Technical Field
[0001] The present invention relates to a footwear sole, more particularly to a sports footwear
sole.
[0002] More particularly, the invention relates to a footwear sole the extension of which
in the transverse direction can be adjusted.
Prior Art
[0003] It is known that both the comfort and the performance of footwear, for example of
sports footwear, are strictly related to the conformity of the footwear to the specific
morphology of the particular user.
[0004] This correlation is especially pronounced in the case in which the footwear comprises
a rigid, non-deformable element, as with a sports footwear comprising a substantially
soft inner liner and a substantially rigid, non-deformable outer shell.
[0005] Reference can be made, by way of example, to ski boots. In the case of ski boots,
not only does the conformity of the footwear to the morphology of the foot of the
particular user increases the user's comfort, but it also improves the maneuverability
of the ski, since even minimal movements of the user's foot are transmitted effectively
to the ski boot and from this to the ski.
[0006] In particular, for the same length of the foot - and therefore for the same footwear
size - there are users with a particularly large plantar surface, and others with
a particularly narrow plantar surface.
[0007] It is therefore evident that the same footwear may not fit all users with the same
footwear size equally well.
[0008] It is also apparent that making custom-made footwear, while allowing efficient customization
on one hand, would on the other hand involve high manufacturing costs and, consequently,
very high, non-competitive market prices.
[0009] In the past sports footwear were developed which, starting from a standard, non-customized
article, which could therefore be manufactured on a large scale, allowed some degree
of customization.
[0010] In particular, footwear were developed having a transversely adjustable sole, so
that the transverse width of the sole could be increased or reduced for adapting it
to users having a wider or narrower plantar surface, respectively, than the average
one.
[0011] Still referring to the specific example of ski boots, ski boots were developed comprising
a substantially soft inner liner and a substantially rigid outer shell, in which the
sole of the outer shell is adjustable in a transverse direction in order to adapt
the shell - and consequently the ski boot as a whole - to users with a wider or narrower
plantar surface than the average one.
[0012] By way of example, the documents
CH 486 857 and
CH 515 002 both describe a ski boot comprising a sole consisting of two separate side portions
connected to each other by means of an elastic joint interposed therebetween and extending
in the longitudinal direction; adjusting screws allow to adjust the transverse extension
of the elastic joint by virtue of its deformability, so as to vary the width of the
sole.
[0013] Document
EP 1 683 434 shows a substantially analogous solution applied to a generic sports footwear.
[0014] These solutions, however, while allowing to adjust the transverse dimension of the
sole of sports footwear, involve several drawbacks.
[0015] The main drawbacks of said solutions arise from the fact that a discontinuity is
introduced in the footwear sole.
[0016] Firstly, the discontinuity represented by the elastic joint brings about a very remarkable
localized reduction in the flexional and torsional rigidity of the sole.
[0017] Secondly, the connecting areas between the side sections of the sole and the elastic
joint interposed therebetween are subject to wear and consequent detachment.
[0018] This leads to a malfunctioning in the adjustment of the sole on one hand and to a
loss of tightness of the sole with respect to the outer environment on the other hand.
In particular, in the case of ski boot, snow and water can penetrate the boot.
[0019] Document
EP 2 335 506 describes a sole intended for the shell of ski boot and comprising a slot extending
in a substantially longitudinal direction and adjusting means for controlling deformation
of said slot so as to bring closer / spread apart the edges thereof: in this way the
overall width of the sole of the ski boot shell can be customized.
[0020] This solution, too, involves several drawbacks related to the presence of a discontinuity
(the slot) in the footwear sole.
[0021] Firstly, there is inevitably a very remarkable localized reduction in the flexional
and torsional rigidity of the sole in the area of the slot.
[0022] Secondly, said slot constitutes a passage to the outside, which may involve snow
and water infiltrations in the boot, unless specific sealing elements are provided,
which would in any case involve a more complex and - therefore - more cost-expensive
structure.
[0023] The main object of the present invention is therefore to provide a footwear sole
that is adjustable in the transverse direction while at the same time being free from
the drawbacks described above.
