U.S. patent application number 09/994783 was filed with the patent office on 2002-07-18 for sole for boot, in particular a sports boot, a method of manufacturing same, and a boot having such a sole.
This patent application is currently assigned to SALOMON S.A. Invention is credited to Girard, Francois, Saillet, Benoit.
Application Number | 20020092207 09/994783 |
Document ID | / |
Family ID | 8857019 |
Filed Date | 2002-07-18 |
United States Patent
Application |
20020092207 |
Kind Code |
A1 |
Girard, Francois ; et
al. |
July 18, 2002 |
Sole for boot, in particular a sports boot, a method of
manufacturing same, and a boot having such a sole
Abstract
A sole for a sports boot, such as for cross-country skiing, and,
more particularly, a sole for a sports boot which makes it possible
to improve the torsional stiffness, flexional flexibility,
efficiency of the boot, durability, lesser weight, protection of
the foot, cost savings, industrial workability. To this end, the
sole has a front portion, a rear portion more rigid in longitudinal
bending than the front portion, and a reinforcement. The front
portion has a front half-sole affixed to the reinforcement, the
rear portion has a rear half-sole affixed to the reinforcement, and
the front and rear half-soles are assembled to one another in a
junction zone, preferably by cementing and/or riveting and/or
welding. In practice, the reinforcement is made of a composite
material. The front half-sole is first fixed on the front portion
of the reinforcement. The rear half-sole is then fixed by cementing
on the rear portion of the reinforcement, such that its front
portion overlaps the rear of the front half-sole. The invention
also relates to methods of manufacturing the sole and the boot
having such a sole. The boot itself is also covered by the
invention.
Inventors: |
Girard, Francois; (Veyrier
Du Lac, FR) ; Saillet, Benoit; (Albens, FR) |
Correspondence
Address: |
GREENBLUM & BERNSTEIN, P.L.C.
1941 ROLAND CLARKE PLACE
RESTON
VA
20191
US
|
Assignee: |
SALOMON S.A
Metz-Tessy
FR
|
Family ID: |
8857019 |
Appl. No.: |
09/994783 |
Filed: |
November 28, 2001 |
Current U.S.
Class: |
36/117.3 ;
36/107; 36/117.2 |
Current CPC
Class: |
A43B 13/223 20130101;
A43B 5/0482 20130101; A43B 5/0411 20130101; B29D 35/122 20130101;
A43B 13/08 20130101; A43B 13/12 20130101; A43B 13/26 20130101; A43B
13/026 20130101 |
Class at
Publication: |
36/117.3 ;
36/117.2; 36/107 |
International
Class: |
A43B 005/04; A43B
005/16 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 29, 2000 |
FR |
0015431 |
Claims
What is claimed is:
1. A sole for a boot, especially a sports boot, said sole
comprising: a front portion and a rear portion more rigid in
longitudinal bending than the front portion, at least one
reinforcement in said two portions, wherein: the front portion
comprises a front half-sole affixed to the reinforcement; the rear
portion comprises a rear half-sole affixed to the reinforcement;
and the front and rear half-soles are assembled to one another in a
junction zone, preferably, by cementing and/or riveting and/or
welding.
2. A sole according to claim 1, wherein the limit between the
flexible front portion and the rigid rear portion is located
substantially at the rear of the so-called metatarsophalangeal
bending zone.
3. A sole according to claim 1, wherein the two front and rear
half-soles overlap one another in the junction zone and wherein the
length of the junction zone is adjustable depending on the
size.
4. A sole according to claim 3, wherein the rear half-sole (seen
from the bottom) overlaps the front half-sole in the junction
zone.
5. A sole according to claim 1, wherein the junction/overlapping
zone is located in and/or behind the so-called metatarsophalangeal
bending zone.
6. A sole according to claim 1, wherein it includes a reinforcement
constituted by at least one laminated or non-laminated plate
extending from the junction zone, both on at least half of the
front portion and on at least half of the rear portion.
7. A sole according to claim 1, wherein the reinforcement has a
length corresponding substantially to at least 60%, preferably at
least 70% and even more preferably at least 80%, of the length of
the sole.
8. A sole according to claim 1, wherein at least one of its front
or rear portions is designed to cooperate with a sports
apparatus.
9. A sole according to claim 1, wherein at least one of the front
or rear half-soles is constituted by at least one piece for guiding
and for connecting to a sports apparatus.
10. A sole according to claim 9, wherein it has, on its lower
surface, in the front portion and/or rear portion: at least one
guiding member, adapted to cooperate with complementarily shaped
guiding means provided on a sports apparatus, preferably a gliding
support, to which the sole is designed to be coupled; and possibly,
at least one adherent and wear resisting pad.
11. A sole according to claim 1, wherein the reinforcement is
assembled to the front and rear portions of the sole by
cementing.
12. A sole according to claim 1, wherein at least one of the front
or rear (preferably front) half-soles is duplicate molded on the
reinforcement, this duplicate molding being preferably selected
from the moldable plastic materials, reinforced or non-reinforced,
and having appropriate mechanical qualities for rigidity in the
rear portion and flexibility in the front portion.
13. A sole according to claim 12, wherein the front half-sole is
duplicate molded on the reinforcement, and wherein the rear
half-sole is cemented on the reinforcement.
14. A sole according to claim 1, wherein the reinforcement is made
of a composite material.
15. A sole according to claim 1, wherein the reinforcement has a
sandwich structure.
16. A sole, wherein the reinforcement has a sandwich structure
having a thickness less than or equal to 3 mm.
17. A sole according to claim 1, wherein the reinforcement is a
plate covered, at least on one of its surfaces, with at least one
compatibility layer, advantageously constituted by at least one
synthetic film forming polymer, especially selected from the group
including polyamides and/or polyolefines and/or polyurethanes.
18. A sole according to claim 12, wherein the reinforcement is a
plate comprising perforations adapted to enable the passage of
bridges of molding material(s) connecting the portions of the
half-sole located above and beneath the reinforcement.
19. A sole according to claim 1, wherein the front portion
comprises at least one element for coupling to a gliding
support.
20. A sole according to claim 1, wherein, in the rear portion, the
reinforcement has one or several upward extensions, and/or is
associated with at least one other reinforcement.
21. A sole according to claim 1, wherein the rear portion forms an
integral assembly with a stiffener covering the heel, the rear
portion preferably having a different, and even more preferably
greater rigidity than that of the stiffener.
22. A sole according to claim 1, wherein the front half-sole, the
rear half-sole, the reinforcement, and possible the stiffener, are
made of different materials.
