Note: Descriptions are shown in the official language in which they were submitted.
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
Springing element for shoe soles, shoe sole and shoe
having such element
The invention relates to a springing element for
shoe soles, consisting of at least one resilient cap or
dome-like member.
r
Various types of springing~~elements as described
hereinbefore are known, which find application in the
field of footwear, e.g. of sports footwear, and have
the purpose of absorbing shocks deriving from athletic
activities. Other examples of such type of shoes are
those designed to be worn for long periods of time,
which are to have so-called "relax" features. A
discharge system, i.e. a system that can remove
overstresses on the lower part of the locomotor system
a.s the best solution to drastically reduce strains on
articulations, meniscuses, tendons, muscles and bones.
Typically, one or more of said springing elements are
provided a.n the insole region, i.e. the one interposed
between the underfoot member and the actual sole
member, which is in contact with the ground. These
elements are typically applied in the heel zone and in
the plantar zone, i.e. in those subjected to the
highest impact strain.
According to a particularly simple arrangement,
the springing effect may be obtained by providing a
combination of one or more superposed and glued layers
made of one or more elastic materials. As an
alternative thereto, elastic inserts may be provided in
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
2
the forms of chambers containing a fluid having
suitable properties, e.g. air. A different arrangement
provides the use of helical springs, particularly made
of steel or plastic, or of elastic cylinders,
particularly made of polymers, which also provide a
fairly good reactivity. According to another
arrangement, the springing element has the form of a
cap or dome or of an arched washer with a big central
hole. The cap is made from a relatively elastic
material, and the central hole helps to provide the
element with a relative resilience. In order to
increase resilience, another embodiment provides that
the hole is surrounded by a ring of resilient tabs,
which increase the swinging action. According to a
different arrangement, the springing element: may be
composed of a plurality of hollow members, particularly
having a cylindrical shape made of an elastomer, and
connected to each other by bridges of material. Each of
the cylindrical elements has such an internal shape as
to generate two superposed chambers, which communicate
by a duct having a much smaller diameter than the two
chambers, thereby reducing the speed of the air flow
from one chamber to the other and creating the desired
shock absorbing effect, due to the pressure caused by
the walking action. The joined elastic cylinders are
positioned in the insole region with their axes
perpendicular to the sole. In accordance with an
additional improvement, a plurality of domes are
provided, in the form of elastic pads made of a solid
material having suitable resilience properties.
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
3
While the various arrangements as proposed above
allow a fairly good shock absorbing effect as regards
simple walking or sports activities, they have several
drawbacks, which are addressed by this invention.
First, most of the proposed arrangements are quite
expensive and difficult to manufacture, particularly
due to the use of highly specific materials, to the
need of providing complex structures or even air
cushions. In this particular case, it shall be noted
that an extensive use might reduce efficiency of said
cushions and an accidental hole thereon might cause the
shoe to lose all of its functions. Also, according to
the proposed arrangements, the shock absorbing effect
might be insufficient or excessive. Moreover, most
prior art arrangements may cause walking instability
due to an excessive shock absorbing effect, and to the
lack of means fox limiting the springing stroke.,
Therefore, the invention has the object of
providing, by simple and inexpensive means, a springing
element for soles as described herein, as well as a
sole and a shoe which allow to obviate the above
drawbacks, while providing an enhanced or improved
functionality, Whereby the dynamic behavior of the shoe
may be optimally adapted to physiological functional
needs. Another object is to predetermine a limited
springing stroke, thereby reducing the local
instability effect caused by the element. By limiting
the springing stroke, a very important additional
object is achieved, i.e. a certain local compression or
massage-like action on the plantar part, to reduce
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
4
fatigue and assist microcirculation, whose reduced
speed often causes tiredness. In a few cases, the
provision of therapeutic shoes might be desired, for
instance to address vascular problems, like the serious
vascular problems of diabetic patients. A customizable
positioning of the springing element is also desired,
at least within certain limits, as related to specific
needs or particular anatomic conformations. A further
object is to allow an increased air circulation within
the shoe or air exchange with the outside, to provide
obvious foot comfort enhancement advantages.
