WO2010079191A1

WO2010079191A1 - Sporting device made of thermally modified wood

Info

Publication number: WO2010079191A1
Application number: PCT/EP2010/050095
Authority: WO
Inventors: Michael Schneider
Original assignee: Tt-Tuning Center Gmbh
Priority date: 2009-01-08
Filing date: 2010-01-07
Publication date: 2010-07-15
Also published as: KR20110110148A; DE202009000321U1; JP2012514508A; DE102009042695A1; CN102271769A

Abstract

The invention relates to a sporting device (1), in particular a table tennis racket or a golf club, comprising a handle area and an impact area (100) connected to the handle area (200), wherein the impact area (100) is composed at least partially of wood that has been thermally modified.

Description

Sports equipment made of thermally modified wood

The invention relates to a sports device according to the preamble of claim 1.

In many sports equipment with a grip area and a range associated with the handle area especially in table tennis or golf, there is an essential part of the impact area of the material wood. In part, this is due to standard regulations of sports federations, the far more important Grand lies however in the characteristics, which are the material wood own, in particular these are weight, surface condition, elasticity and also strength.

The perception of the course of use of the sports equipment is strongly influenced by the materials used, in particular those in the construction of the striking area. This applies especially to wood as a material and leads to previous attempts to replace the material wood in the field of impact of the sports equipment - are also accompanied by little acceptance - regardless of normative regulations.

Furthermore, sports equipment is usually tuned to the preferences and needs of the user, so that by customization of the sports equipment, an improvement of the usage for a specific user is achieved. In this case, however, material-related limits are set by the material wood, which concern, for example, the weight and the strength of the construction. Moreover, the robustness of the striking area is structurally difficult to achieve by the nature of the wood, the robustness also relates to the weather protection, especially if the sport is preferably practiced outside closed spaces. And in addition, the natural material wood also makes it necessary to comply with special boundary conditions - in particular regarding temperature and humidity. Moreover, the use of high quality woods, e.g. in the form of so-called tropical wood a not inconsiderable cost factor.

Object of the present invention is therefore to improve a sports equipment according to the preamble of claim 1, structurally robust to make and its production inexpensive and easy to enable.

This object is solved by the features of claim 1. Advantageous developments are the subject of the dependent claims. According to the invention, the sports equipment, in particular designed as a table tennis or golf club, has a grip area and a striking area connected to the grip area. The impact area consists at least partially of a wood which has been thermally modified. By thermal modification is generally meant a permanent one

Change of wood properties across the whole of the wood, by increasing the temperature at the same time prevailing low-oxygen atmosphere without the addition of chemicals. Among other things, the choice of the temperature range significantly determines the change in the material properties. Usually temperatures of 140 ⁰ C are exceeded, since from this temperature range, a degradation of hemicellulose begins. However, a preferred temperature range for the thermal modification is the range 170 ⁰ C- 230 ⁰ C. For a modified according to the above-described boundary conditions, wood is among others the name Therrnoholz common.

This wood, in its material properties is changed so that it compared to an untreated wood of the same species has a flexural strength increase of up to 45%, while weight reduction of up to 10%. Moreover, there is an increased resistance to environmental influences, which allows advantageous processing and use of the wood. In particular, the thermally modified wood has a reduced swelling and shrinkage and the compensation moisture is reduced by up to 70%. Likewise, there are advantages in the processing because internal stresses of the wood are degraded during the thermal treatment and an excellent dimensional stability is achieved.

Thus, the use of thermally modified wood according to the invention makes it possible to adapt the course of use to individual needs, to make the construction more robust than conventional wood and to reduce the production costs.

In an advantageous development, it is provided that the thermally modified wood is arranged on the outer visible boundary surfaces of the impact area. Thus, an outer surface is created, which is extremely dimensionally stable and robust and in particular has improved dimensional stability. Furthermore, it can also be provided to extend the use of thermowood on the handle area, so that even this not insignificant for the game area the dimensional stability of the thermally modified wood comes to good. Furthermore, the sports equipment is preferably designed weatherproof. The above-described basic weather resistance of the thermowood by reduced water absorption and low swelling and Schwindmaß offers a cost-effective way with structurally little effort and thus hardly changing the usage process measures to produce the weather resistance of the sports equipment.