23. A sole according to claim 1, wherein it is an outer sole.
24. A sole according to claim 1, wherein it includes one or several
recesses provided at least in its lower surface and showing a
portion of the reinforcement.
25. A method of manufacturing a sole according to claim 1, said
method comprises: using a plate adapted to be the reinforcement of
the sole and having a form corresponding substantially to the form
of the projection, on a plane, of a human foot placed on this
plane; assembling (by cementing, riveting, or duplicate molding)
the reinforcement to a front half-sole to obtain an intermediate
piece.
26. A method of manufacturing the sole according to claim 25,
wherein the assembly, obtained by duplicate molding, the assembly
step comprises: placing the reinforcement in a mold whose cavity
corresponds to the form of the front and/or rear (preferably front)
half-sole of the sole; possibly placing in the mold at least one
element for coupling to a sports apparatus, preferably a gliding
support; duplicate molding the reinforcement by means of identical
or different material(s), preferably different at least for the
front half-sole and the rear half-sole; extracting from the mold
the intermediate piece formed by the reinforcement on which the
front half-sole (or the rear half-sole) is duplicate molded.
27. A method according to claim 26, wherein: a mold of the front
(or rear) half-sole is used in the duplicate molding step; the
duplicate molding of the front (or rear) half-sole is then
undertaken according to the step 3; one then retrieves an
intermediate piece formed by the reinforcement on which the front
half-sole (or the rear half-sole) is duplicate molded.
28. A method of manufacturing the sole according to claim 25,
wherein, subsequent to the process, the rear half-sole (or the
front half-sole) is fixed on the intermediate piece, for example by
cementing.
29. A method according to claim 25, wherein: the intermediate piece
is placed in a mold of the rear (or front) half-sole; the rear (or
front) half-sole is duplicate molded; the sole comprising the
duplicate molded reinforcement is extracted from the mold.
30. A method of manufacturing a boot, especially a sports boot,
said method comprising: manufacturing an intermediate piece
comprising a sole front portion on which a reinforcement is
assembled; assembling the intermediate piece, preferably by
cementing, to an upper portion of the boot (vamp/upper); and fixing
a rear half-sole (or a front half-sole), preferably by cementing,
on the intermediate piece assembled to the upper portion of the
boot (vamp/upper).
31. A boot, especially sports boot, wherein it comprises a sole
according to claim 1.
32. A boot, especially sports boot, wherein it comprises a sole
manufactured by the method according to claim 25.
33. A boot, especially sports boot, wherein it comprises a boot
made according to manufacturing method according to claim 30.
34. A boot according to claim 31, adapted to be fixed on a sports
apparatus, preferably pertaining to the group including: ski boot,
in particular cross-country or telemark ski boot; cycling shoe;
roller skate; ice skate; rowing; water ski; surf; snowboard; ski
surf; wakeboard; climbing crampons.
35. A use of the sole according to claim 1.
36. A use of the sole according to the method of claim 25.
37. A use of the sole according to the intermediate piece as
defined in claim 25.
38. A use of the sole according to the manufacturing of a boot
according to claim 30.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon French Patent Application No.
00 15431, filed Nov. 29, 2000, the disclosure of which is hereby
incorporated by reference thereto in its entirety, and the priority
of which is hereby claimed under 35 U.S.C. .sctn.119.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the field of boots, in
particular sports boots, and more particularly boots adapted to
sports that require rolling/unrolling movements of the foot and/or
to gliding sports involving supports of the same name, such as, but
not limited to, cross-country skiing.
[0004] The invention also relates to gliding sports not involving
rolling/unrolling movement of the foot, such as ice skating, roller
skating, with or without in-line wheels, snowboarding,
skateboarding, etc.
[0005] The present invention relates to a sole, especially an outer
sole for a boot, for example a sports boot. This sole is of the
type of those having a reinforcement or an insert made of a
composite material adapted to provide rigidity in the transverse
direction (high torsional stiffness), combined with a longitudinal
flexibility, especially in the metatarsophalangeal zone (low
longitudinal stiffness).
[0006] The invention also relates to methods of manufacturing the
aforementioned soles via molding techniques.
[0007] Finally, the invention relates to a boot, especially a
sports boot, provided with such a sole.
[0008] 2. Description of Background and Relevant Information
[0009] Sports in which the foot and, therefore, the boot are
subject to more or less pronounced rolling/unrolling movements are,
for example, hiking, running, biking, cross-country skiing
involving the evolutive technique so-called "alternate step" or
"skating step", alpine skiing, telemark skiing, or snowshoeing,
etc.
[0010] There are also gliding sports that do not involve
rolling/unrolling movement of the foot, such as ice skating, roller
skating, with or without in-line wheels, snowboarding,
skateboarding, etc.
[0011] The aforementioned sports have common requirements with
respect to the boot, and especially to the sole, which requirements
are, at the outset, incompatible.
[0012] In fact, all of the aforementioned sports generally require
a shifting of the user's center of gravity from the heel zone of
the foot to the so-called metatarsophalangeal area of natural
bending of the foot, and vice versa. These shiftings serve to
direct and/or propel the user's body, for example, by means of edge
setting or equivalent maneuvers, such as the movement impulse
performed by striding with a roller skate, or a cross-country ski,
whether with the conventional technique or the skating technique.
These shiftings of the center of gravity are accompanied by a
transmission of forces in the heel zone, on the one hand and, in
some cases, by a bending in the metatarsophalangeal bending zone,
on the other hand.
[0013] This generates the requirement for a good transmission of
the forces, without any losses by shock absorption and undesirable
deformation in the area between at least the heel and the
metatarsophalangeal zone and, consequently, a requirement for
rigidity of the sole in this zone, often accompanied by a
requirement for as natural a rolling/unrolling movement as possible
and, therefore, for flexibility of the sole in the
metatarsophalangeal zone, so that it can bend easily with respect
to the metatarsophalangeal joint. This joint can be defined as
being that whose axis forms an angle of about 71.degree. with the
internal tangent of the foot, and crosses the longitudinal median
axis at about 73% of the total length of the foot, from the
heel.
[0014] It is obvious that the integration of two different, and
even incompatible requirements in one element, i.e., the sole,
generally can only be performed to the detriment of one of these
requirements, i.e., the transmission of the forces coming from the
leg in the zone comprised between the heel and the
metatarsophalangeal zone and/or the flexibility in the latter
zone.
[0015] The resulting problem is that, generally, this construction
of the sole cannot meet all of the requirements at the same time,
and it usually represents a more or less satisfactory compromise
between rigidity and flexibility.
