1. Technical Field
[0001] The present invention relates to a stabilizing element for a shoe, in particular
a mountaineering shoe, and to a shoe comprising such stabilizing element.
2. Prior Art
[0002] Mountaineering shoes are required to support a wearer's foot in steep and rough terrain,
to protect it from injuries caused by stones and ice, and to allow for the attachment
of crampons if needed. Therefore, mountaineering shoes usually have very stiff soles,
i.e. the force and / or torque needed to bend the soles to a certain degree is high
compared to other types of shoes, such as e.g. running shoes. To this end, typical
mountaineering shoes include a sandwich construction with a rigid plate directly above
a rubber outsole and a cushioning midsole above the rigid plate.
[0003] For example,
US RE40,474 E relates to a multilayer sole for sport shoes. The sole comprises three layers, including
an outer or ground contact sole having flexibility, ground-gripping, and abrasion
resistance properties, an upper or comfort layer positioned directly beneath the foot
and having elastic shock-absorption properties, and an intermediate layer or rib positioned
directly between the upper portion of the contact layer and the lower portion of the
comfort layer and having torsional rigidity properties which provide both for the
distribution of shocks sensed by the contact layer and for their diffusion over the
comfort layer before they come into contact with the foot.
[0004] EP 0 981 973 A1 relates to an inner sole for a sports shoe, in particular a mountain-climbing or
hiking boot, having an anatomically shaped body made of plastic material, and a strengthening
insert embedded in the body; the insert has a longitudinally ribbed structure, and
includes a main portion extending along the sole of the foot and wide enough to provide
a high degree of torsional rigidity of the inner sole, and a narrow front appendix
extending from the main portion and connected to the main portion substantially at
the metatarsus.
[0005] However, such prior art soles have several disadvantages. First, rigid plates used
to increase the stiffness of the soles tend to become brittle especially at low temperatures
(as typically experienced at high altitudes) and, thus, require reinforcement and
insulation. Such measures, however, increase the weight of such soles. Second, a rigid
plate arranged above a rubber outsole decreases adaptability of the outsole to the
ground which in turn decreases traction.
[0006] It is therefore the object of the present invention to provide a stabilizing element
for a shoe, in particular a mountaineering shoe, which is able to provide a high degree
of stiffness to the shoe, is durable especially at low temperatures, yet lightweight,
and does not impair traction.
3. Summary of the Invention
[0008] According to a first aspect of the present invention, this problem is solved by a
stabilizing element for a shoe sole, in particular for a mountaineering shoe, comprising
(a.) a first plate, comprising at least one opening; (b.) a second plate arranged
at least partially in the opening; and (c.) a third plate arranged at least partially
in the opening and arranged at least partially above the second plate, wherein the
third plate comprises a substantially higher stiffness than the second plate.
[0009] In the stabilizing element according to the invention, the third plate has a substantially
(i.e. within manufacturing tolerances) higher stiffness than the second plate and
is arranged above the second plate, i.e. nearer to a foot of a wearer. The arrangement
of the stiff third plate above (i.e. closer to the foot) the more flexible second
plate provides a high degree of stiffness to the stabilizing element, and thus the
shoe sole into which it is to be integrated.
[0010] Furthermore, the stiff and rigid third plate is insulated between the foot and the
second plate (and the outsole and midsole in the finished shoe). This arrangement
on the one hand avoids or at least reduces the risk of fracture of the stiff and rigid
third plate due to the impact of e.g. rocks or ice. On the other hand, the insulating
arrangement maintains the temperature of the stiff and rigid third plate in acceptable
ranges, thus avoiding or at least reducing the risk that it becomes brittle. Due to
this arrangement, no additional reinforcement or insulation of the stiff and rigid
third plate is required, which would otherwise increase the weight of the shoe sole
into which the stabilizing element is to be integrated.
[0011] Thus, the third plate can have a much higher stiffness because of the insulation
due to its placement by the foot and, owing to this placement, it experiences little
bending.
[0012] Furthermore, since in the shoe sole into which the stabilizing element is to be integrated,
the stiff and rigid third plate is spaced apart from the outsole (by the second plate
between), the shoe sole is more adaptable to the ground and traction is increased,
because the second plate closer to the outsole is less stiff than the third plate.
Moreover, by the arrangement of plates according to the invention, a balance is achieved
between the required stiffness for the mountaineering shoe while allowing flexibility
for walking.