In a further development it can be provided that the sports device has a core area which is completely covered with a plastic film. The ratio of the thickness of the film to the thickness of the core region is less than 1: 9 in at least two mutually perpendicular spatial directions. On the one hand, this is one way to design and improve the weather resistance. At the same time, however, it is also possible to produce a special surface finish, for example for the permanent connection of further elements of the impact area. Particularly simple and advantageous, the sheath designed in conjunction with thermally modified wood due to the material properties. Furthermore, the changes in the characteristics of the field of impact of the sports equipment by this shroud are barely perceptible. However, further improvements are conceivable.

In particular, a number of further measures can be provided to adapt the properties of the impact area. For example, the impact area may at least partially have a region made of conventional wood. An embodiment of the invention also does not exclude an extension of the use of conventional woods on the grip area, which may lead under certain circumstances to an improved weight distribution.

In a further development, the impact area consists of several layers. Likewise, this is conceivable for the grip area. Both may require adaptation and tuning of the damping performance of the sports equipment when performing a strike and, moreover, this structure simplifies a purposeful modification of the characteristics of the strike area.

To create further specific customization options and to further reduce the design effort, in this case be provided that the boundary surfaces of the layers are oriented plane-parallel in at least one Raumriehtung. Preferably, the plane-parallel orientation of the layers is perpendicular to a preferred direction of the impact area.

In the case of a layered design, targeted coordination measures prove to be particularly simple. For example, the impact properties of the impact area are adjusted by the material selection of the layer system. In particular, it is conceivable to provide materials with different bending elasticity. And moreover, for example, it is also conceivable that a weight adjustment takes place via the material selection of the layer system.

In an advantageous development, the impact area consists of at least three layers. For example, this may be a thicker compared to the other layers carrier layer, which determines the weight and the strength of the structure substantially. Moreover, at least two further layers are advantageously combined with this carrier layer in order to be able to adapt the damping behavior by material selection in a targeted manner.

Furthermore, it can be provided that the impact area has a layer

Having composite materials, which are known especially by their tensile strength and their low weight. In particular, carbon, aramid or glass fiber prove to be suitable, but also metallic materials such as e.g. Titanium. This allows a stiffer construction with almost unchanged overall weight and therefore contributes significantly to the individual adjustment of the bumping properties of the sports equipment. In particular, the use of these materials is not limited to the impact area. For example, it is also conceivable to equip the grip area with these materials, even in a different form of a layer structure.

A further aspect of the invention is to specify a method for weight reduction of a sports device having a grip area and a striking area connected to the grip area, wherein the sports device is at least partially constructed of wood. This is taken into account by a method according to claim 12, and provides to replace a substantially wood existing area by a section of thermally modified wood identical or lower flexural elasticity, so that a construction of identical or higher bending strength with significantly reduced weight is the result.

A further object underlying the inventive concept is, moreover, to specify a method for increasing the flexural strength of a sports device having a grip area and a striking area connected to the grip area, wherein the sports device is constructed at least partially from wood.

According to the invention this is achieved in a method according to claim 13, characterized in that a substantially consisting of wood area of the sports equipment is replaced by a section of thermally modified wood of the same type of wood.

A further object of the present invention is to provide a method which advantageously ensures a durable and environmentally resistant connection of the materials of the impact area.

This is solved by claim 14 of the invention. Advantageous developments are the subject of the dependent claims.

A method for producing a sports device with a grip area and a striking area connected to the grip area sees in the case of a layered

Structure of the Sehlagbereichs and the at least partial use of thermally modified wood in the impact area before that the compound of the layers at least partially by Heißlamination therefore at temperatures higher than 100 ⁰ C takes place.

It is with this method a way to create a durable durable and especially weatherproof compound of the layers of sports equipment, the method by eliminating or reducing the duration Moreover, possible baking steps by the use of thermowood is much easier.

An advantageous development provides that the application of the uppermost covering layer of the impact area is effected by hot lamination. In particular, this creates a permanent connection, which offers the opportunity to meet increased weather protection requirements.

