FR2719199A1 - Method of assembling a shoe and shoe obtained by assembly according to such a method. - Google Patents

Abstract

A method for adhering the upper (2) of a shoe or boot (1) to the sole (3) thereof, wherein the upper (2) and the sole (3) are assembled so as to define a sealed cavity (14) therebetween, the cavity (14) is filled with an adhesive (16), and the adhesive (16) is allowed to dry or polymerise. The resulting footwear is also disclosed.

Description

Method of assembling a shoe and shoe obtained by assembling

according to such a method.

  The present invention relates to the field of bonding shoes, in particular those which have a relatively rigid sole. In general, such shoes are used in sports such

  like surfing, skiing, mountain hiking, roller skating or whatever.

  These sports require that the shoe allow a user to take

  reliable supports, while providing a certain comfort.

  A rigid sole allows for example to secure a shoe to a gliding device such as a surf or a ski, or to reduce the fatigue of the foot of the user by avoiding the contraction of the muscles of the arch of the foot in particular

  in case of occasional support of the sole on the ground.

  However, whatever the mode or field of use of this type of shoe, significant mechanical stresses are exerted on the level of the

  connection between the upper and the sole.

  Indeed, the forces exerted by the user and the flexion movements of the leg relative to the foot stress the connection between the upper and the sole; it is therefore necessary that this bond is strong if we want to avoid any risk of

decoupling.

  From a general point of view, a good bonding is obtained between two parts when these are strongly pressed one on the other during drying or

adhesive polymerization.

  A classic example is that of shoes with flexible soles. The rod is mounted on a rigid and glued form. The sole is then displayed on the upper, then a pressure is exerted between the sole and the shape so as to effect the bonding. The flexibility of the sole allows it to fit well on the upper mounted on the form. The quality of the bonding essentially depends on the pressure exerted during

of this operation.

  The problem is more complex in the case of shoes with rigid soles. It is impossible to use the traditional bonding technique because the sole cannot be deformed enough to be pressed onto the upper which

whatever pressure is exerted.

  The solution then consists in trapping the sole and the rod mounted on the form inside a mold. Then, just inject glue under high pressure between the sole and the upper so that the glue fills all the voids and

  "catches" the differences in shape between the upper and the sole.

  However, such an injection bonding method has many drawbacks. First of all, it requires many molds (one for each size), the production of which is often long and costly, and whose

  financial amortization requires mass production of shoes.

  In addition, any change in shoe model results in a change

mold also expensive.

  Pressure injection of the adhesive requires appropriate equipment.

  The implementation of such a process is complex and requires material

  sophisticated and qualified people.

  Consequently, such a bonding method is not really satisfactory.

  The object of the present invention is to remedy these drawbacks by developing an economical and easy-to-implement bonding process as well.

  as a shoe designed for the implementation of such a method.

  The method of bonding the upper and the sole of a shoe according to the invention is characterized in that it comprises the steps consisting in: - assembling the sole and the upper by delimiting a sealed cavity between the two, - fill the cavity with glue,

  - and let the glue dry or polymerize.

  Preferably, the filling is done at low pressure, for example by simple

  gravity at atmospheric pressure.

  Surprisingly, filling the cavity at low pressure, and in particular at atmospheric pressure, has proved to be sufficient for good

  distribution of the adhesive between the upper and the sole.

  Furthermore, the technique used according to the method of the invention does not require an injection mold, which considerably reduces financial investments. This therefore makes it possible to produce small or large series of shoes at will and therefore facilitates adaptation to the constraints of supply and demand

steps.

  As the adhesive is introduced at low pressure in the absence of any expensive and complex material, the implementation is easy and does not require

special qualification.

  Other characteristics and advantages of the invention will be better understood from

  using the description which follows, with reference to the attached schematic drawing

  illustrating, by way of nonlimiting example, how the method can be implemented and in which: - Figure 1 shows the assembly of a rod and a sole before bonding, - Figure 2 shows the filling by glue from the cavity defined between the sole and the upper, through a hole located at the rear of the sole, - Figure 3 shows a sole and a stem glued together, - Figure 4 is a section on IV-IV of Figure 3, - Figure 5 is a section along VV of Figure 4, - Figure 6 shows a sole and a rod o the seal of the cavity defined between the sole and the rod is provided by a seal. FIG. 1 schematically represents the upper 2 and the sole 3 used for the

  manufacture of a shoe 1 using the method according to the invention.

  The rod 2 is a conventional high rod, an upper end 4 of which surrounds the

  lower leg and a lower part 5 of which surrounds the foot of a user.

  It could also be a so-called low rod which has only one

part 5.

  The sole 3 is relatively rigid and in particular comprises a heel 6 located on

its lower side 8.

  The sole 3 is extended vertically by a belt 13 whose outline

  forms a peripheral line or edge 18.

  This belt 13 successively comprises a side wall 9, one end

  front 10, a side wall 11 and a rear end 12.

  The bonding method according to the invention comprises a first step which consists in assembling the upper 2 and the sole 3 as indicated by the arrow F1

of figure 1.

  The shapes of the upper 2 and of the sole 3 are such that a cavity 14, which will be shown in the following figures, is delimited between the upper 2 and the sole 3, on

the entire surface of the sole 3.

  The cavity 14 communicates with the outside via a filling orifice 15

  practiced for example in the thickness of the sole 3.

  A second step in the method according to the invention is shown in FIG. 2.

  Preferably, the shoe 1 is positioned so that the sole 3 is substantially vertical. The orifice 15 which opens into the cavity 14 is located at the rear end 12 of the sole 3. An adhesive 16 more or less liquid is

  prepared for example in a container 17.