[0016] Another problem concerns the manufacture of the soles of the
aforementioned type in one piece. These soles entail high
manufacturing costs, because it is necessary to provide soles of
specific and various lengths for all the desired sizes. This
results in a necessity of manufacturing and storing a large number
of different soles, and of cutting the edges of a sole to obtain a
smaller size. This latter technique, which is only used for the
wear soles, is a waste of material and burdens the production
costs.
[0017] In addition to the mechanical characteristics of torsional
stiffness in the rear portion and of flexibility in longitudinal
bending along the metatarsophalangeal axis, other parameters must
be taken into consideration, including, in particular, lightness,
cost, industrial workability, and durability.
[0018] It is known to use upper/vamp or sole reinforcements in an
attempt to control rigidity and bending. A certain number of prior
technical propositions exist, but none is entirely
satisfactory.
[0019] The patent document No. EP 0 931 470 describes a sports boot
including a stiffening element integrated into the lower portion
(sole unit of the boot). This stiffening element is an insole or an
outsole or a sandwich-type internal reinforcement including an
inner layer 15 made of expanded plastic foam (made of light wood,
touching plastic cylinders, cellular or honeycombed core), this
core being inserted between two layers 13 and 14 based on polymer
(nylon, polyurethane, polypropylene), resin or composite material
including synthetic resins in which carbon, aramide or glass fibers
are inserted. The rigidity of the layers 13 and 14 is greater than
that of the inner layer 15. The thickness of the latter is greater
than that of the layers 13 and 14. It is apparent from FIG. 5 and
the text, column 3, lines 41-53, of EP 0 931 470 that the
stiffening element can include portions of variable cross-section
and different flexibilities, in particular having greater
longitudinal flexibility at the forefoot.
[0020] The sandwich reinforcement according to EP 0 931 470 is
adapted to provide rigidity to the sole unit so as to render it
rigid, or at least semi-rigid. The target applications are mountain
boots, cycling shoes, and roller skate boots. In all these
applications, it is clear that one is not looking for a
longitudinal flexibility in the metatarsophalangeal area which
would enable rolling/unrolling movements with respect to the front
tip of the foot. In addition, this stiffening element complicates
the manufacture and appears to be perfectible with respect to its
mechanical properties.
[0021] The French Patent Publication No. 2 600 868 (based upon
Application No. 86 10130) relates to a sole for a cross-country ski
boot, which is stiff in torsion and flexible in the longitudinal
direction. This sole includes a reinforcement located at least in
the metatarsophalangeal zone and corresponding to an insole
constituted by a composite sheet (glass, carbon or aramide fibers
embedded in epoxy or polyester resins). This composite sheet has
the characteristic of having fibers that are oriented in two or
three directions with respect to the longitudinal axis of the sole
(multidirectional fabric). This is supposed to enable desired
stiffnesses to be obtained in the longitudinal transverse direction
or in torsion. Furthermore, this boot sole does not have optimum
qualities with respect to transverse rigidity, therefore with
respect to the steering of the ski, flexibility, durability,
lightness, efficiency, uniformity and sensitivity of the
rolling/unrolling movement, and with respect to the protection of
the foot during bendings.
[0022] The French Patent Publication No. 2 682 011 (based upon
Application No. 91 12376) relates to a cross-country ski boot whose
torsional stiffness and longitudinal flexibility in the
metatarsophalangeal zone are improved, and which has an outer sole
covered by an insole defining therebetween a peripheral assembly
zone, so-called lasting allowance, which makes it possible to affix
the upper and the vamp to the lower portion of the boot. The outer
sole has properties of torsional rigidity, and it is mounted in
combination with the insole made of a flexionally flexible material
(rubber) in a zone corresponding to the front portion of the foot.
Furthermore, the insole is made of leather or cellulose fibers in
its front end area corresponding to the zone of the toe bones,
while the rear portion is made, for example, of cardboard.
[0023] In this boot, the torsional stiffness in the zone of the
metatarsophalangeal bending axis and, therefore, the control of the
ski remain perfectible.
[0024] Furthermore, this boot could also be improved with respect
to optimizing its efficiency, which results from the spring effect
in this zone of the metatarsophalangeal bending axis.
[0025] Finally, the materials used in the insole of this boot do
not offer all the desired guarantees in terms of stability of the
mechanical properties over time.
[0026] The prior art also includes a certain number of references
that are directed more specifically to soles, and which will be
addressed hereinafter.
[0027] U.S. Pat. No. 2,581,524 proposes to manufacture a two-part
midsole. However, this sole is adapted to a boot for spare-time
activities and, consequently, the rear portion remains flexible,
although it has a higher rigidity with respect to the front
portion. The flexibility and a certain shock-absorption of the rear
portion are obtained by making it out of materials such a cork,
sawdust, or latex. Therefore, the known sole of this document is
not capable of transmitting forces intended for edge setting, for
example, and therefore does not provide a satisfactory solution to
the problems described hereinabove.
[0028] The same is true with the teachings of the U.S. Pat. Nos.
1,428,356 and 3,984,925.
[0029] The French Patent Publication No. 2 743 989 relates to a
sole, especially for a boot adapted to sports requiring an
unrolling movement of the foot, or to gliding sports. This document
describes an outer sole constituted of a front portion and a rear
portion. The rear portion covers at least the base of the heel and
extends up to the metatarsophalangeal bending zone. It is rigid and
substantially non-flexible. The front portion is flexible and has,
at its end corresponding to the end of the foot, at least one
member for coupling to a gliding support such as a cross-country
ski. The adjacent front and rear portions overlap one another in
the junction zone where they are assembled by cementing or
riveting. In the junction or assembly zone, the end involved of the
front portion is overlapped by the corresponding end of the rear
portion. A stiffener of the upper can be affixedly attached on the
rear portion.
[0030] It appears that such a sole can still be improved with
respect to torsional rigidity and the possibility to bend in the
area of the metatarsophalangeal joint.
[0031] The German Patent Publication No. 41 20 136 relates to a
boot sole, especially a sports boot sole, which is sufficiently
flexible in the area of the forefoot in order not to hinder the
rolling/unrolling movements of the foot, on the one hand, and which
is sufficiently rigid, especially in torsion in the journal zone
and in the rear portion, on the other hand. This sports boot sole
has a composite material (matrix+woven or nonwoven fibers) in which
the continuous fibers are oriented in several directions. This
composite material is enclosed in a sole body arranged on the edges
of the sole, made of thermoplastic or elastomeric material and
affixedly attached to the composite material by welding or chemical
bonding, or even by (duplicate) molding. As shown in FIGS. 1 and 2,
the sole can have two composite plates 71a, 71b located in the
front portion and in the rear portion, respectively. These two
composite plates 71a and 71b are housed and fixed in a sole body
forming a frame and including a transverse bridge 72 separating the
two plates 71a and 71b.
