DE102007048562B4 - Water sports equipment, in particular water ski or surfboard - Google Patents

Abstract

Water sports board (10, 50), in particular water ski or surfboard, with a core area defining the volume of the board and with a closed jacket surrounding the core area, which is essentially made of a fiber composite material, wherein at least the jacket area consists of a carbon fiber fabric (31 ) and the core region enclosed thereby is substantially hollow and wherein the cladding region is reinforced by one or more aramid fiber layers (32), characterized in that the aramid fiber layers (32) are attached to an upper side of the water sport board (10, 50). not quite reach to the longitudinal edges, while at an underside of the board, the aramid fiber layers (32) are laid down in rounded edge portions of the water sports board (10, 50).

Description

The present invention relates to a water sports device, in particular a water ski or a surfboard, and the construction of a water sports device having the features of the preamble of independent claim 1.

The first known board-shaped surfboards, water boards, water skis, etc. that served water sports were stiff and heavy and often had hard outer surfaces. Later, more and more synthetic materials were used to make lightweight boards. For example, boards were made of a plastic core wrapped with resin-impregnated material to prevent water from being absorbed. The hard outer skin of conventional heavy boards offered good resistance to bending forces, whereas due to the bending and torsional forces repeatedly encountered in water sports, the light boards are sometimes broken quickly.

The DE 31 29 007 C2 describes a conventional fiberglass-reinforced synthetic water ski and a method of making the same. The cavity between the mating shells can be filled with plastic foam, for example. DE 83 28 489 U1 and DE 33 35 974 A1 show pairwise to be used so - called dolphin - water skis, which have movably mounted large fins on their underside. The floats are fully foamed with GFK.

The FR 26 38 374 A1 shows an arrangement by which a board of several layers of plywood obtains advantageous qualities in terms of strength and flexibility. The board consists of five layers of plywood, which are each arranged so that the wood fibers of adjacent layers are perpendicular to each other and a layer of carbon fiber or Kevlar. The arrangement is preferably intended for use in skateboards (with or without sails) and snowboards, but can also be used for swimming boards.

The EP 783 429 B1 discloses an improved water sports board having an elongated core made of a low density filler material (e.g., extruded polystyrene foam or the like) and enclosed by a highly stable composite skin. Between the composite outer skin and the core, an elastic, impermeable layer is arranged.

The DE 296 20 466 U1 describes a Wasserwanderlaufski, which consists of two non-rigidly coupled together floats. As the floating body, a hollow body made of plastic or other material is used, which may be filled. JP 11079075 AA shows a water ski consisting of a main body, bindings and a fin. The main body includes a longitudinally oriented core material consisting of a hollow body of aluminum. The main body is enclosed by a surface layer reinforced with carbon fiber.

From the JP 10165559 AA is a very lightweight sports board known that meets great mechanical requirements. The core material again consists of foamed plastic between a lower layer and an upper layer, the layers being made of a textile material previously impregnated in epoxy resin. DE 198 53 265 C1 shows a multilayer sliding board with a weight-saving core stretched in the direction of thickness thermoplastic. Between the running or sliding surface and the lightweight core layers of epoxy fiberglass and aluminum are arranged.

The FR 27 87 088 A1 describes a surfboard that is sandwiched. It consists of a calibrated core of soft foam, for example polystyrene and a skin, for example of glass fiber or carbon fiber. The skin is additionally impregnated with an epoxy resin. Subsequently, this polymerization and flattened under vacuum. In order to control the flexibility, carbon fiber reinforcements may be used which are oriented in one direction. The board is further protected with a layer of protective paint against ingress of water.

The DE 601 09 725 T2 discloses an assembly for manufacturing a Gleitschwimmkörpers. The assembly includes a wall that extends in the longitudinal direction of the float. It is used for reinforcement and can be made of foam or wood.

The DE 197 41 917 A1 discloses a method for producing a shaped article. For reinforcement, the molding has a core made of foam or similar material. The core is covered with a laminate layer on which a thermoplastic film is applied.

Next discloses the DE 30 40 791 A1 a surfboard with a reinforcing unit. The reinforcing unit has a web extending in the longitudinal direction. The surfboard is made of plastic and is produced by extrusion blow molding.

