U.S. patent application number 11/642767 was filed with the patent office on 2007-07-26 for device for receiving a foot or a boot on a sports apparatus.
This patent application is currently assigned to SALOMON S.A.. Invention is credited to Bernard Couderc.
Application Number | 20070170697 11/642767 |
Document ID | / |
Family ID | 37441661 |
Filed Date | 2007-07-26 |
United States Patent
Application |
20070170697 |
Kind Code |
A1 |
Couderc; Bernard |
July 26, 2007 |
Device for receiving a foot or a boot on a sports apparatus
Abstract
A device for receiving a foot or a boot on a sports apparatus,
the device including a rear support element, the rear support
element having a support surface adapted to support the back of the
lower part of a user's leg, as well as a free surface opposite the
support surface. The rear support element includes a first wall
located on the side of the support surface, as well as a second
wall located on the side of the free surface, the first wall
including a traction-resistant material, the walls being affixed to
one another.
Inventors: |
Couderc; Bernard; (Annecy,
FR) |
Correspondence
Address: |
GREENBLUM & BERNSTEIN, P.L.C.
1950 ROLAND CLARKE PLACE
RESTON
VA
20191
US
|
Assignee: |
SALOMON S.A.
Metz-Tessy
FR
|
Family ID: |
37441661 |
Appl. No.: |
11/642767 |
Filed: |
December 21, 2006 |
Current U.S.
Class: |
280/619 |
Current CPC
Class: |
A63C 10/06 20130101;
A63C 10/24 20130101 |
Class at
Publication: |
280/619 |
International
Class: |
A63C 9/06 20060101
A63C009/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 26, 2006 |
FR |
06.00737 |
Claims
1. A device for receiving a foot or a boot on a sports-apparatus,
said device comprising: a rear support element comprising: a
support surface adapted to support a rear of a lower part of a
user's leg; and a free surface opposite the support surface; the
rear support element further comprising: a first wall positioned on
a support-surface side of the rear support element; a second wall
positioned on a free-surface side of the rear support element; the
first wall comprising a traction-resistant material; the first and
second walls being affixed to one another.
2. A device according to claim 1, wherein: the traction-resistant
material of the first wall comprises reinforcement fibers.
3. A device according to claim 1, wherein: the first wall comprises
longitudinally oriented fibers, the fibers being embedded in a
resin.
4. A device according to claim 1, wherein: the first and second
walls are removably affixed together.
5. A device according to claim 1, wherein: the first and second
walls are non-removably affixed together.
6. A device according to claim 1, wherein: the second wall has a
peripheral groove defined on a front surface to receive the first
wall.
7. A device according to claim 1, wherein: the second wall has ribs
projecting with respect to the front surface; screws are threaded
in the ribs through the first wall.
8. A device according to claim 1, wherein: the rear support element
has an inner cavity between the first and second walls.
9. A device according to claim 8, wherein: the inner cavity
receives, at least in part, a mechanism to adjust an angular
position of the rear support element.
10. A device according to claim 1, wherein: the first and second
walls of the rear support element are flatly pressed against one
another.
11. A device according to claim 6, wherein: the peripheral groove
is set back with respect to the ends and to the edges; the contour
of the first wall being positioned In the groove of the second
wall.
12. A device according to claim 1, wherein: the first and second
walls are affixed by ratchet.
13. A device according to claim 1 further comprising: a seat,
flanges, and linkages, the rear support element being rotatably
mounted relative to the seat.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority under 35 U.S.C. .sctn.119
of French Patent Application No. 06.00737, filed on Jan. 26, 2006,
the disclosure of which Is hereby incorporated by reference thereto
in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a device for receiving a foot or a
boot on a sports apparatus, such as a gliding or rolling
apparatus.
[0004] More particularly, although not limiting, the invention
relates to devices of the aforementioned type for practicing
snowboarding, snowsurfing, snow skiing, water skiing, snowshoeing,
roller-skating, and the like.
[0005] 2. Description of Background and Relevant Information
[0006] Some devices according to the prior art include a base
provided to receive the sole of the user's foot or boot, as well as
a rear support element, or highback, provided to support the lower
part of a user's leg. The rear support element has a support
surface opposite a free surface. The support surface, turned toward
the base, is adapted to receive the lower part of the leg.