[0032] As shown in FIG. 6, this sole can include a single element,
or composite plate 171 extending along the entire length and
ensuring a transverse rigidity. In this embodiment, the rear
portion has a second composite plate 67 having a longitudinal,
diagonal or isotropic rigidity. Also provided is a layer 68 made of
rubber, inserted between the composite plates 171 and 67 in the
rear portion.
[0033] It must be noted that the peripheral sole body forming a
frame in which the composite plate or plates are housed and fixed
is integral. Therefore, here is a problem related to the industrial
manufacture of the soles in one piece for several sizes. The
drawbacks associated with this problem, both economical and in
terms of workability, have been presented hereinabove.
[0034] Moreover, this type of known sole does not offer the
possibility of providing projecting elements on the lower surface
of the sole, such as guiding central grooves or wear resisting
adherence pads.
[0035] Furthermore, the sole according to DE 41 20 136 includes a
relatively large number of elements, which complicates the
industrial manufacture thereof.
[0036] Finally, the mechanical characteristics (optimizing
efficiency, elasticity, resistance) weight, durability, are not
optimized.
[0037] Therefore, one has to establish that the prior technical
propositions are not entirely satisfactory, or are ill-adapted to
solving the overall technical problem consisting of:
[0038] increasing the torsional stiffness:
[0039] so as to improve the steering and the control of the sports
apparatus, especially gliding apparatus (e.g., ski), while
optimizing the bending ability in the metatarsophalangeal zone;
and
[0040] so as to enable the foot to perceive the reactions of the
terrain and of the apparatus;
[0041] optimizing the flexional flexibility, so as to enable a
uniform and easy rolling/unrolling movement of the foot;
[0042] improving the efficiency of the boot by optimizing the
spring effect in the metatarsophalangeal zone, without hindering
the flexibility and torsional stiffness;
[0043] using materials meeting the mechanical requirements
mentioned hereinabove, and capable of maintaining these mechanical
qualities over a long period of time;
[0044] further lightening the weight on the boot;
[0045] protecting the foot during bendings by minimizing the
compressive stress to which the foot is subject;
[0046] maintaining the production cost within acceptable
limits;
[0047] ensuring industrial workability;
[0048] developing a reinforcement that can be easily manufactured
industrially.
SUMMARY OF THE INVENTION
[0049] One of the objects of the present invention is to provide a
boot sole, especially a sports boot sole (e.g., cross-country ski
boot), which procures significant advances, in particular with
respect the aforementioned technical specifications.
[0050] Another object of the invention is to propose a sole for a
cross-country ski boot which makes it possible to improve the
efficiency, steering of the ski, durability, while conserving or
gaining flexibility, weight loss, cost, foot protection, and
industrial workability.
[0051] Another object of the present invention is to provide a
boot, especially a sports boot, and more specifically a
cross-country ski boot, having a reinforcement in the bottom
assembly that is capable of meeting the aforementioned working
specifications as much as possible.
[0052] Another object of the invention is to provide a sole, in
particular an outer sole for a boot, especially a sports boot,
which is lightweight, requires a small quantity of plastic
material, and which makes it possible to replace, or even eliminate
the conventional insole.
[0053] Another object of the invention is to provide a sole for a
boot, especially a sports boot, having a structure such that it is
possible to vary the mechanical characteristics in a wide range,
without unduly complicating the manufacturing process.
[0054] Another object of the invention is to propose a
manufacturing method for the aforementioned sole, as well as a boot
provided with such a sole.
[0055] Another object of the invention is to propose a method of
manufacturing a boot provided with such a sole.
[0056] To achieve these objects, among other things, credit goes to
the inventors for finding a sole that is flexible at the front and
rigid at the rear due to a reinforcement (for example, a composite
reinforcement that is cemented or duplicate molded), this
reinforcement being assembled with two front and rear half-soles
affixedly attached to one another.
[0057] Therefore, the present invention relates primarily to a sole
for a boot, especially a sports boot:
[0058] having a front portion, and a rear portion that is more
rigid in longitudinal bending than the front portion,
[0059] including at least one reinforcement in these two
portions,
[0060] wherein:
[0061] the front portion has a front half-sole affixed to the
reinforcement,
[0062] the rear portion has a rear half-sole affixed to the
reinforcement; and
[0063] the front and rear half-soles are assembled to one another
in a junction zone, preferably, by cementing and/or riveting and/or
welding.
[0064] According to the invention, the construction of the sole
around the reinforcement (which can also be called a core or an
insert), by providing two distinct half-soles for the front and the
rear (preferably duplicate molded at the front), with an assembly
affixed to these two half-soles in a junction zone, contributes to
achieving the desired results in terms of longitudinal flexibility
and torsional rigidity in the front portion, and of longitudinal
and torsional stiffness in the rear portion. The same is true with
respect to:
[0065] the efficiency of the boot (spring effect at the front);
[0066] the steering of a sports apparatus (for example a gliding
support) possibly coupled to the boot sole;
[0067] durability;
[0068] lightness;
[0069] ease;
[0070] the precision of the rolling/unrolling movement of the foot
and of the boot;
[0071] the perception of the sensations coming from the reactions
of the terrain and of the apparatus; and
[0072] the protection of the foot during bendings.
[0073] The rigidity and the non-flexibility at the rear enable an
efficient transmission of the forces coming from the user's leg,
which are adapted to direct or propel the user's body, especially
by enabling an efficient edge setting, or to cooperate with a
guiding system of the ridge-type in cross-country skiing.
[0074] Preferably, the limit between the front portion,
substantially flexible in the longitudinal direction and stiff in
torsion, and the rear portion, rigid in torsion and in the
longitudinal direction, is located substantially at the rear of the
so-called metatarsophalangeal bending area.
[0075] According to another preferred characteristic of the
invention, the two front and rear half-soles overlap one another in
the junction zone, and the length of the junction zone is
adjustable depending on the size.
[0076] The length of this junction zone is adjustable within
certain limits depending on the size. The variation in the
overlapping length allows for the manufacture of soles of various
sizes on the base of the identical rear and front portions,
respectively, which considerably reduces the production and storage
costs through the diminution of the number of various parts to be
manufactured. This construction also provides a better precision in
manufacturing and adjusting the soles to the boots.
[0077] Clearly, there is a limit to the variation in the
overlapping length L (L1, L2). This limit is due to the length of
the reinforcement (for example, composite reinforcement) in
relation to the total length of the sole, but more so to the length
of the half-soles.
