EP1004335B1 - Sliding board and method of manufacturing the same - Google Patents

Abstract

A board for sliding on for example snow, comprises a honeycomb type light weight core with numerous hollow chambers bordered by cell walls. The core (4) consists of an extended thermoplastic and the hollow chambers and cell walls are formed by stretching the plastic in the direction of the board thickness.

Description

The invention relates to a gliding board for gliding on snow or another Underground, with a honeycomb-like lightweight core that can pass through a variety of Cell walls have limited cavities. The invention further relates to a method for the production of such a sliding board.

Such a gliding board that a ski, a snowboard or other sports equipment for Gliding on snow, another solid surface or on water can, for example, is described in AT-PS 23 13 23. From this script is a ski with one between an upper and a lower outer plate Lightweight construction known, by a large number arranged side by side and multiple corrugated plastic strips are formed. Because of their wavy The plastic strips touch each other in shape and thus enclose a large number of hollow chambers, the vertical side walls of which they form. This honeycomb structure formed by the plastic strips is with the glued upper and lower outer plate, so that between the two outer plates a weight-saving core, a so-called lightweight core, is created.

However, the stiffness and shear strength of a sliding board of this type are low. The plastic strips are glued to the outer panels Manufacturing process problematic. Different adhesive techniques and Joining process with additional components proposed, but their own weight the weight saving achieved by the cavity structure reduces or even picks.

In view of the described disadvantages of conventional ski constructions in lightweight construction it is the object of the present invention to provide a gliding board, which has a higher rigidity and shear strength and moreover builds easier.

This object is achieved by the combination of features of the claim 1 solved. The core consists of a stretched thermoplastic Plastic and the cavities and cell walls are due to stretching of the plastic shaped in the thickness direction of the sliding board. The through the thermoplastic The core structure produced by stretching is not only inherently more stable than the known one Structure made of corrugated plastic strips, but points to their top and bottom - According to the large contact area of the stretching used Metal components - essential compared to the conventional plastic strip structure larger areas of typically 50% of the full area, which for Gluing with upper and lower chord can be used and any tension that occurs and transfer loads. Therefore, the gliding board according to the invention much more stable against shear or impact loads. in view of the large adhesive surface, no additional fasteners are required. The weight and moment of inertia of a sliding board of this design are extremely small. Such a sliding board is even lighter in practical use rotatable and more maneuverable than known sliding boards according to the prior art Technology.

Preferred embodiments of the invention result from the Subordinate claims following main claim.

Accordingly, it has proven to be particularly advantageous to use thermoplastics from the group polystyrene, polypropylene, polycarbonate, ABS, polyacetate or Select polyethylene terephthalate.

According to a preferred embodiment of the invention, the cell walls extend the honeycomb structure inclined to the thickness direction. This version has compared to the previously known honeycomb structures with vertical Cell walls have the advantage of further increased strength against impact stress and shear.

The top and bottom of the lightweight core is made of the material of the Core and the molded open cavities. The surface preferably exists the top and bottom are less than 80% voids. To high To achieve strength, fill the end faces of the cell walls or integrally with them molded core material preferably more than 30%, in particular more than 40% of the surface of the top and bottom. Typically this is for gluing available area about 50% of the total upper or bottom of the core. For special applications such as Downhill Rennsportski the area of the core material can still be considerably larger than 50% his.

The lightweight core is made of one layer and has the length of the Sliding boards seen different thicknesses. In particular, the core is in the middle of the sliding board is thicker than towards its front and rear ends.

A preferred embodiment provides side walls that are flat with the thermoplastic stretched plastic are glued. These serve for additional Stabilization of the sliding board. The side walls can be advantageous Epoxy fiberglass, wood veneer or temperature-stable thermoplastics and thermosets exist.

Since the thermoplastic stretched plastic encloses a large number of cavities, it is advantageous if in a stretched through the thermoplastic Plastic and partial volume surrounded by cavities is a solid material is incorporated. Such massive materials, for example within in the lightweight core milled channels are used for fastening binding screws or other holding devices more suitable than the one according to the invention, lightweight structure itself with cavities. Thanks to this embodiment the majority of the core volume can be filled in a way that saves material and weight without sacrificing pull-out strength.

In the method mentioned at the outset, the above object is achieved according to the invention solved in that the core from a thermoplastic core blank is formed, which is thermally stretched in the thickness direction such that the Cavities and the cell walls delimiting them are formed. In particular the core blank is placed between two heated plate-shaped tools and brought into contact with them. Once the surface of the core blank both melt and adhere to the plate-shaped tools Plates apart. By flowing the semi-melted plastic the blank is stretched in the thickness direction and the honeycomb structure with the Cavities and the cell walls delimiting them.

