WO1993003799A1 - Handle with a covering made of ethylene/vinyl acetate copolymer, and sports equipment with such a handle - Google Patents

Abstract

The invention concerns the use of ethylene/vinyl acetate copolymer as the covering for the core (2) of the handles of sports equipment in the form of a bat, raquet or club, in particular a golf club. The surface of the ethylene/vinyl acetate copolymer on the handle (1) of such a club is slightly rough, thus providing a particularly good grip, even when the surface of the handle is moist. The good grip offered by the covering means that other aids designed to improve the grip, such as gloves or power, are largely unnecessary. In addition, ethylene/vinyl acetate copolymer can be used to cover hand-grips on medical aids, such as crutches or invalid-chair push rims.

Description

 Handle and sports equipment with a jacket made of polyethylene vinyl acetate

The present invention relates to a handle, in particular a handle for sports equipment in the form of a racket according to the preamble of claim 1, furthermore a sports equipment for hitting a ball or a ball-like object according to the preamble of claim 8 and the use of polyethylene vinyl acetate as a jacket Handle core according to claim 15.

It is known to use sole inserts for ski shoes made from polyethylene vinyl acetate. When using polyethylene vinyl acetate in this way, its soft nature with a given mechanical stability is in the foreground.

Furthermore, it is known to cover those surfaces of a surfboard on which a surfer prefers to stand with a polyethylene vinyl acetate layer. In this application of polyethylene vinyl acetate, the focus is on the high coefficient of friction between polyethylene vinyl acetate on the one hand and the rubber sole of a surfer's boot typically made of neoprene.

Furthermore, polyethylene vinyl acetate is used for covering booms in windsurfing devices and for covering the handlebars of catamaran tiller. The use of polyethylene vinyl acetate in these cases is supported by the fact that this material has a high resistance to UV light and seawater, since these properties are of particular importance in water sports.

SPARE BLADEΓ In addition, the softness of the polyethylene vinyl acetate is of particular importance in the boom of a windsurfing device, since the hard pipe material, usually metal or glass fiber material, without covering during continuous holding during the practice of windsurfing can lead to pressure points on the hands of a surfer.

In the case of sports equipment for hitting a ball or a ball-like object, such as a golf club or a tennis or squash racket, the handle core of such a club has so far been spirally wrapped with a wide variety of materials, such as leather, terry cloth and various plastic materials, which are produced in tape form . Disadvantages of such a spiral wrapping of the grip part of a racket for ball sports, however, lie in the fact that the grip tape material is partially set up on the overlapping winding transitions of the grip tape, so that this leads to inconveniences for the hand of the player, such as e.g. B. leads to blistering. In particular in the case of golf clubs, the winding technique was therefore abandoned at an early stage, and handles in stocking form, which consisted essentially of rubber material, were placed on the tubular shaft of such a golf club. In order to improve the grip of such a golf club grip, deep notches were made in the rubber material on the one hand, and on the other hand the rubber material was provided with a grid-shaped textile net. This textile net is embedded in the rubber mass in such a way that a part of the textile net protrudes from the rubber surface, so that there is a certain roughness of the surface which leads to a golfer finding a better grip on the club handle.

Such golf club grips, however, have the disadvantage that, on the one hand, they have a relatively rough surface, which leads to inconveniences, on the other hand, a golf club with such a grip of the prior art can slip in the hand of the golfer in the hand of the golfer in the event of becoming damp, both due to transparency and due to weather influences due to the hydrophobic and smooth surface of the rubber grip , so that the precision of the shot that is typically required in golf is no longer given. As a result, most golfers, despite a roughened grip structure, wear gloves to at least largely reduce the risk of the golf club handle slipping and turning in the hand of the player during the striking process. This applies all the more to women and children who naturally have sensitive skin - in comparison to an adult man - since otherwise blistering can occur as an undesirable result of frequent gripping and striking movements during the game, in particular during the game of golf.

