U.S. patent application number 14/802463 was filed with the patent office on 2016-01-21 for impact-absorbing helmet.
This patent application is currently assigned to SALOMON S.A.S.. The applicant listed for this patent is SALOMON S.A.S.. Invention is credited to Stephane LATRUFFE.
Application Number | 20160015111 14/802463 |
Document ID | / |
Family ID | 51483488 |
Filed Date | 2016-01-21 |
United States Patent
Application |
20160015111 |
Kind Code |
A1 |
LATRUFFE; Stephane |
January 21, 2016 |
IMPACT-ABSORBING HELMET
Abstract
The invention relates to a helmet that includes an outer shell
and a cap, the cap being comprised of a material such as EPS or EPP
and arranged inside the shell. The shell has an upper portion
designed to cover at least the crown portion of the skull, the cap
further comprising a first layer having a thickness covering
substantially the upper portion and a plurality of pads of height
projecting from the first layer towards the head, the first layer
and the pads forming a single piece, and the height of the pads
being greater than the thickness of the first layer.
Inventors: |
LATRUFFE; Stephane; (LA
BALME DE SILLINGY, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SALOMON S.A.S. |
Metz-Tessy |
|
FR |
|
|
Assignee: |
SALOMON S.A.S.
Metz-Tessy
FR
|
Family ID: |
51483488 |
Appl. No.: |
14/802463 |
Filed: |
July 17, 2015 |
Current U.S.
Class: |
2/412 |
Current CPC
Class: |
A42B 3/06 20130101; A42B
3/125 20130101 |
International
Class: |
A42B 3/12 20060101
A42B003/12; A42B 3/06 20060101 A42B003/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 18, 2014 |
FR |
14/01633 |
Claims
1. A helmet comprising: an outer shell; a cap, comprising EPS or
EPP, arranged inside the outer shell and having an upper portion
designed to cover at least a crown portion of a wearer's head, the
cap comprising: a first layer having thickness covering
substantially the upper portion; and a plurality of pads having a
height projecting from the first layer in a direction away from the
outer shell, the first layer and the pads forming a single piece;
the pads having a height greater than a thickness of the first
layer.
2. A helmet according to claim 1, wherein: the thickness of the
first layer is between 1.0 mm and 17.5 mm.
3. A helmet according to claim 1, wherein: the thickness of the
first layer is less than 10 mm.
4. A helmet according to claim 1, wherein: the height of the pads
in the upper portion of the cap is between 10 mm and 35 mm.
5. A helmet according to claim 1, wherein: an average cross section
of the pads is between 0.5 mm.sup.2 and 5.0 mm.sup.2.
6. A helmet according to claim 1, wherein: a plurality of the
plurality of pads of the upper portion of the cap are dimensioned
such that their height is greater than a smallest dimension of an
average cross section of the plurality of pads.
7. A helmet according to claim 1, wherein: a first plurality of the
plurality of pads are dimensioned and arranged for axial
compression along a height of the pads in response to an impact;
and a second plurality of the plurality of pads are dimensioned and
arranged to be deformed in a non-axial direction.
8. A helmet according to claim 7, wherein: the second plurality of
the plurality of pads are dimensioned and arranged to buckle or
bend in the non-axial direction
9. A helmet according to claim 1, wherein: the pads are distributed
randomly in the upper portion of the cap.
10. A helmet according to claim 1, wherein: tops of the pads are
designed to be in contact with the wearer's head or an inner cap
covering the wearer's head.
11. A helmet according to claim 1, wherein: the pads have a
substantially parallelepipedic shape.
12. A helmet according to claim 1, wherein: the cap is a unitary
piece.
13. A helmet according to claim 1, wherein: a plurality of the
plurality of the pads have respective bases; and a cross section of
each of the bases is substantially the same as respective cross
sections of tops of the pads.
14. A helmet according to claim 1, wherein: the plurality of pads
are oriented such that their height extends substantially along a
vertical direction.
15. A helmet according to claim 1, wherein: the cap is a molded
cap.
16. A helmet according to claim 1, wherein: the plurality of pads
are recessed.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon French Patent Application No.
