WO2002011572A1

WO2002011572A1 - A method of assembling leather soles for shoes and a shoe produced by the method

Info

Publication number: WO2002011572A1
Application number: PCT/IT2000/000343
Authority: WO
Inventors: Silvio Novello; Alberto Del Biondi
Original assignee: Dba S.R.L. Via Oltrebenta, 14; Novello Meccanica Di Novello Silvio
Priority date: 2000-08-03
Filing date: 2000-08-03
Publication date: 2002-02-14
Also published as: AU2000267250A8; WO2002011572A9; AU2000267250A1

Abstract

A method of assembling leather soles for shoes is described and comprises the steps of providing two sets of multi-layer sheet material of identical composition, each including an outer leather layer (10) with an inner surface (11) which is intended to face the inside of the sole in use, a layer of thermally adhesive film (13) made of plastics material of predetermined thickness, coupled with the inner surface, a sheet-like layer (15) of plastics material compatible with the thermally adhesive film and fixed thereto by thermal bonding, of providing a sole core (4) and fitting the sets of multi-layer material thereon with the sheet-like layers (15) of plastics material face to face so as to cover the core (4), the sheet-like layers of the two sets being caused to meet in a peripheral edge region (17) of the sole, and of heat sealing the sets of sheet material together in the peripheral edge region (18), preferably by high-frequency welding.

Description

A method of assembling leather soles for shoes and a shoe produced by the method Technical field

The present invention relates to a method of assembling leather soles for shoes and to a shoe with a sole produced in accordance with the method. Technological background

The invention relates to the technical field of shoes the soles of which are produced by the covering of a sole core of suitable thickness and stiffness made, for example, of expanded plastics material such as EVA.

The current state of the art consists of the manual assembly of the leather sole by wrapping of the sole core. The main disadvantage of this technique is a considerable production cost and, moreover, the leather tends to form wrinkles in the sole which produce an impractical and aesthetically displeasing result . Description of the invention

The problem upon which the invention is based is that of providing a method suitable for at least partial automation of the steps of the assembly of a leather sole. This problem is solved by the invention by means of a method of assembling leather soles comprising the steps indicated in the appended claims . A further subject of the invention is a shoe the sole of which is produced in accordance with the above-mentioned method. Brief description of the drawings

The characteristics and the advantages of the invention will become clearer from the following detailed description of two embodiments thereof, described by way of non-limiting example with reference to the appended drawings, in which: - Figure 1 is a schematic side elevational view of a shoe produced by the method of the invention,

- Figure 2 is a partial section taken on the line II-II of Figure 1, - Figure 3 is an elevational view of the sole of the shoe of the preceding drawings, with parts separated,

- Figure 4 is a perspective view of the same shoe, from below,

Figures 5 and 6 are a side elevational view and a perspective view from below, respectively, of a second model of the shoe according to the invention. Preferred embodiment of the invention

In Figure 1 a shoe, generally indicated 1, includes an upper 2 and a sole 3. The sole 3 comprises a sole core 4, preferably made of expanded resin such as EVA or the like, possibly including a stiffener 5 incorporated in a shank region 6 of the sole.

The term "shank region" is intended to define the region of the sole which extends from the heel as far as the sole region of the foot .

The sole 3 is produced by covering the sole core with two sets of multi-layer sheet material of identical composition, each set including an outer hide or leather layer 10 with an inner surface 11 which is intended to face the sole core in use, a layer 12 of liquid glue, which preferably has a polyvinyl chloride polymer base and is applied to the inner surface 11 so as to impregnate it at least superficially, a layer 13 of thermally adhesive film made of plastics material with a thickness, for example, of about 20-30 μm, applied to the layer of glue by thermal bonding, and a sheet-like layer 15 of plastics material compatible with the thermally adhesive film 13, preferably also made of material with a polyvinyl chloride polymer base, and fixed to the thermally adhesive film 13 by thermal bonding. One of the two sets of sheet material, that is, the upper set in Figure 1 and the lower set in Figure 5, is then subjected to thermoforming in a mould so as to provide a seat 16 for housing the sole core 4.

The two sets of multi-layer sheet material are then arranged one above the other so as to cover the sole core 4, the sheet-like layers 15 being caused to meet in a peripheral edge region 17 of the sole.

The sheet-like layers of plastics material are then heat-sealed in the peripheral edge region 17, preferably by a high-frequency welding technique. The two sheet-like layers 15 of plastics material are thus fixed together and the two sets of multi-layer sheet material are consequently fixed on the sole core .

The outer hide or leather layer 10 of the lower set of sheet material preferably has a plurality of through-holes 20 at least in the region of the sole of the foot and possibly in the heel region. The sheet-like layer 15 of plastics material in turn has a corresponding plurality of appendages 21 which, once the above-mentioned layers are fixed together, project through the corresponding plurality of holes 20 to constitute a tread of the sole. These appendages 21 can be produced by thermoforming of the sheetlike layer 15 of plastics material in a suitable mould under a press. A particularly strong shoe sole with a pleasing finish is thus produced and the peripheral edge region 17 of the sole enables the upper 2 to be connected easily by sewing or similar techniques as well as constituting an effective decorative motif. The invention thus achieves the object set and affords many advantages over previously known techniques. In particular, it enables the tread surface of the sole to be produced directly at the stage of the assembly of the sole, if desired, by virtue of the appendages of the sheet-like layer of plastics material. The sole is also well formed and sufficiently rigid for the shape imparted to be retained over time .

Claims

1. A method of assembling leather soles for shoes, characterized in that it comprises the steps of : providing two sets of multi-layer sheet material of identical composition, each including:

- an outer leather layer (10) with an inner surface (11) which is intended to face the inside of the sole in use,

- a layer (13) of thermally adhesive film made of plastics material of predetermined thickness, coupled with the inner surface (11) ,

- a sheet-like layer (15) of plastics material compatible with the thermally adhesive film (13) and fixed to the film by thermal bonding,

' providing a sole core (4) and fitting the sets of multi- layer material on the core with the sheet-like layers (15) face to face so as to cover the core (4) , the sheet-like layers of the sets being caused to meet in a peripheral edge region (17) of the sole, and heat-sealing the sets together in the peripheral edge region (17) .

2. A method of assembling leather soles for shoes according to Claim 1, in which the inner surfaces (11) of the leather layers (10) are impregnated with a liquid glue (12) prior to the application of the thermally adhesive film.

3. A method of assembling leather soles for shoes according to Claim 1 or Claim 2, in which the layer of thermally adhesive film (13) and the sheet-like layer (15) have a polyvinyl chloride polymer base.

4. A method of assembling leather soles for shoes according to Claim 1 or Claim 2 in which the glue (13) has a polyvinyl chloride polymer base.

5. A method of assembling leather soles for shoes according to one or more of the preceding claims in which the layers are coupled to one another thermally.

6. A method of assembling leather soles for shoes according to one or more of the preceding claims, in which at least one of the sets of multi-layer sheet material is thermoformed to define a seat (16) for housing the sole core (4) prior to being fitted on the sole core (4) .

7. A method of assembling leather soles for shoes according to one or more of the preceding claims in which, in one of the sets, the outer leather layer (10) has a plurality of through-holes (20) and the sheet-like layer (15) of plastics material has a corresponding plurality of appendages (21) projecting through the holes (20) to constitute a tread for the sole .

8. A shoe with a sole produced in accordance with the method of one or more of the preceding claims .

9. A shoe according to Claim 9, comprising an upper (2) connected to the sole (3) in the peripheral edge region (17) .