FR2701360A1 - Preformed component, particularly a blank for an inner bootee - Google Patents

Abstract

The subject of the invention is a preformed component, particularly a blank for an inner bootee or partial blank elements for such an inner bootee, comprising surface layers arranged at a distance from one another and, between the latter, an intermediate layer made from synthetic foam, these layers all being connected by means of a linking layer, so as to form a sandwich element, characterised in that the central layer (21), which has a practically uniform initial thickness, is compressed, at least along the contour line (31) of the blank (32) of an inner-bootee component to an inner thickness of 0.5 mm by means of an application of pressure and heat, in that the surface layers (16, 17) are kept by the synthetic foam (20) in this position at ambient temperature, and in that a cutting edge extends in the compressed zone of the synthetic foam, and its further subject is a method for manufacturing preformed components, particularly inner bootees, for example for boots including a plastic outer shell, such as ski boots, work boots and the like, according to which a plate formed from a central plastic layer is linked to two surface layers, compressed and then the blank is cut out.

Description

The invention relates to a preformed part, in particular blank for a bootie

  interior or partial blank elements for such an interior liner, comprising

  surface layers, spaced apart from each other, and between these

  nières, an intermediate layer of synthetic foam, these layers all being united by means of a bonding layer so as to form a sandwich element,

  as well as a process for manufacturing such preformed parts.

  In shoes, in particular sports or work shoes which often include shell parts, upper parts, etc. consisting of preformed parts made of rigid plastic material, inner booties are used,

  intended to receive the foot of the user, which allow an adaptation to the

  anatomical regularities of the foot and therefore an advantageous distribution of pressure

  and which, thanks to the materials used, provide thermal insulation and ventilation.

  Cellular materials or foams are often used for this purpose, as well as

  textiles or combinations of plastics and tex-

  tiles According to a known embodiment, corresponding to document DE-A-

  2,638,994, to obtain a suitable suitable shape, these shoes are manufactured

  interior sounds from a very large number of elementary parts In addition, these interior slippers include housings for added parts

  additional, in order to use at will materials with elastic properties-

  different ticks, for example in the sole area, in the malleolus area, etc. In this embodiment, the manufacture of such inner slippers is

  complex and therefore very expensive In addition, the numerous

  connecting elements between the elementary parts constitute a discomfort at the place of

  the contact surface between the inner boot and the foot.

  In other known embodiments, the inner booties are provided with air compartments into which compressed air is injected, in order to thus adapt the inner bootie to the contour of the foot. It is also often also provided to fill such compartments of a multi-component foam, so

  to obtain a contour adapted to the foot which is permanent In these inner slippers

  laughers also, a very large number of elementary parts is necessary for their manufacture, so that they are expensive and that there is also the risk of

  premature wear due to damaged compartments.

  The object of the invention is to provide an inner boot which consists only of a very small number of elementary parts and in which these parts are

  preformed before assembly It must also provide a process,

  the developed projection of an inner liner or making it possible to obtain a blank for such an inner liner, certain operations of which are eliminated and

  which allows a bond and a three-dimensional shape of the blank which are perma-

  nentes. According to the invention, this object is achieved by a preformed part, of the type defined in the preamble, characterized in that the central layer, which has an essentially uniform initial thickness, is compressed, at least along the contour line the blank of a piece of inner liner, to a thickness of less than 0.5 mm under pressure and temperature, in that the surface layers are maintained by the synthetic foam in this position at room temperature and in that a cutting edge extends into the

  compressed area of synthetic foam.

  Such a preformed part has the surprising advantage that one thus obtains, in a manufacturing operation, a developed projection, in one piece, of the blank which is necessary to produce the inner liner and which, at the location of the lines

  contour constituting the connection locations, is shaped into a ma-

  permanently in order to form sewn parts without a bead, which thus makes it possible to obtain a permanent connection between the surface layers and

  sealing of the foam layer disposed between these surface layers.

  It is also possible to envisage a development according to which the central layer is compressed to a thickness less than the initial thickness inside the contour line of the inner liner piece and along shaping zones. and / or stiffening, which makes it possible to obtain a three-dimensional shaping which is adapted to the anatomical particularities of the foot of the user and thanks to which the additional parts, such as for example

  padding, can be removed.

  According to another advantageous development, it can be provided that, in the region of the contour line, there are disposed continuous strips which extend inwards from the side edges and in which the central layer is compressed to a thinner than in neighboring areas, which provides areas corresponding to overlapping connections by means of which

  high mechanical resistance is obtained.