[0024] Another object of the present invention is to provide a footwear sole that is adjustable
in the transverse direction while at the same time having a simple and cost-effective
structure, with a limited number of components.
[0025] These and other objects are achieved with the footwear sole as claimed in the appended
claims.
Disclosure of the Invention
[0026] Owing to the fact the footwear sole according to invention comprises a deformable
portion which is made of the same material as the rest of the sole and is made without
discontinuity with the rest of the sole, the non-uniformity in the features of flexional
and torsional rigidity are remarkably limited with respect to known solutions.
[0027] In addition, the absence of connecting areas between portions of the sole that are
made of different materials eliminates the possibility of detachment and the consequent
risks of malfunctioning and infiltration of water and foreign bodies from the outer
environment. Said deformable portion extends in the longitudinal direction of the
footwear sole - along the longitudinal axis of said sole or in parallel thereto -
at least over a substantial portion of the length of said sole.
[0028] According to a preferred embodiment, said deformable portion is made as a bellows-like
portion, the pleats of which can be more or less compressed / stretched so as to vary
the extension of said bellows-like portion in the transverse direction and therefore,
in the end, of the sole as a whole.
[0029] According to a preferred embodiment, the deformable portion is made as a single piece
with the rest of the sole, during a single step of injection molding.
[0030] According to an alternative embodiment of the invention, the deformable portion is
made as a an element which is double-molded or over-molded with respect to the rest
of the sole; such construction allows, for the same material, to obtain, for the deformable
portion, a lower rigidity than the rest of the sole.
[0031] In its simplest embodiment, the deformable portion is deformed as a consequence of
the insertion of the user's foot into the footwear.
[0032] However, the footwear sole of the invention preferably comprises an adjusting arrangement
for adjusting said deformable portion in order to vary the extension thereof in a
transverse direction.
[0033] Advantageously, according to a preferred embodiment of the invention, said adjusting
arrangement is configured so as to vary the extension of the deformable of the sole
by overcoming its resistance and to adjust the deformation of said deformable portion
to a desired value so that the sole maintains unchanged its flexional and torsional
rigidity.
[0034] For this purpose, the adjusting arrangement comprises one or more rigid members,
to which the deformable portion of the sole is anchored at one or both of its longitudinal
ends and which support the adjusting elements of said deformable portion.
Brief Description of the Drawings
[0035] Further features and advantages of the invention will become more apparent from the
following detailed description of a preferred embodiment of the invention, given by
way of non-limiting example with reference to the annexed drawings, in which:
- Figure 1 schematically shows the footwear sole according to the invention, viewed
from the outside and illustrated in a first configuration;
- Figure 2 1 schematically shows the footwear sole according to the invention, viewed
from the outside and illustrated in a second configuration;
- Figure 3 is a section taken along the line III-III of the footwear sole of Figure
1;
- Figure 4 schematically shows a detail of the footwear sole according to the invention
relating to the adjusting arrangement for adjusting the deformable portion of said
sole, viewed from the inside.
[0036] It is clear that herein the term "inside" means the side of the sole facing the user's
foot and the term "outside" means the side of the sole facing the outer environment.
Detailed Description of a Preferred Embodiment of the Invention
[0037] The preferred embodiment of the invention described below in detail refers to the
application of the invention to a sole for a ski boot, and more particularly to a
sole for the outer shell of a ski boot.
[0038] This embodiment is in no way to be intended as limiting the scope of the invention
and the invention can be applied to the sole of any footwear for which it is deemed
necessary or advantageous to customize the width of the sole of the footwear for adapting
it to the specific morphology of a particular user.
[0039] Further non-limiting examples of application of the invention comprise footwear for
skates (both roller skates and ice skates), mountaineering and trekking footwear,
motorcycle footwear and safety footwear.
[0040] Referring to Figures 1 and 2, there is schematically illustrated the sole 1 of a
substantially rigid outer shell of a ski boot.
[0041] According to the invention, said sole 1 comprises a deformable portion 3 extending
longitudinally along said sole 1 and is arranged between two side portions 5a, 5b.
