in that the blowing agent-containing thermoplastic has a melting temperature which is below a temperature at which the hybrid yarn is consolidated. Tennisschlägerrahmen nach Anspruch 7, dadurch gekenzeichnet, daß das Hybridgarn der Brücke ein Thermoplastfaser/Kohlenstoffaser-Hybridgarn ist.Tennis racket frame according to claim 7, characterized in that the hybrid yarn of the bridge is a thermoplastic fiber / carbon fiber hybrid yarn. Tennisschlägerrahmen nach Anspruch 7, dadurch gekenzeichnet, daß der treibmittelhaltige thermoplastische Kunststoff in einem flexiblen, dünnwandigen Schlauch enthalten ist, welcher in das Hybridgarngeflecht der Brücke eingeführt wurde.Tennis racket frame according to claim 7, characterized in that the blowing agent-containing thermoplastic is contained in a flexible, thin-walled tube which has been inserted into the hybrid yarn braid of the bridge. Tennisschlägerrahmen nach Anspruch 7, dadurch gekenzeichnet, daß der thermoplastische Kunststoff in der Brücke eine Dichte zwischen 20 g/l und 400 g/l aufweist.Tennis racket frame according to claim 7, characterized in that the thermoplastic in the bridge has a density between 20 g / l and 400 g / l. Tennisschlägerrahmen nach Anspruch 7, dadurch gekenzeichnet, daß die Thermoplastfasern aus einem Polyamid bestehen.Tennis racket frame according to claim 7, characterized in that the thermoplastic fibers consist of a polyamide. Tennisschlägerrahmen nach Anspruch 7, dadurch gekenzeichnet, daß der thermoplastische Kunststoff in der Brücke aus einem Polyamid, einem Polysulfon oder einem Polyethersulfon besteht.Tennis racket frame according to claim 7, characterized in that the thermoplastic plastic in the bridge consists of a polyamide, a polysulfone or a polyethersulfone.
EP96118475A 1992-01-29 1993-01-21 Tennis racket frame Ceased EP0763372A3 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE4202335A DE4202335A1 (en) 1992-01-29 1992-01-29 TENNIS RACKET FRAME
DE4202335 1992-01-29
EP93100859A EP0555666B1 (en) 1992-01-29 1993-01-21 Method of manufacture of a tennis racket frame

Related Parent Applications (2)

Application Number Title Priority Date Filing Date
EP93100859.3 Division 1993-01-21
EP93100859A Division EP0555666B1 (en) 1992-01-29 1993-01-21 Method of manufacture of a tennis racket frame

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EP0763372A2 true EP0763372A2 (en) 1997-03-19
EP0763372A3 EP0763372A3 (en) 1997-03-26

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JP (1) JPH05253322A (en)
CN (1) CN1079919A (en)
AT (1) ATE153247T1 (en)
DE (2) DE4202335A1 (en)
ES (1) ES2102535T3 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102631768A (en) * 2012-03-19 2012-08-15 刘自平 Method for manufacturing solid racket
RU2762639C1 (en) * 2020-11-16 2021-12-21 Юрий Михайлович Тебенко Base of table tennis racket

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU2003211064A1 (en) 2002-02-19 2003-09-09 Stx Llc Vibration damping field hockey stick
US7462118B2 (en) 2004-01-09 2008-12-09 Stx, Llc Back and edge weighted field hockey sticks

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0156599A1 (en) 1984-03-15 1985-10-02 BASF Aktiengesellschaft Composite carbon fibre and thermoplastic fiber blends
DE3925740A1 (en) 1989-08-03 1991-02-07 Basf Ag METHOD FOR PRODUCING EXPANDABLE GRANULES AND FOAMS THEREOF

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Publication number Priority date Publication date Assignee Title
BE795562A (en) * 1972-02-18 1973-06-18 Franz Volkl O H G TENNIS RACKET
GB2234909A (en) * 1989-08-05 1991-02-20 Heh Chien Hwa Racket frame
JPH0687903B2 (en) * 1989-12-05 1994-11-09 住友ゴム工業株式会社 Tennis racket frame

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0156599A1 (en) 1984-03-15 1985-10-02 BASF Aktiengesellschaft Composite carbon fibre and thermoplastic fiber blends
DE3925740A1 (en) 1989-08-03 1991-02-07 Basf Ag METHOD FOR PRODUCING EXPANDABLE GRANULES AND FOAMS THEREOF

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102631768A (en) * 2012-03-19 2012-08-15 刘自平 Method for manufacturing solid racket
RU2762639C1 (en) * 2020-11-16 2021-12-21 Юрий Михайлович Тебенко Base of table tennis racket

Also Published As

Publication number Publication date
EP0763372A3 (en) 1997-03-26
EP0555666A1 (en) 1993-08-18
ES2102535T3 (en) 1997-08-01
EP0555666B1 (en) 1997-05-21
DE59306477D1 (en) 1997-06-26
ATE153247T1 (en) 1997-06-15
DE4202335A1 (en) 1993-08-05
JPH05253322A (en) 1993-10-05
CN1079919A (en) 1993-12-29

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