WO1996013183A1

WO1996013183A1 - Innerboot for sports shoes and method for manufacturing the same

Info

Publication number: WO1996013183A1
Application number: PCT/EP1995/004062
Authority: WO
Inventors: Flavio Bacchiega; Riccardo Perotto
Original assignee: Nordica S.P.A.
Priority date: 1994-10-27
Filing date: 1995-10-16
Publication date: 1996-05-09
Also published as: ITTV940124A0; ITTV940124A1; IT1273915B

Abstract

An innerboot for sports shoes, in which at least the heel region (3) and the metatarsal region (5, 6) are made of a heat-expanding material. The material also has the additional characteristic of being stable once it has assumed its configuration after the insertion of the foot on the part of the user.

Description

INNERBOOT FOR SPORTS SHOES AND METHOD FOR MANUFACTURING THE

SAME

Technical Field

The present invention relates to an innerboot for sports shoes.

Background Art

It is known to manufacture sports shoes, such as for example ski boots or roller skates or ice skates, which are substantially constituted by a shell and by at least one quarter. The shell and the quarter are rigid because they are produced by injecting thermoplastic material. Therefore, a soft innerboot, adapted to improve comfort, is placed inside the boot. Many types of innerboot to be applied inside sports shoes are currently known. Some of them are sewn and fitted on a last by means of an assembly that entails, sequentially, the perimetric sewing of an insole, the insertion of the last, the spreading of an adhesive, the reactivation of said adhesive by heating, the gluing of an inner sole by pressing, and then extraction from the last.

It is also known to manufacture innerboots that have a strobel stitch on the edge of the sole for fixing the upper.

Innerboots are also known which have, at the foot instep region, a tongue or two flaps that overlap: said innerboots are used exclusively for shoes, such as ski boots, of the front-entry type and therefore to facilitate foot insertion.

If instead ski boots of the rear-entry type are used, innerboots with a rear opening over which a tongue can be partially superimposed are used, again to facilitate foot insertion.

All these conventional innerboots have drawbacks tha are substantially due to the fact that they can be used onl for a particular type and size of shoe, whether boots o skates, of the front-entry or rear-entry type, so that it i necessary to have various components and various sizes i stock, with a consequent increase in costs. Disclosure of the Invention

The aim of the present invention is therefore to solv the described technical problems, eliminating the drawback of the prior art by providing a method for manufacturing a innerboot for sports shoes that allows to industrialize th product while reducing the number of components required i stock and the number of sizes to be manufactured.

Within the scope of the above aim, an important object is to achieve a significant reduction in manufacturing costs and in investments.

Another object is to provide a product that is reliabl and safe in use and is good in quality.

This aim, these objects, and others which will become apparent hereinafter are achieved by a method fo manufacturing innerboots for sports shoes, characterized in that it comprises: a) a first step for inserting a last of the desired size in an innerboot; b) a second step for heating and consequently causing the expansion of at least the heel region and the metatarsal region of said innerboot; c) a third step for extracting said last from said innerboot, maintaining the assumed configuration. An innerboot thus obtained is characterized in that at least the heel region and the metatarsal region are made of a heat-expanding material that stably maintains the assumed configuration.

Brief Description of the Drawings Further characteristics and advantages of the invention will become apparent from the detailed description of a particular but not exclusive embodiment, illustrated only by way of non-limitative example in the accompanying drawings, wherein: figure 1 is an exploded view of the innerboot; figure 2 is a perspective view of the configuration that the innerboot can assume according to the lasts that can be inserted therein prior to the heating step; figure 3 is a plan view of various configurations that the innerboot can assume after extracting the last. Ways of carrying out the Invention

With reference to the above figures, the reference numeral 1 designates an innerboot particularly for sports shoes such as for example boots, roller skates, ice skates, or climbing boots. Said innerboot is constituted by a sole 2, a heel pad 3, a cuff 4, an upper 5 that affects the metatarsal region 6 and partially affects the foot instep region 7, a tongue 8 for the tibial region, and a transverse part 9 that can be arranged on the foot instep region 7 and can be connected to a strengthening element that mutually connects said sole 2, said heel pad 3, said cuff 4, and said upper 5.

The interconnection of the various elements, including the connection of the tongue 8 to the upper 5, can occur according to one of the conventional methods.

The method for manufacturing the innerboot initially entails the assembly of the various components thereof, with the characteristic that at least the heel pad 3 and the upper 5 are made of a heat-expanding material that is stable in the assumed configuration.