The invention achieves the above purposes by
providing a springing element as described
hereinbefore, which has at least one notch, but
preferably at least two transverse notches which form a
cross-shaped notch. This notch allows to divide the cap
into at least four independent limbs or sectors which
are joined together along the base edge of the cap.
According to a preferred embodiment of the
invention, the cross-shaped notch may be positioned at
the center, to divide the cap into four identical
sectors. Moreover, the two notches Which form the
cross-shaped notch may have the same width.
Advantageously, especially relative to prior art,
the element may have means for limiting the resilience
range of the sectors defined by the cross-shaped notch.
As reminded above, this allows to limit the instability
sensation due to the springing action and have a
massage-like return action on the plantar part.
These means for limiting the resilience range may
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
be provided by the facing edges of the sectors along
the notches in combination with the width thereof.
Hence, as will be more clearly apparent from the
drawings, when a certain flexing compression is
5 reached, at least some or all of the sector edges come
to contact with each other, thereby creating a "dome"
effect, i.e. an optimized force discharge, and stop the
elastic stroke.
The element may have any size and shape, e.g. the
shape of a cone or truncated cone or combinations of
shapes of cones, truncated cones and/or sectors of a
sphere or spheroid. According to a preferred
embodiment, it may have the shape of a sector of a
spheroid, With an elongated and essentially elliptic
plan shape.
The plan shape of the element may have a longer
and a shorter symmetry axes, with the longer axis being
preferably oriented in the longitudinal direction of
the shoe or in the front to back direction of the foot.
Specific anatomic and/or therapeutic needs might
require one or more different orientations.
The height of the element may be greater than
Width, i.e. the dimension parallel to the bearing base,
so that a proper stability sensation is transmitted to
the user.
The element may be made of one or more relatively
rigid, though intrinsically elastic materials, such as
plastic and/or metal, particularly harmonic steel or
combinations of materials.
In order to obtain a particular elastic behavior,
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
6
the element may have a multilayer laminar composition,
or be made of a single homogeneous material.
Advantageously, the element is smaller than a shoe
sole and its thickness substantially has the same order
of magnitude as the sole thickness.
According to an advantageous improvement, the
dome-like element may have a flat base edge, or an
outer peripheral annular flange whereby the element may
be laid on and/or fastened to the sole, e.g. by gluing
or the like.
According to another advantageous improveanent, the
element may have means to increase the flexibility,
i.e. resilience of one or more sectors. These means may
consist of one or more lateral facing widened parts or
recesses of the notch edges. These recesses may be
obtained, for instance, by providing a number of holes,
particularly four, each at an end of each of the
notches which form the cross-shaped notch, and whose
diameter is slightly greater than the width of each
notch. This essentially reduces the angular extension
of the area whereby each sector is connected to the
basis of the dome and increases the bending potential
of each sector.
The springing element may be provided in
combination with a sole, one or more of said springing
elements being arranged in predetermined patterns
between two superposed sole layers, i.e. an upper
layer, so-called underfoot, and a lower layer, which
forms the actual sole.
Advantageously, the one or more springing elements
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
7
may be disposed with the convex side turned toward the
underfoot, so as to provide a massage-like action on
the sole of the foot, as desired.
The springing elements may be evenly arranged over
the surface of the sole, or mainly concentrated or
exclusively disposed in a few partial zones of the
sole, in response to specific strains over the sole
surface and/or to particular therapeutic massage needs.
Particularly, they may be provided mainly or
exclusively in the heel and/or in the plantar zone.
According to another highly advantageous
improvement of the invention, means for locally
increasing the massage-like action of the dome on the
sole of the foot may be provided.
In accordance with a preferred embodiment of the
invention, these means may consist of a pushbutton-like
element, positioned at the crossing point of the two
notches which form the cross-shaped notch, which has
such a size as to lay over the corner area of each
sector to simultaneously act on all sectors.