A similar procedure is used in the prior art for the sweat-inducing sport of squash: many players prefer a wrapped grip tape on the grip of their squash racket, which is designed as part of a surface zipper. The counterpart of this surface zip is formed on the surface of a glove facing away from the skin of the player. If a squash player with a glove of this type grasps the appropriately designed handle of his racket, the surface fastener parts of the glove and grip tape engage in one another like a Velcro and thus fix the racket handle in a defined position almost immovably in the hand of a squash player.

A disadvantage of this method, however, is that, on the one hand, a greater manufacturing outlay for the grip tape and racket is required. On the other hand, the glove and the club handle must always be coordinated. So have to all of the player's rackets are equipped with such a handle.

In addition, such a method of the prior art has the further disadvantage that the player is prevented during squash playing from changing the opening angle of the racket head conveniently and easily, for example by simply turning the handle in his hand with the the player holds his racket without using the other hand. Rather, he needs his second hand because he has to hold the racket with it first in order to open the Velcro-like surface zipper by pulling away the hand that holds the racket during the game in order to separate the glove and the racket grip. Only then is the squash player able to grip the handle of his racket in the desired racket position and / or opening angle of the racket head with the glove-reinforced hand.

It is therefore an object of the present invention to provide a handle and a sports device which have a material which, during use, can ensure an improved, secure grip in the hand of the user, without the use of aids such as gloves or having to resort to the same.

This object is achieved in relation to a handle by the features of claim 1, in relation to a sports device by the features of claim 8 and in terms of use by the features of claim 15.

The fact that the jacket of the handle core contains foamed, closed-cell polyethylene vinyl acetate as the main component ensures, on the one hand, that the grip of the material as such is sufficient without the need for structuring that extends into the depth of the material. is such. Rather, the surface structuring caused by the production process of polyethylene vinyl acetate is generally sufficient for the purposes of the present invention. Due to this structuring of the polyethylene vinyl acetate surface of a handle according to the invention, the use of additional aids, such as gloves or the like, to increase grip and feel while playing the respective sport, in particular golf, can be omitted.

A particular advantage of the present invention lies in the fact that, in particular, people with sensitive skin, in particular women and children, use a sports device according to the invention, in particular a golf club, as intended - without gloves or similar aids can occur without inconvenience, such as mechanical irritation or even blistering. This also enables this group of people to complete stroke training programs in which the frequency of strokes is far higher than in a normal game without irritation or blisters occurring in the area of the fingers or hands.

In addition, the hydrσphopbe polyethylene vinyl acetate ensures that moisture runs off the foam cells of the handle surface. This is brought about by the fact that, due to the manufacture, a surface structuring occurs which results in the breaking open of foam cells lying on the surface. As a result, moisture adhering to the surface of the grip jacket can run off through a capillary-like channel and groove system formed by the structuring between the hand of a player and the surface of the grip jacket facing this, the grip being provided by the surface structuring however is preserved. In addition, the hydrophobicity of the polyethylene vinyl acetate prevents the entire handle casing from becoming damp. In extreme humidity, the handle can be almost completely dried if necessary by briefly wiping it with a towel or clothing due to the hydrophobic properties of its jacket.

The material used ensures that the properties of a handle of a device, e.g. B. a sports device in the form of a club can be improved in such a way that a player, for example a golf player, gets a considerably improved feeling for the sports device, in particular a golf club, when playing, since such a handle has increased slip resistance in the Hand of the player and therefore twisting or slipping of the racket in the hand of the player is greatly reduced even in the presence of perspiration or weather-related moisture on the handle surface.

A further advantage lies in the compression behavior of polyethylene vinyl acetate, since this material initially deforms slightly under gentle pressure - but with increasing deformation the compressive force opposes more and more resistance, so that the material behaves temporarily quasi-plastic, that is shows the shape of the areas of the hand surface surrounding the grip jacket and exerting pressure in an inverse manner. When a handle made of polyethylene vinyl acetate is released, the surface of the polyethylene vinyl acetate jacket springs back at least approximately back to its starting position. This promotes the biomechanical sequence of movements between an athlete and his sports device, in particular a golf player and his golf club, because the grip material gives a better feeling, which results in a more sensitive relationship between the club handle and a player's hand. From a neurophysiological point of view, this is because of the material structure more nerve end points are in contact with the handle surface. Therefore, a grip, in particular the grip of a golf club, is also particularly suitable for older people because they have a greater feeling for their stroke.

