[0001] The object of this invention is a shoe provided with an interposed cavity which can
be inflated with compressed air to regulate the flexibility of the sole.
[0002] It is known that in all the daily activities performed by people major importance
is attached to comfort during walking, which is greatly influenced by the type of
shoe worn by the user; in particular such comfort in walking is determined by the
degree of characteristic flexibility of the sole of the shoe, which flexibility should
differ for different needs such as, for example, the practice of sporting activities
which necessitates rigid soles to restore the necessary force of reaction, for example
when jumping, or the normal gait of an elderly person who needs greater softness to
cushion the rebound sustained by the foot with each step on the ground.
[0003] There are also known certain developments intended to provide a solution to this
problem and based either on the use of different materials capable of imparting higher
or lower rigidity to the sole, or on the use of insoles with air chambers of various
designs.
[0004] Such air insoles known in themselves, for example by Patent EP 0 293 034 in the name
of the same applicant, do however pose major disadvantages on being applied to a shoe,
either because of the difficulty of insertion therein during a normal industrial processing
cycle, or because of the basic impracticability of achieving correct regulation of
the pressure in the air chamber without rendering uncomfortable the said insole, which
is either too deflated, and therefore superfluous, or too inflated, resulting in the
foot being supported on hard surfaces which soon cause aching feet and an awkward
gait.
[0005] There is therefore posed the technical problem of developing a shoe which is provided
with a sole of inflatable type in order to regulate the flexibility of such sole so
as to modify the features of the shoe and make it suitable both for normal walking
and for the practice of sporting activities.
[0006] The shoe should furthermore ensure maximum comfort and waterproofness under any conditions
and should be capable of easy, repeatable and low-cost production.
[0007] Such problems are solved according to this invention by a shoe formed by an upper
and by a flat sole of the type comprising an air chamber made up of compartments,
capable of being inflated by means of valves, in which the flat sole is provided with
a raised perimetrical edge to which are made integral such air chamber, a rigid countersole
and the upper by means of stitching, gluing or the like, there being also included
in such flat sole a rigid layer, such combination providing a flexible cavity capable
of allowing flat and parallel relative movement of the arch support of the shoe in
relation to the outer sole.
[0008] In a preferred form of implementation of the shoe according to the invention, such
compartmented air chamber is made integral with the sole in a reversible manner, and
furthermore such raised edge of the outer sole is provided with at least one through
hole at right angles to the surface of the said edge.
[0009] Provision is also made for such rigid layer integral with the outer sole to be preferably
included within the thickness of the said sole, albeit divided into two parts, comprising
a front part and a rear part, articulated to one another by means of a transverse-axis
hinge.
[0010] In the shoe according to the invention such rigid countersole is in turn divided
into two parts, comprising a front part and a rear part, articulated to one another
lengthwise by means of a transverse hinge, such front and rear parts being delimited
peripherally by a raised edge capable of being made integral with the matching raised
edge of the outer sole.
[0011] Further features of the shoe according to the invention will become apparent from
the following description with reference to the accompanying drawings, which show:
In figure 1 : an axonometric view of a shoe according to the invention;
In figure 2 : an exploded view of the shoe in fig. 1;
In figure 3 : a sectional view of the shoe according to plotting plane II-II in fig.
1, and
In figure 4 : a plan view of the air cavity according to the invention.
[0012] As shown in the figure, shoe 1 according to the invention consists of an upper part
commonly known as an upper 2, the lower part of which is formed according to the right
or left shape of the foot.
[0013] To such upper 2 is made integral, for example by stitching 2a or the like, a perimetrical
strip 2b made of the same material as used for upper 2, capable of being turned from
top to bottom, and vice versa, around such line of stitching 2a, as will become more
clearly apparent from the following.
[0014] The part of the shoe forming the sole is in turn formed of several parts made integral
with one another; more particularly it consists of an outer sole 4 which has a surrounding
vertical band 4a provided with holes 4b on a horizontal axis; in such outer sole 4
is furthermore included, using a method known in itself, a thin layer 5 of rigid material
capable of imparting greater rigidity to the said sole.
[0015] Such layer 5 is divided into two parts, a front part 5a and a rear part 5b, which
are articulated to one another by means of a transverse hinge consisting of a thin
strip of flexible material. To outer sole 4 is made integral an air chamber 6 suitably
shaped (figs. 2 and 4) which, as shown in the figures, is preferably divided into
three spaces capable of being inflated separately and corresponding respectively to
heel area 6a, arch support area 6b, 6c and toe area 6d.