According to a preferred embodiment of the invention, the thickness profile of the Kerns formed without cutting. The non-cutting shaping causes damage avoided the honeycomb structure of the lightweight core, such as by Cutting, milling, planing or the like can be effected easily. In particular the thickness curve of the same seen over the length of the sliding board, the usually increases from both ends towards the middle of the board, without cutting into the core formed. The course of the thickness of the core can also in the width direction, in particular its top contour, can be molded without cutting, also special contour designs such as thickening in the bond area can be formed in this way become.

In particular, the course of the thickness can occur directly when the core blank is stretched be formed. The core blank becomes different in the thickness direction severely stretched. For thicker areas, the core blank is made in these sections just pulled stronger, i.e. stretched more in the thickness direction.

The thickness profile of the core can also be formed by the Core blank initially to a substantially cuboid body Thickness is stretched and the stretched body by acting on it Pressure and heat are transformed into the desired thickness profile in a mold becomes. In particular, the core thickness distribution can coincide with the pressing process can be obtained by the stretched core body through the pressing process under pressure and temperature in a suitable form simultaneously with the Pressing the other ski components into the correct core thickness distribution becomes. At the same time for joining the outer layer or the outer layers this is brought to the core in the desired thickness profile.

The previously described execution of the thickness training immediately at Stretching can advantageously also be used for materials that a subsequent formation of the thickness curve by applying heat and pressure not allow or difficult to allow.

Fig. 1:

Einen Querschnitt einer ersten Ausführungsform eines Gleitbretts mit einem Kern aus thermoplastisch verstrecktem Kunststoff,

Fig. 2:

eine weitere Ausführungsform im Querschnitt in Schalenbauweise mit wannenförmigem Obergurt,

Fig. 3:

eine weitere Ausführungsform der vorliegenden Erfindung im Querschnitt,

Fig. 4:

eine Ausführungsform der Erfindung im Querschnitt mit massiven, in den Leichtbaukern eingearbeiteten Werkstoffblöcken,

Fig. 5:

einen Querschnitt durch eine letzte Ausführungsform mit stabilisierenden Seitenwangen und

Fig. 6-9:

eine schematische Darstellung des Herstellverfahrens des Leichtbaukernes.

Further details and advantages of the invention result from the following explanation of preferred exemplary embodiments. Show it:

Fig. 1:

1 shows a cross section of a first embodiment of a sliding board with a core made of thermoplastic stretched plastic,

Fig. 2:

another embodiment in cross section in shell design with trough-shaped upper flange,

Fig. 3:

a further embodiment of the present invention in cross section,

Fig. 4:

1 shows an embodiment of the invention in cross section with solid blocks of material incorporated into the lightweight core,

Fig. 5:

a cross section through a last embodiment with stabilizing side walls and

Fig. 6-9:

is a schematic representation of the manufacturing process of the lightweight core.

In the embodiment according to FIG. 1 there is between the respective multilayer Upper and lower chords of thermoplastic stretched plastic 4 introduced into the core, close off the walls 3 laterally. The top flange of the alpine ski shown here typically consists of layers of epoxy fiberglass 5, aluminum 6 and ABS 7. The side walls 3 are also made of ABS 7, while the tread 8 of the lower flange is laterally surrounded by steel edges. Between the running or sliding surface of the lower flange and the core 4 are layers 5, 6 made of epoxy fiberglass and aluminum.

In Fig. 2, an alpine ski is shown in sandwich construction, the lightweight core 4, the top and side of a trough-shaped upper flange 10 transparent thermoplastic and various epoxy GF prepreg reinforcements 11 is surrounded. The sliding surface 8 again consists of polyethylene, wherein the sliding surface is again bordered by steel edges 9.

The alpine ski shown in Fig. 3 has a lightweight core 4, initially is glued on top and bottom with cover layers 15 with epoxy fiberglass. The so stabilized The core is then in a two-point process step in the polyurethane injection process with a themoplastic cover layer 10 and the lower flange have been connected, both on the side facing the core with Reinforcing inserts 12 are provided. The lower belt has one Slide surface 8 made of polyethylene, which is edged on the side with steel edges 9. The Cover layers of the thermoplastic stretched plastic core 4 preferably exist made of aluminum and technical synthetic fibers such as carbon or kevlar.

Fig. 4 shows a lightweight core 4 with two solid blocks of material 13, the areas are introduced within the pre-milled channels in the lightweight core 4 and alone or with the help of inserts for receiving binding screws or the like serve. Typical core materials for these massive blocks of material 13 are wood, thermoplastics or thermosets.

5, instead of a trough-shaped upper chord, a thicker, preferably inclined side cheek 14 each inserted laterally become. The bonding of flat ski building materials such as epoxy fiberglass, laminates, Wood veneers or temperature-stable thermoplastics or thermosets can at the same time as the core and top and bottom chords are glued or in one own process step.