This also applies if the handle according to the invention is used on a tennis or squash racket or other sports equipment in racket form.

A further advantage for the use of polyethylene vinyl acetate results from its high mechanical stability and its good skin tolerance, in particular its hypoallergenic properties.

A handle of the present invention is particularly suitable as a handle for sports equipment in racket form, such as tennis, squash, golf, racquetball, table tennis, ice hockey or field hockey sticks. However, the grip of a golf club is particularly preferred with the present invention. *

In addition, there is a particular advantage of a handle according to the invention, which contains polyethylene vinyl acetate as the main component, in addition to the use of such handles in other sports equipment, such as paddling and rowing boats, fishing rods, gymnastics equipment, such as bars and rings, and wall bars. also in its usability for tools, e.g. B. Hammers, saws, files etc. However, the use in the field of medical aids, such as the handles of crutches and the turning wheel of wheelchairs or the like, is particularly advantageous.

In addition, the present invention can also be used on bicycle handlebars, lawn mower and stroller handles and also on a motor vehicle steering wheel. The measure that the sheath is formed like a stocking or tube has the advantage that the core of a sports equipment handle can be coated with the foamed closed-cell polyethylene vinyl acetate in one operation, a stocking or tube made of polyethylene vinyl acetate being applied to the core, and is shrunk onto the core of the sports equipment by heat treatment, so that there is a rotationally fixed connection between the jacket and the core. In the case of polyethylene vinyl acetate applied in the form of a tube, the end of the handle core facing away from the racket head is generally provided with a closure cap. In the case of a stocking-shaped jacket made of polyethylene vinyl acetate, this is advantageously not necessary.

Polyethylene vinyl acetate layer thickness ranges from approx. 1 mm to 10 mm, in particular approx. 2 mm to 6 mm, preferably approx. 3 mm to 5 mm, have the advantage that through these areas the grip core of a sports device or also of a medical device is approximately a crutch can be covered with a coat made of polyethylene vinyl acetate, adapted to the application. Golf clubs preferably have a layer thickness range of approximately 3 to 5 mm. This also applies to squash and tennis rackets.

The use of uncrosslinked polyethylene vinyl acetate has the advantage that a particularly soft coat can be achieved with it. Such a soft coat adapts ergonomically to the player's hand during the intended use of the associated racket.

The use of crosslinked polyethylene vinyl acetate has the advantage that the hardness of a grip jacket is adjusted, inter alia, by the degree of crosslinking of the polyethylene vinyl acetate. can, which makes it possible to adapt the hardness of the jacket to any purpose.

Polyethylene vinyl acetate with Shore hardness according to DIN 53 505 of approximately A 40 to A 85, in particular approximately A 55 to A 80, advantageously approximately A 60 to A 75, preferably approximately A 65 to A 75, particularly preferably approximately A Using 70 to A 75 has the advantage that with these Shore hardness ranges, almost all applications, both in the sports sector and for medical aids, can be individually adapted to the respective intended use. Polyethylene vinyl acetate is also commercially available in all Shore hardness ranges of interest.

Structuring the surface of the polyethylene vinyl acetate jacket in such a way that it is adapted to the respective application in such a way that the surface unevenness in relation to its depth is generally smaller than the average diameter of the foam cells of the polyethylene vinyl acetate has the advantage that the surface of the polyethylene vinyl acetate is very large is easy to grip without large recesses in the surface being necessary, so that on the one hand water drainage within these broken hydrophobic foam cells is possible, the mechanical stability being nevertheless guaranteed since no deep incisions in the material of the jacket are required.

