DE9218550U1 - Handle and sports equipment with a jacket made of polyethylene vinyl acetate - Google Patents

Description

MiBO1105Bl.doc - 1 -* ' *

Handle and sports equipment with cover 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 to a sports equipment for hitting a ball or a ball-like object according to the preamble of claim 8 and to the use of polyethylene vinyl acetate as a casing of a handle core according to claim 15.

It is known to use sole inserts made of polyethylene vinyl acetate for ski boots. When polyethylene vinyl acetate is used in this way, the focus is on its soft nature and its mechanical stability.

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

Furthermore, polyethylene vinyl acetate is used to cover booms on windsurfing equipment and to cover the handles of catamaran tillers. The use of polyethylene vinyl acetate in these cases is supported by the fact that this material is highly resistant to UV light and seawater, as these properties are particularly important for water sports.

In addition, the softness of the polyethylene vinyl acetate is particularly important for the boom of a windsurfing device, since the hard tube material, usually metal or

M:BOll05Bl.doc - 2 -*

Fiberglass material without insulation can cause pressure points on a surfer’s hands when held for a long time while practicing windsurfing.

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 racket has so far been wrapped in a spiral with a wide variety of materials made in the form of a band, such as leather, terry cloth and various plastic materials. The disadvantages of such a spiral wrapping of the handle part of a racket for ball sports, however, are that the grip band material sometimes stands up at the overlapping winding transitions of the grip band, causing discomfort for the player's hand, such as blisters. In the case of golf clubs in particular, the wrapping technique was abandoned early on and grips in the form of a sock, which essentially consisted of rubber material, were put on the tubular shaft of such a golf club. To improve the grip of such a golf club handle, deep notches were made in the rubber material and 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 part of the textile net protrudes from the rubber surface, resulting in a certain roughness of the surface, which means that a golfer can get a better grip on the club handle.

Such golf club handles, however, have the disadvantage that on the one hand they have a relatively rough surface, which can lead to discomfort, and on the other hand a golf club with such a handle of the state of the art can, if it becomes wet, be damaged by both transpi-

M:BO1105Bl.doc - 3 -

The rubber grip can slip in the golfer's hand during the stroke due to both the hydrophobic and smooth surface of the rubber grip, which means that the precision of the stroke typically required when playing golf is no longer present. This means that the vast majority of golfers wear gloves despite a roughened grip structure in order to at least largely reduce the risk of the golf club grip slipping and turning in the player's hand during the stroke. This is all the more true for women and children, who naturally have sensitive skin compared to an adult man, as otherwise blisters can form as an undesirable consequence of frequent gripping and striking movements during the game, especially when playing golf.

The current state of the art is similar in the sweaty sport of squash: many players prefer a wrapped grip tape on the handle of their squash racket, which is designed as part of a surface zipper. The counterpart of this surface zipper is designed on the surface of a glove facing away from the player's skin. If a squash player with such a glove grasps the correspondingly designed handle of his racket, the surface fastener parts of the glove and grip tape engage with each other like Velcro and thus fix the racket handle in a defined position almost immovably in the hand of a squash player.

The disadvantage of this method is that, on the one hand, it requires more effort to manufacture the grip tape and the racket. On the other hand, the glove and racket handle must always be coordinated. Accordingly, all of the player's rackets must be equipped with this type of handle.

M:B01105Bl.doc - 4 -

Furthermore, such a prior art method has the further disadvantage that the player is prevented from changing the opening angle of the racket head comfortably and easily while playing squash, for example by simply turning the handle in the hand with which the player holds his racket without using the other hand. Rather, he needs his other hand to do this, as he must first hold the racket with it in order to open the Velcro-like surface zipper by pulling away the hand that holds the racket during play, thereby separating the glove and racket handle. Only then is the squash player able to re-grip the handle of his racket in the desired racket position and/or opening angle of the racket head with the gloved playing hand.

Furthermore, it is known from EP-A-03 88 764 to form a moisture-absorbing cover for sports equipment handles made of open-cell foamed polyethylene vinyl acetate in the form of a shrink tube. However, such covers have the disadvantage that, due to their moisture-absorbing properties, they absorb water like a sponge in the event of rain or heavy perspiration, which causes the covers to become too soft and thus largely lose their grip.