[0078] According to a remarkable characteristic of the invention,
the rear half-sole overlaps the front half-sole in the junction
zone.
[0079] Thus, seen from the bottom, the front end zone of the rear
half-sole is located above and covers the rear end zone of the
front half-sole.
[0080] Advantageously, the assembly between the front half-sole and
the rear half-sole is obtained in this junction/overlapping
zone.
[0081] Preferably, the latter is located in and/or behind the
so-called metatarsophalangeal bending zone.
[0082] Such a construction enables a significant weight loss while
guaranteeing the desired mechanical characteristics due to the
reinforcement. Thus, there are less compressive stresses on the
reinforcement compared to the known embodiments as described, for
example, in EP 0 931 470, in which the reinforcement is used as an
insole, or as an insole reinforcement.
[0083] The fact that the rear half-sole, in a bottom view, overlaps
the front half-sole in the junction/assembly zone, precisely
ensures a better assembly and makes it possible to prevent
incipient separations of the rear end zone from the front half-sole
which bends, since the latter is sandwiched between the
reinforcement and the rigid rear half-sole which does not bend.
BRIEF DESCRIPTION OF DRAWINGS
[0084] The invention will be better understood and other
characteristics thereof will become apparent from the description
that follows, with reference to the annexed schematic drawings
showing, by way of non-limiting examples, a plurality of
embodiments, and in which:
[0085] FIG. 1 is a bottom view of a sole according the present
invention;
[0086] FIG. 2 shows a straight transverse cross-section along the
line II-II of FIG. 1;
[0087] FIG. 3 is a side view of a sole according to a second
embodiment of the present invention;
[0088] FIGS. 4a and 4b are side views of a sole according to the
preferred embodiment of the invention as shown in FIGS. 1 and
2;
[0089] FIG. 5 is a bottom view of an intermediate piece for
manufacturing the sole according to the invention (third
embodiment) including the reinforcement on the front area of which
the front half-sole is duplicate molded; and
[0090] FIG. 6 is a lateral view of a boot incorporating a sole
according to the invention (fourth embodiment) as well as a
stiffener.
DETAILED DESCRIPTION OF THE INVENTION
[0091] FIGS. 1, 2, 4a, 4b correspond to the preferred embodiment of
the sole according to the invention.
[0092] In the non-limiting example described here, the sole
according to the invention is an outer sole for a cross-country ski
boot, this sole being generally designated by the reference numeral
1. As shown in the figures, this sole includes a reinforcement 2,
preferably made of a composite material, which, in this case, is
made in the form of an insert included in two front and rear
half-soles designated by the reference numerals 3 and 4,
respectively. The front half-sole 3 and the rear half-sole 4 are
integral with, and can be unitary with, the front portion and the
rear portion, respectively, of the sole 1.
[0093] The front half-sole 3 and the rear half-sole 4 are assembled
to one another in a junction zone L, L1, L2, L3 in FIGS. 3, 4a, 4b,
6, respectively, along a contact plane that can be substantially
perpendicular (FIG. 3: 2nd embodiment) to the plane of the sole, or
which forms, with the latter, an angle less than 90.degree.,
preferably less than or equal to 45.degree. (FIGS. 4a, 4b, 6:
preferred embodiment and 4th embodiment).
[0094] The assembly of the half-soles 3, 4 along this contact plane
is obtained by any appropriate means known to a person with
ordinary skill in the art, for example, by welding and/or cementing
and/or riveting.
[0095] In the preferred embodiment and the fourth embodiment shown
in FIGS. 1, 4a, 4b, and 6, this junction zone corresponds to the
intermediate area of the sole 1 in which, above and beneath the
reinforcement 2, at least a portion of the front end zone 5 of the
rear half-sole 4, in a bottom view, overlaps (or covers) the rear
end zone 6 of the front half-sole 3. This appears clearly in FIGS.
4a, 4b, and 6 in which the junction/overlapping zones are
designated by the references L1, L2, L3.
[0096] As shown in FIGS. 1, 4a, 4b, and 6, the rear end zone 6 of
the front half-sole 3 is beveled and covered (in a bottom view) by
the front end zone 5, also beveled, of the rear half-sole 4,
beneath the reinforcement 2.
[0097] According to the invention, each front 3 or rear 4 half-sole
includes the constituent material located beneath the reinforcement
2, which material may or may not extend above the reinforcement
2.
[0098] In the preferred embodiment of the sole shown in FIGS. 1 and
2, the front half-sole 3 at least partially encloses the front of
the reinforcement 2, such that the constituent material of the
front half-sole 3 is present beneath and above the reinforcement 2.
On the other hand, the rear half-sole 4 does not, or virtually does
not overlap above the rear of the reinforcement 2.
[0099] It is different with the embodiments shown in FIGS. 3, 4a,
4b, and 6, according to which the reinforcement 2 is included in
the two front 3 and rear 4 half-soles, such that the constituent
material of these half-soles is present beneath and above the
reinforcement 2.
[0100] With respect to the reinforcement 2, it is preferably
constituted by at least one laminated or non-laminated plate
extending from the junction zone, both on at least half of the
front portion and on at least half of the rear portion.
[0101] Advantageously, the reinforcement 2 has a length
corresponding substantially to at least 60%, preferably at least
70%, and even more preferably at least 80%, of the length of the
sole.
[0102] It is also preferable that the composite plate 2 forming the
reinforcement have a form corresponding substantially to the form
of the projection, on a plane, of a human foot placed on this plane
of projection. In practice, the total length of the plate 2
corresponds substantially to 90% of the total length of the sole
1.
[0103] According to one advantageous embodiment of the invention,
at least one of these front 3 or rear 4 portions is designed to
cooperate with a sports apparatus.
[0104] In practice, it is naturally the lower surface of the sole
1, or more precisely of the front 3 and/or rear 4 half-sole that
has a form and means provided to cooperate with a sports apparatus,
for example a cross-country ski. Thus, the half-sole or half-soles
3, 4 themselves can be constituted by at least one piece 8, 8a,
9.sub.3, 9.sub.4, 13 for guiding and/or for connecting to a sports
apparatus.
[0105] The result is that, according to an advantageous alternative
embodiment of the invention, the sole 1 has, on its lower surface,
in the front portion and/or rear portion:
[0106] at least one guiding member 8, 9.sub.3, 9.sub.4, adapted to
cooperate with complementarily shaped guiding means provided on a
sports apparatus, preferably a gliding support (for example a
cross-country ski), to which the sole 1 is designed to be coupled;
and
[0107] possibly, at least one adherent and wear resisting pad
8a.