[0007] The rear support element transmits forces for steering the
apparatus, directed toward the user's heel.
[0008] This is frequently the case in snowboarding. In this field,
the rider's feet are both retained on a single board and are
oriented in a substantially transverse direction relative to the
board. The transverse forces are therefore localized toward the tip
of the feet or toward the heels. In the case where the forces are
directed toward the tip of the feet, no or insignificant forces are
transmitted through the rear support elements. Conversely, when
forces are directed toward the heels, the rear support elements
receive forces that can be very high.
[0009] For example, during rear edging, i.e., forces transmitted
toward the heels, the rear support element of each device transmits
rear impulses from the lower part of the leg. In other cases, the
rear support element transmits to the rider impulses originating
from the terrain over which the board glides.
[0010] To ensure that the board steering-related impulses are
accurately transmitted, it is known to provide the rear support
element with a certain amount of rigidity. In particular, the
element must resist a rear flexional force directed around a
transverse axis. This force is the one that tends to bend the rear
support element away from the base.
[0011] To provide the rear support element with good flexional
strength, it is known to make it in the form of a slightly concave
plate. The support surface of the rear support element, therefore,
is concave, and, consequently, the free surface is convex. For
example, the rear support element can be made by shaping a plastic
material. The form and the material provide the element with an
adequate flexional strength and a reduced mass. The strength of the
receiving device tends to facilitate precise steering and the
reduced weight of the receiving device tends to facilitate easier
steering.
[0012] It has been noted, however, that for certain types of
snowboarding, the flexional strength of the rear support element is
insufficient.
[0013] This Is the case, for example, when gliding down a steep
and/or bumpy slope or when performing certain freestyle maneuvers.
The rear impulses can be momentarily very intense, constituting a
force equivalent to several times the rider's weight.
[0014] It has therefore been proposed to reinforce the rear support
element by incorporating fibers into the plastic material, or by
using fibers embedded in a binder such as a synthetic-resin matrix.
The fibers are embedded In the entire thickness of the support
element. These fibers can include glass, carbon, aramid, metal, or
the like. A fiber-reinforced element provides increased mechanical
strength, especially in flexion. However, it has been noted that
the reinforced element deteriorates over time. Indeed, successive
forces can cause cracks or incipient breaks, mainly on the side of
the free surface. This is due to the fact that each flexional
deformation compresses a portion of the support element. In other
words, the rear support element according to the prior art is not
adequately fatigue resistant, due to the fact that the free surface
works alternately In compression.
SUMMARY OF THE INVENTION
[0015] The invention improves the fatigue strength of a rear
support element.
[0016] More particularly, the Invention limits, or even avoids,
cracks or incipient breaks on a rear support element that includes
reinforcement fibers.
[0017] To this end, the invention proposes a device for receiving a
foot or a boot on a sports apparatus, the device including a rear
support element, the rear support element having a support surface
adapted to support the rear of the lower part of a user's leg, as
well as a free surface, opposite the support surface.
[0018] The rear support element of a device according to the
invention includes a first wall located on the side of the support
surface, as well as a second wall, located on the side of the free
surface, the first wall including a traction-resistant material,
the walls being affixed to one another. For example, the
traction-resistant material of the first wall includes
reinforcement fibers.
[0019] In the device according to the invention, the rear support
element Includes two walls, that is, one more than in a device
according to the prior art. Consequently, in case the rear support
element is biased in rear flexion, the first wall is biased in
traction whereas the second wall is biased in compression.
[0020] In the invention, the traction-resistant material is
displaced toward the support surface. Consequently, when rearward
biases are applied by the lower part of the leg, or when impulses
are returned to the lower part of the leg, the flexion of the first
wall causes traction biases in the material. These biases prevent
cracks or incipient breaks from forming In the wall. Indeed, the
compression stresses are what cause them to appear. In the case
where the traction-resistant material includes fibers, such fibers
are those biased In traction.
[0021] Thus in the support device according to the invention, the
rear support element has a high mechanical strength and is
lightweight. Furthermore, the support element has good fatigue
strength and good long-term structural stability.