  Following an advantageous development, it can be expected that, in the area

  marginal parts connecting to the surface layers, the foam

  is compressed by mechanical and thermal means so as to have a higher specific weight than that of the inner zone of the

  central layer, which makes it possible to obtain a support effect for the superficial layers

  skies and therefore achieve a better distribution of the pressure exerted by the

  forces applied to the intermediate layer.

  According to an advantageous development, it can be provided that one of the surface layers has a three-dimensional curved shape which is turned towards the other surface layer, which makes it possible to obtain an adaptation to the different

  surface forces to which the inner liner formed from the pre-formed piece

mée is subject.

  It is also possible to envisage a development according to which the blank is formed by the developed projection of a piece of rod, since this fact avoids bonding locations in the area of the calf or Achilles tendon which are sensitive to pressure forces. We can also consider a development according to which the blank is formed from the developed projection of a piece of rod and a piece of forefoot, since the number of formed pieces constituting the inner liner is

thus reduced.

  A development according to the latch the blank constitutes a developed part of the inner liner which is in one piece is also possible, since the necessary means of manufacture and assembly allowing the manufacture or the

  realization of the inner liner are thus reduced.

  According to an advantageous development in accordance with the invention, it can be

  provided that reinforcing elements, for example attachments, are placed

  in the area of one of the two surface layers or between a layer

  surface and the central layer so that particularly sub-

  put to efforts are permanently armed so as to endure

  these efforts and that there are no occasional localized efforts.

  The reinforcing elements may consist of nets, grids, fabrics, mat-

  wear of feathers or fibers of metal, mineral matter or synthetic substances

  ticks and natural fibers, in particular glass fibers, graphite fibers, wool fibers and

  analogues, the use of materials suitable for the reinforcing elements

  putting to obtain an adaptation to the different conditions of use of a ma-

  in accordance with the type of employment provided.

  According to another development, it is also advantageous to provide that the density or the specific weight of the synthetic foam of the central layer or of the marginal zones of the central layer is distributed differently over the extent of the surface of the blank, so that '' a combination of preformed parts with

  other elements may often no longer have any reason to exist.

  According to a development according to which partial areas of the blank are reinforced by means of an additional layer deposited on one of the two surface layers makes it possible to oppose in a localized manner a premature wear by means of the arrangement of a layer additional serving of

reinforcement.

  In accordance with an advantageous development in which an intermediate layer of plastic, in particular synthetic foam with high elastic modulus, in particular flexible foam, is disposed between the additional layer and the surface layer closest to the latter, it is possible to double the reinforced areas from below, using a material to

  high elasticity, thus obtaining greater adaptability.

  An advantageous development according to which the additional layer and / or the intermediate layer are joined to the surface layer and / or between them by means of bonding and sealing layers, in particular in dry adhesive powder, fused sheets or added impregnated sheets makes it possible to keep at a

  reduced level of manufacturing resources required to prepare the pre-formed part

  mée, by means of additional or intermediate layers having a provision

localized tion.

  A development according to which the additional layer is bonded to the surface layer by means of the plastic of the intermediate layer,

  associated with this surface layer, which is shaped by metallic means

  thermal and / or thermal avoids additional adhesives, as well as

  technical devices for placing additional materials.

  We can also consider a development according to which the additional layer

  Mentaire and / or the intermediate layer are arranged in a part set back from the surface layers of the blank and are connected to the surface layer by means of the intermediate layer compressed by mechanical or thermal means, which also makes it possible to put the additional layers and /or

  intermediate layers in place in areas of the preformed part for

  which a modification of the thickness profile is not possible.

  An advantageous development according to which the specific weight or the den-

  sity of the middle layer is weaker in the area of a recessed part

  of the surface layer only in the areas adjacent to the latter

  both an intermediate layer compressed by mechanical and thermal means

  mics provides a balance with regard to elastic behavior

  tick between areas with higher elasticity and areas with lower elasticity.

  According to an advantageous development, it can be provided that the central layer and / or the intermediate layer may possibly consist of a

  synthetic open-cell foam, which provides a ventilation effect

  tion which also allows the evacuation of moisture or air with

high in humidity.

  We can envisage a development according to which the specific choice of the synthetic foam of the central layer and / or of the intermediate layer is more

  lower in the interior area than in marginal areas, marginal areas

  However, preferably having a specific weight at least three times

  larger than that of the interior area, which provides a support effect

  yours for the foot placed in the inner liner, even in intermediate areas

  diaries in which the tightening effect which is exerted on the foot by means of

  tightening through the rigid plastic shell is lower.