The invention will be explained in more detail with reference to the accompanying drawings.

FIG. 1 shows exemplary embodiments of sports equipment according to the invention, as

Table tennis or golf clubs.

FIG. 2 schematically shows a possible layer structure of the impact area.

FIG. 3 shows a further performance example of a layer structure of FIG

Impact area.

FIG. 4 shows a further variant of the striking area.

FIG. 5 shows the schematic structure of a table tennis racket

FIG. 6 shows a further exemplary embodiment of a layer construction of the

Field of action of a table tennis racket.

Sporting devices 1 according to the invention, for example in the form of a table tennis racket or a golf club, are shown in FIG. These have a striking area 100 and a grip area 200 connected to the striking area. The design of the impact area 100 is provided according to the invention at least partially with a thermally modified wood. By way of example, in FIG

Embodiment of a table tennis racket shown, which in the handle portion 200 with two handles 201, 202 and whose impact area 100 in the form of a base plate with handle transition areas 220, 230 is executed. This base plate is also part of the grip area 200. Due to the above-described properties of thermowood, there are various advantages for the use, construction and manufacture of a sports device 1 according to the invention.

In particular, compared to ordinary woods a stiffer construction can be achieved with simultaneous weight reduction, which is usually associated with cost advantages in the production. This is particularly important when it comes to the ratio to be achieved between acceleration of the impact area 100 and acceleration of the object to be hit or hit. The change in the perception of the use is limited in the

It is important to point out the intended modifications and, in particular, that the impact sound is almost unchanged by the use of the thermally modified wood.

In an advantageous construction, the thermally modified wood is provided on the externally visible boundary surfaces of the impact area 100. In the case of a table tennis stick, this also particularly advantageously includes the area which is usually covered by a foamed, rubber-like covering. The outer surface thus formed proves extremely dimensionally stable, which opens up design freedom for the internal structure of the impact area 100. Due to the low swelling and Schwindmaßes and the low absorption of compensatory moisture beyond constant characteristics of the impact area 100 are given under all environmental conditions, so that the play characteristics hardly change. In particular, this also applies to periods which correspond approximately to the lifetime of the sports equipment 1, since volatile ingredients and resins have been substantially removed during the thermal modification of the wood. The hydrophobic properties of the thermally modified wood in the form of a compensating moisture content reduced by up to 70% significantly improve the weather resistance. Thus, the arrangement of the thermowood on the outer surfaces of the impact area 100 thus provides a climate buffer, which also provides a basic weather protection.

Moreover, it may be provided in an advantageous embodiment to extend the weather resistance to the entire sports equipment. In particular, it may also be provided to use the thermally modified wood in the grip region 200. An all-weather weatherproof design also means that no new weather-sensitive areas arise due to decomposition. Overall, this contributes to the longevity of the sports equipment.

The weatherproof design in the form of thermally modified wood does not exclude the use of additional measures to achieve the weather resistance. However, the thermal wood offers the possibility of largely dispensing with the use of secondary protection agents in the area of the wood. In particular, it may be provided to arrange the thermally modified wood in the core area or center of the impact area 100, preferably also in addition to the above-described sheathing of the impact area 100 with thermowood. The fungus resistance of the thermally modified wood eliminates the need for impregnation with a fungicidal agent. In addition, it may be provided that a weatherproof coating, e.g. in the field of thermally modified wood, is applied. Due to the basic weather resistance of the thermally modified wood, a significantly lower paint thickness compared to a conventional design can be achieved. Thus, the negative properties of this protective lacquer layer, e.g. Changing the hardness and weight distribution largely avoided, thereby improving the playing properties.

In addition, the use of thermally modified wood reduces the dependence on supplementary weather protection measures. Especially in case of minor mechanical damage e.g. In the area of the protective lacquer layer the weather resistance is still guaranteed. In general, the additives to achieve the weather resistance of a certain volatility, which is reflected on the one hand in a burden on the environment and on the other hand endangering the durability of the sports equipment 1. The use of thermally modified wood, for example on the outer surfaces of the sports equipment 1, in conjunction with weatherproof adhesive and paint materials provides an identical design of the other weather protection measures an improved durability forecast, which is not significantly deteriorated, especially by minor damage. Therefore, it is additionally provided that the adhesive and paint materials used are also designed weatherproof.