BRIEF DESCRIPTION OF DRAWINGS
[0022] Other characteristics and advantages of the invention will
be better understood from the description that follows, with
reference to the annexed drawings showing, according to
non-limiting embodiments, how the invention can be implemented, and
in which:
[0023] FIG. 1 is a front perspective view of a receiving device
according to the first embodiment of the Invention;
[0024] FIG. 2 is a partial view of the device, similar to FIG. 1,
in a case where a first wall of the rear support element has been
removed;
[0025] FIG. 3 is a partial front view of the device of FIG. 1, in a
case where the first wall of the rear support element has been
removed;
[0026] FIG. 4 is a cross-section along IV-IV of FIG. 3;
[0027] FIG. 5 is similar to FIG. 4, for a second embodiment of the
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Although the embodiments described hereinafter relate more
particularly to the field of snowboarding, it is to be understood
that they also apply to other fields, as mentioned above.
[0029] The first embodiment is presented by means of FIGS. 1 to
4.
[0030] As shown in perspective in FIG. 1, a receiving device 1,
shown as a snowboard binding, allows a boot to be temporarily
received and retained on a board 2, i.e., a snowboard in this case.
A receiving device according to the invention has certain
structural aspects in common with those disclosed, for example, In
commonly owned U.S. Patent Application Publication No.
2005/0057009, published on Mar. 17, 2005, the disclosure of which
is hereby incorporated by reference thereto in its entirety.
[0031] In a known manner, the receiving device 1 includes a seat 3,
which extends lengthwise between a rear end 4 and a front end 5,
and widthwise from a first side 6 to a second side 7.
[0032] The seat 3 has an upper surface 8 provided to be opposite
the boot sole, and a lower surface 9 provided to be face the board
2.
[0033] In the particular embodiment illustrated, the seat 3
includes a baseplate 10 covered by a cushion 11 or pad. The
baseplate 10 is a rigid element that demarcates, at least in part,
the lower surface 9. The cushion 11 demarcates, at least in part,
the upper surface 8. According to the first embodiment illustrated,
the cushion I1 extends from the rear end 4 to the front end 5 of
the seat 3. This enables a dampened contact with the entire surface
of the boot sole. A rear portion and a front portion of the cushion
11 demarcate a housing space for the baseplate 10.
[0034] Other structures for the seat 3 can be provided, such as,
for example, a baseplate associated with two cushions, one at the
rear, and one at the front.
[0035] The baseplate 10 of the seat 3 is retained to the board 2 by
an arrangement that includes a disk, which itself is secured to the
board 2 by screws. Examples of such arrangements are disclosed in
U.S. Pat. No. 6,068,283 and U.S. Pat. No. 6,676,152, both of which
are commonly owned herewith, the disclosures of which are hereby
incorporated by reference thereto in their entireties.
[0036] Other arrangements for securing the baseplate 10 of the seat
3 to the board could alternatively be provided.
[0037] The seat 3 and baseplate 10 are laterally bordered with a
first part shown in the form of a first flange 20, as well as a
second part shown in the form of a second flange 21. In this case,
the first flange 20 is lateral and the second flange 21 is medial,
although the reverse is also possible. The flanges 20, 21 demarcate
a zone 22 for receiving the foot/boot. When the foot/boot is
positioned on the device 1, the flanges 20, 21 laterally extend
along the sole. Something other than the lateral and medial flanges
20, 21 could be provided to form the lateral and medial portions.
For example, mere abutments could be used.
[0038] In a particular construction, the baseplate 10 and the
flanges 20, 21 form a single unitary element made, for example, of
a synthetic material. However, the flanges 20, 21 could be affixed
to the baseplate 10 by any suitable means, such as adhesive or
glue, welding, screws, nesting, or other means or mechanisms.
[0039] Two linkages, or straps, are also provided for removably
retaining the foot/boot on the baseplate 10 of the seat 3, between
the flanges 20, 21 in the receiving zone 22.
[0040] A first strap 23 is located toward the front, in the area of
the metatarsophalangeal joint when the foot is retained. A second
strap 24 is located toward the rear, in the area of the Instep when
the foot is retained.
[0041] Each of the straps 23, 24 transversely extends between the
flanges 20, 21.
[0042] A different number of straps/linkages could be provided.
[0043] The first strap 23 Includes, for example, a lateral portion
25 and a medial portion 26, which are attached to the lateral and
medial flanges 20, 21, respectively. A connecting device 27 makes
it possible to reversibly connect together the lateral and medial
portions 25, 26 of the first strap 23. The connecting device 27
makes it possible to tighten the boat to a desired level.