  This adhesive 16 can be mono or multi-component; glue 16 can also be

  a resin or any other substance with adhesive properties.

  One can for example use a polyurethane type adhesive with two

  components such as that of CIBA-CEIGY's 2018 reference.

  The filling of the cavity 14 with the adhesive 16 is carried out through the orifice 15, which is therefore located above the cavity 14 in the filling position, by pouring the

  glue 16 of container 17 by simple gravity.

  The method has the advantage of being simple and easy to implement. When the adhesive 16 has filled the cavity 14, it suffices to wait until the setting is final for

ability to use shoe 1.

  It is also possible to envisage filling the cavity 14 at low pressure, by any means known to those skilled in the art. The pressure is that available in most workshops and between 0

and 10 bars.

  In this case, the shoe 1 need not necessarily be kept in a vertical position during the implementation of the process which is the subject of the invention, since the

  pressure replaces the effect of gravity.

  This technique is possible because the rigidity of the sole belt

avoids any deformation.

  In a way, the sole 3 behaves like a mold capable of keeping

  its shape when it is subjected to reduced pressure.

  In all cases, the method makes it possible to obtain a bonding of the rod 2 and of the

  sole 3 to form a shoe 1 such as that shown diagrammatically in FIG. 3.

  A cross section IV-IV of the shoe 1 shown in FIG. 4 shows the distribution of the adhesive 16 inside the cavity 14 in one direction

cross-section of shoe 1.

  On the other hand, a longitudinal section V-V of the shoe 1 shown in FIG. 5 shows the distribution of the glue 16 inside the cavity 14 in a

  longitudinal direction of the shoe 1.

  Ultimately, these two transverse sections IV-IV and longitudinal V-V illustrate the complete distribution of the adhesive 16 in the cavity 14, which cavity extends over

  the entire surface of the sole 3 facing the upper 2.

  The glue 16 therefore fills the cavity 14 in all directions without

  discontinuity, and over the entire surface of the sole.

  The continuity of the adhesive thickness guarantees that the connection between the upper 2 and the sole 3 is made on a surface which is as large as possible, and in any case more

  larger than those obtained in the traditional bonding technique.

  Consequently, the stresses will be less at equal stress, all the more since the sole does not tend to return to its initial shape, since it does not have

  was distorted during bonding.

  For a good implementation of the method, it is desirable that the cavity 14 is sealed so as to avoid loss of glue during the gluing of the rod 2 and

of the sole 3.

  The cavity 14 can be made watertight simply by the complementarity of the

  upper 2 and sole 3 shapes.

  In such a case, the peripheral edge 18 of the sole 3 is designed so as to be flexible enough to form a sealing lip coming to marry the

outer contour of the rod.

  This solution is possible because the pressure undergone by the adhesive 16 during assembly is reduced. The cavity 14 can also be sealed before bonding by means of a seal

  peripheral 20, an example of which is affixed is shown in FIG. 6.

  The seal 20 can for example be made of a flexible waterproof tape glued along

  line 18, straddling the upper 2 and the sole 3.

  A rubber band 1 mm thick and 20 mm wide, by

example, fits perfectly.

  Optionally, the seal 20 can remain integral with the shoe 1 after bonding and then constitutes a decorative or utility element by providing a

additional sealing.

  According to another embodiment, the seal 20 could be a paste

  seal applied between sole 3 and upper 2.

  In all cases, it is possible to add a plug, not shown, to

  close the cavity 14 by filling the orifice 15.

  The stopper can play an aesthetic role; but it can also play a functional role by preventing the adhesive 16 from flowing from the cavity 14 after filling. It is then possible to move shoe 1 even if taking

glue is not finished.

  This advantageously results in a saving in production time.

  The stopper can also also be used to avoid overflow in the case where the adhesive 16 is an expandable foam. In this case, the foam exerts a slight pressure between the sole 3 and the upper 2, which guarantees perfect distribution. Furthermore, the use of an expanding foam guarantees optimal filling.

of the cavity 14.

Claims (12)

  1. A method of bonding the upper (2) and the sole (3) of a shoe (1), characterized in that it comprises the steps consisting in: - assembling the sole (3) and the upper (2 ) by delimiting a sealed cavity (14) between the two, - filling the cavity (14) with an adhesive (16),   - and allow the glue to dry or polymerize (16).   2. Method according to claim 1, characterized in that the filling is done at low pressure.   3. Method according to claim 2, characterized in that the filling is done by gravity.   4. Method according to any one of claims 1 to 3, characterized in that   that the cavity (14) is sealed by means of a seal (20) before bonding.   5. Method according to claim 4, characterized in that the seal (20) remains   secured to the shoe (1) after bonding.   6. Method according to any one of claims 1 to 3, characterized in that   that the cavity (14) is sealed by the complementarity of the shapes of the rod (2) and the sole (3).   7. Method according to any one of claims 1 to 6, characterized in that that the glue (16) is a resin.   8. Method according to any one of claims 1 to 7, characterized in that   that the filling of the cavity (14) with the adhesive (16) is made by an orifice (15) located   above the cavity (14) in the filling position thereof.   9. Method according to claim 8, characterized in that the orifice (15) is located   at a rear end (12) of the sole (3).   10. Method according to any one of claims 8 and 9, characterized in that   that a plug closes the cavity (14) by filling the orifice (15).   11. Method according to any one of claims 1 to 10, characterized in   that the cavity (14) extends over the entire surface of the sole (3) opposite the rod (2).   12. Shoe (1) characterized in that it is obtained by the process according to   any one of claims 1 to 11.