[0013] Finally, the second plate and the third plate are housed in an opening of the first
plate. In this way, the first plate protects the second plate and in particular the
stiff and rigid third plate from the outside, for example from rocks and ice. Furthermore,
the first plate provides for insulation and helps maintaining the temperature of the
rigid and stiff third plate within acceptable ranges, thus avoiding or at least reducing
the risk that the third plate becomes brittle.
[0014] The second plate may comprise a substantially higher stiffness than the first plate.
In this way, the second plate adds to the overall stiffness of the stabilizing element.
However, since the stiffness of the second plate is substantially lower than the stiffness
of the third plate, low temperatures are not as critical for the second plate (which
is arranged closer to the outsole and farther from the foot) than for the more stiff
and rigid third plate. Furthermore, due to the lower stiffness of the second plate,
the outsole is more adaptable to the ground and traction is improved.
[0015] The base material of the second plate and the base material of the third plate may
be reinforced with fibers. Fiber reinforcement is a very effective measure for increasing
the stiffness of materials. Furthermore by varying the degree, i.e. the fiber density,
of fiber reinforcement, stiffness and elasticity of the plates can easily and precisely
be adjusted.
[0016] The second plate may comprise 5% to 20% fiber reinforcement and the third plate may
comprise 20% to 50% fiber reinforcement. In a preferred embodiment, the second plate
may comprise approximately 15% fiber reinforcement and the third plate may comprise
approximately 50% fiber reinforcement. These degrees of fiber reinforcement have shown
to result in sufficient stiffness of the stabilizing element, while at the same time
limiting the risk that the plates become brittle at low temperatures.
[0017] The fibers may be glass fibers. Glass fibers are readily available, rather simple
to handle and may easily be applied to suitable base materials.
[0018] The base material of the first plate may not be reinforced with fibers. Thus, the
risk that the first plate (which forms a kind of frame for the second and third plates)
becomes brittle at low temperatures is at least reduced.
[0019] The first plate, the second plate and the third plate may be made from the same base
material. The use of the same base material makes bonding between the materials easier
than if the materials were different. This eases manufacturing of the stabilizing
element and adds to its durability.
[0020] The base material of the first plate, the second plate and the third plate may be
polyamide. Polyamide is much more durable than the nylon used in conventional mountaineering
shoes. The construction of the stabilizing element according to the invention allows
the more brittle polyamide to be used instead of nylon. Moreover, polyamide does not
experience any kind of permanent deformation after multiple uses.
[0021] Furthermore, the base material of the first plate, the second plate and the third
plate may be TPU or polyether block amide (PEBA). Furthermore, the base material of
the third plate may comprise carbon, as the third plate can experience a very high
stiffness owing to its placement.
[0022] The third plate may be approximately 1 to 3 mm thick. Such a thickness has shown
to result in a sufficiently stiff stabilizing element which at the same time is rather
lightweight.
[0023] The bending stiffness of the third plate may be at least two times higher than the
bending stiffness of the second plate. In this way, the third plate adds the required
stiffness to the stabilizing element, while its insulating arrangement between the
foot and the second plate avoids or at least reduces the risk that it becomes brittle
at low temperatures. Furthermore, since the less stiff second plate is arranged near
the outsole, the shoe sole into which the stabilizing element is to be integrated,
remains more adaptable to the ground.
[0024] The bending stiffness of the second plate may be at least two times higher than the
bending stiffness of the first plate. The second plate adds to the overall stiffness
of the stabilizing element, while the first plate may safely extend to the outside
without the risk of becoming brittle at low temperatures and with sufficient ductility
to withstand snow, ice and rocks.
[0025] The modulus of elasticity of the first plate may be 600 to 1500 MPa. The modulus
of elasticity of the second plate may be 2000 to 4000 MPa. The modulus of elasticity
of the third plate may be 9000 to 13000 MPa. In a preferred embodiment, the modulus
of elasticity of the first plate may be approximately 1100 MPa, the modulus of elasticity
of the second plate may be approximately 3000 MPa, and the modulus of elasticity of
the third plate may be approximately 11500 MPa. These moduli of elasticity have shown
to provide a stabilizing element being sufficiently stiff, yet lightweight and durable.
[0026] The third plate may comprise ribs arranged in a longitudinal direction of the stabilizing
element. Furthermore, the second plate may comprise ribs arranged in a longitudinal
direction of the stabilizing element. Ribs save weight by decreasing material used.
Furthermore, ribs in the longitudinal direction (i.e. in the direction from a heel
portion to a toe portion of a shoe into which the stabilizing element is to be integrated)
increase the bending stiffness by prevention or at least restriction of bending.