[0044] In the same context, the second strap 24 includes, for
example, a lateral portion 28 and a medial portion 29, which are
attached to the lateral and medial flanges 20, 21, respectively. A
connecting device 30 makes it possible to connect together, and to
disconnect, the lateral and medial portions 28, 29. The connecting
device 30 makes it possible to tighten the boot to a desired
level.
[0045] The second strap 24 also includes, according to the
illustrated embodiment, a rear segment 31. The rear segment extends
the second strap 24 toward the rear, in order to extend around the
heel, or the rear of the user's ankle or lower leg. Consequently,
the associated lateral and medial portions 28, 29 together form a
front segment 32 of the second strap 24. The second strap 24,
therefore, completely surrounds the ankle or lower leg. A resulting
advantage is that the foot or the boot is better retained on the
seat.
[0046] Whether or not it includes the rear segment 31, the second
strap 24 always enables the function of retaining the foot/boot on
the device 1.
[0047] The device 1 also includes a rear support element 40, or
highback, to enable the rider to be rearwardly supported with the
lower part of the leg.
[0048] The rear support element 40 includes a body 41, which
extends longitudinally between first and second fastening ends 42,
43 and a free end 44, transversely between a first or lateral side
45 and a second or medial side 46, and thicknesswise between a
support surface 47 and a free surface 48.
[0049] The support surface 47 is provided to receive the rear of
the lower part of the rider's leg, the rear support element 40 and
the baseplate 10 thereby being associated.
[0050] According to the first embodiment illustrated, as shown
generally in FIGS. I to 5, the rear support element 40 is mounted
for articulation with respect to the seat 3. To this end, the rear
support element is connected to the flanges 20, 21 by means of a
first articulation 49, located in the area of the first fastening
end 42, and by means of a second articulation 50, located in the
area of the second fastening end 43. The articulations 49, 50 are
oriented along first and second transverse axes 51, 52,
respectively, of the device 1. Each articulation 49, 50 can Include
any component, such as a screw, a rivet, a washer, a nut, a swivel
pin, or the like.
[0051] Each articulation 49, 50 allows a rotational movement of the
rear support element 40 toward the seat 3. A resulting advantage Is
to enable the rear support element to be folded downwardly to
facilitate storage of the device 1.
[0052] According to the first Illustrated embodiment, an abutment
60 limits the rearward rotation of the rear support element 40.
[0053] In a non-limiting manner, the abutment 60 includes a linkage
61, which extends along the rear support element 40. The linkage 61
is arranged on the seat 3 and cooperates with the rear support
element 40 to limit the rearward rotation of the rear support
element 40. The path of the linkage 61 is described hereinafter.
The linkage 61 Includes, for example, a first portion or lateral
portion 62 and a second portion or medial portion 63, one extending
the other. Each portion 62, 63 of the linkage 61 is connected to
the baseplate 10 by a first lower connection 64 and a second lower
connection 65, respectively. The lower connections 64, 65 are
located at the front of the first and second articulations 49,
50.
[0054] The linkage 61 can take the form of a cable, such cable
having a first or lateral end 66, as well as a second or medial end
67. The ends 66, 67 are connected to the lateral and medial flange
20, 21 by any means, known to one having ordinary skill in the art,
to form the first and second lower connections 64, 65. A crimped
end piece can be used. Between the lower connections 64, 65, the
cable 61 follows each flange 20, 21 while extending away therefrom,
to extend along the rear support element 40, in a position that is
farther away from the flanges.
[0055] More particularly, the first and second portions 62, 63 are
each connected to the rear support element 40 by first and second
upper connections 68, 69, which are located between the first or
the second fastening end 42, 43, respectively, and the free end 44.
In a non-limiting manner, the upper connections 68, 69 each include
a first guide 70 and a second guide 71.