The DE 100 36 185 A1 describes a method for producing a composite material from a particle foam made of a thermoplastic Plastic and at least one associated with this layer.

The DE 10 2005 037 386 A1 shows a pneumatic body having a compressed air acted upon lust and gas-tight flexible cavity-forming envelope. The shell is made of plastic sheets or foils. The US 2006/0178061 A1 describes an arrangement to be used on the water consisting of a foamed core within which a hollow structure is arranged. On the surface are structured fibers, for example. Fiberglass fibers, carbon fibers or thermoplastic materials.

Another problem with the lightweight boards with a hard porous skin is that the boards are essentially very stiff. As a result, these boards are generally easily fragile, which entails an enormous risk of injury.

In water sports, water sports enthusiasts generally prefer "soft" water skis with a good flex value for better performance. To give these desired properties to conventional water skis, these are often made "softer" by drilling to increase the flexibility of the board. However, these holes pose a great danger. Since the board is deliberately weakened at the drilling points, there is an increased risk of breakage. The boards may break during use, u. z. preferably between the bonds or at the points where the bonds begin.

For this reason, the object of the present invention is to provide a water sports device which is lightweight, has controlled flexibility and is free from breakage. Furthermore, it should be possible to design boards with specific flexibility characteristics according to customer requirements and to reproduce exactly

This object of the invention is achieved with the subject matter of the independent claim. Features of advantageous developments of the invention will become apparent from the dependent claims.

The invention relates to a water sports device, in particular a water ski or a surfboard. The invention will be described primarily with reference to a water ski, but is equally applicable to other board-type water sports equipment and sports equipment.

A water ski according to the invention is produced at least in its mantle region essentially with carbon fiber fabric. This is a web of industrially produced fibers made from carbonaceous raw materials, which are converted by pyrolysis into graphitic carbon. In this case, isotropic and anisotropic fibers can be produced. Technically important are the anisotropic fibers, which have high strengths and stiffness with low elongation at break. Carbon fibers are electrically very good and thermally conductive little. They have a negative thermal expansion coefficient in the longitudinal direction. When heated, they are therefore shorter and thicker. Another advantage of the carbon fiber fabric is that it is particularly lightweight with high strength. In addition, the elastic properties can be defined very precisely by varying the layers of fabric in terms of fiber orientation, their density, their thickness and number. These properties can be found in industrial, d. H. reproduce very precisely during automated production with precisely manufactured fabric blanks so that a series production with very little scattering of the mechanical properties is possible.

The water ski generally has the conventionally known shape. For example, the water ski is bent up at the front end and has a soft rubber cuff or corresponding bindings in which the feet find support. The guiding of the water ski is ensured by a small fin on the underside of the board in the back area.

The invention is applicable to different versions, for example. In those in which the athlete stands on two parallel water skis. Preferably, the invention relates to a so-called. Monoski in which the athlete stands with both feet on a board. The monoski consists of only one ski with fin, on which behind the binding a simple loop for the second foot is attached. Optionally, a second binding, similar to the front binding may be provided. The underside of the monoski is generally curved inward in the middle of the length.

The water ski according to the invention, in contrast to the conventionally known Monoskiern preferably has no foam core, but is hollow inside. Of course, optionally, a foam core o. The like. Be present, which is enclosed by a cladding region impregnated with epoxy resin carbon fiber fabric. The ski can be very stable and at the same time very light. The ski can be individually adapted to the needs of the customer, as the desired flex value can be set individually.

The mantle area of the board is reinforced by layers of aramid fibers. This very much Tear-resistant aramid fibers reliably prevent all breakthroughs of the board, for example, in its failure in case of overload. The aramid fibers may optionally be embedded in the epoxy resin and / or in the region of the fabric layers of the carbon fiber fabrics.