This pushbutton may be held in position by a stem
which starts from an intermediate, particularly central
point of the bottom face thereof. The stem extends
perpendicularly downwards to an extent essentially
corresponding to the thickness of the sectors and ends
with a widened retaining head which rests on the bottom
faces of the sectors.
Elastically compressible support means may be
provided between the bottom face of the pushbutton and
the sector area whereon it lays, which means are made
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
8
of a rubber material or the like, and particularly
consisting of at least one O-ring element, designed to
also provide an elastic connection in the contact area
between the button and the small dome and to generate a
further limited instability.
The button may have any suitable shape for
concentrating the micro-massage action but, according
to a preferred embodiment, a,t has a top dome-like face,
so that the massage-like action may be better
concentrated. The shoe may be arranged to have all
springing elements or only some of them provided with
the pushbutton, not only to allow a proper walking
support, but also to customize the above mentioned
massage-like action.
The springing element may consist of combinations
of two or more cap-like elements, made of the same oil
different materials and having the same or different'
curvatures, alternated in a predetermined order.
To this end, associated pumping means may be
provided to increase air circulation inside the shoe,
which means are advantageously controlled by the
compression stroke run by the springing element. In
accordance with a preferred embodiment, these means
consist of an additional dome-like element, made of a
resilient material, which is relatively soft and
airtight, such as rubber or the like.
The pumping element may be complementary a.n shape
to the springing element and be enclosed therein, in
such a manner as to rest on the inner walls of the
springing element.
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
9
Obviously, all the springing elements of a shoe
sole or only some of them may have the internal pumping
member.
According to a preferred embodiment of the
invention, which will be described in greater detail
hereafter, the springing element has the form of a
combined element, i.e. composed of a plurality of
springing elements or members, having the
characteristics as described hereinbefore, and joined
together by a structure.
The springing members may be connected to each
other to form composite, possibly prefabricated
springing elements, arranged all along the sole or only
over some portions thereof.
The composite springing elements may be made by
overlapping composite springing elements provided with
a plurality of coincident springing members, having
different shapes and/or a materials and/or
characteristics. Within a combined springing element,
the springing members may be identical or different,
either individually or in groups, as regards materials,
elastic properties and sizes, whereby, for instance,
the springing action may be customized in relation with
the different areas of the plantar zone.
The springing members which form the combined
element may be interconnected by bridges of material in
the form of flat ribs or the like, particularly made of
the material which forms the springing members, so that
fabrication may be simplified and costs thereof may
reduced. Nevertheless, the small domes may be also used
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
as individual separate elements.
The bridges for connecting the springing members
may be arranged to be at least partly grooved, like
connecting channels, with the concavity turned
5 downwards, i.e. having the same orientation as the
concavity of the springing members.
Similarly, at least some of the pumping members
may be interconnected by a structure of bridges, again
made of the same material as the pumping members.
10 The pumping members may be interconnected by
grooved bridges having the form of connecting channels,
whose concavity has the same orientation as the pumping
members, to form a combined air pumping element. The
function of these channels a.s to provide passageways
from one pumping member to the other, thereby allowing
to balance the presence of air in the various areas
beneath the sole of the foot. Non connected elements
may be also provided. The main purpose is to create an
air blow to improve circulation within the shoe.
Further, negative and positive pressures are alternated
in the shoe, for an increased air exchange with the
outside.
Advantageously, the combined springing element and
the combined pumping element may have complementary
shapes, so that the former may be laid over the latter
to cause the pumping action.
The springing elements either in the form of
separate domes or of a combined springing element
having channel-like connecting elements, may be
disposed on a support plate.
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
11
According to a preferred embodiment, which will be
described in greater detail in the description of the
drawings, the support plate may be a saddle member to
be slidably engaged on another support and guide
member, which may be permanently fastened to the top
face of the shoe sole.
Particularly, the support plate may have, at each
of its two opposite side edges, a saddle member to be
slidably engaged in one of the two opposite side edges
of the guide member, which preferably has an
essentially flat shape.
The sliding plate and/or the support element may
have removable position lock means.