  A development according to which the central layer is formed from a foam

  flexible, for example synthetic polyether or polyester foam, having no-

  In particular, a specific weight between 10 kg / m 3 and 150 kg / m 3, preferably equal to 60 kg / m 3 makes it possible to take account of the different weights of the users.

  Following an advantageous development, it is intended that the surface layers

  these and / or the central layer are permeable to air, but preferably

  provided with moisture and that at least one of the surface layers and / or at

  at least one of the marginal areas is provided with additional impregnation

  l Mentary without moisture, which allows the inner boot to be worn with

  more comfort, even for prolonged use or in climatic conditions

  extreme ticks, such as temperature change, humidity, etc. Individual adaptation to the conditions of use is obtained

  development by which the surface layer is made of synthetic leather

  tick, leather, felt, velvet or fabric, knitted product, net or thread quilting or

  metal fibers, plastic, natural or synthetic fibers.

  The invention also relates to a method for manufacturing preformed parts, in particular inner booties, for example for shoes comprising an outer shell of plastic material, such as ski boots, boots

  of work and the like, whereby a plate, formed of a central layer, is bonded

  plastic sheeting, particularly of synthetic foam, with two super layers

  perfect, preferably in a different material, possibly with

  the interposition of adhesive layers, the plate having a continuous thickness.

  The object which the invention aims to achieve is obtained by the fact that it is compressed,

  up to a thickness of less than 0.5 mm, the contour line of the blank includes

  mant the plastic material of the central layer, by raising the temperature of the synthetic foam by means of heating molds or by using a field H F,

  then by applying a compression force or with the subsequent application or if-

  multiple of a compression force, and this contour line is kept in contact until the cellular structure, shaped and formed by means of mechanical and thermal compression, has solidified to the point that the two surface layers maintain the desired position at room temperature for them, and by the fact that the blank is then cut out with a cookie cutter in the

  plate, along the contour line.

  This process has the surprising advantage that by means of the mechanical action

  thermal and thermal on the cellular structure of the synthetic foam placed between the surface layers, one obtains, on the one hand, the permanent bonding and sealing of the surface layers in the marginal zone or along the

  cutting edges, but also three-dimensional shaping that is perma-

  nente and is maintained, while preserving the properties of insulation and

  cushioning of synthetic foam by means of surface layers.

  According to other advantageous developments of the method, it can be provided that: simultaneously with the production of the contour line, the blank is compressed

  in different areas of its surface, so as to bring them to different thicknesses

  sors, by raising the temperature of the plastic material of the central layer and applying at the same time a pressure, and that this compression of the central layer takes place at the same time as the realization of the external delimitation of the blank, which is raised the temperature of the plate at the same time as the line for delimiting the blank is made and possibly at the same time as the recessed areas and the reinforcement areas are made in the other parts of the surface, and by applying a compression force, the central layer is compressed in the marginal zones so as to bring them to a specific weight or a density higher than that or that of the interior zone and a projection developed for part or all is produced of the inner liner and the plastic of the central layer is compressed

  up to a thickness of less than 0.5 mm along the contour line of the pro-

  developed jection, while at the same time raising the temperature of the plate and subjecting it to a pressure, as a result of which the surface layers are maintained in this position, in the area of the contour line, until '' a point of solidification or creep point of the plastic material is passed downwards, so that the two surface layers are kept at the temperature

  room in the position chosen beforehand between them.

  In order to facilitate understanding of the invention, the latter is exposed

  below in detail with the aid of embodiments shown in the drawings.

We see:

  in FIG. 1, a perspective view of an inner boot according to a

  very simplified schematic presentation, in Figure 2, a side view, partially in section, of the inner boot of Figure 1, in Figure 3, a front view of the inner boot of Figures 1 and 2, in

  section along line 11 I-111 of Figure 2, this view showing an area of overlap

  chement and connection between different areas of the contour line of a blank, in Figure 4, a blank corresponding to the inner liner of Figures 1 to 3, in Figure 5, a sectional view of the blank of Figure 4 following line VV of this figure,

  in FIG. 6, another embodiment of a blank corresponding to the inner liner

  laughing, in Figure 7, a sectional view of the blank of Figure 6 along line VII-V II thereof, the figure showing reinforcing inserts arranged between the surface layers, in Figure 8, a partial area of another embodiment of an inner boot according to the invention comprising an additional layer arranged in addition to the surface layers, in FIG. 9, a front view, in section, of a partial area of a boot

  interior, in the area of the central layer compressed with different intensity

  rent, this view schematically representing the cell structure, in FIG. 10, a front view, in section, of a partial area of another embodiment of an inner liner according to the invention comprising an intermediate layer, placed on the surface layer, and an additional layer covering this intermediate layer, in FIG. 11, a front view, in section, of a partial area of another embodiment of an inner liner according to the invention comprising intermediate layers and additional compressed in a different way, in Figure 12, a front view, in section, of a partial area of the inner liner according to the invention, in the marginal area and in the case of a compressed central layer by thermal means, and

  in Figure 13, an alternative embodiment of a blank in several parts cor-

corresponding to the inner liner.