[0042] The deformable portion 3 can extend along the longitudinal axis L of the sole 1 (as
in the illustrated example) or in parallel thereto.
[0043] The deformable portion 3 can extend over the whole length of the sole 1 (as in the
illustrated example) or over a portion of said length.
[0044] According to the invention, the deformable portion 3 is made of the same material
as the side portions 5a, 5b and is made continuously with said side portions and without
discontinuity therewith.
[0045] In particular, said deformable portion can be made as a single piece with the side
portions 5a, 5b or, alternatively, as an element double-molded or over-molded with
respect to said side portions, but in any case of the same material as said side portions
and without junctions between the different portions.
[0046] The deformable portion 3 is therefore deformable not by virtue of the material of
which it is made, but rather because of its geometrical configuration, which allows
to vary the extension thereof in the transverse direction, i.e. to vary the distance
between the two side portions 5a, 5b.
[0047] In particular, in the illustrated embodiment, the deformable portion 3 is made as
a bellows comprising a plurality of longitudinally oriented pleats 7, as better visible
in Figure 3:
- by exerting a traction in the transverse direction (arrows F1) onto the pleats 7 it
is possible to spread them apart from one another, thus increasing the extension of
the deformable portion 3 in the transverse direction and spreading apart the two side
portions 5a, 5b, thereby obtaining a configuration suitable for users with a wide
plantar surface (configuration shown in Figure 1);
- by exerting a compression in the transverse direction (arrows F2) onto the pleats
7 it is possible to bring them closer to one another, thus reducing the extension
of the deformable portion 3 in the transverse direction and bringing the two side
portions 5a, 5b closer to each other, thereby obtaining a configuration suitable for
users with a narrow plantar surface (configuration shown in Figure 2).
[0048] By virtue of the fact that the deformable portion 3 is made of the same material
as the side portions 5a, 5b and has no junctions, the sole 1 has no areas of discontinuity,
which ensures more robustness and integrity of the sole and more uniform features,
especially regarding its flexional and torsional flexibility.
[0049] Still referring to Figures 1 and 2, although it is possible to imagine that the sole
1 is not provided with any adjusting elements and that the deformation of the portion
3 takes place spontaneously as a consequence of the insertion of the user's foot into
the footwear, it is preferable to provide adjusting elements for adjusting the deformation
of said deformable portion.
[0050] In the illustrated embodiment, the deformable portion 3 of the sole 1 is anchored
at its opposite longitudinal ends to corresponding rigid members 9, 11.
[0051] In particular, said rigid members are made as plates 9, 11 made of a material having
a much higher stiffness than the material of which the sole 1 is made, and arranged
at the toe region and at the heel region of the sole 1, respectively. Fastening means
13 - for example in the form of screws or the like - are provided for firmly anchoring
each of the plates 9,11 to the sole 1, at the corresponding ends of the deformable
portion 3 of said sole.
[0052] The plates 9, 11 support the adjusting elements 15 for adjusting the transverse extension
of the deformable portion 3, said adjusting elements 15 being arranged on the plates
9, 11 at a distance from the fastening means 13 enough to allow adjustment of the
deformation of the deformable portion 3 in the transverse direction.
[0053] Said adjusting elements can be arranged on one side only or - preferably - on both
sides of the deformable portion 3, so as to be capable of exerting a traction / compression
force onto the pleats 7 of the deformable portion 3 on one side only or on both sides,
respectively.
[0054] In addition, the adjusting elements can be configures so as to cause a symmetric
traction / compression of the deformable portion 3 or so as to selectively cause a
traction on either side of the deformable portion 3, respectively.
[0055] In the shown embodiment, two pair of adjusting elements 15 are provided, namely a
first pair on a first plate 9 close to the toe portion of the sole 1 and a second
pair on a second plate 11 close to the heel portion of the sole 1, each pair comprising
two elements arranged on opposite sides of the deformable portion 3.
[0056] The plate 9 with its corresponding fastening means 13 and corresponding adjusting
elements 15 is also shown in more detail in Figure 4.
[0057] In the illustrated embodiment, the adjusting elements 15 consist of corresponding
eccentric elements.