These means may be at least two lugs, preferably
two rows of lugs, and preferably having a rounded
shape, disposed on the bottom face of the support
plate, each row being provided in the proximity of one
of the two saddle-like side edges, and two
corresponding rows of recesses, disposed on the top
face of the support element, or vice versa, so that the
support plate may be snap-fitted at predetermined
locations, here again to allow shoe customization, as
regards the spring and/or massage-like action.
The support element may be arranged to be secured
inside an enclosure of a sole, particularly in the heel
zone. This enclosure has such a size as to allow the
sliding plate to slide from front to back on the
support element, i.e. is slightly longer than the
latter, with reference to the longitudinal direction.
The support element may be secured to the sole in
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
12
a lifted position, e.g. by means of fastening feet, to
allow the support plate to slide.
This invention also relates to a shoe which, as is
known, typically includes a sole part which is formed
by the combination of at least two superposed layers,
the so-called underfoot and the actual sole, and an
upper part. The invention obviously also relates to
the sole.
One or more springing elements with the
characteristics as described above may be provided
between the underfoot and the sole.
These elements may extend in a lifted position
relative to the lower layer of the sole, essentially to
an extent corresponding to the resilience range
thereof .
Advantageously, the underfoot may be removably
anchored to the sole, at least a.n the zones of the
enclosures for the above movable springing elements, so
that these enclosures may be accessed for displacement
and adjustment thereof.
The shoe may also have a heel which causes the
sole, and the shoe in general, to be slanted. In this
case, the springing elements may be themselves
slanted, particularly in the heel zone, with reference
to the horizontal bearing surface, and more
particularly, have the same inclination as the sole,
whereby the inclination of the foot on the shoe may be
partly or wholly compensated. In some particular
cases, the springing elements may have a different,
particularly opposite inclination, with respect to the
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
13
sole.
The advantages of this invention are apparent from
the above, and consist in allowing to provide a shoe
which has an effective springing and shock absorbing
system, and may be also used for the above interesting
and effective therapeutic applications. The springing
element used herein is fabricated simply and
inexpensively, and allows to walk comfortably, while
avoiding the instability effects provided by the shoes
having prior art springing elements.
Further characteristics and improvements will form
the subject of the dependent claims.
The characteristics of the invention and the
advantages derived therefrom will be more apparent from
the following detailed description of the drawings
annexed not by way of limitation, in which:
Fig. 1 is a top plan view of the springing element
of the invention.
Fig. 2 is a sectional view with reference to the
shorter axis of symmetry of the element as shown in
Fig. 1, in an essentially uncompressed condition.
Fig. 3 is the same view as Fig. 2, with the
element in an end of compression stroke condition.
Fig. 4 is a sectional view of the detail of the
pushbutton application area.
Fig. 5 is a top plan view of the springing element
with the pushbutton.
Figs. 6 and 7 are two different perspective views
of a combined springing element, a combined pumping
element and the corresponding sliding support element,
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
14
in a disassembled condition.
Fig. 8 shows the same elements as Figs. 6 and 7 in
a partly assembled condition.
Fig. 9 shows the same elements as Figs. 6 and 7 in
an assembled condition.
Fig. 10 is a sectional view of the heel part of a
shoe with the elements as shown in Figs. 6 and 7
inserted therein.
Fig. 11 a,s the same view as Fig. 10, the springing
elements being fastened in a different manner.
Fig . 12 is a sectional view of the heel part of a
shoe whose sole has an inclined profile.
Referring to Fig. 1, a springing element according
to the invention includes a cap, dome, or arched
washer-like member 1. Obviously, this shape shall be
intended without limitation. The springing member may
also have spheroid shapes or arched non-round shapes
like cones, truncated cones or combined shapes. The
dome-like member 1 a.s made of one or more relatively
rigid but resilient materials, such as plastic or
metal. The preferred embodiment as shown in the
Figures, has the shape of a sector of a spheroid, and
an elongated plan shape. The plan shape has longer and
shorter axes of symmetry, denoted as AA' and BB' in
Fig. 1 and, as shown in Figures 6 to 12, when the
element a.s inserted in the shoe the longer axis AA' is
oriented in the longitudinal direction of the shoe and
in the front-to-back direction of the foot. Different
orientations may be obviously provided to address
particular springing needs and/or particular shoe
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
conformations.