[0108] In addition, according to another interesting alternative
embodiment of the invention, the sole 1, in particular the front
portion, includes at least one member 13 for coupling to a sports
apparatus, preferably a gliding support (for example a
cross-country ski).
[0109] According to an embodiment of the invention, at least one of
the front 3 and rear 4 half-soles (preferably the front half-sole)
is duplicate molded, co-molded, on the reinforcement 2, this
duplicate molding being preferably selected from the moldable
plastic materials, reinforced or non-reinforced, and having
appropriate mechanical qualities for rigidity in the rear portion
and flexibility in the front portion.
[0110] Still preferably, the front half-sole 3 is duplicate molded
on the front of the reinforcement 2 (FIG. 5) and the rear half-sole
4 is cemented on the rear of the reinforcement 2.
[0111] However, it is also possible for the reinforcement to be
assembled on the two half-soles by other assembly techniques, such
as cementing or riveting.
[0112] The type of constituent matrix material(s) of the front
half-sole 3 and of the rear half-sole 4 assembled to one another in
the junction/overlapping zone (L, L1, L2, L3) will be discussed in
more detail hereinafter.
[0113] Advantageously, the reinforcement 2 is made of a composite
material. Thus, it can be constituted of a matrix (for example a
thermoplastic or thermosetting resin) in which short or long
reinforcing fibers are embedded. The reinforcement 2 can also be
made in the form of a composite laminate including one or several
textile layers, woven or nonwoven, which are coated and embedded in
a preferably thermosetting matrix, such as polyester or epoxy
resins. The textile fibers used are, for example, glass, carbon, or
polyaramide fibers.
[0114] According to an improved embodiment, the reinforcement 2 is
formed by a plate having a sandwich-type structure including a core
inserted between two single or multi layered laminas. In the case
where the sandwich structure has a thickness less than or equal to
3 mm, it is referred to as a "microsandwich," such a
"microsandwich" structure being preferably provided in the rear
portion.
[0115] The "sandwich" structures are known in the field of
composite materials. Conventionally, at least one of the laminas
(preferably both) of the "sandwich" structures is made of composite
based on woven or non-woven fibers included in a matrix.
[0116] The outer laminas are constituted by a material selected
from the following group of composites:
[0117] the composites:
[0118] whose matrix is made of thermosetting polymer resin such as
epoxy resins, phenolic resins, polyester resins, and their
mixtures; and
[0119] whose woven or nonwoven fibrous material includes
polyethylene fibers, glass fibers, carbon fibers, polyaramide
fibers (poly-paraphenylene-terephthalamide: KEVLAR.RTM.), metallic
fibers, polyethylene fibers, natural or synthetic textile fibers
and their mixtures; the carbon and glass fibers being more
particularly preferred;
[0120] the composites:
[0121] whose polymeric matrix is made of thermoplastic polymer,
advantageously made of polyamide, polyurethane, polyolefine, or
polyacrilobutadiene styrene (ABS), and their mixtures; and
[0122] whose woven or nonwoven fibrous material includes glass
fibers, carbon fibers, poly-paraphenylene-terephthalamide fibers
(KEVLAR.RTM.), metallic fibers, natural or synthetic textile fibers
and their mixtures; the carbon and glass fibers being more
particularly preferred;
[0123] the composite laminates constituted at least partially by
one or several microsandwich composite sheets each having a
thickness less than or equal to 3 mm and including a core inserted
between at least two composite laminas.
[0124] By way of examples of fibers that can be used in these
composites, one can cite those provided in the table below, which
mentions the type of weaving laps and the mechanical
characteristics of these networks or fibrous laps.
1 Breaking Stress Modulus greater Fibers Weaving greater than than
Glass Unidirectional 700 MPa 25000 MPa Glass Multidirectional 350
MPa 12000 MPa Carbon Unidirectional 1500 MPa 70000 MPa Carbon
Multidirectional 700 MPa 35000 MPa
[0125] Advantageously, the core of the sandwich structure is made
of synthetic foam, preferably polyurethane, polymethacrylate,
polyvinyl chloride, of wood or honeycomb, cellular cores. In the
case of "microsandwich" structures, the core can be a composite
structure having lower mechanical characteristics and/or cost than
those of the laminas. Thus, composite structures having paper or
silk embedded in a matrix can be used.
[0126] In addition to the composites, the reinforcement 2 can be
made of any appropriate material, for example, wood, metal (steel),
thermoplastic polymer.
[0127] According to an advantageous alternative embodiment of the
invention, the reinforcement 2 (composite or non-composite) is a
plate covered, at least on one of its surfaces, with at least one
compatibility layer adapted to promote compatibility between the
reinforcement 2 and the half-sole(s) 3 and 4, preferably duplicate
molded plastic(s), or between the reinforcement 2 and the boot
upper, or yet between the (composite or non-composite)
reinforcement 2 and the rear half-sole. This layer is
advantageously constituted by at least one synthetic film forming
polymer, especially selected from the group including polyamides
and/or polyolefines and/or polyurethanes.
[0128] According to yet other alternative embodiments, the
reinforcement 2 can be composed of a plurality of composite plates
or layers at least partially superimposed or non-superimposed.
[0129] The reinforcement 2 (e.g., composite reinforcement), in this
case the plate, can also be envisioned not to have the shape of the
foot and to occupy a markedly smaller surface than that
corresponding to the preferred embodiment (namely 90% of the
surface of the sole).
[0130] Furthermore, the reinforcement 2 could be formed of a
plurality of elements that are not in the form of plates.
[0131] In one embodiment, the reinforcement 2 is made of a
single-layer type composite formed by an epoxy matrix reinforced by
woven carbon fibers.
[0132] The front 3 and rear 4 half-soles will be discussed in more
detail hereinafter.
[0133] As indicated hereinabove, the front and rear half-soles 3, 4
in the preferred embodiment have, on their lower surface, guiding
blocks or ribs 8 that define a guiding groove 9.sub.3, 9.sub.4
along the longitudinal axis .beta. of the sole 1. A portion 9.sub.3
of this guiding groove 9 is arranged in the front portion, on the
front half-sole 3, and another portion 9.sub.4 of this groove 9 is
located in the rear portion, on the rear half-sole 4.
[0134] This guiding groove 9.sub.3, 9.sub.4 is adapted to cooperate
with a complementarily shaped rib provided on a gliding support,
namely a cross-country ski in this case.
[0135] In this case, these guiding blocks or ribs 8 are constituted
by some types of beams in the longitudinal direction and adapted to
cooperate with a correspondingly shaped guiding edge of the
binding.