[0027] The ribs of the third plate may coincide with the ribs of the second plate. In this
arrangement high stiffness can be achieved because the ribs in the third plate engage
with corresponding ribs in the second plate.
[0028] The ribs of the third plate may have a height of approximately 1 to 3 mm. The ribs
of the second plate may have a height of 1 to 5 mm. Such heights have shown to provide
sufficient bending stiffness while at the same time keeping the strain in the ribs
sufficiently low when the stabilizing element is bent.
[0029] The material of the third plate may have 4 % strain at break at 0° C. With the advantageous
arrangement of plates in the stabilizing element according to the invention, strain
of the third plate is well below this limit even at extreme bending angles.
[0030] The stabilizing element may be adapted to essentially cover the entire foot of a
wearer of a shoe into which the stabilizing element is to be integrated. In this way,
a high bending stiffness is achieved over the entire length of the foot.
[0031] The opening in the first plate may be arranged such that the second plate and the
third plate do not extend to the outside of a shoe into which the stabilizing element
is to be integrated. Thus, the second plate and in particular the stiff and rigid
third plate are protected from the outside, in particular from low temperatures, rocks
or ice.
[0032] A further aspect of the present invention relates to a shoe, in particular a mountaineering
shoe, comprising (a.) an outsole; (b.) an upper; and (c.) a stabilizing element as
described above arranged between the outsole and the upper.
[0033] The shoe may comprise a midsole arranged between the outsole and the stabilizing
element. The midsole may provide cushioning to the shoe. Furthermore, the midsole
may further insulate the second plate and in particular the stiff and rigid third
plate.
[0034] The outsole may be made from rubber. Rubber is readily available, durable, and provides
for very good traction.
4. Short Description of the Drawings
[0035] In the following, further aspects of the present invention are explained in detail
referring to the drawings. These drawings show:
- Fig. 1A:
- An exemplary embodiment of a stabilizing element according to the invention;
- Fig. 1B:
- A cross-sectional view of the embodiment of Fig. 1A;
- Fig. 1C:
- The third plate of the stabilizing element of figures 1A and 1B in more detail;
- Fig. 2A:
- A finite element analysis of an exemplary embodiment of a stabilizing element according
to the invention regarding the strain at a bending angle of 15°;
- Fig. 2B:
- A finite element analysis of an exemplary embodiment of a stabilizing element according
to the invention regarding the strain at a bending angle of 60°;
- Fig. 3:
- A finite element analysis of an exemplary embodiment of a stabilizing element according
to the invention regarding the stress at a bending angle of 30°;
- Fig. 4:
- A finite element analysis of an exemplary embodiment of a stabilizing element according
to the invention regarding the strain at a bending angle of 30°; and
- Fig. 5:
- An exemplary embodiment of a shoe according to the invention.
5. Detailed Description of Preferred Embodiments
[0036] In the following, embodiments and variations of the present invention are described
in detail.
[0037] Figures 1A, 1B and 1C show an exemplary embodiment of a stabilizing element 10 according
to the present invention, wherein Fig. 1B shows a cross-sectional view of the stabilizing
element 10 and Fig. 1C shows the third plate 14 of the stabilizing element 10 in more
detail. The stabilizing element 10 comprises a first plate 11, a second plate 13,
and a third plate 14. The first plate 11 comprises at least one opening 12 as shown
in Fig. 1C. The second plate 13 is arranged at least partially in the opening 12.
Also the first plate 14 is arranged at least partially in the opening 12. For example,
as can be seen in Fig. 1B, the border of the second plate 13 and of the third plate
14 overlap a corresponding border of the opening 12 in the first plate 11. However,
the most part of the second plate 13 and of the third plate 14 is fully arranged in
the opening 12 of the first plate 11.
[0038] Furthermore, the third plate 14 is arranged at least partially above the second plate
13. This means that the third plate 14 is arranged closer to a foot of a wearer of
a shoe into which the stabilizing element 10 according to the invention is to be integrated.
Likewise, the second plate 13 is arranged closer to an outsole of a shoe into which
the stabilizing element 10 is to be integrated.
[0039] Furthermore, the third plate 14 comprises a substantially higher stiffness than the
second plate 13. Stiffness can be measured by bending the plates and/or the stabilizing
element while at the same time measuring the force and / or torque needed to bend
the plate and/or the stabilizing element to a certain angle. Stiffness is higher if
a higher force and / or torque is needed to achieve the same bending angle.