[0056] An arrangement is also provided for adjusting the angular
position of the rear support element 40 with respect to the
baseplate 10 Depending upon this arrangement, the abutment 60
includes a cursor 72, or slider, that Is movable along the rear
support element 40. The cursor 72, located between the guides 70,
71, retains the cable 61. To modify the free length of the portions
62, 63 of the linkage 61 between the lower connections 64, 65 and
the rear support element 40, the cursor 72 only has to be moved
closer to or away from the free end 44. To this end, any
Immobilization mechanism known to one having ordinary skill in the
art can be used. The Immobilization mechanism includes, for
example, a screw 73 to tighten or loosen the cursor 72 with respect
to the rear support element 40. Here, the immobilization mechanism
includes complementary teeth 74, 75 on the cursor 72 and on the
rear support element 40, respectively, which allow positioning one
on the other. These teeth 74, 75 are well-known to one having
ordinary skill in the art. The teeth 74, 75 enable an
Immobilization by a blocking of the cursor with respect to the rear
support element. However, an Immobilization by friction is also
possible. In this case, the teeth are replaced by regular
surfaces.
[0057] According to the invention, the rear support element 40
includes a first wall 81 located on the side of the support surface
47, as well as a second wall 82 located on the side of the free
surface 48, the first wall 81 including reinforcement fibers, the
walls 81, 82 being affixed to one another.
[0058] The affixing of the walls 81, 82 to one another is to be
understood as a mechanism for temporarily or definitely
immobilizing one with respect to the other. This immobilization
mechanism can include, as will be described further below, a gluing
mechanism, a screw mechanism, a nesting mechanism, any combination
of the foregoing, or the like.
[0059] When the rider is rearwardly supported with the lower part
of his/her leg, the rear support element 40 is biased in flexion
along a transverse axis of the element 40. This axis is
substantially parallel to the axes 51, 52 of the articulations 49,
50. The flexion in the direction of the arrow F0 in FIG. 4 is
carried out so that the free end 44 of the support element 40 tends
to move away from the seat 3. The abutment 60 limits the rotation
of the support element 40.
[0060] The flexional bias of the rear support element 40 translates
simultaneously into a longitudinal traction of the first wall 81
and into a longitudinal compression of the second wall 82. Thus,
the wall 81 containing fibers is biased in traction only. This is
due to the first wall being offset relative to the neutral line of
the rear support element. The neutral line is an imaginary line of
the rear support element 40, within which no constraint Is applied
during flexion.
[0061] A resulting advantage of the aforementioned structure is the
durability of the rear support element, especially in the area of
the first wall 81. Fatigue-strength is enhanced. The incipient
breaks due to compression forces are, if not completely avoided, at
least substantially reduced.
[0062] According to the first embodiment of the invention, the
first wall 81 Includes, for example, an incurved plate 83, which
extends longitudinally between first and second ends 84, 85,
transversely between first and second edges 86, 87, and
thicknesswise between a front surface 88 and a rear surface 89. The
thickness of the wall 81 Is substantially constant, but could
alternatively be provided to vary.
[0063] The plate 83 of the first wall 81 includes, for example,
longitudinally oriented fibers between the ends 84, 85. These
fibers provide the wall with great tractional strength in the
longitudinal direction. The first wall 81 also includes
transversely oriented fibers between the edges 86, 87. These fibers
provide the wall 81 with great flexional strength along a
longitudinal axis. The fibers can be woven and embedded in a resin
such as polyester resin, or in any synthetic material, which
provides the wall 81 with a stable shape. The fibers used are made
of glass, mainly for cost-effectiveness. Other materials, such as
carbon, aramid, or the like, can alternatively be used. The wall 81
can include a fabric made of either only one type of fibers, or of
several types of fibers.
[0064] The second wall 82 includes an incurved plate 95, which
extends longitudinally between a first end 96 and a second end 97,
transversely between a first edge 98 and a second edge 99, and
thicknesswise between a front surface 100 and a rear surface
101.
[0065] According to the first embodiment of the invention, the
ends. 96, 97 and the edges 98, 99 of the second wall 82 merge with
the ends 42, 43, 44 and the edges 45, 46 of the rear support
element 40. But this is not a necessity.
[0066] The plate 95 of the second wall 82 includes a plastic
material shaped by any technique, such as molding, injection,
machining, or the like.
[0067] A structural arrangement Is provided to affix the first wall
81 to the second wall 82. For example, the first and second walls
81, 82 are affixed by being nested in and screwed to one another.
The walls are therefore reversibly affixed, but could also be
provided to be non-reversibly affixed, for example, by gluing,
riveting, or the like.
[0068] To enable nesting, the second wall 82 has a peripheral
groove 105 provided on its front surface 100 to receive the first
wall 81. The groove is set back relative to the ends 96, 97 and the
edges 98, 99. The second wall 82 also has ribs 106, 107, 108, 109,
which project with respect to the front surface 100.