A particular advantage lies in the fact that a certain surface structuring can already be set during and in particular through the manufacturing process. It is thus possible to determine the degree of roughness of the polyethylene vinyl acetate surface, for example, by the rheological properties of the polyethylene vinyl acetate used in production, the temperature and the ratio of flowability and peel rate from one roller Plastic rolling machine, in particular a so-called calender, to be discontinued during production.

Furthermore, there is also the possibility of designing the surface of the rollers used in the production in accordance with the desired polyethylene vinyl acetate surface.

Post-processing of the surface of the polyethylene vinyl acetate jacket is generally not necessary, but can, of course, be carried out using the measures customary in the prior art, if required.

Such a measure makes it possible to produce handles for sports equipment in the form of a racket which, even in the event of becoming damp due to sweat or weather, meet the highest demands with regard to the grip of the handle in the player's hand.

Particularly preferred handles are those of golf clubs, squash and tennis rackets as well as table tennis rackets and the like.

The invention is explained in more detail with reference to the description of an exemplary embodiment and that of the drawing. It shows:

Figure 1 is a perspective view of a handle according to the invention.

2 shows a cross section of a handle according to the invention;

3 shows a perspective illustration of a handle of the prior art;

Fig. 4 shows a cross section of a handle of the prior art 5 shows a perspective illustration of an embodiment of a sports device according to the invention.

6 shows a perspective illustration of a further embodiment of a sports device according to the invention.

In Figure 1, 1 denotes a handle of a golf club as a handle for a sports device in the form of a club. The handle 1 has a stocking-shaped casing 4 made of foamed closed-cell crosslinked around a tubular metal core 2! Polyethylene vinyl acetate. The layer thickness 3 of the jacket 4 is approximately 4 mm. The Shore hardness of the polyethylene vinyl acetate of the jacket 4 is approximately A 70 according to DIN 53 505.

In contrast to a handle of the prior art according to FIG. 3 or FIG. 4, the handle of the present invention has a surface which does not have the depressions 5 in the rubber jacket 6 of a handle of the prior art.

Such a handle 1 with a jacket 4 made of polyethylene vinyl acetate has the advantage that, due to its slightly rough surface structure 7, such a handle 1 lies securely in the hand of a golfer while he is playing his stroke.

This feeling of security is also not significantly impaired by moisture on the surface of the jacket 4, since it is in particular attributable to the jacket 4 made of polyethylene vinyl acetate that such a grip maintains its grip even when moisture is present on the surface 8 of the jacket Coat 4 adheres. This grip results from the fact that the surface 8 of the casing 4 is structured in such a way that the surface irregularities are generally smaller than that in terms of their depth average diameter of a foam cell of the polyethylene vinyl acetate. This results in a large number of micro-grooves and channels which, on the one hand, ensure that moisture adhering to the surface 8 can run off between the remaining walls 10 of a foam cell 11. A roughening or structuring of the surface 8 caused by the rupture of the foam cells means that the walls 10 of the foam cell 11 have a particularly good grip on the skin of the player due to their large surface.

As a result, it is no longer necessary for a golf player to have to wear a glove to better guide a golf club 12.

In addition, the softness and conformability of the polyethylene vinyl acetate jacket 4 improves the sensitive relationship between the golf club 12 and the hand of a golfer. Such a combination of grip and comfort improves the biomechanics of the entire movement sequence of body and golf club 12, because the grip material polyethylene vinyl acetate gives a better feeling for a hit on a ball than was previously possible in the prior art .

To produce a golf club 12 as a sports device for hitting a ball or a ball-like object, a handle core 2 of a shaft 14 extending from a club head 13 is covered with a stocking-shaped jacket made of foamed closed-cell, crosslinked polyethylene vinyl acetate and shrunk by heat treatment so that the handle 1 is non-rotatably connected to the jacket 4.

