Note: Descriptions are shown in the official language in which they were submitted.
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METHOI) FOR MANUFACTURING BLADES FOR ICE SKATES, AND BLADES
OBTAINED WITH SAID METHOD
The present invention relates to a method for
manufacturing blades for ice skates and to blades obtained
with said method.
Currently, it is known to use cold-rolled carbon steel
(C.70/C.100) or stainless steel as raw material for
manufacturing blades for ice skates. This is done to
prevent the blade frorn having excessive rounding-off on the
punch penetration side and to prevent the steel being used
from undergoing excessive deformations during subsequent
treat:ments in the various production steps. In practice, it
is necessary to increase the toughness and flatness of the
steel by means of the known cold-rolling process.
The steel in sheet form is then blanked by using so-
called "American-style" dies which are equipped with
powe~-ful blank holder<;.
The blanking process always causes microcracks or
microscopic fissures inside the steel which, by expanding
during hardening, often lead to breakage.
Moreover, these microcracks are observed only at the
end of the process, or even in the very last step of the
production of the finished product (the skate), during the
injection of the plastic material in a mold in which the
blade has already been inserted in an appropriately
provi.ded seat in order to obtain supports for a shoe.
The known manufacturing method also entails honing the
blanked blade by means of sand belts with a suitable
machi.ne. This system llows to remove the rounding-off and
the inclined plane formed during blanking and reduces as
CA 02231982 1998-03-12
much as possible the~ microcracks that have formed due to
blanking shear.
Honing compromises the qualities of the product in
terms of dimensions and finish, since it is in fact
impossible to maintain the length and the profile of the
blacle exactly.
The blade, formed as mentioned above, is not very
tough and has various irregularities, especially on its
prolile.
In order to achieve greater strength of the steel and
the sharp edge (for example 55/56 HRC) required on the
profile, it is necessary to austenitize the blade and
therefore subject it to hardening with oil or salt
quenching in order to obtain a chosen hardness (for example
15 62/63 HRC).
The known system for fixing ice-skating blades then
entails subjecting the blade, after the above-mentioned
treatments, to tempering and stress relieving, so as to
achieve flatness of the part, a hardness of 53/54 HRC and
make the material tension-free.
Accordingly, stress relieving in a pack configuration
is performed by bolting to clamps and tempering.
However, the deformation of the perimetric shape is
not eliminated, which often causes problems in the
insertion of the blade in the seat of the injection mold,
cau<,ing breakage of the mold.
The method for manufacturing conventional ice-skating
blades further entails lapping the two sides by means of
lapping machines. The lapping of the two sides of the blade
becomes necessary to remove from the blade the oxide and
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the scale that have formed during hardening.
Lapping is performed by usinc~ abrasive belts supported
by rubber rollers at: a pressure of 2/3 atm: this system
yields good results :in terms of removal of oxide and scale
5 residues from the blade, but at the same time causes a
rounding-off of the profile and alters the thickness of the
blacle.
The altered thickness and the rounding-off of the
blacle sometimes make the blade unusable, thus generating a
lo large number of prodl;lction rejects; in any case, the final
result does not meet the demands of the users of these
products.
The known method for manufacturing ice-skating blades
furt:her entails a chromium-plating process with a nickel
15 baching for adhesion to the hardened metal and a flash of
opaque chromium, used to protect the blade against rust and
at t:he same time give an aesthetic covering.
The known manuiacturing method provides for a final
step which consists in checking the final products and
20 therefore the blades.
As mentioned above, there are many technical
ope:-ations to which the raw material is subjected initially
and to which each bl,~de is subjected subsequently.
Each operation is aimed at achieving an important
25 aspect of the finished product, such as hardness, strength,
dimensions and profile, but at the same time these
treatments produce changes in the material and in the
shape, but most of all in the finish.
This known method therefore entails production rejects
30 which considerably increase the overall cost of the
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finished product; these rejects can be assessed as
constituting 3-4% of the manufactured product.
The aim of the present invention is to solve the
above-mentioned prob:Lems, eliminating the drawbacks of the
s cited prior art, and thus to provide a method which allows
to obtain blades for ice skates having an optimum degree of
finish and at the same time has very low manufacturing
cost:s.
Within the scope of this aim, an important object of
10 the present invention is to provide a method which allows
to obtain blades for ice skates which are free from any
kincl of perimetric deformation.
Another important object of the present invention is
to provide a method for manufacturing ice-skate blades
lS whi,-h have constan1: characteristics, such as to allow
product certification.