[0136] In addition to the fact that they define the guiding groove
9.sub.3, 9.sub.4, these blocks or ribs 8 have the function of
improving the adherence of the boot sole on the support with which
it cooperates, due to the anti-slip pad 8a with which each is
provided. They also have the role of providing the sole with wear
resistance properties, and more particularly resistance to
abrasion.
[0137] It must also be noted that the longitudinal median axis (M)
of the front portion forms an angle with the longitudinal median
axis (M') of the rear portion (FIG. 1).
[0138] This FIG. 1 also shows the axis .DELTA. of the
metatarsophalangeal joint which corresponds substantially to the
bending axis of the front portion of the sole 1. This axis .DELTA.
forms an angle .alpha. on the order of 70.degree. with respect to
the internal tangent of the sole. In addition, this axis .DELTA.
intersects with the longitudinal median axis at a point located at
about 73% of the total length of the sole 1 along the axis .beta.
and from the heel.
[0139] On their upper surface, the front 3 and rear 4 half-soles
have a peripheral edge 10 (duplicate molding) on at least a portion
of the periphery of the sole 1, in this case on the entire
periphery. This peripheral edge or cementing board 10 is adapted to
enable a good assembly, for example by cementing, of the outer sole
1 with the upper/vamp 11 shown in FIG. 6. This cementing board 10
is designed such that it makes it possible to compensate for the
imperfections of the upper/vamp 11, namely roughing, fold,
stiffener, for example.
[0140] According to another advantageous embodiment of the
invention, the sole 1 includes one or several recesses 12 provided
at least in its lower surface and showing a portion of the
preferably composite reinforcement 2.
[0141] Furthermore, the drawings also show that the front half-sole
3 has at least one element 13 for coupling to a gliding support,
for example a cross-country ski. In the present example, it is a
transverse metallic cylindrical rod, perpendicular to the axis
.beta. and affixedly fixed by its two ends to the inner flanks of
the two guiding blocks or ribs 8, in the vicinity of the front end
of the sole 1.
[0142] In the embodiment shown in FIG. 5, two coupling elements 13
are provided.
[0143] The assembly between the front 3 and rear 4 half-soles in
the junction zone L is done with overlapping (FIGS. 1, 4a, 4b, 6)
or without overlapping along a plane substantially perpendicular to
the plane of the sole (FIG. 3). This assembly is obtained by any
known and appropriate means, such as heat bonding, cementing, or
riveting, for example.
[0144] The extreme front limit of the overlapping zone L, L1, L2 is
advantageously constituted by the axis .DELTA. of the
metatarsophalangeal joint. For reasons related to progressiveness
and comfort, and to ensure a better rolling/unrolling movement of
the foot, without rupture, the junction/overlapping zone L, L1, L2
preferably has a rigidity comprised between that of the rear
portion and of the front portion, or even a rigidity that
diminishes progressively from its zone of junction with the rear
portion, up to its zone of junction with the front portion for a
perfect transition with these two extreme rigidities.
[0145] As shown in FIGS. 4a and 4b, it is possible, in the case of
an overlapping of the front 6 and rear 5 ends of the half-soles 3,
4, respectively, to vary the length L, L1, L2, L3 of the
junction/overlapping zone by modifying the degree of overlapping.
In FIG. 4a, the sole has a junction zone having a length L1, and in
FIG. 4b, the latter has a shorter length L2, such that the total
length P1 of the sole 1 of FIG. 4a is shorter than the total length
P2 (size) of the sole 1 of FIG. 4b. The variation margin is
comprised, for example, between 14 and 21 mm. This makes it
possible to cover two to three boot sizes, with a single size of
the front 3 and rear 4 portions, with a reinforcement 2 of a given
length, and without significantly modifying the manufacturing
parameters, which will be developed hereinafter.
[0146] According to an alternative, the reinforcement 2 has, in the
rear portion of the sole, one or several upward extensions (at the
level of the heel, for example) to increase the torsional
rigidity.
[0147] According to another alternative, whether or not cumulative
with the above-mentioned alternative, this reinforcement 2 can be
associated with at least one other reinforcement, preferably at the
rear, in order to increase the rigidity of this portion.
[0148] It can also be envisioned that the reinforcement 2 have
longitudinal corrugations, at least in the metatarsophalangeal
bending zone, to increase the torsional stiffness, without
increasing the flexional stiffness.
[0149] The rear half-sole 4 is preferably rigid and substantially
non-flexible so as to avoid losses of energy by shock-absorption
and parasitic deformation, which enables a better transmission of
forces. To this end, the matrix material selected is advantageously
constituted by a plastic material (thermoplastic) with appropriate
rigidity, possibly reinforced by glass or carbon fibers or a
metallic material. By way of examples of matrix plastic materials
for the rear portion, one can cite: polyamides (ZITEL.TM.),
polyurethanes, polyacetates, polyoxymethylene, polycarbonates,
polyether block amide. In any event, the materials of the rear
portion and of the composite reinforcement are selected such that
this rear portion preferably has a modulus of elasticity comprised
between 260 MPa and 200 000 MPa.
[0150] The front half-sole 3 is flexible to enable the
rolling/unrolling movements of the foot as naturally as possible.
The material(s) used for the front matrix assembly 3 are therefore
selected by taking into account the mechanical qualities specific
to the composite reinforcement 2 in the front portion. For example,
these are plastic materials (thermoplastics) that are suited for
the molding techniques. By way of examples of such plastic
materials, one can cite: polyether block amides (Pebax.TM.),
polyamides, polyurethanes, polyacetates, polyoxymethylene,
polycarbonates.
[0151] It is clear that each front 3 or rear 4 half-sole can be
constituted of several different materials. In this case, the
adherence and wear resisting pads 8a are constituted of a material
distinct from the remainder of the half-sole. For example, it can
be elastomers [such as rubber, styrene-butadiene:
"Styrene-Butadiene Rubber" (SBR)], thermoplastic elastomers [such
as "thermoplastic-rubber"], or thermoplastics [such as polyurethane
(PU), polyethylene butadiene (PEBA), polyamide (PA)].
[0152] FIG. 5 shows an intermediate piece 15 for manufacturing the
sole 1 according to the invention. This intermediate piece only
includes the front half-sole 3, to which the reinforcement 2 is
assembled. In the embodiment shown, this assembly is ensured by
duplicate molding the front half-sole around the front portion of
the reinforcement 2. The reinforcement formed by a composite plate
2 having perforations 7 for enabling the passage of bridges of
duplicate molding plastic material(s) forming the front 3 and rear
4 half-sole or half-soles and connecting the portions of the
half-sole or half-soles located above and beneath the reinforcement
2. The purpose of these perforations 7 is to ensure that, in
obtaining the sole by duplicate molding of the composite
reinforcement 2 with plastic matrix material, the latter extends
through the composite reinforcement. This makes it possible to
improve the mechanical fixing of the duplicate molded half-sole or
half-soles 3, 4 on the composite reinforcement 2. In this case,
this intermediate piece only includes the composite reinforcement 2
with perforations 7, which composite reinforcement is duplicate
molded by the front matrix assembly 3 which has guiding blocks 8, a
groove 9.sub.3 and transverse rods 13 for coupling to the
cross-country ski.