Furthermore, as the embodiment in FIG. 4 provides, the weather protection can additionally be achieved by means of a foil 115 -for example made of PU, PVC or PE-which completely surrounds a region of the impact area 100. The thickness of the film 1 15 is negligible compared to the thickness of the coated area. It is preferably between 1 μm and 1 mm and more preferably between 20 μm and 500 μm. Thus, a weatherproof core area is provided, on the outside of which preferably a thermally modified wood 141, 142 is attached, so that a weatherproof complete enclosure of the impact area is formed. The play properties are hardly noticeably changed by the film 115 formed thinly relative to the core region 150, in that the ratio of the thickness of the film to the thickness of the core region 50 is less than 1: 9 in at least two mutually perpendicular spatial directions. And moreover, these characteristics can be adjusted by the configuration of the core region 150. Thus, a unique weather resistance, with respect to a conventional construction almost unchanged impact properties, given.

Furthermore, this film can serve for permanent coating of the impact area 100 and thus form a mounting base for further individual adjustments of the impact area 100. In the case of the table tennis racket shown in Figure 1 in particular the use of the film is provided as a mounting base for a foam material.

Preferably, as an adaptation measure of the impact area 100, it is conceivable that the impact area 100 has at least partially conventional wood. In particular, thermally modified woods have significantly altered material properties, so that the combination with conventional woods the diversity of

Material properties significantly increased again. Thus, a sensitive adjustment is guaranteed. Especially this offers the possibility to adjust the impact characteristics as well as the weight distribution. Therefore, the use of conventional woods is not only limited to the field of impact, but also offers, for example, in the grip area.

As already indicated by FIGS. 4 and 6, provision is made in an exemplary embodiment shown in FIG. 2 for the impact region 100 to be formed from a plurality of layers 110-114. It proves to be advantageous to define a preferred direction for the derivation of forces by a layer system. This is clarified again in FIG. 2, in particular by the illustrated layer structure two preferred directions 131 and 132 set »which show the force deflection in different directions. In particular, the force deflection is determined by the bending elasticity of the layered materials, so that use of the thermally modified wood in one of these layers, for example, opens up the possibility of selectively adjusting the force deflection and preferably increasing the force in the direction of the object to be hammered. In the case of the table tennis rackets shown in FIG. 6, these are preferably the outer layers 112 and 114.

It is particularly advantageous if the boundary surfaces of the layers 112-114 have a plane-parallel orientation in at least one spatial direction 120, wherein the direction of the plane-parallel orientation 120 is perpendicular to a preferred direction 130 of the impact area 100. In addition to the force absorption of the impact area 100 by the guidance and fastening of the grip area 200, it is of decisive importance how the forces on the object to be hit or hit are derived. Due to the plane-parallel orientation, the possibility is provided with the help of the layer thickness to create different flexural elasticity regions, which - in combination - lead to an altered flexural elasticity and bending dynamics through a modified natural frequency spectrum of the overall system. Thus, it can be provided to make an adjustment of the impact properties in a preferred direction of collapse by varying the thickness of the thermally modified wood.

In an advantageous development, it is provided that the adjustment of the impact properties of the layer system 110-114 takes place through the selection of the materials of the system. In particular, at fixed layer thicknesses leads

Use of thermally modified wood usually to an increase in the so-called return height.

In the case of the table tennis racket shown in Figure 1, for example, be provided to carry out the replacement of a wood by a thermally modified wood identical type of wood. This has an increased impact dynamics - which is measurable in the form of an enlarged recess height - the result. Woods with a relatively low specific weight, such as balsa wood, usually have a strong flexural elasticity. This is usually undershot by a thermally modified wood of the same type of wood, so that when replacing a light wood by a thermally modified wood better preservation of the intrinsic momentum of the true or beating object is present, resulting in a more dynamic, harder stroke results. Therefore, a replacement of woods with thermally modified wood of the same wood species can be provided, which in turn leads to a reduction in weight, since the thermal modification process can result in a mass reduction of up to 10%. This can serve, for example, to adapt the impact properties by a suitable material selection.