Based on the prior art of EP-A-03 88 764, it is therefore the object of the present invention to provide a handle and a sports device which have a material which can ensure an improved, secure grip in the user's hand during use, without having to resort to aids such as gloves or the like.

This object is achieved with respect to a handle by the features of claim 1, with respect to a sports

M:B01105Bl.doc - 5 -

is characterized by the features of claim 8 and in terms of use by the features of claim 15.

The fact that the casing of the handle core contains foamed, closed-cell polyethylene vinyl acetate as its main component ensures that the grip of the material as such is sufficient without the need for structuring extending into the depth of the material. Rather, the surface structuring caused by the manufacturing 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 during the practice of the respective sport, in particular golf, can be dispensed with.

A particular advantage of the present invention is that people with sensitive skin, especially women and children, can use a piece of sports equipment according to the invention, especially a golf club, as intended - without gloves or similar aids - without any discomfort, such as mechanical irritation or even blistering. This also makes it possible for 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 finger or hand area.

In addition, the hydrophobic polyethylene vinyl acetate ensures that moisture drains away from the foam cells of the handle surface. This is achieved by the fact that, due to the manufacturing process, a surface structure occurs that prevents the foam cells on the surface from breaking up.

M:BO1105Bl.doc - 6 -

This allows moisture adhering to the surface of the handle to drain through a capillary-like system of grooves and furrows formed by the structuring between the player's hand and the surface of the handle facing it, while the grip is retained thanks to the surface structuring.

In addition, the hydrophobicity of the polyethylene vinyl acetate prevents the entire handle coating from becoming damp. In extreme humidity, the handle can be dried almost completely by briefly wiping it with a towel or clothing due to the hydrophobic properties of its coating.

The material used ensures that the properties of a handle of a device, e.g. a sports device in the form of a club, are improved in such a way that a player, e.g. a golfer, has a significantly improved feel for the sports device, in particular a golf club, when playing, since such a handle has increased slip resistance in the player's hand and therefore twisting or slipping of the club in the player's hand is greatly reduced, even when there is moisture on the handle surface due to perspiration or weather.

Another advantage is the compression behavior of polyethylene vinyl acetate, as this material initially deforms slightly when gently pressed - but with increasing deformation it offers more and more resistance to the compressive force, so that the material temporarily behaves quasi-plastically, i.e. it inversely reflects the shape of the areas of the hand surface that surround the handle and exert pressure. When you let go of a handle made of polyethylene vinyl acetate, the surface of the polyethylene vinyl acetate

M:BOl105Bl.doc - 7 -

acetate coating, the grips return to their original position at least approximately. This promotes the biomechanical movement sequence between an athlete and their sports equipment, especially a golfer and their golf club, because the grip material provides a better feel, which results in a more sensitive relationship between the grip and the player's hand. From a neurophysiological point of view, this is because the material structure means that more nerve endings are in contact with the grip surface. Therefore, a grip, especially the grip of a golf club, is also particularly suitable for older people because they have a better feel for their swing.

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

A further advantage of using polyethylene vinyl acetate is its high mechanical stability and its good skin compatibility, especially its hypoallergenic properties.

A handle of the present invention is particularly suitable as a handle for sports equipment in the form of a racket, such as tennis, squash, golf, racketball, table tennis, ice hockey or field hockey rackets. However, the present invention particularly preferably addresses the handle of a golf club.

In addition, 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, gymnastic equipment, such as parallel bars and rings, and wall bars, is also its usability in tools, e.g. hammers, saws, files

M:B01105Bl.doc - 8 -

etc. However, the application is particularly advantageous in the field of medical aids, such as the handles of crutches and the swivel wheels of wheelchairs or the like.
5

In addition, the present invention can also be used on bicycle handlebars, lawnmower and stroller handles and also on a car steering wheel.

The measure that the cover is designed in the shape of a stocking or tube has the advantage that the core of a sports equipment handle can be covered with the foamed closed-cell polyethylene vinyl acetate in one operation, whereby a stocking or tube made of polyethylene vinyl acetate is applied to the core and is shrunk onto the core of the sports equipment by heat treatment, so that a torsion-proof connection is created between the cover and the core. In the case of polyethylene vinyl acetate applied in the shape of a tube, the end of the handle core facing away from the club head is usually provided with a closure cap. With a stocking-shaped cover made of polyethylene vinyl acetate, this is advantageously not necessary.