According to the invention, the water ski between the carbon fiber fabric layers comprises a layer of aramid fibers or aramid fabric. Aramid fibers are golden yellow organic synthetic fibers. The fibers were marketed under the brand name Kevlar. The fibers are characterized by very high strength, high impact strength, high elongation at break, good vibration damping and resistance to acids and alkalis. They are also very heat and fire resistant. Because of their tensile strength and low weight aramid fibers are often used in sports equipment, such as the suspension lines for paragliders, for sail sailboats and surfboards or as strings for tennis rackets. In the context of the present invention, the layer of aramid fiber serves as additional security to prevent breakage of the board and thus injuries during use of the water sports equipment (usually only in case of overload or misuse, because normally it does not break) to avoid ,

The inner cavity can optionally be divided by several longitudinal webs into a plurality of hollow chambers. The bars are made of resin-reinforced carbon fiber fabric. But there are also variants without such longitudinal webs possible. Optionally, instead of closed bar profiles and open profiles with openings, individual column sections o. The like. Serve as longitudinal webs. The longitudinal webs can also be designed in each case as raised profile strips of defined height on the upper and / or lower inner side of the jacket region. These longitudinal webs thus form no connection between the top and bottom of the board. Numerous other variants are conceivable and possible. There are two, three or more such longitudinal webs conceivable. In addition, transverse webs may be provided, optionally also in a closed or open embodiment. With closed longitudinal webs and closed transverse webs a plurality of each closed chambers are formed, which can reliably prevent sinking in the water in case of breakage of the board.

However, the mentioned webs - with or without connection between the top and bottom of the board - offer many significant advantages of the ski according to the invention. The webs can, for example, be replaced or supplemented by regularly arranged columns connecting the top and bottom. It is also possible, only at the top or only on the underside or on both inner sides to install webs lesser height, which are not connected to the other side and thus do not form closed chambers. Such webs of defined height, material thickness and fiber structure serve to increase the flexural rigidity, as would, for example, also allow beads or stiffening webs in steel or metal construction. Last but not least, the webs also serve to define the elasticity and the deformation behavior of the board over its length and width very accurately and to make it reproducible as accurately as possible during repeated production.

The preparation of the water sports equipment, in particular water skis, according to the known state of the art, for example, in a suitable mold, which dictates the length and shape of the ski. This mold can consist of different materials, such as. From CFRP plastic material, which makes it very wear. With such a mold, a large number of skis can be made before the mold must be renewed. The impregnated with epoxy resin carbon fiber fabric is inserted into the mold. Between the upper layer of carbon fiber fabric, which forms the top of the board and the lower layer of carbon fiber fabric plastic hoses can be inserted. Between these plastic hoses comes resin-impregnated carbon fiber fabric for transverse webs or longitudinal webs, which is connected to the upper and the lower fabric layer and gives the board additional stability. Then the prepared arrangement comes into an oven. There, the temperature and pressure within the plastic hoses are increased in a controlled manner so that they inflate and the impregnated carbon fiber fabric attaches itself to the mold, thus assuming exactly the desired shape. Subsequently, the mold with the ski thus produced is taken out of the oven and the ski cools down in the mold. Since preferably both the mold and the ski made of very hard CFK material, no thermal expansion takes place, so that a board can be accurately reproduced. This is one of the major advantages over conventional water skis. These are often cured outdoors, which can lead to a distortion of the board. The preference for each board can be different and unpredictable, so that no identical water skis can be made.

The water sports board according to the invention is especially reproducible because each item previously exactly (with cutter) in an identical form (identical orientation, layers, etc.) is produced and when inserted into the form fits only in a single position (comparable to a puzzle). The blanks, the order and position of the blanks when inserting into the mold and the structure of the individual layers and layers is always fully documented and therefore exactly reproducible. The shape then prevents any distortion, which can guarantee the exact reproducibility.

The carbon fiber-made skis can be adjusted exactly to the needs of the water sportsman. For example, the webs described above in the interior can be made thicker or thinner, also the number of webs used can be varied accordingly. Furthermore, the selection of the carbon fiber fabric used plays a crucial role, since, for example, by changing the direction of the fiber, the location and the strength of the flex value can be specifically influenced. Another variable factor is the density of the fabric used. For example, in certain areas on the top or bottom or in the sidewalls, more or fewer layers of carbon fiber fabric may be used to provide the desired flexibility desired. More or less layers can be used. In addition, a variation of the orientation and / or the material (for example, also mixed with aramid) can be selected. Thus, the Flex value is variable according to need and customer request, but can also be reproduced exactly.