[0069] The nesting is carried out by positioning the first wall 81
on the front surface of the second wall 82, so that the periphery
110 of the first wall 81 can be positioned in the groove 105 of the
second wall 82. After nesting, the ribs 106, 107, 108, 109 are
substantially in contact with the first wall 81.
[0070] To keep the walls 81, 82 together, the affixing arrangement
includes screws 115 that are threaded into the ribs 106, 107, 108,
109 through the first wall 81. The screws 115 are distributed over
the wall 81, particularly toward the ends 84, 85 and the edges 86,
87. Thus, the walls 81, 82 are uniformly affixed to one another.
Alternatively, other structural arrangements can be used. For
example, the first and second walls 81, 82 can be affixed by a
ratchet-like structure.
[0071] After the walls 81, 82 are affixed, the rear support element
40 has an inner cavity 120 between the two walls 81, 82. Such
cavity is due to differences in the curvature of the walls 81, 82.
The periphery of the cavity 120 is substantially equal to the
periphery 110 or to the length of the groove 105. The thickness of
the cavity 120 can vary, in the sense that it corresponds to the
spacing between the plates 83, 95 of the walls 81, 82. Thus, the
thickness of the cavity 120 is reduced toward the groove 105, and
more substantial in the area of the ribs 106, 107, 108, 109. The
latter ones demarcate the thickness of the cavity 120 apart from
the junction of the walls 81, 82.
[0072] According to the first illustrated embodiment, the cavity
120 does not receive any filler, although a filler could be
provided, within the scope of the invention.
[0073] The cavity 120 receives the cursor 72 of the abutment 60. In
other words, the cavity 120 receives, at least in part, the
mechanism for adjusting the angular position of the support element
40. For this reason, in order to cooperate with the cursor, the
front surface 100 of the second wall 82 has teeth 75 adapted to
cooperate with the teeth 74 of the cursor. However, as described
below, other arrangements allow the association of an abutment with
a rear support element. The cursor cannot be housed in the cavity
120.
[0074] During steering of the board, the rear support element 40 is
biased in flexion along a transverse axis, especially due to the
lower part of the leg being supported on the first wall 81.
[0075] In this case, the first wall 81 is longitudinally
constrained in traction, and the second wall 82 is longitudinally
constrained in compression. This constraint distribution
occurrences are due to the fact that the neutral line is located in
the cavity 120. It is to be understood that the neutral line is an
imaginary line, which sets the boundary between the tensioned
portions and the compressed portions during flexion.
[0076] In fact, the wall 81 mostly works In traction, the forces
applied thereto passing through the screws 115.
[0077] As a result, the first wall 81 is not constrained in
compression. Thus, the assembly Including the fibers and the resin
is not compressed. A resulting advantage is an Increased fatigue
strength, because incipient breaks can no longer occur.
[0078] The second wall 82 is biased In compression but withstands
less forces than the first.
[0079] A second embodiment of the invention is described
hereinafter with reference to FIG. 5. For reasons of convenience,
only the differences with respect to the first embodiment are
shown.
[0080] A rear support element 140 includes a first wall 141 and a
second wall 142. The walls 141, 142 are affixed to one another by
being flatly pressed one against the other. They are affixed by any
structural arrangement, such as nesting or gluing. Consequently,
they can be reversibly or irreversibly affixed. Here, no cavity is
defined between the walls 141, 142. The neutral line is
substantially located at the junction of the walls. Thus, the first
wall 141 always works in traction. The cursor 143 of the abutment
144 Is located on the rear surface 145 of the second wall 142.
[0081] Generally speaking, the invention is implemented using
materials and according to techniques known to one having ordinary
skill in the art. In particular, the traction-resistant material
can include a metal or a synthetic material.
[0082] The invention is not limited to the particular embodiments
herein described and includes all the technical equivalents that
fall within the scope of the claims that follow.
[0083] The rear support element can be provided with a different
architecture.
[0084] For example, a cushion can be added on the front surface of
the first wall. This rear support forces to be dampened.
[0085] The second wail can also include fibers, which can be
embedded in resin.
[0086] The walls can be Irreversibly affixed to one another, for
example by gluing or welding.
* * * * *