Using polyethylene vinyl acetate layer thicknesses of approx. 1 mm to 10 mm, in particular approx. 2 mm to 6 mm, preferably approx. 3 mm to 5 mm, has the advantage that these areas allow the handle core of a piece of sports equipment or a medical device, such as a crutch, to be coated with a polyethylene vinyl acetate coating, depending on the application. Golf clubs preferably have a layer thickness of approx. 3 to 5 mm. This also applies to squash and tennis rackets.

Using non-crosslinked polyethylene vinyl acetate has the advantage that a particularly soft coating can be achieved

MiBO1105Bl.doc - 9 -

Such a soft cover adapts particularly ergonomically to the player's hand during the intended use of the corresponding racket.

Using cross-linked polyethylene vinyl acetate has the advantage that the hardness of a handle coating can be adjusted, among other things, via the degree of cross-linking of the polyethylene vinyl acetate, which makes it possible to adapt the hardness of the coating to any intended use.

Using polyethylene vinyl acetate with Shore hardnesses according to DIN 5 3 5 05 of approx. 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, 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. Furthermore, polyethylene vinyl acetate is commercially available in all Shore hardness ranges of interest.

Structuring the surface of the polyethylene vinyl acetate sheath to suit the respective application in such a way that the surface irregularities in terms of their depth are 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 becomes very gripable without the need for large depressions in the surface, so that on the one hand water can drain away within these broken up hydrophobic foam cells, while the mechanical stability is still guaranteed, since no deep cuts in the material of the sheath are required.

A particular advantage is that a certain surface structure can be created during and after

M:BO1105Bl.doc - 10 -

can be adjusted in particular by the manufacturing process. It is therefore possible to adjust the degree of roughness of the polyethylene vinyl acetate surface through the rheological properties of the polyethylene vinyl acetate used in production, the temperature and the ratio of flowability and removal speed from a roller of a plastic rolling machine, in particular a so-called calender, during production.

Furthermore, it is also possible to design the surface of the rollers used in production according to the desired polyethylene vinyl acetate surface.

Post-processing of the surface of the polyethylene vinyl acetate sheath is generally not necessary, but can of course be carried out if necessary using standard state-of-the-art methods.

Such a measure makes it possible to produce handles for sports equipment in the form of rackets which, even if they become damp due to sweat or weather, meet the highest standards in terms of the grip of the handle in the player's hand.

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

Further advantages and features of the present invention will become apparent from the description of an embodiment and from the drawing. It shows:

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

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

MiBO1105Bl.doc - 11 -

Fig. 3 is a perspective view of a prior art handle;

Fig. 4 a cross section of a handle of the prior art

Fig. 5 is a perspective view of an embodiment of a sports device according to the invention.
10

Fig. 6 is a perspective view of another 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 shape of a club. The handle 1 has a stocking-shaped casing 4 made of foamed, closed-cell, cross-linked polyethylene vinyl acetate around a tubular core 2 made of metal. The layer thickness 3 of the casing 4 is approximately 4 mm. The Shore hardness of the polyethylene vinyl acetate of the casing 4 is approximately A 70 according to DIN 53 505.

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

Such a handle 1 with a cover 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 makes his stroke.

This feeling of security is also not significantly affected by moisture on the surface of the jacket 4, as it is particularly suitable for the jacket 4 made of polyethylene vi-

M:BO1105Bl.doc - 12 -

nylacetate is that such a handle retains its grip even when moisture adheres to the surface 8 of the casing 4. This grip is achieved by the fact that the surface 8 of the casing 4 is structured in such a way that the surface irregularities are generally smaller in terms of their depth than the 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 drain between the remaining walls 10 of a foam cell 11. A roughening or structuring of the surface 8 caused by the breaking up of the foam cells. The remaining walls 10 of the foam cell 11 have a particularly good grip on the player's skin due to their large surface area.

As a result, it is no longer necessary for a golfer to wear a glove to better control a golf club 12.

In addition, the softness and suppleness of the polyethylene vinyl acetate cover 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 the body and golf club 12 because the polyethylene vinyl acetate grip material provides a better feeling for hitting a ball than was previously possible with the state of the 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 cover made of foamed, closed-cell, cross-linked polyethylene.