This is particularly advantageous because many water sports professionals train at several locations and do not always want to take their sports equipment, but want to deposit devices with as exactly the same properties at these different training locations. In the conventional boards, this exact reproducibility is not given due to the above-described distortion during curing, so that each board has its own characteristics. Although the differences can be very small, but feels a professional even these small differences as disadvantageous.

After curing of the board, the additional components are attached. These include, on the one hand, the adjustable fin for control and devices for attaching the bindings. The fin consists of a dimensionally stable, corrosion-resistant material, for example. Of light metal or carbon and may have different shapes. In general, the fin has a rounded shape. The fins are adjustable (in the direction of travel and in height). The fin is attached in the back of the water ski on the bottom, for example, the fin is screwed or glued. As a rule, there is a glued box made of machined aluminum or CFK plastic glued to the ski. The fin itself is usually clamped, for example by means of two or three screws. The fin can be adjusted or removed from the fin box when the clamp is released.

Furthermore, fastening devices for the bindings are provided in the middle region. Preferably, such binding plates are not attached directly to the ski but via intermediate means, for example via Velcro fasteners, bolts or the like, which are, for example, glued attached. For example, a type of hook-and-loop fastener (eg, 3M dual-lock) may be used, which is adhered to the board and to which the bindings are then attached via a corresponding adhesive surface ("backslide"). Another alternative is the use of so-called "studs" or "click bonds", which are also glued to the board and with which a plate can be screwed, on which the bonds are or a glued thin steel plate with threaded bolt.

Another advantage of this water sports equipment is that due to the material used, the life is virtually infinite, while conventional water sports equipment must be replaced in general after a certain period of use. Conventional skis are softened after a limited time (see Alpinski), because the foam core crumbles. The foam core hardens - even inside, d. H. in the absence of light irradiation - over time and tends to break or decay, thereby affecting the structural strength of the board. Under heavy load - for example, in professional use - therefore, the boards age very quickly and are often "softened" after less than two years and can no longer be used under competitive conditions, as the properties suffer and worsen. Another disadvantage of the foam core is due to the fact that in all cracks and damage occurs water, causing the foam core fully sucks, significantly increases in weight and rotted after a long time.

Due to the stable high quality material used, the walls of the water sports equipment can be made relatively thin. Furthermore, the water sports device according to the invention preferably contains no foam core, as it is used in many conventional boards or water skiing. As a result, a huge reduction in weight is possible.

The invention is conceivable for a large number of variants and modifications which make use of the inventive idea and therefore also fall within the scope of protection. In particular, the invention is suitable for the production of other water sports equipment (surfboards o. Ä.) And should include these.

In the case of surfboards, for example, there is the additional requirement that they should not sink in the event of a break, crack in the wall o. Ä., As the board also serves the athlete as a survival board to which he can hold on and thus save. Boards of carbon fiber fabric impregnated with the resin of the invention and reinforced with aramid should have no breaks, cracks, etc. As an additional safeguard, however, further transverse webs can serve in the interior of the board, which allow a further subdivision into smaller hollow chambers. In the case of a crack, the area into which water can penetrate would thus be locally limited, so that not the entire board inside can run full and thus sink.

Other features, objects and advantages of the present invention will become more apparent from the following detailed description of a preferred embodiment of the invention given by way of non-limiting example and with reference to the accompanying drawings. The same components in principle have the same reference numerals and will not be explained several times.

1a / b generally show the shape of water ski with fin and bindings (known prior art);

2a / b / c show a cross section through a water ski constructed according to the invention;

3a / b show two embodiments of a partially cut-open surfboard 50 of inventive construction

A possible embodiment of a water ski 10 corresponds in the outer structure known from the prior art water ski and is based on 1a / b illustrated.

The water ski 10 has a board shape. The front end 20 is tapered, rounded and slightly bent upwards. In the middle area 24 The water ski has devices for attaching bindings 26 on. In the back area is a fin 22 appropriate. The back area 22 can have different shape. For example, the rear area 22 also taper to the rear and complete rounded.

The Finn 22 For example, consists of a stainless steel, for example. Of a light metal or salt water resistant stainless steel material. The fin can also be made of another corrosion-resistant, dimensionally stable material, for example. From a CFRP material. The fin may have the shape indicated in the drawings or - for example, depending on the customer - be designed differently.