14/01633, filed Jul. 18, 2014, the disclosure of which is hereby
incorporated by reference thereto in its entirety, and the priority
of which is claimed under 35 U.S.C. .sctn.119.
BACKGROUND
[0002] 1. Field of Invention
[0003] The invention relates to a protective helmet for sporting
activities. Such activities may in particular include alpine
skiing, ski touring, or snowboarding. The invention also extends to
the practice of rock climbing, mountaineering, cycling, and
snowmobiling. Generally, a helmet provides head protection to
protect the skull from impacts to which it may be subjected when
the user falls, when an object is thrown at the user, or in a
collision with an object or another person.
[0004] 2. Background Information
[0005] A conventional helmet construction includes an outer shell
and a cap. The outer shell is generally rigid and, as an example,
is made by molding/injection of a thermoplastic material such as
ABS (Acrylonitrile Butadiene Styrene) or PC (polycarbonate).
Typically, the cap is made of a foam material such as EPS
(Expandable Polystyrene) or EPP (Expandable Polypropylene). To
ensure good user comfort, the helmet is generally provided with an
inner cap that, for example, can be made of foam covered with
fabric. The inner cap is attached to the inside of the cap.
[0006] A helmet is designed to reduce the risk of injury in the
area of the skull of the user, while having the smallest possible
weight in order not to affect the comfort of the user.
[0007] Therefore, a good helmet should meet two conflicting
requirements, namely, to contain as much damping material as
possible, on the one hand, and to be as lightweight as possible in
order to be easily portable and not impede the user.
[0008] To ensure the safety of users, there are several standards
generally defining tests and acceptance thresholds that are applied
to helmets requiring certification in a related discipline. The
normative requirement may differ, depending on the sporting
activity. Thus, a standard covers a specific activity. These
requirements give rise to characteristics that the helmet must have
to provide the required protection. For example, depending on the
activity practiced, these characteristics correspond to properties
of resistance to penetration and shock absorption in various zones
of the helmet.
[0009] Thus, there appears to be a strong need to design a helmet
having good damping in its crown portion, as this zone is often
critical for successfully passing the tests for homologation.
[0010] In this zone, the helmet damping characteristics depend
mainly on the design of the cap.
[0011] The most common cap construction is in the form of a casing
assuming the morphology of the skull. Achieving the desired damping
requires using suitable materials and/or varying the thickness of
the casing, which results in a dimensioning that can weigh down the
helmet, thus creating a source of discomfort for the user.
[0012] Other constructions propose attaching independent pads
directly to the outer shell (see U.S. Pat. No. 4,766,614), to an
inner shell (see GB 2 240 255; U.S. Pat. No. 4,239,106), or
associating them with the inner cap (see U.S. Pat. No. 7,774,866;
EP 0 423 379). In any case, these pads are dimensioned to operate
in compression. Damping is thus obtained by compressing the pads.
In certain embodiments, the pads are used to wedge the head. These
various constructions, incorporating attached pads, are complex and
expensive to produce. One difficulty relates to fixing and
maintaining the pads on the helmet.
[0013] Another construction provides for a cap fitted with
ventilation channels defining projections projecting toward the
head of the user. This type of structure is characterized by a cap
having a relatively thick layer from which the projections extend
along a small height. Damping is achieved here by the thick layer,
the projections having the role of channeling the flow of air
providing ventilation at the top of the skull. In this
construction, to obtain the desired properties, the projections
have a height less than the thickness of the cap. The document EP 2
716 175 illustrates this type of helmet.
SUMMARY
[0014] The invention provides an improved helmet.
[0015] In particular, the invention provides a lightened helmet
structure having good damping properties.
[0016] The invention also provides a helmet, the structure of which
includes few assembled constituent elements.
[0017] The invention further provides an economical helmet, the
implementation process of which is simple.
[0018] To these ends, the invention provides a helmet comprising:
[0019] an outer shell; [0020] a cap, made of a material such as EPS
or EPP, for example, the cap being arranged inside the shell and
having an upper portion designed to cover at least the crown
portion of the wearer's head, the cap comprising a first layer of
thickness "e" covering substantially the upper portion and a
plurality of pads of height "h" projecting from the first layer
towards the head, the first layer and the pads forming a single
element.