  Figures 1 to 3 show an inner boot 1 associated with a foot 2.

  The inner boot 1 comprises a part of the upper 3 which is delimited by a marginal zone 4 of the tibia The part of the upper 3, which partially surrounds the foot 2, is

  extended by a forefoot part 5 The forefoot part 5 is linked to a

  lateral forefoot tie 8 both in an instep area 6 and in a malleolus area 7, preferably by means of a seam 9, thereby forming a

closed housing for the foot 2.

  The upper part 3 and the forefoot part 5 are closed towards a bearing surface 10 by means of a sole part 11 In addition, in a toe area 12, the lateral part d the forefoot 8 and the forefoot portion 5 are also linked by means of the seam 9 In the area of the heel 13 of the foot or of the Achilles tendon, the inner liner comprises a rear rod portion 14 which n 'is linked only in part to the lateral part of the forefoot 8 and to the part of the rod 3, so that an opening 15 is formed which is large enough for the introduction of the foot 2 into the inner boot 1 as Figures 2 and 3 show better, the structure

  of the material used for the inner liner 1 has several layers.

  The preferred materials used for the surface layers 16 and 17 are in particular sheets of plastic, synthetic leather, leather 18, textile fabric 19 and knitted product. A central layer 21, preferably made of synthetic foam, has an open cell structure, the weight specific being understood

  between 10 kg / m 3 and 150 kg / M 3, preferably equal to 60 kg / m 3.

  By subjecting the central layer 21 to a thermal action and a mechanical action, this layer is shaped, so that there is formed, with different values depending on the location, a spacing 22 between the surface layers 16 and 17 of the inner liner 1 in the finished state, the spacing 22 in the sole portion 11 being for example less than the spacing 23 io in the instep area 6 or in the marginal area 4 of the tibia Par elsewhere, repelled portions 26 are formed, preferably by means of thermal and mechanical shaping, in transition zones 24 and also in an overlap zone 25, in such a way that a line is formed. folding 27 for example in the transition zone from the forefoot part 5 to the

  sole 11 Furthermore, in the overlapping zone 25, the parts repel-

  sées 26 ensure a connection without a bead between adjacent zones, thanks to the seam 9 which does not create any pressure location on the foot 2 which could be troublesome. Figures 4 and 5 show a developed projection 28 of the boot

  interior 1 This developed projection 28 includes the sole portion 11, the part

  rear rod tie 14, rod part 3, forefoot part 5 and lateral forefoot part 8 As can be seen from this top view of an interior surface 29 of the developed projection 28, the latter is provided with shoulders 30 and repelled parts 26 distributed over the surface layer 17 The shoulders 30 allow that, for example along a line of

  contour 31 and in particular in the overlapping parts in the overlapping area

  25, the inner surface layer 17 is pushed back towards the

  outer surface layer 16 or that the outer surface layer 16 pre-

  feels a shoulder towards the inner surface layer 17, so

  that these areas overlap without a bead.

  The shoulders 30 are preferably located in the instep area 6 of the forefoot portion 5 or the forefoot side portion 8 and in the toe area 12, as well as at the place of the transition with the sole portion 11 and, thus

  as already indicated, they allow the overlapping of the above-mentioned parts.

  A repelled part 26 is for example located at the point of the transition of the

  forefoot part 5 with sole part 11.

  As, moreover, FIG. 5 better shows, a blank 32 comprises, between the two surface layers 16 and 17, thicknesses 33, 34 which are different

  for the different zones, the central layer 21, located between the surface layers

  skies, having for this purpose a variable thickness obtained by thermal and mechanical shaping It can be seen, for example, that the sole part 11, which supports a higher load, has a central layer 21 more strongly

  compressed, and therefore a thickness 33 smaller, than the other areas of the blank 32.

  In particular, the rod part 3, in which a more intense insulating effect must for example be obtained between the malleolus and the plastic shell of the

  ski or work boot, has a greater thickness 34.

  In order to increase the tear resistance between the surface layers 16 and 17 and the central layer 21, an increase in density or specific gravity of the central layer 21 can be provided in marginal zones 35, also by means of a mechanical and thermal shaping carried out in

  at the same time as the shaping of the other areas of the blank 32.