[0040] The base material of the first plate 11, the second plate 13, and the third plate
14, may for example be polyamide. Other materials are possible as well, such as TPU
or polyether block amide (PEBA). The material of the third plate 14 may be based on
carbon. The first plate 11, the second plate 13, and the third plate 14 may be made
from the same base material. Alternatively, different base materials may be used.
Generally, the material of the third plate 14 may have e.g. a 4% strain at break at
0° C. The construction of the stabilizing element according to the invention guarantees
that the strain of the third plate 14 even in extreme situations is well below this
level.
[0041] The material of the second plate 13 and the material of the third plate 14 may be
reinforced with fibers, such as for example glass or carbon fibers. For example, the
second plate 13 may comprise approximately 15% fiber reinforcement and the third plate
14 may comprise approximately 50% fiber reinforcement. The first plate 11 may not
be reinforced with fibers at all. Consequently, the stiffness of the second plate
13 is higher than the stiffness of the first plate 11. For example, the bending stiffness
of the second plate 13 may be at least two times higher than this bending stiffness
of the first plate 11. Furthermore, due to the different degrees fiber reinforcement,
the bending stiffness of third plate 14 may at least be two times higher than the
bending stiffness of the second plate 13. The desired degree of stiffness may also
be achieved by other means than fiber reinforcement, for example by using different
materials for the plates.
[0042] The modulus of elasticity of the first plate may be 600 to 1500 MPa. The modulus
of elasticity of the second plate may be 2000 to 4000 MPa. The modulus of elasticity
of the third plate may be 9000 to 13000 MPa. Specifically, the modulus of elasticity
of the first plate 11 may be approximately 1100 MPA. The modulus of elasticity of
the second plate 13 may be approximately 3000 MPA and the modulus of elasticity of
the third plate 14 may be approximately 11500 MPA.
[0043] In the exemplary embodiment of figures 1A, 1B and 1C the third plate 14 is approximately
1 mm thick. Due to the arrangement of plates according to the invention, this thickness
is sufficient to achieve the desired high stiffness of the entire stabilizing element
10.
[0044] In the exemplary embodiment of figures 1A, 1B and 1C the third plate 14 comprises
ribs, two of which are denoted by the reference numeral 15. The ribs 15 are arranged
in a longitudinal direction of the stabilizing element 10, i.e. in a direction from
a heel portion to a toe portion of a shoe into which the stabilizing element 10 is
to be integrated. The ribs 15 of the third plate 14 have a height of approximately
1 to 3 mm.
[0045] Also in the exemplary embodiment of figures 1A, 1B and 1C, the second plate 13 comprises
ribs, two of which are denoted by the reference numeral 16. The ribs 16 are arranged
in a longitudinal direction of the stabilizing element 10 and have a height of approximately
1 to 5 mm. As shown in Fig. 1B, the ribs 15 of the third plate 14 coincide with the
ribs 16 of the second plate 13. However, it is also possible that the ribs do not
coincide.
[0046] As shown in figure 1A, the stabilizing element 10 essentially covers the entire foot
of a wearer of a shoe into which the stabilizing element is to be integrated. Thus,
the stabilizing element extends from a heel portion 17a over a midfoot portion 17b
to a toe portion 17c.
[0047] Furthermore, as shown in figures 1A, 1B and 1C, the opening 12 in the first plate
11 is arranged such that the second plate 13 and the third plate 14 do not extend
to the outside of a shoe into which the stabilizing element 10 is to be integrated.
Thus, the first plate 11 provides for a rim 18 which protects the second plate 13
and the third plate 14 from the outside, for example from rocks and ice.
[0048] As shown in figures 1A and 1C, the first plate 11 of the stabilizing element 10 may
comprise a second opening 19 in the heel portion. A cushioning or shock-absorbing
member (not shown in the figures) may be arranged in the opening 19.
[0049] Furthermore, as shown in figures 1A and 1C, the stabilizing element 10 may optionally
comprise in the heel portion 17a a heel support member 110. In the exemplary embodiment
of figures 1A and 1C the heel support member 110 is cup-shaped and entirely surrounds
the heel of a foot of a wearer of a shoe into which the stabilizing element 10 is
to be integrated. However, it is also possible that the heel support member 110 only
covers a part of the heel. Furthermore, in the exemplary embodiment of figures 1A
and 1C, the heel support member 110 is integrally formed with the first plate 11.
This adds overall strength and stability, and gives a simpler construction. However,
it is also possible that the heel support member 110 is attached to the first plate
11, for example by gluing or welding.