[0153] Advantageously, the transverse metallic rods 13, used as
coupling members, are affixed to the front matrix assembly 3, in
the area of the tip of the sole 1, during duplicate molding.
[0154] FIG. 6 shows a boot having an outer sole 1 according to a
fourth embodiment of the invention. This sole is affixed to an
upper/vamp 11, and has a stiffener 14 in its rear portion.
[0155] This rear portion forms an integral or unitary assembly with
the stiffener 14 which covers the heel, the rear portion preferably
having a different, and even more preferably greater rigidity than
that of the stiffener 14.
[0156] This stiffener 14 surrounds the heel of the foot in the
manner of a shell. Preferably, the stiffener 14 extends from the
heel zone up to the metatarsophalangeal natural bending zone L3.
The effect of holding the heel of the foot, in the manner of a
shell, by the integral assembly formed by the rear portion of the
sole 1 and the stiffener 14, is markedly improved when the
stiffener 14 is substantially rigid and has a rigidity similar to
that of the sole. Preferably, the rigidity of the stiffener 14 is
lower than the rigidity of the rear portion of the non-flexible
sole 1. The choice of rigidity for the stiffener 14, the portion
and the rear half-sole 4 of the sole 1, respectively, can be done
optimally by selecting or not selecting a same material for these
three elements, while keeping the integral assembly. The preferred
materials for the stiffener 14 are leather or plastic materials
possibly reinforced by inserts made of metallic material or glass
or carbon fibers.
[0157] According to an advantageous characteristic of the
invention, the front half-sole 3, the rear half-sole 4, the
reinforcement 2, and possibly the stiffener 14 (FIG. 6), are made
of different materials.
[0158] Advantageously, the stiffener 14 could be associated with
possible upward extensions (or lateral extensions) mentioned
hereinabove and not shown in the drawings. These two elements could
thus cooperate to provide more torsional rigidity.
[0159] According to another one of its aspects, the present
invention relates to a method for manufacturing the sole 1
according to the invention as defined hereinabove.
[0160] Advantageously, this method essentially comprises:
[0161] (1) using a plate 2 adapted to be the reinforcement of the
sole 1 and having a form corresponding substantially to the form of
the projection, on a plane, of a human foot placed on this
plane;
[0162] (2) assembling (by cementing, riveting, or duplicate
molding) the reinforcement 2 to a front half-sole 3 to obtain an
intermediate piece.
[0163] When the assembly is made by duplicate molding, the assembly
step comprises:
[0164] (a) placing this reinforcement 2 in a mold whose cavity
corresponds to the form of the front 3 and/or rear 4 (preferably
front) half-sole of the sole 1;
[0165] (b) possibly placing in the mold at least one element 13 for
coupling to a sports apparatus, preferably a gliding support;
[0166] (c) duplicate molding the reinforcement 2 by means of
identical or different material(s), preferably different materials
at least for the front half-sole 3 and the rear half-sole 4;
[0167] (d) extracting from the mold the intermediate piece 15
formed by the reinforcement 2 on which the front half-sole 3 (or
the rear half-sole 4) is duplicate molded.
[0168] Subsequent to the process, the rear half-sole 4 (or the
front half-sole 3) is fixed on the intermediate piece 15, for
example, by cementing.
[0169] FIG. 5 shows the intermediate piece 15 as obtained in the
preferred embodiment described hereinabove.
[0170] According to an alternative corresponding to the making of
the two half-soles 3 and 4 by duplicate molding, in two distinct,
successive molding operations:
[0171] this intermediate piece 15 is placed in a mold of the rear
half-sole 4 (or front half-sole 3) according to a step a';
[0172] the rear half-sole 4 (or front half-sole 3) is duplicate
molded according to a step b';
[0173] the sole including the duplicate molded reinforcement 2 is
extracted from the mold.
[0174] According to an alternative of the method according to the
invention leading to the sole of the boot of FIG. 6, a stiffener 14
is affixedly fixed to the rear matrix assembly of the sole 1, such
that they form an integral or unitary assembly.
[0175] Due to its design and particularly to its manufacture, at
least partially, by duplicate molding:
[0176] the sole according to the invention has thin layers of
plastic material, such that the plastic matrix is less sensitive to
aging with respect to the mechanical properties;
[0177] it can be envisioned to use a single mold for the sole to
obtain variable mechanical characteristics by merely duplicate
molding reinforcements of various forms and thicknesses.
[0178] According to another one of its aspects, the invention
relates to a quite particular and advantageous method of
manufacturing a boot, especially a sports boot. This method
comprises:
[0179] using the intermediate piece 15;
[0180] assembling the latter, preferably by cementing, to the upper
portion of the boot (upper/vamp); and
[0181] fixing the rear half-sole 4 (or the front half-sole 3),
preferably by cementing, on the intermediate piece 15 assembled to
the upper portion of the boot (upper/vamp).
[0182] Still regarding the boot manufacture according to the
invention, it must be noted that the sole having one or two
half-soles can be used in a "strobel" type assembly method (upper
peripherally sewn to a "strobel" sole), which makes it possible to
avoid the need of a conventional insole which is more rigid and
heavier, resulting in a significant weight loss.
[0183] In all of these sole and/or boot manufacturing methods, all
types of conventional assemblies can be used: cementing, welding,
duplicate molding, screwing, riveting.
[0184] According to another one of its objects, the present
invention relates to a boot, especially a sports boot, having a
sole 1 as defined hereinabove, or a sole 1 obtained by the
aforementioned method.
[0185] The invention also relates to a boot such as defined in the
previous paragraph, and which pertains to the group including:
[0186] ski boot, in particular cross-country or telemark ski
boot;
[0187] cycling shoe;
[0188] roller skate;
[0189] ice skate;
[0190] or any other sport requiring the coupling of a boot to a
sports apparatus, such as rowing, water skiing, wakeboarding,
surfing, snowboarding, ski surfing, climbing crampons.
[0191] Finally, the invention relates to the use of the sole 1 as
described hereinabove, as such or as a product obtained by the
method according to the invention, for the manufacture of a boot as
described hereinabove.
* * * * *