As bonds 26 can - as in 1b shown - the conventionally known bindings in ski boot-like shape or simplified bindings in loop form o. Ä. Are used.

The 2a / b / c show a cross section of a water ski according to the invention 10 , And indeed, the water ski at the interface A (see. 1b ) cut open. The water ski 10 consists of a resin impregnated carbon fiber fabric reinforced in sections with aramid fibers 30 , The structure of the board in the area of the top and bottom is based on 2c shown. There you can see that between several layers of carbon fiber fabric 31 at least one layer of aramid fiber fabric 32 is integrated. The reinforcement by means of the layer of aramid fabric 32 serves the additional resistance to breakage, as breaking through the board can be additionally prevented by the integration of the fabric layer of break and tear-resistant material.

The cross-sectional view of 2 B shows a possible distribution of longitudinally oriented aramid fiber layers 32 in the area of the top and bottom of the board. At the top, the aramid fibers are enough 32 not quite to the longitudinal edges, while at the bottom of the board the aramid fibers 32 are laid in the rounded edge sections.

The water ski according to the invention 10 is in the longitudinal direction several times in hollow chambers 40 divided. The demarcation between the different chambers 40 done with bars 36 made of resin-impregnated carbon fiber fabric 31 consist. The bridges 36 Both with the upper layer and with the lower layer aramid fibers reinforced carbon fiber fabric 30 be connected. In the chambers 40 are the remains of the plastic tubes used in the manufacture of the board (not shown), which do not interfere with the properties of the board and also lead to no significant additional weight. For this reason, the tubes do not become out of the chambers after manufacture 40 away.

The 3a and 3b show a surfboard 50 in that of resin impregnated aramid fiber reinforced carbon fiber fabric 30 was produced. According to the in 2a / b / c illustrated construction of water skiing 10 is the in 3a illustrated embodiment by means of longitudinal webs 36 into several hollow chambers 40 divided. In the 3b illustrated embodiment is also by further transverse webs 38 in several small cavities 41 divided up. The longitudinal webs 36 and the crossbars 38 each consist of resin-impregnated carbon fiber fabric 31 , This is an additional safety factor. Should the board 50 have a crack, the water would be limited only locally in the corresponding chamber 41 penetration. This will prevent the board 50 fully sucks and goes down.

In a relatively simple way, a variant with a continuous crossbar can be realized. In each case hoses are inserted from the front and from the rear, which are separated by the cross bar.

The invention is not limited to the above embodiments. Rather, a variety of variants and modifications are conceivable that make use of the inventive concept and therefore also fall within the scope.

LIST OF REFERENCE NUMBERS

10

Water-skiing

20

curved tip

22

fin

24

Area where bindings are located

26

bonds

30

resin impregnated aramid reinforced carbon fiber fabric

31

resin impregnated carbon fiber fabric

32

Aramid layer

36

Longitudinal webs (resin impregnated carbon fiber fabric)

38

Transverse webs (resin impregnated carbon fiber fabric)

40

chamber

41

chamber

50

surfboard

Claims (5)

Water sports board ( 10 . 50 ), in particular water ski or surfboard, with a core region defining the volume of the board and with a closed jacket surrounding the core region, which is essentially made of a fiber composite material, wherein at least the jacket region consists of an epoxy resin-impregnated carbon fiber fabric ( 31 ) and the core region enclosed thereby is substantially hollow and wherein the cladding region is formed by one or more aramid fiber layers ( 32 ), characterized in that the aramid fiber layers ( 32 ) on a top of the water sports board ( 10 . 50 ) do not extend all the way to the longitudinal edges, while at a lower side of the board the aramid fiber layers ( 32 ) to rounded edge portions of the water sports board ( 10 . 50 ) are laid. Water sports board according to claim 1, characterized in that the carbon fiber fabric ( 31 ) Has reinforcements of aramid fibers. Water sports board according to claim 1 or 2, characterized in that the aramid fibers are embedded in the carbon fiber fabric of the shell region. Water sports board according to one of the preceding claims, characterized in that the hollow core area by at least one longitudinal web ( 36 ) into several hollow chambers ( 41 ) is divided. Water sports board according to one of the preceding claims, characterized in that the hollow core area by at least one transverse web ( 38 ) into several hollow chambers ( 41 ) is divided.

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