[0050] Fig. 2A shows a finite element analysis of a stabilizing element 10 according to
the invention. In particular, the strain level in percent at a bending angle of 15°
is shown. The strain in the third plate 14 is at approximately at 0% meaning that
there is no risk of breaking the plate, even at very low temperatures. The finite
element analysis also shows that the plate stiffness at a bending angle of 15° is
at approximately 27 Nm.
[0051] Fig. 2B shows a finite element analysis of a stabilizing element 10 according to
the invention. In particular, the strain level in percent at a bending angle of 60°
is shown. The strain in the third plate 14 is between 0% and approximately 1% meaning
that there is almost no risk of breaking the plate, even at very low temperatures.
As shown in Fig. 2B, the strain in the second plate 13 is higher, namely about 4%.
However, as the second plate 13 comprises a substantially lower stiffness than the
third plate 14, it is less brittle, especially at low temperatures, and the risk of
breaking the second plate 13 is low.
[0052] Fig. 3 shows a finite element analysis of a stabilizing element 10 according to the
invention. In particular, the stress level in percent at a bending angle of 30° is
shown. As can be seen, the stress in the first plate 11 and the second plate 13 is
rather low, whereas the third plate 14 experiences a medium stress level. Accordingly,
the third plate 14 is mostly responsible for the stiffness of the entire stabilizing
element 10.
[0053] Fig. 4 shows a finite element analysis of a stabilizing element 10 according to the
invention. In particular, the strain level in percent at a bending angle of 30° is
shown for almost the entire bending element 10. The strain level is moderate and at
most approximately 1% for the third plate 14. Also in the region of the heel support
member 110, the strain level does not exceed 4% and is for the most part at approximately
2%. This means that the risk of breaking the heel support member 110 is rather low.
[0054] Fig. 5 shows an exemplary embodiment of a shoe 50 according to the invention. The
shoe 50 is a mountaineering shoe comprising an outsole 51, an upper 52, a midsole
53 and a stabilizing element 10 as described above arranged between the midsole 53
and the upper 52. The stabilizing element 10 may be glued, sewn, welded or otherwise
be fixed to other components of the shoe 50, e.g. the outsole 51, upper 52, midsole
53 etc. The outsole 51 may be made from rubber and the upper 52 may be made from conventional
materials like polyester, etc.
[0055] The shoe 50 also comprises a midsole 53 arranged between the outsole 51 and the stabilizing
element 10. However, such a midsole is an optional element and may be omitted in certain
embodiments.
[0056] In the following, further embodiments are described to facilitate the understanding
of the invention:
- 1. Stabilizing element (10) for a shoe sole, in particular for a mountaineering shoe,
comprising:
- a. a first plate (11), comprising at least one opening (12);
- b. a second plate (13) arranged at least partially in the opening (12); and
- c. a third plate (14) arranged at least partially in the opening (12) and arranged
at least partially above the second plate (13), wherein the third plate (14) comprises
a substantially higher stiffness than the second plate (13).
- 2. Stabilizing element (10) for a shoe sole according to the preceding embodiment,
wherein the second plate (13) comprises a substantially higher stiffness than the
first plate (11).
- 3. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the base material of the second plate (13) and the base material of the third
plate (14) is reinforced with fibers.
- 4. Stabilizing element (10) for a shoe sole according to embodiment 3, wherein the
second plate (13) comprises 5% to 20% fiber reinforcement and the third plate (14)
comprises 20% to 50% fiber reinforcement.
- 5. Stabilizing element (10) for a shoe sole according to one of embodiments 3 to 4,
wherein the fibers are glass fibers.
- 6. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the base material of the first plate (11) is not reinforced with fibers.
- 7. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the first plate (11), the second plate (13) and the third plate (14) are made
from the same base material.
- 8. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the base material of the first plate (11), the second plate (13) and the third
plate (14) is polyamide.
- 9. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the third plate (14) is approximately 1 to 3 mm thick.
- 10. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the bending stiffness of the third plate (14) is at least two times higher
than the bending stiffness of the second plate (13).
- 11. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the bending stiffness of the second plate (13) is at least two times higher
than the bending stiffness of the first plate (11).
- 12. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the modulus of elasticity of the first plate (11) is 600 to 1500 MPa.
- 13. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the modulus of elasticity of the second plate (13) is 2000 to 4000 MPa.
- 14. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the modulus of elasticity of the third plate (14) is 9000 to 13000 MPa.
- 15. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the third plate (14) comprises ribs (15) arranged in a longitudinal direction
of the stabilizing element (10).