  As a result, the structure of the plastic, in particular of the synthetic foam 20, is denser in a zone 36 of bonding and of connection with the surface layers 16 and 17, which makes it possible to obtain a better distribution of the point charges. over a larger area, this better distribution

  opposing the separation of the different layers.

  At the location of the shoulders 30, the central layer 21 is delimited towards

  the exterior by one of the surface layers 16 and 17 At its border with the surface

  inner face of the surface layers 16 and 17, the central layer 21 comprises

  a marginal zone 37 having a higher density The surface layer in-

  17 and the outer surface layer 16 are located at a distance from one of

  the other, the distance 38 decreasing towards the sole portion 11 This dimi-

  nution of the distance results from the fact that the inner surface layer 17

  extends in an inclined manner with respect to the outer surface layer 16.

  The repelled part 16, or a narrowed part of stepped shape, is provided in di-

  rection of the sole portion 11, so that, in the region of this sole portion 11, the inner surface layer 17 extends approximately parallel to

  the outer surface layer 16.

  Along the contour line 31, the surface layers 16 and 17 are arranged at a distance from each other which is of the order of magnitude of about 1

  0.2 mm, preferably 0.5 mm, using appropriate thermal compression

  required This means that, in this zone, the central layer 21 is brought, at least at the surface, into a plastic state under the effect of the application of a thermal action and also of a mechanical action and that, because from the compression of the plasticized cell walls and veils on the surface, a layer 39 of bonding and sealing forms, after solidification, a thin plastic film between the surface layers 16 and 17 This also prevents sealing in the marginal zone and therefore preferably a penetration of moisture in the area of

  the contour line 31 or cutting line.

  Figures 6 and 7 show another embodiment of the developed projection 28 and the cross section of the blank 32 used for the

inner bootie

  laughing 1, this other embodiment including the sole part 11, the rear rod part 14, the rod part 3, the forefoot part 5 and the front forefoot part

foot 8.

  In this case, unlike FIG. 4, the rear rod part 14 is made

  bound integral, during forming, a heel area 40 of the front side part

  foot 8 As can be seen further from this top view of the

  inner surface 29 of the blank 32, the forefoot part 5 and the lateral forefoot part

  foot 8 both have, in the malleolus zone 7, parts

  tees 41 These added parts 41 are for example formed from a cellular material

  laire which has a specific gravity different from that of the cellular material of the central layer 21 It is possible that, in the area of the added part 41, the central layer 21 has been removed locally by mechanical means and that the

  added part 41 is fitted, and optionally glued or welded, in the lo-

  gement thus formed This makes it possible to adapt various areas of the

  inner liner 1 under different stress conditions.

  The blank 32 has shoulders 30 at the location of its contour line 31, in particular on the rod part 3, the forefoot part 5 and the lateral part

  forefoot 8 In these overlapping parts, the upper surface layer

  lower 17 is disposed backwards towards the outer surface layer 16 or this outer surface layer 16 is arranged backwards towards

  of the inner surface layer 17.

  In the marginal area of the tibia 4 of the rod part 3, an edge 42 is provided which has a specific weight other than the rod part 3 and which extends to the

Achilles tendon area 43.

  FIG. 8 represents a partial area of the inner liner 1 which consists of the surface layers 16 and 17, for example formed of leather 18 and a textile fabric 19, and of synthetic foam 20 disposed between these layers

  The inner liner 1 includes, for example in the tension zone.

  gift of Achilles 43, a compressed part 44 thanks to which the internal surface 29 has a repelled part 45 in the form of a bowl The compressed part 44 is for example obtained under the action of temperature, for example by means of placing plates shaped at high frequency or heated, and pressure, so that, in this area, due to sagging or compression of the cell structure which is maintained until cooling, thanks to the bonding obtained during softening , a permanent stiffening of the cell structure is obtained. This also makes it possible to achieve a specific gravity higher by 1 1

  synthetic foam 20 which provides a more intense effect of support for the foot.

  To compensate for the anatomical features of the foot in the tension zone

  Achilles don 43, an intermediate layer 46 of synthetic foam 47 is applied in the region of the compressed part 44 and on its internal surface 29, for example by bonding, welding, foaming, etc., this inter-layer medial 46 having a specific weight or elasticity which differs from that or that of the synthetic foam 20 of the central layer 21, while in the direction of a

  surface 48 which is turned towards the foot, this same intermediate layer 46 comprises

  wears a covering layer 49, for example a fabric, knitted or matte product

  bonding 50 The connection between the covering layer 49 and the surface layer

  17 can for example be obtained by means of an adhesive 51 It is however possible to

  Also manage a heat treatment which is carried out while applying pressure at the same time, possibly with the interposition of an adhesive sheet or a hot-melt adhesive, so that the bonding is carried out by melting the synthetic foam. 47 and that after cooling, an adhesion is obtained between the surface layer 17 and the cover layer 49, on the one hand, and the

  synthetic foam 47, on the other hand.