Another preferred use of closed-cell foamed polyethylene vinyl acetate is that a Handle core 2 of a squash racket 15 is covered with a stocking-shaped jacket made of polyethylene vinyl acetate. Even in such an application of foamed closed-cell crosslinked polyethylene vinyl acetate, there is a particular advantage over the prior art, since the integral design of the casing 4 of the handle 16 means that there is no disruptive overlap of the grip tapes typically used in the prior art and nevertheless a non-slip and twist-proof stroke can be carried out with the squash racket 15, although in this sport in particular a large amount of perspiration occurs on the hands, so that the surface of the hand is moist and the jacket 4 of the handle 16 nevertheless due to the advantages of the above-described Roughening or structuring of the polyethylene vinyl acetate surface provides a secure hold.

It is also conceivable to use foamed, closed-cell polyethylene vinyl acetate in medical aids, such as handles on crutches or turning wheels of wheelchairs, a particular advantage in the adjustability of the Shore hardness according to DIN 53 505 of approximately A 40 to A 85, in particular approx. A 55 to A 80, advantageously approx. A 60 to A 75, preferably approx. A 65 to A 75, particularly preferably approx. A 70 to A 75, u. a. is possible by the degree of crosslinking of polyethylene vinyl acetate or via its vinyl acetate portion.

In these applications too, good grip, even on a moist surface, and the hypoallergenic properties of polyethylene vinyl acetate, as well as the suppleness of this material to the hand gripping the handle, are in the foreground.

REPLACEMENT LEAF

Claims

Claims 1. Handle, in particular handle for sports equipment, with a generally cylindrical core and a sheath enveloping the core at least on its circumferential surface, the sheath containing a foamed polyethylene vinyl acetate as the main component, characterized in that the polyethylene vinyl acetate is closed cell. 2. Sports device for hitting a ball or a ball-like object, preferably a golf club, with a club head, a shaft and a grip core, the grip core being surrounded by a jacket made of foamed polyethylene vinyl acetate, characterized in that the polyethylene vinyl acetate is closed cell. 3. Handle or sports device according to claim 1 or 2, characterized in that the jacket is formed like a stocking or hose. 4. Handle or sports device according to one of claims 1 to 3, characterized in that the jacket has a layer thickness range of approximately 1 mm to 10 mm, in particular approximately 2 mm to 6 mm, preferably approximately 3 to 5 mm . 5. Handle or sports device according to one of claims 1 to 4, characterized in that the polyethylene vinyl acetate is not cross-linked. 6. Handle or sports device according to one of claims 1 to 4, characterized in that the polyethylene vinyl acetate is cross-linked. 7. Handle or sports device according to one of claims 1 to 6, characterized in that the polyethylene vinyl acetate, depending on the application, different Shore hardnesses according to DIN 53 505 of approximately A 40 to A 85, in particular approximately A 55 to A 80, advantageous approximately A 60 to A 75, preferably approximately A 65 to A 75, particularly preferably approximately A 70 to A 75. 8. Handle or sports device according to one of claims 1 to 7, characterized in that the surface of the polyethylene vinyl acetate jacket is structured in a manner adapted to the respective application, the surface irregularities being smaller in relation to their depth as a rule than the average diameter of the foam cells of the polyethylene vinyl acetate. 9. Use of foamed, closed-cell polyethylene vinyl acetate as the jacket of a grip core, in particular the grip core of a sports device for hitting a ball or a ball-like object, preferably a golf club. 10. Use according to claim 9, characterized in that the jacket is formed like a stocking or hose; or the jacket in particular has a layer thickness range of approximately 1 mm to 10 mm, in particular approximately 2 mm to 6 mm, preferably approximately 3 to 5 mm; or the polyethylene vinyl acetate is uncrosslinked or crosslinked; or the polyethylene vinyl acetate, depending on the application, has different Shore hardnesses according to DIN 53 505 of approximately A 40 to A 85, in particular approximately A 55 to A 80, advantageously approximately A 60 to A 75, preferably approximately A 65 to A 75, particularly preferably about A 70 to A 75; or the surface of the polyethylene vinyl acetate jacket is structured in a manner adapted to the particular application, the surface irregularities in terms of their depth generally being smaller than the average diameter of the foam cells of the polyethylene vinyl acetate.