- 16. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the second plate (13) comprises ribs (16) arranged in a longitudinal direction
of the stabilizing element (10).
- 17. Stabilizing element (10) for a shoe sole according to embodiments 15 and 16, wherein
the ribs (15) of the third plate (14) coincide with the ribs (16) of the second plate
(13).
- 18. Stabilizing element (10) for a shoe sole according to one of embodiments 15 to
17, wherein the ribs (15) of the third plate (14) have a height of approximately 1
to 3 mm.
- 19. Stabilizing element (10) for a shoe sole according to one of embodiments 16 to
18, wherein the ribs (16) of the second plate (13) have a height of approximately
1 to 5 mm.
- 20. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the material of the third plate (14) has a 4 % strain at break at 0° C.
- 21. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the stabilizing element (10) essentially covers the entire foot of a wearer
of a shoe into which the stabilizing element (10) is to be integrated.
- 22. Stabilizing element (10) for a shoe sole according to one of the preceding embodiments,
wherein the opening (12) in the first plate (11) is arranged such that the second
plate (13) and the third plate (14) do not extend to the outside of a shoe into which
the stabilizing element (10) is to be integrated.
- 23. Shoe, in particular a mountaineering shoe, comprising:
- a. an outsole;
- b. an upper; and
- c. a stabilizing element (10) according to one of the preceding embodiments arranged
between the outsole and the upper.
- 24. Shoe according to the preceding embodiment, comprising a midsole arranged between
the outsole and the stabilizing element (10).
- 25. Shoe according to one of embodiments 23 to 24, wherein the outsole is made from
rubber.
1. Stabilizing element (10) for a shoe sole, in particular for a mountaineering shoe,
comprising:
a. a first plate (11), comprising at least one opening (12);
b. a second plate (13) arranged at least partially in the opening (12); and
c. a third plate (14) arranged at least partially in the opening (12) and arranged
at least partially above the second plate (13), wherein the third plate (14) comprises
a substantially higher stiffness than the second plate (13).
2. Stabilizing element (10) for a shoe sole according to the preceding claim, wherein
the second plate (13) comprises a substantially higher stiffness than the first plate
(11).
3. Stabilizing element (10) for a shoe sole according to one of the preceding claims,
wherein the base material of the second plate (13) and the base material of the third
plate (14) is reinforced with fibers.
4. Stabilizing element (10) for a shoe sole according to claim 3, wherein the second
plate (13) comprises 5% to 20% fiber reinforcement and the third plate (14) comprises
20% to 50% fiber reinforcement.
5. Stabilizing element (10) for a shoe sole according to one of the preceding claims,
wherein the base material of the first plate (11) is not reinforced with fibers.
6. Stabilizing element (10) for a shoe sole according to one of the preceding claims,
wherein the first plate (11), the second plate (13) and the third plate (14) are made
from the same base material.
7. Stabilizing element (10) for a shoe sole according to one of the preceding claims,
wherein the bending stiffness of the third plate (14) is at least two times higher
than the bending stiffness of the second plate (13).
8. Stabilizing element (10) for a shoe sole according to one of the preceding claims,
wherein the bending stiffness of the second plate (13) is at least two times higher
than the bending stiffness of the first plate (11).
9. Stabilizing element (10) for a shoe sole according to one of the preceding claims,
wherein the modulus of elasticity of the first plate (11) is 600 to 1500 MPa.
10. Stabilizing element (10) for a shoe sole according to one of the preceding claims,
wherein the modulus of elasticity of the second plate (13) is 2000 to 4000 MPa.
11. Stabilizing element (10) for a shoe sole according to one of the preceding claims,
wherein the modulus of elasticity of the third plate (14) is 9000 to 13000 MPa.
12. Stabilizing element (10) for a shoe sole according to one of the preceding claims,
wherein the third plate (14) comprises ribs (15) arranged in a longitudinal direction
of the stabilizing element (10).
13. Stabilizing element (10) for a shoe sole according to one of the preceding claims,
wherein the second plate (13) comprises ribs (16) arranged in a longitudinal direction
of the stabilizing element (10).
14. Stabilizing element (10) for a shoe sole according to claims 12 and 13, wherein the
ribs (15) of the third plate (14) coincide with the ribs (16) of the second plate
(13).
15. Shoe, in particular a mountaineering shoe, comprising:
a. an outsole;
b. an upper; and
c. a stabilizing element (10) according to one of the preceding claims arranged between
the outsole and the upper.