  FIG. 9 shows the compressed part 44, provided for the inner boot

  1, which has for example been produced by application of temperature and pressure As shown schematically by the grain limits of the cellular foam 20, thermal compression achieves a shaping of the synthetic foam 20 with open cells That therefore modifies the three-dimensional structure of the synthetic foam 20 in the compressed part 44, while

  actions which influence for example the specific weight of the synthetic foam

  tick 20 can be influenced depending on the material, the temperature

  plicated and applying pressure so it is possible to spare at the same

  time of the repelled parts 45 which are adapted to the anato-

  mics, as well as influencing at the same time the distance 38 between the layers

superficial 16 and 17.

  The application of a temperature allowing shaping or deformation

  tion of the synthetic foam, while exerting pressure, can be obtained

  by means of pressure plates heated electrically and / or by means of

  fear of water, adjusting devices to maintain a range of tem-

  peratures which is suitable for shaping.

  To increase the temperature of the synthetic foam with a view to its thermal shaping, it is also possible to envisage using high-frequency radiation fields, the area of action thus being able to be determined in advance. in a very precise way and areas delimited from a

  in an exact manner which can, if necessary, be shaped.

  The compression of the cellular structure which results from the application of time

  temperature and pressure makes it possible to increase the specific weight in places, for example in marginal areas or in isolated central areas. This makes it possible to influence the cellular structure, in particular to reduce the distances between neighboring cell walls, this operation, also called thermal cracking, taking place at a temperature at which a deformation occurs

  cell structure and to which, thanks to the choice of temperature

  ture, it occurs, for example in particular in the marginal zones or on the cutting surfaces of the blank 32, a partial fusion of the central layer 21 and therefore

  1 o a bond in the molten state between the surface layers 16 and 17.

  The heat treatment makes it possible to adapt the blank 32 to different anatomical features of the feet and to associate several ranges of sizes with

* a shell size of the outer shoe.

  Figures 10 and 11 show other embodiments of a blank

  consisting of the surface layers 16 and 17 and the synthetic foam 20 available

  laid between them, with intermediate layers 46 and cover layers 49 arranged in places Additional layers 52 in one or more thicknesses are placed between the surface layer 17 facing towards

  the inner surface 29 and the cover layer 49, or between the intermediate layer

  diary 46 and the cover layer 49, these additional layers 52 constitute

  killing, for example, pressure distribution layers 53 It is thus possible, in the zone where the forces are higher, to obtain the necessary undeformability between the foot and the inner liner 1 and to distribute therein the forces applied, d 'a

  optimally and in a gentle manner.

  FIG. 12 shows the design provided at the location of the marginal zone of the inner liner 1 The surface layers 16 and 17, with the synthetic foam 20 disposed between them, are compressed along the marginal part 35, between a lower part mold 54 and an upper part of

  mold 55 and by applying a pressure exerted along arrow 56.

  The lower mold part 54 and the upper mold part 55 at the same time comprise, in the region of the marginal part 35, heating elements 57 by means of which the lower mold part 54 and the upper mold part 55 are brought into a temperature range in which the synthetic foam 20 passes to the plastic state Thus, in a connection zone 58, the synthetic foam 20 is compressed to a thickness 59 which is between 1 and 0.2 mm, preferably equal to about 0.5 mm, so that the layers

  surface 16 and 17 rest almost on top of each other and the synthetic foam

  tick 20 melted creates an adhesive bond 60 which, after solidification, ensures

  a permanent bond between the surface layers 16 and 17.

  Furthermore, it is possible, simultaneously with the compression operation along the marginal part 35, to move a cutting blade 61 in the direction of the lower mold part 54 along an outer peripheral surface 62 of the upper part. mold 55, along arrow 63, and therefore to cut the blank 32 in the connection area 58 in a manner consistent with the desired external dimensions. FIG. 13 shows an embodiment of a blank intended to constitute the inner liner 1 which is in several parts For example, a partial blank element 64 consists of the lateral forefoot part 8 and the rod part 3 and the rear rod portion 14 which are linked to the latter in one piece, while

  that another partial blank 65 element comprises another lateral front part

  foot 66 and the sole part 11 linked to the latter in one piece To form the inner liner 1, the partial blank elements 64 and 65 are linked together in the heel area 40, at the points where the shoulders 30 are arranged opposite

  one from the other, the connection being effected for example by stitching, gluing, etc. The

  pushed back tie 26 corresponding to the outer contour of the foot 2 is for example arranged in the transition zone between the lateral forefoot part 66 and the sole part 11, which makes it possible to form the fold line 27 which facilitates the

shaping.