At the center of the cap 1, two transverse notches
2, 3 are provided, whose profile substantially
corresponds to the two axes of symmetry AA' and BB',
5 and which form a cross-shaped notch. This cross shaped
notch 2, 3 allows to divide the cap 1 into four
independent and identical sectors 4 which are joined
together along the base edge of the cap 1. As the
sectors 4 bend, the springing element accomplishes its
10 shock absorbing function. The position of the cross-
shaped notch 2, 3, as shown in Fig. 1 is only a
preferred arrangement, while notches having different
profiles and/or positions may be also provided. The
dashed lines outline another possible notch 5 which is
15 angularly staggered with respect to the notch 2, 3, and
may be provided as an alternative thereto or in
combination therewith. Several different arrangements
may be also provided, e.g. a division of the dome 1
into three sectors by a notch which has no cross-like
shape but a Y or T-shape.
The two notches 2, 3 have a constant width which
defines, as will be apparent hereafter, the resilience
range limit of the sectors 4. The dome 1 may have a
flattened base edge, i.e. a peripheral outer annular
flange, denoted as 6 in Figures 2 and 3, whereby the
springing element may be laid on and/or fastened on the
top surface of a sole or of any support plate 7 (Figs.
6 and 7). The members may be arranged in any manner
over the sole surface and may follow predetermined
patterns, adapted both to~the physiological features of
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
16
the user and to the specific use of the shoe.
In order to further enhance the flexibility
properties of the sectors 4, at each end of each of the
notches 2, 3 Which form the cross-shaped notch, a hole
8 is provided, whose diameter is slightly longer than
the width of each notch 2, 3 and such as to exeate
pairs of lateral widened or recessed portions of the
edges of the notches 2, 3. This actually reduces the
angular extension of the area which connects each
sector 4 to the basis of the dome 1, in such a manner
as to locally weaken each sector 4 and increase the
resilience thereof.
Referring now to Figures 2 and 3, the behavior of
the springing element is shown, upon compression
thereof. In Figures 2 and 3, the element is shown in
combination with and beneath a schematic compression
surface 9, i.e. generally the underfoot. In fact, the
element, as mentioned above, is designed to be inserted
in the insole between the actual sole 10 and the
underfoot 9. In Fig. 2 the element is shown in an
essentially uncompressed condition, whereby the facing
edges of the sectors 4 along the notch 3 are
substantially parallel. When the element is subjected
to a compression force, as denoted by the arrow of Fig.
3, typically the foot pressure on the underfoot 9, the
width of the notch 3 decreases and the edges of the
sectors 4 come at least partly in contact with each
other, thereby stopping the elastic range. It shall be
noted that, in this end of compression stroke condition
a real dome effect is reconstructed, so that no further
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
17
give may be provided. It shall be further noted that
this provides a possible return effect on the sole of
the foot in the form of a pleasurable massage-like
i
effect .
Referring now to Figures 4 and 5, a highly
advantageous improvement of the invention may include a
pushbutton element 11 which has the function to locally
increase the micromassage action of the dome 1 on the
sole of the foot. The pushbutton has a circular shape
with a substantially flat bottom surface 111, which
rests on the corner area of each sector 4 and
simultaneous acts on all sectors. On the other hand,
the top surface 211 has the form of a dome, so that the
massage-like action is better concentrated. Fin O-ring
member is provided between the bottom face 111 of said
pushbutton 11 and the region whereat the latter rests
on the sectors 4, said O-ring being made of an
elastically compressible material, like rubber or the
like. The pushbutton 11 is held in position by a stem
13 which starts from the center of the bottom face 211
of the button 11, which stem 13 extends perpendicularly
downwards to an extent which essentially corresponds to
the thickness of the sectors 4 and ends by a Widened
retaining head 14 which rests on the bottom faces of
the sectors 4. The button 11 may be made from one piece
and be applied by a downward press fitting action, or
may be made of two pieces, and the widened head 14 may
be applied after introducing the stem and be secured in
any manner, for instance by gluing or the like.
