Classifications

• • A—HUMAN NECESSITIES
  • A43—FOOTWEAR
  • A43B—CHARACTERISTIC FEATURES OF FOOTWEAR; PARTS OF FOOTWEAR
  • A43B23/00—Uppers; Boot legs; Stiffeners; Other single parts of footwear
  • A43B23/02—Uppers; Boot legs
  • A43B23/04—Uppers made of one piece; Uppers with inserted gussets
  • A43B23/042—Uppers made of one piece
• • A—HUMAN NECESSITIES
  • A43—FOOTWEAR
  • A43B—CHARACTERISTIC FEATURES OF FOOTWEAR; PARTS OF FOOTWEAR
  • A43B23/00—Uppers; Boot legs; Stiffeners; Other single parts of footwear
  • A43B23/02—Uppers; Boot legs
  • A43B23/0245—Uppers; Boot legs characterised by the constructive form
  • A43B23/0265—Uppers; Boot legs characterised by the constructive form having different properties in different directions
• • A—HUMAN NECESSITIES
  • A43—FOOTWEAR
  • A43B—CHARACTERISTIC FEATURES OF FOOTWEAR; PARTS OF FOOTWEAR
  • A43B3/00—Footwear characterised by the shape or the use
  • A43B3/02—Boots covering the lower leg
• • A—HUMAN NECESSITIES
  • A43—FOOTWEAR
  • A43B—CHARACTERISTIC FEATURES OF FOOTWEAR; PARTS OF FOOTWEAR
  • A43B3/00—Footwear characterised by the shape or the use
  • A43B3/02—Boots covering the lower leg
  • A43B3/04—Boots covering the lower leg with rubber or elastic insertions or gussets
• • A—HUMAN NECESSITIES
  • A43—FOOTWEAR
  • A43B—CHARACTERISTIC FEATURES OF FOOTWEAR; PARTS OF FOOTWEAR
  • A43B9/00—Footwear characterised by the assembling of the individual parts