[0016] Each of these spaces is then connected, by means of a perforated cylindrical chamber
7, to one-way valves 8 through which it is possible to pump into each space the volume
of air needed to obtain the desired rigidity; in order to allow improved distribution
of air in such spaces they are isolated from one another as illustrated in figure
4, and more precisely heel 6a is independent, two spaces 6b of the arch support are
connected to one another and a third space 6c of the arch support is connected to
spaces 6d of the toe, such gluing being carried out by means of connecting channels
109.
[0017] Such spaces 6a and 6d are furthermore separated transversally from spaces 6b and
6c by thin-transverse, continuous, solid strips 9 made of the same material, acting
as a transverse-axis hinge around which such spaces are articulated to enable them
to adapt to the different movements of the foot when walking. Likewise, spaces 6b
and 6c of the arch support are divided by like strips 9a of material arranged longitudinally.
[0018] Such air chamber 6 is made integral with outer sole 4 by means of perforated cylinders
7 restraining valves 8, which are forced into holes 4b of edge band 4a until each
circular edge flange 7a protrudes from holes 4b, causing the locking of air chamber
6 to sole 4.
[0019] As is apparent from figure 3, in the still available thickness of band 4a is inserted
a countersole 10 which is divided into two parts, front 10a and rear 10b, by means
of a strip 10c of thin material forming a horizontal/transverse-axis hinge which allows
articulation of the front part relative to the rear part in the manner already described
for air chamber 6.
[0020] Countersole 10 is then completed by a surrounding vertical edge 10c the height of
which is such as to arrive substantially at the level of the upper free end of edge
4a of outer sole 4 (fig. 3). Once upper 2 is assembled to the outer sole, completed
in the manner described above, band 2b is turned down to overlap edge 4a, whereupon
the shoe is made ready for final stitching 11.
[0021] Such final stitching not only makes upper 2 integral with outer sole 4, but also
fixes in relation to the latter the assembly formed by air chamber 6 and countersole
10, thus making it possible for such assembly to function as a proper shock absorber
having two fixed points: at the top, the final stitching, and at the bottom the outer
sole and therefore the ground, the regulation of the stiffness of such shock absorber
being achieved by the higher or lower internal pressure of the air chamber.
[0022] It should moreover be emphasized that the insertion of countersole 10 makes it possible
to obtain uniform distribution of the pressure of the air chamber on the plan of upper
2, and therefore on the wearer's feet, which pressure would in the absence of the
countersole be concentrated in much smaller surface areas which would be equivalent,
in regard to the feet, to the presence of foreign bodies such as pebbles or the like
inside the shoe.
[0023] Many alternatives may be introduced in the practical implementation of the constructional
details without thereby departing from the scope of protection of this invention as
described in the following claims; in particular many alternatives may be adopted
to render sole 4 integral with upper 2 as an alternative to the method described with
reference to the example in the figure, depending on the type of model and of the
materials used to manufacture the shoe.
1. Shoe formed by an upper (2) and a flat sole (4) of the type comprising an air chamber
(6) made up of compartments, capable of being inflated by means of valves (8), characterized
in that flat sole (4) is provided with a raised perimetrical edge (4a) to which are
made integral such air chamber (6), a rigid countersole (10) and upper (2) by means
of stitching, gluing or the like, there being also included in such flat sole (4)
a rigid layer (5), such combination providing a flexible cavity capable of allowing
flat and parallel movement of the arch support of the shoe in relation to the outer
sole.
2. Shoe according to claim 1 characterized in that such compartmented air chamber (6)
is made integral with sole (4) in a reversible manner.
3. Shoe according to claim 1 characterized in that such raised edge (4a) of outer sole
(4) is provided with at least one through hole (4a) at right angles to the surface
of the said edge.
4. Shoe according to claim 1 characterized in that such holes are preferably three in
number.
5. Shoe according to claim 1 characterized in that such rigid layer (5) integral with
outer sole (4) is preferably included within the thickness of the said sole.
6. Shoe according to claim 1 characterized in that such rigid layer (5) is divided into
two parts comprising a front part (5a) and a rear part (5b) which are articulated
to one another by means of a transverse-axis hinge.
7. Shoe according to claim 1 characterized in that such rigid countersole (10) consists
of two parts comprising a front part (10a) and a rear part (10b) which are articulated
to one another lengthwise by means of a transverse hinge (10c), such front and rear
parts being delimited peripherally by a raised edge (10d) capable of being made integral
with the matching raised edge (4a) of the outer sole.
8. Shoe according to claim 1 characterized in that to such upper (2) is made integral
a strip (2b) capable of being turned over around its line of adherence to the said
upper.
9. Shoe according to claim 1 characterized in that such strip (2b) is made integral with
upper (2) by means of stitching (2a) on one of its edges, the other edge being free
so as to be turned over the edge (4a) of sole (4).