[0021] The height of the pads of the helmet is greater than the
thickness of the first layer.
[0022] This structure makes it possible to have, with few parts, a
cap attached to an outer shell, a lightweight helmet with good
damping characteristics. This construction enables good anchoring
of the pads on the cap, and the height of the pads allows for
bending and/or buckling deformation, which improves the damping
properties of the helmet. In addition, the helmet is compact and
strong. A helmet according to the invention is lightweight and
ventilated due to this specific construction. It also allows for
the use of a simple, removable inner cap that can easily be
replaced.
[0023] Optionally, the invention can have any of the following
optional features, taken alone or in combination: [0024] The
thickness "e" of the first layer is between 1.0 mm and 17.5 mm.
[0025] The height "h" of the pads in the upper portion is between
10 mm and 35 mm. [0026] The average cross section of the pads is
between 0.5 and 5.0 square centimeters. [0027] A plurality of the
plurality of pads of the upper portion are dimensioned so that
their height "h" is greater than the smallest dimension
characterizing the average cross section of the pads. [0028] The
pads are distributed randomly in the upper portion. [0029] The tops
of the pads are designed to be in contact with the head of the
wearer or an inner cap covering the head. [0030] The pads have a
substantially parallelepipedic shape. [0031] The cap is a
monolithic element, that is, it is made of a single piece of
material. [0032] The cross section of the base of the pads is
substantially the same as the cross section of the top of the pads.
[0033] The pads are oriented so that their height extends
substantially along a vertical direction. [0034] The cap is made by
molding. [0035] The pads are recessed.
BRIEF DESCRIPTION OF DRAWINGS
[0036] The invention will now be described by way of non-limiting
exemplary embodiments, with reference to the annexed drawings, in
which:
[0037] FIG. 1 is a perspective view of a main embodiment of a
helmet according to the invention;
[0038] FIG. 2 is a perspective bottom view of the interior of the
helmet;
[0039] FIG. 3 is a bottom view of the helmet;
[0040] FIG. 4 is a cross-sectional view along the line IV-IV of
FIG. 3; and
[0041] FIGS. 5 to 6 are partial cross sections showing various
deformation modes of the pads of the invention.
DETAILED DESCRIPTION
[0042] The helmet 10 comprises an outer shell 11, a collar 12, a
cap 13, cushions 14 for protecting the ears, and a chin strap
15.
[0043] The following description makes use of terms such as
"horizontal", "vertical", "longitudinal", "transverse", "upper",
"lower", "top", "bottom", "front", "rear", "anterior", "posterior".
These terms should be interpreted as relative terms with respect to
the position that the helmet occupies on the head of a user in
normal posture, and the normal advance direction of the wearer.
[0044] The helmet comprises an upper portion 101 designed to cover
at least the "crown portion" of the skull, that is to say, the top
of the skull. It is defined by a zone covering an upper portion of
the frontal bone and an upper portion of the parietal bone. In this
example, this upper portion 101 of the helmet is comprised of an
upper portion 111 of the outer shell and an upper portion 131 of
the cap.
[0045] The outer shell 11 is monolithic, that is to say, made in a
single piece. Here, it is made of polycarbonate (PC).
Alternatively, it is made of acrylonitrile butadiene styrene (ABS),
or a material embedded with carbon fibers or natural fibers. The
outer shell 11 is molded, such as by injection molding, for
example.
[0046] The cap 13 here is also monolithic. It is made of expanded
polystyrene foam (EPS, i.e., Expandable Polystyrene).
Alternatively, it can be made of expanded polypropylene (EPP, i.e.,
Expandable polypropylene), or other material, such as a foam
material. It is fixed to the outer shell 11 to cover an inner
surface 112 of the outer shell 11.
[0047] The cap 13 is designed to also wrap the head of the user.
The construction of its inner envelope is described in greater
detail, below.
[0048] The cap 13 can be an element separate from the outer shell
11, and assembled to the outer shell 11. Alternatively, it can be
overmolded onto the outer shell 11; reference can be made to
so-called thermoforming or "in-mold" technology.
[0049] To improve comfort, the outer shell 11 and the cap 13 can
include openings positioned opposite one another so as to enable
the inlet and/or discharge of a flow of air ensuring ventilation
for the head of the user.