Definitions

• the present invention is related to footwear items and production methods thereof. Particularly, it is related to boots made of elasticized natural leather obtained by means of an improved manufacturing process.
• the non-elastic nature of the leather and the need to ensure a close-fitting to the leg require insertion of means into the boot that make more comfortable and easier to put on and to take off the boots especially those that reach or exceed the knee.
• some types of known boots made of substantially rigid natural leather have a zip closure along the upper while others comprise stitched elastic inserts (named "gores") stitched into either side of the upper.
• the zip or the lateral elastic insert are replaced by other fastening means such as laces and eyelets. All these known types of leather boots do not present a "one-piece shape" i.e. a structure in which the upper and the leg of the boot are integrated with each other (i.e.
• the synthetic nature of the stretch materials which imitate the natural leather leads to poor or no breathability of the boots.
• hygienic problems e.g. unpleasant odors, fungal infections, etc.
• a poor comfort feeling e.g. skin irritations
• the boot would not assume the features and the hand of one made of natural leather, and would not be suitable for use in harsh or rainy climates.
• the stretch materials used do not present the valuable characteristics and attractiveness of natural leathers, especially in the luxury market.
• footwear artisans and factories have dedicated themselves to experiment with new materials suitable for making boots in natural stretched leather that are able to meet the growing demand from a high-end female customers.
• these attempts have proved unsatisfactory despite the strong market demand and availability of elastic natural leathers (for example those made by the French company Cuirs du Futur), which are potentially useful for achieving this task in combination with the great wealth of technical knowledge in the footwear field.
• the present invention intends to overcome the existing disadvantages related to footwear items and particularly to boots made of elasticized natural leather.
• this object includes the manufacturing of skin-tight boots that even if made of natural leather and not of elasticized fabric resemble high denier stockings and similarly to stockings are easy to wear and easy to take off from the leg.
• a third important object of the present invention is to obtain an elasticized boot, with no evident external seams, by means of an improved process which starts from a single piece of suitably-shaped elastic natural leather.
• the third object includes an elasticized boot obtained by means of said improved process wherein such seams can be reduced to a single one, that is the minimum possible for a 3-dimensional item made from a flat and non-tubular material.
• a fourth object of the present invention to disclose a elasticized footwear item, particularly a boot, made of natural leather obtained by means of a process that can be applied to a wide range of shapes and range of natural leather, in such a way as to follow fashion trends and fulfill market demands specifically of the luxury market.
• the last object of the present invention is to provide said footwear item and said process by means of known technologies.
• Figure 1 depicts a three-dimensional view of the footwear item according to the preferred embodiment of this invention, represented by a female boot made of "velour stretch";
• Figure 2 represents, again with reference to the preferred embodiment of the present invention, in (a), the 2-dimensional model of a typical piece of shaped elasticized leather which, once seamed, allows to construct the leg part of the boot integrated to the upper part, while in (b), a detail of the structure of the shaped elasticized leather one-piece;
• Figure 3 is a schematic view from below of the boot during the assembling step, again with reference to the preferred embodiment according to the invention.
• the first advantage consists in a boot featuring an highly aesthetic "one-piece” appearance, i.e. having only one external seam (unlike the known leather stretch boots that have at least two or three external seams) that represents the smallest possible number for a 3d shape made from a flat 2-dimensional single piece of leather.
• the boot structure and the manufacturing process result in an elasticized boot made of natural leather that is close-fitting to the foot and to the leg, and looks like an high denier stocking.
• boots according to the present invention are easy to wear and easy to take-off, just like a stocking. At the same time, they guarantee an optimal breathability and comfort that traditional known boots, i.e. based on synthetic tubular stretch fabrics or imitation leather, cannot achieve.
• boot designates in the broadest meaning a footwear item for men, women or children, with or without fastening means, provided with a part (for the sake of clarity is named “leg of the boot” or “leg part” in short) seamed to the upper of the boot and which generally reaches or exceeds the knee but can also reach a lower height. Therefore, the term “boot” includes footwear such as half boot, thigh boot, ankle boot, or other technically equivalent types, even if defined with terms other than those used in the present description.
• the terms “bi-directional elasticity” or “bi-elastic” shall mean, mutatis mutandis, an elastic material capable of reversibly extending along two distinct directions.
• natural leather or simply “leather” will designate any animal hide or skin subjected to tanning, even if from a technical point of view the term “leather” is more correctly used to define the resulting final product from the chemical or vegetable processing of such animal skin regardless of intended use.
• the terms “elastic leather” or “elasticized leather” will indicate a natural skin which has been made mono-elastic or bi-elastic through appropriate procedures and treatments.
