LIGHT STRUCTURAL CORE AND METHOD FOR THE PRODUCTION THEREOF

NOYAU LEGER ET SON PROCEDE DE PRODUCTION

English Abstract

The invention relates to a light structural core made of wood for sliding
bodies, for example skis, especially cross-country skis, having grooves or
slots (3) arranged in the longitudinal rows, extending in lines in a staggered
manner in the longitudinal direction of the skis. The grooves or slots (3) are
only open towards the running surface. When seen from a longitudinal section,
said grooves or slots are shaped like the arc of a circle or are provided
lengthwise with rounded corners.

French Abstract

L'invention concerne un noyau léger en bois pour des corps de glisse, par exemple des skis, notamment des skis de fond, présentant des rainures ou des fentes (3) placées en lignes longitudinales, s'étendant dans le sens longitudinal du ski et décalées les unes par rapport aux autres par files. Selon l'invention, les rainures ou les fentes (3) ne sont ouvertes de préférence dans la zone des fixations qu'en direction de la surface de glisse et sont réalisées en coupe longitudinale avec des coins arrondis de manière allongée ou en arc de cercle.

Claims

CLAIMS
1. A light-weight construction core made of wood for a ski
having a binding region and a running surface, including grooves
or slits (3) arranged in longitudinal rows, wherein the grooves
or slits extend longitudinally along the ski and are offset row-
wise relative to each other, characterized in that the grooves
or slits (3) in the binding region are formed to be open towards
the running surface only, and when viewed longitudinally, are
designed to be circular-arc-shaped or elongate having rounded
corners.
2. A light-weight construction core according to claim 1,
characterized in that the grooves or slits (3) of the neighboring
groove rows are offset by half the groove length relative to each
other.
3. A method for the production of a light-weight construction
core according to claim 1 or claim 2, characterized in that the
grooves or slits, which extend longitudinally along the ski, are
made by moving circular saw blades into the core material to a
maximum depth which is lesser than the thickness of the wood.
4. A method according to claim 3, characterized in that after
having moved the circular saws into the core material, said
circular saws are moved longitudinally along the ski by the
length of the grooves to be produced.
5. A method according to claim 4, characterized in that the
neighboring groove rows are offset relative to each other
longitudinally along the ski.
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Description