In particular, thermoplastic closed-cell materials, such as PE, EVA, or foamed materials in general, may be used for the heel pad 3 and the upper 5. These materials, if heated, can be easily deformed in terms of their length, width, and thickness; in order to improve their resistance to abrasion and tearing as well as comfort or aesthetic appearance, they must be coupled on one or both sides with fabrics or spread products that must have two specific characteristics: they must be of the double- stretch type and resistant to high temperatures, which can be indicated as being between 80° and 120°.

If the heel pad 3 and the upper 5 are made of these materials, it is necessary to initially preset the thickness thereof to compensate, due to the thermoforming process, for the possible loss of their initial supporting characteristic, since with heat they tend to become partially open-cell materials due to compression, which causes the closed cells of the material, which contain gas, to explode.

Once the innerboot has been produced, with the heel pad 3 and the upper 5 made of the above-mentioned materials, and after the sole 2 has been sewn with conventional means, the method entails the insertion of a last, designated by the reference numeral 11, inside the innerboot. The last 11 has a size chosen among several available ones.

By virtue of the characteristic of the heel pad and of the upper, the insertion of the desired last entails, as shown in figures 2 and 3, an adaptation thereof by means of their deformation in length, width, and thickness.

The method then entails a second step in which heating occurs; said heating entails the expansion of the regions of the heel pad 3 and of the upper 5, which, after cooling, assume the exact anatomy and volumes of the desired last 11 inserted in the innerboot.

The method then entails the extraction of the last and the preservation of the configuration assumed by the innerboot.

It has thus been observed that the invention has achieved the intended aim and objects, an innerboot for sports shoes having been obtained which can be used, starting from a single structure that is preset, according to a specific size that can be preset according to production requirements. The deformability of the heel pad 3 and of the upper 5 in fact allows to use lasts of the desired size; the method therefore achieves an industrialization of the product that allows to reduce costs, since it is no longer necessary to keep in stock innerboots of all the sizes that correspond to the sizes of the shoe with which they must be associated.

Accordingly, investments are reduced while maintaining high product quality.

The method according to the invention is of course susceptible of numerous modifications and variations, all of which are within the scope of the same inventive concept. The materials and the dimensions that constitute the individual components of the innerboot, and therefore the heel pad and the upper as well, may of course be the most pertinent according to the specific requirements.

Claims

1. Method for manufacturing innerboots for sports shoes, characterized in that it comprises: a) a first step for inserting a last (11) of the desired size in an innerboot; b) a second step for heating and consequently causing the expansion of at least the heel region and the metatarsal region of said innerboot; c) a third step for extracting said last (11) from said innerboot, maintaining the assumed configuration.

2. Innerboot, characterized in that at least the heel region (3) and the metatarsal region (5,6) are made of a heat-expanding material that stably maintains the assumed configuration.

3. Innerboot according to claim 2, comprising: a sole (2); a heel pad (3); a cuff (4); an upper (5) affecting the metatarsal region (6) and partially affecting the foot instep region (7); a tongue (8) for the tibial region; and a transverse part (9) that can be placed on said foot instep region and can be connected to a strengthening element for mutually connecting said sole, said heel pad, said cuff, and said upper, characterized in that at least said heel pad (3) and said upper (5) are made of a heat-expanding material that is stable in the configuration assumed after thermoforming.

4 . Innerboot according to c l aim 2 , characteri zed in that said heel pad ( 3 ) and said upper ( 5 ) are made o f closed-cell thermoplastic material such as PE , EVA , or generally foamed materials , which are optionally coupled , on one or both sides, to fabrics or spread materials.

5. Innerboot according to claim 3, characterized in that said fabrics or spread materials are of the double- stretch type and are resistant to high temperatures, i.e., temperatures between 80° and 120°.

6. Innerboot according to claim 2, characterized in that said heel pad (3) and said upper (5) have thicknesses that are adapted to compensate, due to the ther oforming process, for the possible loss of their initial support characteristic.

7. Method according to claim 1, characterized in that once said innerboot has been manufactured, one of a plurality of lasts (11) that can be selected for the desired size is inserted in said innerboot, with consequent adaptation of said heel pad and of said upper to said last.

8. Method according to claim 7, characterized in that it entails the heating and the consequent expansion of the regions of a heel pad (3) and of an upper (5), which after cooling and extraction of said last (11) assume the exact anatomy and volume of said desired last (11).