• the footwear item made of elasticized natural leather is a "one-piece" woman's boot which covers the leg up to the knee, made of mono- elastic natural suede leather.
• Said elasticized boot is indicated with the number (1 ) and is obtained from a single piece of elasticized natural leather (10) through the method which will be described hereinafter.
• said elasticized natural leather (10) consists of a piece of natural leather (1 1 ) and a piece of elasticized fabric (12) which were first suitably shaped and then joined to a fabric lining (13).
• Said fabric lining (13) consists of a foot lining (131 ) and a leg lining (132) which were also suitably shaped, so as to obtain a 2-dimensional model of the boot such as that illustrated in the enclosed figure 2.
• the edges of the 2-dimensional model are sewn to form a leg part of the boot joined to the upper part.
• the reinforcing elements toe and heel counter
• the innersole, sole and heel the innersole placed above the undersole
• said components can vary in number, aspect, size, or they can be integrated with each other, depending on the needs and the model of the boot.
• the elasticized boot according to the present invention is obtained by means of a process comprising the following steps, listed here and described as a non-limiting example of the present invention:
• Step 1 Boot design and material selection.
• designing the shape of the boot according to the invention is of fundamental importance in order to obtain an item characterized by superior fit and comfort and able to guarantee a complete adherence to the leg as a stocking.
• the designer starting from the characteristics of the elasticized starting leather and evaluating the overall design of the boot, the designer must identify in which portions of the boot is required greater elasticity.
• the method for making the boot according to the present invention starts with an elasticized leather piece (10) comprising a piece of natural leather (1 1 ) coupled with an elasticized fabric (12).
• said natural leather (1 1 ) is suede but other types can also be used provided they have a thickness of between 0.3 and 1 .0 mm and similar softness.
• said stretch fabric (12) is a mono-elastic fabric having a mono-directional elasticity and a thickness selected so that said coupled leather has an overall thickness between about 0.4 and 2 mm.
• said stretch fabric (12) is a mono-elastic fabric having a mono-directional elasticity and a thickness selected so that said coupled leather has an overall thickness between about 0.4 and 2 mm.
• various elasticized fabrics suitable for the purpose which are known to those skilled in the art.
• Coupling of said natural leather (1 1 ) with said elasticized fabric (12) can be performed by known techniques, for example by immersion in elastomeric materials, calendering or other equivalent techniques.
• elastic leathers can be found on the market, for instance those produced by the French company Cuirs du Futur.
• this step it is accomplished the selection of shoe-lasts and shoe patterns which will be used, first, to obtain the different components of the boot, and then during working operations and boot assemblage.
• Step 2 Leather and lining cutting.
• This step includes cutting of the elasticized leather (10) and of the lining (13).
• the elasticized leather (10) is cut to size according to a cutting profile defined by a shoe patterns, taking care to orientate the piece properly so that the unidirectional elasticity is directed along the transverse direction (T) of the boot.
• the cutting operation is made by means of a known cutting tool, for example a hand cutter in such a way as to advantageously determine the curling of said elasticized skin and facilitate the conformation to the mold of the boot.
• Step 3 Leather and lining crimping.
• the cut elasticized leather (10) and the cut lining (13) are placed on a crimping machine to form the boot.
• This operation must take into account the unidirectional elasticity characteristics of the components (10) and (13) and the overall design of the boot.
• the crimping operation is carried out by means of a known crimping machine at a temperature of between 80 and 180 °C for a time comprised between 1 and 300 minutes, depending on the characteristics of the natural leather (1 1 ), which is not always homogeneous since the starting material consist of a natural leather piece.
• the present inventor has experimentally verified that the application of a fabric softener facilitates the boot shaping, especially in those areas characterized by high curvature such as the instep and the leg part.
• the softener is selected from those containing nonionic surfactants in a silicone emulsion.
• other technically-equivalent softeners can be used.
• Step 4 Skin and a lining trimming
• the elasticized leather and the lining obtained from the crimping operation are trimmed manually with a hand cutter and the aid of a precision shoe patterns so as to conform them to the final shape of the boot according to the design defined in the previous Step 1 .
• a trimmed elasticized leather and a trimmed lining are obtained.
• the same numbers (10) and (13) will be indicated with the same numbers (10) and (13) respectively.
• Step 5 Skin and a lining sewing
• the trimmed pieces of elasticized leather (10) and the trimmed pieces of lining (13) obtained in the previous step are superimposed one onto another and then sewn together along the perimeter.
• this operation produces: a first internal seam to join the edges of the foot lining (131 ) along the perimeter (P ⁇ , and a second internal seam to join the edges of the leg lining (132) along the perimeter (P 2 ).
• Said components (10) and (13) must be oriented properly so that once they are sewn together, the unidirectional elasticity along the transverse direction (T) of the boot is preserved.