Referring now to Figures 6 to 12, a preferred
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
18
embodiment of the invention is shown in the form of a
combined springing element which includes a plurality
of elements having the characteristics as described
hereinbefore. The described element is particularly
designed to be applied in the heel zone 15 and
comprises a plurality of caps 1 (particularly three)
arranged over a support plate 7. The caps 1 communicate
with each other by grooves 16 Whose concavities have
the same orientation as the concavities of the domes 1.
The element composed of the plate 7, the domes 1 and
the grooves 16 may be obtained by simple mo7_ding and
further negative deformation on one side of the plate 7
and positive deformation thereof on the opposite side,
followed by notching and drilling of the domes 1, or in
any other manner.
The support plate 7 has, at the two opposite side
edges, a slide member 107 to be slidably engaged in one
of the two opposite side edges of a support and guide
member 17, typically another plate 17.
Two rows or rounded lugs 18 are provided on the
bottom face of the sliding support plate 7. Each row is
disposed at one of the two side saddle-like edges 107.
The support and guide member 17 also has two
corresponding rows of recesses 117 on its top face,
which are designed to cooperate With the lugs 18 in
such a manner that the support plate 16 may be snap
fitted at predetermined locations. By this arrangement,
the massage-like action may be advantageously
customized and localized in response to individual
needs. In Fig. 10, the above sliding member is shown
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
19
inside an enclosure 19 provided in the heel zone 15 of
a shoe. It shall be noted that the support member 17 is
fitted on feet 20 which help the plate 7 with the
springing domes 1 to slide in the front-to-back
direction. The adjustment is made by lifting the
underfoot 9 upwards. Conversely, in Fig. 11, an
additional layer 21 made of a different material with
respect to the heel, for instance a soft material to
enhance the comprehensive springing action, is provided
between the springing elements and the top face of the
housing 19. Fig. 12 shows the fact that the above
described device. may be also combined with a shoe with
a slanted heel 15.
Referring back to Figs. 6 and 7, a highly
advantageous improvement a,s shown, which allows a
proper air circulation inside the shoe and a certain
air exchange with the outside. A combined air pumping
element is provided, which is composed of a plurality
of domes 122 (particularly three) , made of a resilient
material, which a.s relatively soft and airtight, such
as rubber or the like. The pumping domes 122 are
interconnected by grooved bridges 222, which form
connecting channels and whose concavity has the same
orientation as the pumping domes 122. The pumping domes
122 are complementary in shape to the springing domes 1
and the grooved bridges 222 for interconnecting the
pumping domes 122 are complementary in shape to the
grooves 16 of the sliding plate 7. Therefore, the
combined pumping element 22 is complementary in shape
to all the concavities of the plate 7, whereby it can
CA 02452808 2003-12-31
WO 03/015559 PCT/EP02/08827
be inserted beneath the latter in such a manner that,
When the springing domes 1 is deformed, the air pumping
domes 122 are also simultaneously deformed. The element
may be simply placed beneath the sliding plate 7 and
5 rest on the top face of the support member 17. The
channels 222 allow the passage from one dome 122 to the
other and improve the general balance. Obviously,
separate pumping domes 122 may be provided, even in
combination with separate springing domes 1, i.e. when
10 the latter are not secured onto a support plate 7.
The springing elements may be either separated or
combined in~the form of one or more composite springing
elements, in predetermined positions and/or
arrangements, even different from the ones described
15 above. Obviously, the sole may have, in combination
therewith, other individual or combined layers, either
in the form of multilayer laminates or in the: form of
elements composed of several different parts. Still in
combination therewith, the sole according to the
20 invention may also have one or more inserts for
providing it with particular functional features, such
as stiffening and/or shock-absorbing and/or other
inserts.
Obviously, the invention is not limited to the
embodiments described and illustrated herein, but may
be greatly varied, without departure from the guiding
principle disclosed above and claimed below.