Further, for example, a replacement of a wood with high specific gravity such as oak, Wenge, Rio-rosewood or Azobe with a density of 600-1200 kg / m ³ by a thermally modified wood of a lighter wood species such as balsa, Ayous or fir with a Bulk density of 100 - 500 kg / m ³ , be provided. The use of the thermally modified wood thus leads to a weight reduction of the construction. The bending elasticity of the thermally modified wood is comparable to wood species, which have a significantly higher specific gravity. Thus, it can be provided, for example, to replace a relatively heavy wood with a lighter thermally modified wood with identical or higher bending strength with almost unchanged construction and unchanged properties. This can serve, for example, to adapt the weight distribution by means of a suitable choice of material.

By these measures, the weight of a table tennis racket of usually 90-14Og for the case of hard woods in the range of 70-110g can be reduced and in the case of soft woods of usually 60-85g in the range 45-75g.

In the case of the golf club shown in FIG. 1, the possibilities described above apply analogously to table tennis rackets. However, it should be noted that when improving a golf club, the main interest is not in weight reduction. Instead, the design of the impact area 100 with a thermally modified wood opens up the possibility of changing the center of gravity of the club, for example by installing additional weights. In many cases, this makes it possible to widen the optimum baffle surface and can contribute to an improved or easier impact movement. In an analogous manner, this is also conceivable for table tennis rackets.

In a further embodiment, the layer system 110-114 - as shown in Figure 3 - consists of at least three layers. In particular, it is advantageous to define a carrier layer 110. This layer, which is usually thicker than the further layers 111-114, is essentially the weight of the Hit area 100 set. When playing table tennis, efforts are made to make this layer as light as possible, while in golf, the achievable total impulse plays a major role and thus very individual weight adjustments of the support layer are provided. Planar parallel to the carrier layer advantageously more layers are arranged symmetrically. In particular, the contact time of the object to be hit or hit with the sports equipment 1 is of crucial importance for the influencing possibilities of the object. Therefore, it is advisable to provide a layer 111 or 1 12, which is designed to increase the above contact time and therefore has a high flexural elasticity. Moreover, to increase the basic stability, a layer 111 or

112 provided, which has a material of high bending stability. Advantageously, this layer has thermally modified wood.

In the exemplary embodiment of FIG. 3, moreover, a symmetrical arrangement of the layers 113 and 114 relative to the layers 111 and 112 is recognizable, so that a total of five layers are shown. This is particularly advantageous if two sides of the impact area 100 are to have identical impact properties.

In an advantageous development it can be provided that the impact 100 or handle region 200 comprises composite materials such as carbon, aramid, glass fiber or titanium. These composites are known especially for their tensile strength. In combination with thermally modified wood, it is possible to put together layers that achieve the bending elasticity of woods with a high specific weight. However, the dead weight of the thermo-wood composite layer is only a fraction of the weight of the replaced wood, which creates enormous potential for weight reduction.

Since the woods with high specific gravity are usually very expensive so-called tropical woods, for which no sustainable management is customary, is a replacement of this type of wood by a thermally modified wood, both a cost advantage created and as well as an amount to conserve resources. The cost advantage should still be feasible even if the tropical wood layer is replaced by a Thermoholzblick, which is supplemented by composite materials.

The above-described adaptation possibilities for increasing the flexural strength or weight reduction are not limited to a stratified impact area 100 of the sports equipment 1 according to the invention. Such is for example Generally conceivable in a method for weight reduction to carry out a replacement of a substantially constructed of wood area with a substantially formed of thermally modified wood section equal or higher bending strength. This usually causes a construction with comparable stability but reduced weight.

Moreover, in a method for increasing the bending strength, it may be provided according to the invention to carry out a replacement of a section constructed essentially of wood with a section of identical type of wood formed essentially of thermally modified wood in a sports device. This opens up the possibility to increase the strength and in particular to achieve a stiffer design of the construction in a simple and cost-effective manner. In particular, the design effort is thereby significantly reduced, since no further structural measures such as, for example, partial thickening or the design of the sports equipment 1 incurred with support elements.