Another object of the present invention is to provide
a method which allows to obtain a large number of blades,
all having the same characteristics, and at a low cost.
This aim, these objects and others which will become
apparent hereinafter are achieved by a method for
manufacturing ice-skate blades, characterized in that it
comprises the steps of: continuous unwinding from a band or
pack or the use of a flat sheet of carbon steel, alloy
steels, sintered steels, stainless steel, hardened steel,
tempered steel, straightened steel, satin finish steel with
a preset hardness; cutting said sheet with a laser unit to
obtain a blade; and chromium-plating said blade.
Advantageously, the blade has a perfectly sharp and uniform
cutting edge and means for locking and retaining the
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plastic material that constitutes the support for a shoe.
Further characteristics and advantages of the
invention will become apparent from the following detailed
description of a particular but not exclusive embodiment
thereof, illustrated only by way of non-limitative example
in the accompanying drawings, wherein:
figure 1 is a view of a band in which blades have been
cut by means of a laser unit;
figure 2 is a partially sectional lateral perspective
view of the blade, p<~rtially embedded in the support for a
ShO~! .
With reference to the above figures, the reference
numeral 1 designates a laser source which is used to cut
continuously, i.e., from a band 2 or from strips, blades 3
which can be used for ice skates.
Laser cutting is performed for example on carbon steel
(C70/C100) which is hardened, tempered, straightened, satin
finished with a hardness of preferably 53/54 HRC, which is
cert:ifiable.
Use of this m~lterial allows to achieve a better
quality of the blade 3 than allowed by the known hardening
and tempering treatment, as well as better flatness and
strength of the blacle; advantageously, it is possible to
use steel sheets with a thickness of 3 or 4 millimeters.
Laser cutting aLlows to obtain, directly from the raw
material, the blade ready for chromium-plating and without
rounding-offs caused for example by blanking and lapping as
in t:he methods of the prior art.
Laser cutting also allows to meet all demands as to
dimensions, such as length, width and thickness of the
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blade, simultaneously eliminating any kind of perimetric
deformation; this in practice is not possible with the
meth.ods used in the cited prior art.
Use of the source 1 and of the corresponding cutting
of the band 2 allows to modify and/or customize the
material, acting in i.ndividual points or on complete parts,
obta.ining the blade in a short time and with very low
cost.s.
Another characteristic is the high quality of the
lo blad~e: production of high-quality ice-skating blades in
fact: no longer requires investments in machines for
blanking, sand belt<; and equipment of various kinds as
previously mentioned in the prior art; moreover, with the
described technology it is possible to obtain a high-
qual.ity product witll a blade provided with a perfectly
shar-p and uniform cutting edge, without alterations in the
material and shapes, which perfectly meets the demands in
terms of dimensions .~nd profile, all this being obtainable
in a very short time.
The blade thus obtained also allows to give the end
use:r a tool which fully meets the requirements and
expe~ctations, also a:Llowing to introduce products having a
given certification. The certification can be provided
throughout production and can relate to the hardness of the
mate.~rial of which the blade is made and the final treatment
to which it is subjected, thus ensuring the absence of
deformations or microcracks or rounding-offs or other
drawbacks noted in the prior art.
Advantageously, the blade can be obtained so as to
also provide means for locking and retaining the plastic
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material, designated by the reference numeral 4, that
constitutes the support 5 for a shoe. Such means are
constituted by suitable undulated regions 6 formed at
suitable recesses 7 Iefined on the edge of the blade that
does; not interact with the ice.
It has thus been observed that the invention has
achieved the intended aim and objects, a method having ~een
provided which allows to obtain ice-skate blades of high
quality, in a short time and at a low cost, with a
lo periectly sharp and uniform cutting edge, without
alterations in the material and in the shape and which
peri-ectly meets the demands of the user in terms of
dimensions and profile.
The present invention is of course susceptible of
numerous modifications and variations, all of which are
within the scope of t:he same inventive concept.
Thus, for example, the number of blades obtainable
from the individual band can be the most pertinent
according to specific: requirements. The same applies to the
cutling technique whereby the laser source can be
cont:rolled by a numeric-control device in order to optimize
the material so as to obtain a large number of blades with
a very low waste of material.
The type of steel may of course also be the most
pertinent according to specific requirements, like the
shape and the dimensions of the blade; likewise, it is
possible to use carbon steel or sintered steel or alloy
steel or stainless steel.