6-9 is used to manufacture the ones used according to the invention Lightweight cores 4 explained. Fig. 6 shows how sheets made of a thermoplastic Plastic 100 are placed between two heated steel plates 102. Out 7 shows that the steel plates 102 with the surface of the plastic 100 can be brought into contact. Even a little pressure creates an adhesion between the surface of the plastic and the heated plates. From the illustration 8 shows how the two plates 102 move away from one another and how the semi-melted plastic 100 begins to flow. The plastic expands and, as shown in FIG. 9, forms a geometric one uniform core structure, the appearance of which depends on how the surface of the heated plates is structured. The contact surfaces of the metal plates are actually Surface pattern with a variety of cutouts. Examples are conceivable here Rows of squares, circles (as shown here), hexagons, or others geometric shapes. If you create a connection between the forming Openings and the environment, the vacuum breaks at these points together that would otherwise develop. This creates cell walls, to the desired final dimension (the honeycomb height, according to the structure thickness) be stretched. By stretching in the thickness direction, cell walls become formed, which include a plurality of hollow chambers. The cell walls extend from the bottom of the core to its top, d. H. the The top and bottom of the core are connected to each other by the cell walls. US 4,269,586 and US 4,264,293 describe metal components that act as contact surfaces be used for stretching thermoplastic plastic bodies can.

Depending on the ratio between the degree of stretching and the cell diameter the cell walls take different angles to the surface. slanted Cell walls increase resistance to impact and shear stress (Truss effect). Such a structure is with the traditional honeycomb structures cannot be reached with parallel walls. The bending strength of the resulting Structure results from the relatively large remaining original Surface that spreads around the open cells.

The surfaces of such panels are made of approximately 50% solid material. It’s an important differentiator from the previously known honeycomb structures, a certain amount only by applying top layers Achieve bending strength. While the pure stretching is already a flexural strength causes 50 to 100 times that of the extruded starting plate lies, the value can be increased to 300 to 1000 times, if additional Cover layers are applied.

The invention can be used in particular for alpine skiing in the "all mountain" area (skiing on and off the slopes). Build these universal skis in Comparison wider, because stronger waist radii are used here. That would fundamentally lead to a strong weight gain of the ski, which is disadvantageous affects rotatability and maneuverability. Because of the invention Weight reduction, however, can make the rotatability and maneuverability essential be improved. The trend in snowboarding is also towards lightweight construction, because even with snowboarding due to a lighter weight, the turning and Maneuverability can be improved significantly. The inventive one can also be used here Apply solution successfully.

Claims (13)

1. A sliding board for sliding on snow or another surface, with a honeycomb-type light construction core, which has a plurality of hollow chambers defined by cell walls,
   characterized in that
   the core (4) comprises a stretched, thermoplastic plastic and the hollow chambers and cell walls are formed by stretching of the plastic in a thickness direction of the sliding board.
2. The sliding board according to claim 1, wherein the cell walls (16) extend at an incline to the thickness direction.
3. The sliding board according to one of the preceding claims, wherein the core (4) has a non-cutting, formed thickness distribution.
4. The sliding board according to one of the preceding claims, wherein the core (4) is stretched over its length as viewed in the thickness direction in different strengths.
5. The sliding board according to one of the preceding claims, wherein the surface of the top side and/or the bottom side of the core (4) is filled to at least 20 %, preferably to more than 40 %, in particular, approximately to 50 %, by material of the core (4).
6. The sliding board according to one of the preceding claims, characterized in that the thermoplastic plastic is selected from the group consisting of polystyrene, polypropylene, polycarbonate, ABS, polyacetate, or polyethylene-tereftalate.
7. The sliding board according to one of the preceding claims, characterized in that the lateral surfaces of the core are adhered with lateral side plates.
8. The sliding board according to the preceding claim, characterized in that the side walls comprise epoxy fiber glass, wood veneer, or temperature-stabile thermoplastic and duroplastic.
9. The sliding board according to one of the preceding claims, characterized in that in correspondingly excluded hollow chambers of the core, massive core materials, such as wood, thermoplastic, or duroplastic are incorporated.
10. A method for manufacturing a sliding board from a honeycomb-type light construction core (4) with a plurality of hollow chambers defined by cell walls (16) and at least one outer layer, in which the core is molded and joined with the outer layer, characterized in that the core (4) is molded from a thermoplastic core blank, which is thermally stretched in a thickness direction, such that the hollow chambers and the cell walls (16) defining the hollow chambers are formed.
11. The method according to the preceding claim, wherein the thickness distribution of the core is formed to be non-cutting.
12. The method according to one of the preceding claims 10 through 11, wherein the core blank for forming its thickness distribution is stretched in the thickness direction at different strengths.
13. The method according to one of the preceding claims 10 through 12, wherein the core blank first is stretched to a consistent thickness having an essentially square corpus and the stretched body is reformed by impacting with pressure and heath into a shape in the desired thickness distribution, wherein, preferably, the reforming is accomplished simultaneously with the joining of the outer layer.

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