• Preserving the unidirectional elasticity during boot manufacturing steps represents an important object of the present invention.
• This technique consists in the use of two different threads: an elastic thread (e.g. in elastane) where elasticity is required to make easier boot fitting, such as in the upper part (S) of the leg part; an high-resistance thread (e.g.
• a nylon thread is used in those areas more subjected to wear, such as in the lower part (I) of the leg part.
• a layer of glue is spread on the edges of the elasticized leather (10) and of the lining (13) to promote adhesion.
• one or more additional internal seams preferably two with non-elastic thread
• one or more reinforcing elements (13) are applied to improve rigidity of the boot and prevent it from collapsing once worn.
• an anti-slip element (14) made of a silicone material, or other similar material able to adhere to the user's leg, can be applied, preferably glued.
• Step 6 Boot preparation and mounting
• the preparation for mounting the boot involves known techniques and materials. They include the application, by means of glue or mastic and specific machinery/tools, of aids for keeping the boot components in position and for giving them the shape according to the initial design. As usual in the footwear industry these aids are, for example the tip and the heel counter.
• the elasticized leather (10) i.e. the upper part joined to the leg part
• the operator thus takes the shape and fixes the innersole (15) by means of shoe tacks; then he takes said elasticized leather (10) and fixes it with glue over said form using a tack lasting machine; finally he proceeds with the manual shaping of said elasticized leather (10).
• the operator In this step, the operator must join to the sole (15) the lower surface (3 ⁇ 4) of the boot limited by the edge (C), making sure that the lower surface ( ⁇ inf ) is as regular as possible or, in geometrical terms, for all points (x,y) belonging to the lower surface ( ⁇ inf ) the normal versor n ⁇ (x,y) has a variation lower than a prefixed ⁇ value corresponding to an acceptable quality level of the boot.
• the single piece of elasticized leather (10) does not fit perfectly with the shape of the boot (1 ) provided for in the design step (the same problem also applies in the case of models consisting of several portions of elasticized leather).
• elasticized leather (10) is made of a natural material, whose elastic property are never perfectly identical nor repeatable (often not even within the same batch of leather); moreover, the tolerances and the unavoidable errors introduced during machine and manual working operations have to be considered; in addition, the elasticity of said piece of elasticized leather is never perfectly unidirectional and directed along the direction (T), due to the tolerances in cutting and stitching and the intrinsic curvature of the boot; finally, the piece of elasticized leather (10) geometrically has two dimensions but must fit to a three-dimensional shape.
• the present inventor has thus codified a method to guarantee optimal adhesion of the lower surface ( ⁇ inf ) to the shape of the foot and to minimize or eliminate defects or imperfections.
• Said procedure illustrated here by way of example and not limitation of the present invention with reference to the Figure 3, comprises the following sub-steps:
• the lower edge (C) which limits the lower surface ( ⁇ inf ) is fixed to the innersole (15) with mastic, or other adhesive, and optionally with shoe tacks;
• the border (C) is divided into a certain number of segment-edges C, of equal length, where i is an integer which preferably varies between 4 and 16;
• a tension is applied to the segment-edge C, in order to pull it and fix it, preferably by means of shoe tacks, on a perimeter point of the surface of the innersole (15);
• heat is applied to minimize or eliminate the elastic stresses introduced during the mounting step
• edges C can be scanned sequentially following a direction, for example a clockwise, but other sequences may be used, for example by choosing two-by-two opposed segment-edges C, and C j .
• This procedure can be implemented manually, or by using a machine provided with a plurality of grippers able to hold and independently pull one or more of said edges C,.
• the operator acts on the grippers so as to pull a segment-edge (C,), where i is an integer, preferably equal to or greater than 8, and fit the lower surface ( ⁇ inf ) of the elastic leather (10) to the shape of the foot.
• this fixing operation can be carried out manually.
• the finishing step comprises the following processing sequence: first the boot is inserted in an oven to stabilize its shape; then it is subjected to scraping for removing residues of skin or glue; then a pounding machine is used to flatten the seams and the tips of shoe tacks applied in the previous steps. This step also involves to form an impression of the heel and to mount the heel by means of mastic. To conclude, the following operations are made: removal of the shoe-last of the boot introduced in the previous preparation step; insertion of the leather sole; ironing, cleaning and packaging of the finished boot.
• ironing plays an important role and it is carried out by means of special tools heated to a temperature between 70 and 150 °C, and on special preformed and heated legs. In fact, the ironing allows to further flatten the internal seams and to eliminate any wrinkles that may be present. Alternatively or in combination, a hand-ironing step can be added.

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• Footwear And Its Accessory, Manufacturing Method And Apparatuses (AREA)

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Citations (7)

• 2017
  • 2017-02-08 IT IT102017000013395A patent/IT201700013395A1/it unknown
• 2018
  • 2018-02-07 WO PCT/IB2018/050759 patent/WO2018146600A1/en unknown
  • 2018-02-07 EP EP18714599.0A patent/EP3579717B1/en active Active

Patent Citations (7)

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