EP0919262A1

EP0919262A1 - Method for manufacturing blades for ice skates, and blades obtained with said method

Info

Publication number: EP0919262A1
Application number: EP98104127A
Authority: EP
Inventors: Corrado Menegazzo
Original assignee: K & K Srl
Current assignee: K & K Srl
Priority date: 1997-11-26
Filing date: 1998-03-09
Publication date: 1999-06-02
Also published as: CA2231982A1; ITTV970165A1; IT1297299B1; ITTV970165A0

Abstract

A method for manufacturing ice-skate blades and blades obtained with the method, the method entailing the continuous unwinding from a band (2) or pack or the use of a flat sheet of carbon steel, alloys steels, sintered steels, stainless steel, hardened steel, tempered steel, straightened steel, stretched steel with a preset hardness, and the cutting of the sheet with a laser unit (1) to obtain a blade (3) which is subsequently chromium-plated.

Description

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 from having excessive rounding-off on the punch penetration side and to prevent the steel being used from undergoing excessive deformations during subsequent treatments 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 powerful blank holders.
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 provided 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 machine. This system allows to remove the rounding-off and the inclined plane formed during blanking and reduces as 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 blade exactly.
The blade, formed as mentioned above, is not very tough and has various irregularities, especially on its profile.
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 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, causing 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 the scale that have formed during hardening.
Lapping is performed by using 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 residues from the blade, but at the same time causes a rounding-off of the profile and alters the thickness of the blade.
The altered thickness and the rounding-off of the blade sometimes make the blade unusable, thus generating a large number of production 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 further entails a chromium-plating process with a nickel backing for adhesion to the hardened metal and a flash of opaque chromium, used to protect the blade against rust and at the same time give an aesthetic covering.
The known manufacturing method provides for a final step which consists in checking the final products and therefore the blades.
As mentioned above, there are many technical operations to which the raw material is subjected initially and to which each blade is subjected subsequently.
Each operation is aimed at achieving an important 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 which considerably increase the overall cost of the 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 problems, eliminating the drawbacks of the 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 costs.
Within the scope of this aim, an important object of the present invention is to provide a method which allows to obtain blades for ice skates which are free from any kind of perimetric deformation.
Another important object of the present invention is to provide a method for manufacturing ice-skate blades which have constant 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 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, partially embedded in the support for a shoe.
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 certifiable.
Use of this material 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 blade; 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 the methods of the prior art.
Laser cutting also allows to meet all demands as to dimensions, such as length, width and thickness of the blade, simultaneously eliminating any kind of perimetric deformation; this in practice is not possible with the methods 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 individual points or on complete parts, obtaining the blade in a short time and with very low costs.
Another characteristic is the high quality of the blade: production of high-quality ice-skating blades in fact no longer requires investments in machines for blanking, sand belts and equipment of various kinds as previously mentioned in the prior art; moreover, with the described technology it is possible to obtain a high-quality product with a blade provided with a perfectly sharp and uniform cutting edge, without alterations in the material and shapes, which perfectly meets the demands in terms of dimensions and profile, all this being obtainable in a very short time.
The blade thus obtained also allows to give the end user a tool which fully meets the requirements and expectations, also allowing to introduce products having a given certification. The certification can be provided throughout production and can relate to the hardness of the material 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 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 defined 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 been provided which allows to obtain ice-skate blades of high quality, in a short time and at a low cost, with a perfectly sharp and uniform cutting edge, without alterations in the material and in the shape and which perfectly 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 the 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 cutting technique whereby the laser source can be controlled 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.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

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 hardened, quenched, straightened, satin finished steel with a preset hardness; cutting said sheet with a laser unit to obtain a blade; and chromium-plating said blade.
A method according to claim 1, characterized in that said blade has a sharp and uniform cutting edge and means for locking and retaining a support for a shoe.
A method according to claim 2, characterized in that said means for locking and retaining the support are constituted by one or more undulated regions formed at suitable recesses provided on the profile of said blade that does not interact with the ice.
A method according to claim 1, characterized in that said steel is of the carbon or alloy or sintered or stainless type.
A blade for an ice-skate, characterized in that it is manufactured by the method of claim 1.