  As has already been described above, in addition to the connection made in the heel area 40, there is also provision, as has already been described, for a connection of the forefoot side portions 8 and 66 between them in the toe area 12 and instep area 6, while the rear rod portion 14 is also

  forms in the direction of the upper part 3 and is fixed in the heel area 40.

  Of course, in addition to the embodiments shown for the blanks of a single te-

  nant or in several parts, we can also consider a series of other forms of

  blank having different geometric parameters One can, of course, consider

  Also manage blanks that have more than two partial blank elements.

  We should also mention the fact that, for a better representation of the

  inner boot according to the invention, the figures are presented in a ma-

  partially schematic and that the parts are not proportional to each other Isolated parts of the described embodiments may also

  constitute independent solutions in accordance with the invention.

  These are mainly the embodiments shown in Figures 1, 2, 3, 4, 5; 6, 7 8; 9; 10; i 1; 12; 13 which can be the subject of independent solutions in accordance with the invention The aims to be achieved and the solutions in accordance with

  the invention, which concerns them, emerge from the detailed descriptions of these figures.

Claims (22)

  1 preformed part, in particular blank for inner liner or elements   partial blanks for such an inner bootie, comprising superficial layers   these, arranged at a distance from each other, and, between them, an intermediate layer of synthetic foam, these layers all being joined by means of a bonding layer so as to form a sandwich element, characterized in that that the central layer (21), which has a substantially uniform initial thickness, is compressed, at least along the contour line (31) of the blank (32) of an inner liner, to a thickness less than at 0.5 mm under an application of pressure and temperature, in that the surface layers (16, 17) are held by the synthetic foam (20) in this position at the   ambient temperature and that a cutting edge extends into the compression zone even synthetic foam.   2 preformed part according to claim 1, characterized in that the central layer (21) is compressed to a thickness less than the initial thickness inside the contour line (31) of the inner liner part and   along shaping and / or stiffening zones.   3 preformed part according to one of claims 1 and 2, characterized in   that, in the area of the contour line (31), there are disposed contiguous bands   bare which extend inwards from the side edges and in which the central layer (21) is compressed to a thickness which is less than in the neighboring areas.   4 preformed part according to one of claims 1 to 3, characterized in   that in the area of the marginal parts (37) connecting to the surface layers   skies (16, 17), the synthetic foam (20) is compressed by mechanical means   thermal and thermal so as to have a higher specific weight than that   of the inner zone of the central layer (21).   Preformed part according to one of Claims 1 to 4, characterized in that   that one of the surface layers (16, 17) has a three-dimensional curved shape   which faces the other surface layer (16, 17).   6 preformed part according to one of claims 1 to 5, characterized in that   that the blank (32) is formed by the developed projection (28) of a piece of rod (3).   7 preformed part according to one of claims 1 to 6, characterized in   that the blank (32) is formed from the developed projection (28) of a piece of rod (3) and a forefoot piece (5).   8 preformed part according to one of claims 1 to 7, characterized in   that the blank (32) constitutes a developed part (28) of the inner liner (1) which is in one piece.   9 preformed part according to one of claims 1 to 8, characterized in   that reinforcing elements, for example inserts (41), are placed in the area of one of the two surface layers (16, 17) or between a   surface layer (16, 17) and the central layer (21).   Preformed part according to one of claims 1 to 9, characterized in   that the reinforcing elements consist of nets, grids, fabrics, quilting of feathers or fibers of metal, mineral materials or synthetic substances and   natural, including glass fibers, graphite fibers, wool fibers and ana- logues.   11 Preformed part according to one of claims 1 to 10, characterized in   go what the density or the specific weight of the synthetic foam (20) of the central layer (21) or of the marginal zones (35) of the central layer (21) is   distributed differently over the extent of the surface of the blank (32).   12 preformed part according to one of claims 1 to 11, characterized in   that partial areas of the blank (32) are reinforced with a layer   additional (52) deposited on one of the two surface layers (16, 17).   13 Preformed part according to one of claims 1 to 12, characterized in   an intermediate layer (46) made of plastic, in particular synthetic foam (47) with a high modulus of elasticity, in particular a flexible foam, is disposed between the additional layer (52) and the surface layer (16,17) the closer to the latter.   14 Preformed part according to one of claims 1 to 13, characterized in   that the additional layer (52) and / or the intermediate layer (46) are   joined to the surface layer (16, 17) and / or between them by means of layers of   bonding and sealing (39), in particular dry adhesive powder, foil sheets   zion or impregnated sheets added.   