[0058] Each eccentric element 15 has a cylindrical portion fitted in a corresponding through-hole
formed in the rigid plate 9, 11, and an eccentric portion engaged in a corresponding
seat in the sole 1, in the proximity of the deformable portion 3 of said sole.
[0059] In this way, a rotation of the eccentric element 15 exerts a traction or compression
force onto the deformable portion 3 of the sole 1 and a consequent variation of the
transverse extension of said deformable portion 3, whereas the rigid plate 9, 11 remains
fixed to the sole 1 without deformation or displacement.
[0060] Rotation of the eccentric element 15 can be effected by means of an appropriate tool
100 - for example an Allen wrench or a lever specific for amplifying the torque to
be applied - and to this aim each eccentric element 15 has a seat 15a in which said
tool 100 can engage.
[0061] As anticipated above, the adjustment arrangement of the sole according to the invention
comprises at least one adjusting element 15.
[0062] In the illustrated embodiment, the presence of a pair of eccentric elements 15 on
each of the plates advantageously allows separate, independent adjustment of the deformation
of the deformable portion 3 on the medial side and on the lateral side of the sole
1.
[0063] From the above description, it is apparent that the invention allows to achieve the
objects set forth above, as it allows to combine the possibility of adjusting the
transverse extension of a footwear sole, for adapting it to users with a more or less
wide plantar surface, with the need of avoiding any discontinuity and non-uniformity
in the structural features of the sole.
[0064] It is further apparent that the above description has been given by way of non-limiting
example and that several modifications and variants are within the reach of the person
skilled in the art and in any case fall within the scope of the invention as defined
in the appended claims.
[0065] In particular, although the preferred embodiment described above relates to a ski
boot, the invention is profitably applicable to a variety of different footwear as
well.
[0066] Furthermore, although in the embodiment described above reference is made to a deformable
portion made as a bellows, any other geometrical configuration of the deformable portion
that allows to vary the extension thereof in the transverse direction can also be
used.
1. Footwear sole (1), of the kind comprising a deformable portion (3), extending in the
longitudinal direction of said sole (1), and a pair of side portions (5a, 5b), arranged
on opposite sides of said deformable portion (3), characterized in that said deformable portion (3) is made of the same material as said side portions (5a,
5b) and is made continuously with said side portions (5a, 5b), with no discontinuity.
2. Footwear sole (1) according to claim 1, wherein said deformable portion (3) is made
as a bellows comprising a number of pleats (7) oriented along the longitudinal direction
of said sole (1).
3. Footwear sole (1) according to claim 1 or 2, wherein said deformable portion (3) extends
over the whole length of said sole (1) or at least over a substantial portion thereof.
4. Footwear sole (1) according to any of the preceding claims, wherein said deformable
portion (3) is made as a single piece with said side portions (5a, 5b).
5. Footwear sole (1) according to any of the preceding claims, wherein said deformable
portion (3) is provided with an adjusting arrangement (9, 11, 15) for varying the
extension thereof in a transverse direction and for setting said extension at a preset
value.
6. Footwear sole (1) according to any of the preceding claims, wherein said deformable
portion (3) is anchored at one or both of its longitudinal ends to one or more corresponding
rigid members (9, 11), said one or more rigid members being made of a material having
a much higher stiffness than the material of said sole (1).
7. Footwear sole (1) according to claim 6, wherein said deformable portion (3) is provided
with an adjusting arrangement (9, 11, 15) for varying the extension thereof in a transverse
direction and for setting said extension at a preset value and wherein said one or
more rigid members support adjusting elements (15) for adjusting the extension in
the transverse direction of said deformable portion (3).
8. Footwear sole (1) according to claim 7, wherein said adjusting elements comprise respective
eccentric elements (15).
9. Footwear, more particularly sports footwear, comprising a sole (1) according to any
of the claims 1 to 8.
10. Footwear according to claim 9, wherein said footwear comprises a substantially soft
inner boot and a substantially rigid outer shell and wherein said sole (1) according
to any of the claims 1 to 8 is the sole of said substantially rigid outer shell.