MiBO1105Bl.doc - 13 -

vinyl acetate and shrunk on by heat treatment so that the handle 1 is connected to the casing 4 in a rotationally fixed manner.

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 cover made of polyethylene vinyl acetate. In such an application of foamed closed-cell cross-linked polyethylene vinyl acetate, a particular advantage over the prior art also arises, since the one-piece design of the cover 4 of the handle 16 means that no annoying overlaps of the grip bands typically used in the prior art can occur and a slip- and twist-proof shot can still be made with the squash racket 15, even though this type of sport in particular involves a lot of perspiration, particularly on the hands, so that the hand surface becomes moist and the cover 4 of the handle 16 nevertheless provides a secure grip due to the advantages of the roughening or structuring of the polyethylene vinyl acetate surface described above.

It is also conceivable to use foamed closed-cell polyethylene vinyl acetate in medical aids, such as handles on crutches or swivel wheels on wheelchairs, with a particular advantage being the adjustability of the Shore hardness according to DIN 53 5 05 from approx. 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, among other things due to the degree of cross-linking of polyethylene vinyl acetate or its vinyl acetate content.

Even in these applications, the good grip even on wet surfaces as well as the hypoallergenic properties

·

·

M:BO1105Bl.doc - 14 -

of polyethylene vinyl acetate as well as the adaptability of this material to the hand grasping the handle.

Claims (1)

[File:ANM\B01105A1 .DOC] 16.05.1994 EVA handle Dr. Locke-Bogenhauser, Karin, 83083 Riedering S h o u t &zgr; ans &rgr; r ü c he Handle, in particular handle for sports equipment, with a generally cylindrical core and a casing that envelops the core at least on its peripheral surface, wherein the casing contains a foamed closed-cell polyethylene vinyl acetate as its main component, characterized in that the surface of the casing is structured in such a way that foam cells on the surface are broken up, whereby the breaking up of the foam cells by the remaining walls of foam cells results in a roughening of the surface. Sports equipment for hitting a ball or ball-like object, preferably a golf club, with a club head, a shaft and a handle core, the handle core being surrounded by a sheath made of foamed closed-cell polyethylene vinyl acetate, characterized in that the surface of the casing is structured in such a way that foam cells on the surface are broken up, whereby the breaking up of the foam cells by the remaining walls of foam cells results in a roughening of the surface. Handle or sports equipment according to claim 1 or 2, characterized in that the casing is designed in the shape of a stocking or tube. Handle or sports equipment according to one of claims 1 to [File.ÄNM\B01105A1 .DOC] 16.05.1994 EVA-Griff Dr, Locke-Bogenhauser, Karin, 83083 Riedering 3, characterized in that the jacket has a layer thickness range of about 1 mm to 10 mm, in particular about 2 mm to 6 mm, preferably about 3 to 5 mm. Handle or sports equipment according to one of claims 1 to 4, characterized in that the polyethylene vinyl acetate is uncrosslinked. Handle or sports equipment according to one of claims 1 to 4, characterized in that the polyethylene vinyl acetate is cross-linked. Handle or sports equipment according to one of claims 1 to 6, characterized in that the polyethylene vinyl acetate has, depending on the intended use, different Shore hardnesses according to DIN 53 505 of approx. 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. Handle or sports equipment according to one of claims 1 to 7, characterized in that the surface of the polyethylene vinyl acetate casing is structured to suit the respective application, the surface irregularities in terms of their depth are generally smaller than the average diameter of the foam cells of the polyethylene vinyl acetate. Use of foamed, closed-cell polyethylene vinyl acetate as a casing of a handle core, in particular the handle core of a sports device for hitting a ball or a ball-like object, preferably a golf club. [Fite:ANM\B01105A1.DOC] 16.05.1994 EVA-Griff Dr. Locke-Bogenliauser, Karin, 83083 Riederiiig 10. Use according to claim 9, characterized in that the sheath is designed in the shape of a stocking or tube; 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 from approx. 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, or the surface of the polyethylene vinyl acetate sheath is structured to suit the respective application, whereby the surface irregularities are generally smaller in terms of their depth than the average diameter of the foam cells of the polyethylene vinyl acetate.