Preformed part according to one of claims 1 to 14, characterized in   that the additional layer (52) is bonded to the surface layer (16, 17) by means of the plastic of the intermediate layer (46), associated with this surface layer, which is shaped by mechanical means and / or thermal.   16 preformed part according to one of claims 1 to 15, characterized in   that the additional layer (52) and / or the intermediate layer (46) are   laid in a part set back from the surface layers (16, 17) of the blank (32) and are connected to the surface layer (16, 17) by means of the intermediate layer   (46) compressed by mechanical or thermal means.   17 Preformed part according to one of claims 1 to 16, characterized in   that the specific gravity or density of the intermediate layer (46) is lower in the region of a recessed portion of the surface layer (16, 17) than in the regions adjacent to the latter comprising an intermediate layer   (46) compressed by mechanical and thermal means.   18 preformed part according to one of claims 1 to 17, characterized in   that the central layer (21) and / or the intermediate layer (46) are possible   made of a synthetic foam (47) with open cells.   19 Preformed part according to one of claims 1 to 18, characterized in   that the specific choice of synthetic foam (20, 47) of the central layer (21) and / or of the intermediate layer (46) is lower in the interior zone than in the marginal zones (37), the marginal zones (37) however preferably having a specific weight at least three times greater than that of the interior area.   Preformed part according to one of claims 1 to 19, characterized in   that the central layer (21) is formed of flexible foam, for example   synthetic polyether or polyester foam, having in particular a special weight   specific between 10 kg / m 3 and 150 kg / m 3, preferably equal to 60 kg / m 3.   21 preformed part according to one of claims 1 to 20, characterized in   that the surface layers (16, 17) and / or the central layer (21) are   air-permeable, but preferably free of moisture.   22 Preformed part according to one of claims 1 to 21, characterized in   that at least one of the surface layers (16, 17) and / or at least one of the   marginal zones (37) are provided with an additional impregnation view of humidity.   23 Preformed part according to one of claims 1 to 22, characterized in   that the surface layer (16, 17) is made of synthetic leather, leather (18), felt, ve-   fleece or fabric (19), knitted product, net or quilting of metal threads or fibers,   plastic, natural or synthetic fibers.   24 Process for the production of preformed parts, in particular slippers   insoles, for example for shoes comprising an outer shell made of   plastic, such as ski boots, work boots and the like, whereby a plate, formed of a central layer of plastic, especially synthetic foam, is bonded to two surface layers, preferably   in a different material, possibly with the interposition of bonded layers   sives, the plate having a continuous thickness, characterized in that it is compressed,   up to a thickness of less than 0.5 mm, the contour line of the blank includes   mant the plastic material of the central layer, by raising the temperature of the synthetic foam by means of heating molds or by using a field H F,   then by applying a compression force or with the subsequent application or if-   multiple of a compression force, and this contour line is maintained in contact until the cellular structure, shaped and formed by means of mechanical and thermal compression, has solidified to the point that the two surface layers keep the desired position at room temperature for them, and in that the blank is then cut out with a cookie cutter in the plate, along the contour line.   Method according to claim 24, characterized in that, simultaneously   ment to the realization of the contour line, the blank is compressed in different areas of its surface, so as to bring them to different thicknesses, raising the temperature of the plastic of the central layer and applying at the same time a pressure and in that this compression of the central layer has   place at the same time as the realization of the external delimitation of the blank.   26 Method according to one of claims 24 and 25, characterized in   that the temperature of the plate is raised at the same time that the line for delimiting the blank is produced and possibly at the same time that the recessed zones and the reinforcement zones are carried out in the other parts of the surface and in this that by applying a compressive force, the central layer is compressed in the marginal zones so as to bring them to a specific weight or a density more   higher than that of the inner zone.   27 Method according to one of claims 24 to 26, characterized in   than a projection developed for part or all of the inner liner   and in that the plastic material of the central layer is compressed to a thickness of less than 0.5 mm along the contour line of the developed projection, while at the same time raising the temperature of the plate and by subjecting it to a pressure, as a result of which the surface layers are maintained in this position, in the area of the contour line, until a point of solidification or creep point of the plastic material is crossed downwards, so that the two surface layers are kept at the temperature   room in the position chosen beforehand between them.