The use of thermally modified wood moreover allows much easier application of a hot lamination process for bonding a layered structure. Hot lamination is usually understood as the melting of an adhesive material at temperatures greater than 100 ⁰ C, added to a certain pressure for the connection of the components of the laminate, which comprises at least two layers.

The thermal modification of the wood used leads to an extremely low water content, as well as the almost complete absence of volatiles and resins. In addition, this wood is extremely dimensionally stable, as among other things, internal stresses of the wood are degraded during the thermal modification. Thus, the tendency to outgassing when reaching temperatures above 100 ⁰ C is greatly reduced, so that there is a simple Heißlaminationsverfahren with high dimensional stability of the laminate.

In particular, it is also possible to produce weatherproof laminate connections, for example by using an appropriate plastic film or weatherproof resin as the adhesive material. Particularly advantageously, in this way, a core area can be laminated in a plastic film, so that a weather protection for this core area is given in a simple manner. However, the hot lamination of the top coat does not exclusively refer to the use of a plastic film.

In the case of table tennis rackets as well as a non-swelling, weatherproof adhesive bond with a foam rubber-like material is conceivable, so that a weather resistance for the adhesive bond of the covering material is achieved.

Thus, according to the invention, the possibility is created to adapt the impact properties of a sports device specifically to the needs of the user and thus to improve weight, to make the sports equipment robust and durable and to keep the production cost.

Claims

claims

1. sports equipment (1), in particular table tennis or golf clubs with a

Handle area (200), as well as a striking area (100) connected to the Griflbereich (200), wherein the impact area (100) consists at least partially of wood, which has been thermally modified.

2. Sport apparatus according to claim 1, characterized in that at least the outwardly visible boundary surfaces of the impact area (100) and / or handle portion (200) made of thermally modified wood.

3. Sport apparatus according to one of the preceding claims, characterized in that the sports equipment (1) is designed weatherproof.

4. Sports device according to one of the preceding claims, characterized in that the sports device has a core portion which is completely covered with a plastic film, wherein the ratio of the thickness of the film to the thickness of the core region in at least two mutually perpendicular spatial directions less than 1: 9th is.

5. Sports device according to one of the preceding claims, characterized in that the impact (100) and / or handle region (200) at least partially a

Has area which consists of conventional wood.

6. Sports device according to one of the preceding claims, characterized the impact area (100) and / or grip area (200) consists of several layers.

7. Sports device according to claim 6, characterized in that the boundary surfaces of the layers (110, 111, 112, 113, 114) are oriented plane-parallel in at least one spatial direction, wherein the plane-parallel orientation (120) of the layers (110, 111, 112, 113, 114) is preferably perpendicular to a preferred direction of compression (130) of the impact area.

8. Sports device according to one of the preceding claims 6 or 7, characterized in that an adaptation of the impact properties by the material selection of the layer system (110, 111, 112, 113, 114) takes place.

9. Sports device according to one of the preceding claims 6 to 8, characterized in that an adaptation of the weight distribution by the material selection of the layer system (110, 111, 112, 113, 114) takes place.

10. Sports device according to one of the preceding claims 6 to 9, characterized in that the impact (100) and / or handle region (200) consists of at least three layers.

11. Sports device according to one of the preceding claims, characterized in that the impact (100) and / or handle region (200) has composite materials, in particular carbon, aramid, glass fiber or titanium.

12. A method for weight reduction of a sports equipment having a grip area (200) and a striking area connected to the grip area (100), wherein the sports equipment (1) is at least partially constructed of wood, characterized in that an area consisting essentially of wood is replaced by a section of thermally modified wood of identical or lower flexural elasticity.

13. A method for increasing the flexural strength of a sports device having a handle portion (200) and a handle portion connected to the striking area (100), wherein the sports device (1) is at least partially constructed of wood, characterized in that a substantially consisting of wood area is replaced by a section of thermally modified wood of the same type of wood.

14. A method for producing a sports device according to any one of the preceding claims 6-11, characterized in that the compound of the layers (1 10, 111, 112, 113, 114) takes place at least partially by Heißlamination.

15. The method according to claim 14, characterized in that the application of an uppermost cover layer of the impact area (100) is carried out by Heißlamination.