CA 02451322 2008-06-11
Light Structural Core And Method For The Production Thereof
The invention relates to a light-weight construction
core made of wood for a ski having a binding region and a
running surface.
The light-weight construction core is particularly
usable to be incorporated in alpine skis, cross-country
skis, jumping skis and other types of skis or the like
sliding bodies.
A further object of the invention is a method of
producing the light-weight construction core.
So far, honeycomb-type cores have been used for
reducing the weight of ttle subject skis.
From AT 231 323 B a ski has become known in which
a core consisting of a honeycomb core material with
cell foils provided in vertical position, is arranged
between a supporting top and a supporting bottom cover
sheet, the cel?. foils which are made of a corrugated
material being oriented parallel to each other and to
the lontigudinal ski axis and extending over the entire
height of the ski core. The corrugated foils not on1_y
render the production of the ski lnconvenlent, but it
has also been shown that such a ski will meet the de-
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CA 02451322 2006-08-17
mands made thereon in terms of torsional stiffness and
flexural strength only if certain specific construction
features are provided; particularly so in case of a
cross-country ski.
From DE-OS 19 16 043, a construction part for a
ski designed as a foamed body has become known which
has recesses which are already left clear during the
production of the foamed body by insertion of cyl-
indrical elements and do not have an offset arrange-
ment.
From DE 36 39 411 Al, a ski core has become known
which consists of side coats of a synthetic or plastic
material, and a composite insert made of wood, which is
provided with incisions from both the top and bottom
sides and which is elastically compressible in trans-
verse direction so as to obtain a ski with a waist.
On the other hand, the present invention has as
its object to provide a light-weight construction core
which has good strength properties with a high reduc-
tion of weight, and which, moreover, makes it possible
to anchor binding screws on the remainder of the core
surface.
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CA 02451322 2007-08-29
According to the invention, this object is achieved
by a light-weight construction core made of wood for a
ski having a binding region and a running surface,
including grooves or slits arranged in longitudinal rows,
wherein the grooves or slits extend longitudinally along
the ski and are offset row-wise relative to each other,
characterized in that the grooves or slits in the binding
region are formed to be open towards the running surface
only, and when viewed longitudinally, are designed to be
circular-arc-shaped or elongate having rounded corners.
Further features of the invention will be ex-
plained in more detail by way of the drawings in which
two exemplary embodiments of the subject matter of the
invention have been illustrated.
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CA 02451322 2003-12-23
Fig. 1 shows a middle cross-section of a double
core in the direction of arrow I-I of Fig. 2;
Fig. 2 shows a bottom view of the core according
to Fig. 1 in the direction of arrow II-II;
Fig. 3 shows a section in the direction of the ar-
row III-III of Fig. 2;
Fig. 4 shows a cross-section of a double core sim-
ilar to the embodiment according to Fig. 1, wherein the
adhesive bonding of the individual boards is indicated;
and
Fig. 5 shows a section according to line V-V of
Fig. 4.
In Fig. 1, a double core is indicated by 1 which
is adhesive-bonded of lamellae extending in the longit-
udinal direction of the ski. From the running surface
side, grooves 3 or slits, respectively, are cut into
the core 1, preferably by incisions made by means of a
circular saw, which grooves are arranged in successive
rows 4 extending parallel to the longitudinal axis A-A
of the ski, the successive grooves 3 having equal
lengths and, in the present case, being offset by half
a groove length relative to the grooves of the neigh-
boring row. By moving the saw blade or the saw blades,
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CA 02451322 2003-12-23
respectively, in parallel to the longitudinal axis A-A
of the ski, or in the longitudinal axis of the latter,
respectively, as shown in Fig. 3, elongate grooves hav-
ing rounded corners 2 are produced. Of course, it is
also possible to move the ski relative to the saw blade
in the longitudinal direction of the ski. What is es-
sential is that when making grooves extending in lon-
gitudinal direction of the ski, both, a relative
movement between ski and saw blade in the longitudinal
direction of the ski takes place, and also the circular
saw carries out a longitudinal movement in the opposite
direction.
The offset of the grooves can be made in any other
relationship, uniformly or non-uniformly. In this way,
the grooves will be interrupted by the core material
either in periodical or in statistical distances, so
that with an optimum reduction of the ski weight, there
will be a sufficient gluing area for the fastening of
belts on the running side, running surface coatings
and/or the like, wherein the side walls delimiting the
core may be made thicker than the intermediate walls of
neighboring grooves so as to attain a lateral pressure
stability relative to the transverse axis of the ski
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CA 02451322 2003-12-23
and the longitudinal axis of the ski.
As shown in Fig. 3, the grooves extend in the lon-
gitudinal direction of the ski and have rounded corners
2.
In the embodiment of the light-weight construction
core according to Figs. 4 and 5, the lamellae which are
adhesive-bonded to each other are denoted by 6.
In this embodiment of the light-weight construc-
tion core, the grooves 3, as shown by Fig. 5, are semi-
circular in shape and are formed by simply moving the
circular saw into the core 1. The grooves may, of
course, also be sector-shaped.
In the double core illustrated, a massive longit-
udinal web 7 is provided in the middle region which has
twice the width of the lamellae 6 and, when parting the
core into individual cores 1', 1", as indicated by dot-
and-dash lines, is cut apart.
Within the scope of the invention, of course, also
various structural changes may be made. Thus, it is
possible to fill the grooves in the region of the screw
fastenings with a material in which binding screws or
the like fastening means can be introduced.
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Representative Drawing