[0050] In this example, the lower portion of the helmet is
demarcated by the collar 12 fixed to the cap. This collar
concurrently marks the lower edge of the outer shell 11 and the
lower edge of the cap 13. The collar 12 is optional, the invention
also being applicable to helmets with no collar demarcating the
lower edge of the helmet.
[0051] The cap 13 has a structure comprising two levels in the
thickness direction.
[0052] The first level forms a first layer 132 of thickness "e"
covering the skull of the user. This first layer substantially
assumes the shape of the outer shell 11. The outer surface 1321 of
the first layer 132 is fixed to the inner surface 112 of the outer
shell 11. This assembly can be achieved by gluing, melting,
overmolding, or other technology. The thickness "e" of the layer
132 is not necessarily constant over the entire inner surface of
the helmet. For example, the thickness can be greater on the upper
portion of the cap 13 and less on the lower portion, namely, the
frontal, lateral, and posterior portions. As mentioned above, the
first layer 132 can include openings for ventilation of the
skull.
[0053] The second level of the cap structure comprises a set of
projections 133, 134 projecting from the inner surface 1322 of the
first layer 132 toward the head of the user. The shape of these
projections varies as a function of their positioning.
[0054] In the lower portion of the cap (the frontal, lateral, and
posterior portions), the projections form blocks 134, for example
parallelepipedic blocks having a variable thickness. Thus, each
block is thin in its lower portion and thicker in its upper
portion. The blocks are evenly distributed on the lower inner
periphery of the cap 13. Channels are thus formed between the
blocks. These channels are used for circulation of air for
ventilation of the skull.
[0055] The projections form pads 133 in the upper portion 131 of
the cap (crown portion). In the illustrated example, these pads
have a parallelepipedic shape, or a substantially parallelepipedic
shape, having a substantially constant height "h". However, these
parallelepipeds have a variety of different cross sections, in
relation to one another. In an alternative embodiment, they can
have identical cross sections. Alternatively, the pads can assume
other polyhedral or cylindrical shapes. They can be truncated
pyramids, cylinders, truncated cones. Similarly, the height of
these pads is not necessarily constant. Thus, one can provide zones
in which the height of the pads is greater in order to increase
damping, for example. Here again, channels are formed between the
pads. These channels are used for circulation of air for
ventilation of the user's head. According to the illustrated
embodiment, the distribution of the pads is random in the upper
portion 131. Alternatively, such distribution can follow a regular
pattern.
[0056] The total thickness "T" of the cap 13 corresponds to the sum
of the thickness "e" of the first layer and the height "h" of the
projections, blocks 134, or pads 133. The total thickness "T" can
vary depending on the portions of the cap involved.
[0057] In the upper portion 131 of the cap, most of the pads have
sufficient height to obtain a deformation in addition, or as an
alternative, to the compression of the pad, in order to improve the
damping properties of the helmet. This deformation can be obtained
via buckling or bending. In this case, the pads are dimensioned and
arranged so that, not only can they be compressed, they can also be
deformed in a non-axial direction. Thus, the pads do not deform
only by compression as in most of the prior art constructions.
[0058] FIGS. 5 and 6 illustrate examples of deformations of the
pads following an impact materialized by the vector "F". The pad
133, biased by the force "F" comes pressing against the skull or
the inner cap, represented here by the plane "P". The pad 133 then
deforms, first in compression, and then along a non-axial
direction, due to its dimensioning. In FIG. 5, the deformation is
similar to buckling. In FIG. 6, the deformation is similar to
bending. The deformation of the pad can vary from one pad to
another depending on the impact zone and the dimensions of the pad.
It is not necessary that all pads meet the recommended ratio, as
the impact can be absorbed by a few pads. The damping properties
are nevertheless better if a number of pads have a height greater
than the thickness of the first layer.
[0059] To obtain this additional or alternative deformation, the
proposed construction includes sufficient anchoring for the base of
the pads and a height of the pads enabling this additional
deformation. The first layer 132 of thickness "e" thus makes it
possible to affix the pads to one another to create a unitary and
homogeneous structure. Moreover, in order to obtain a satisfactory
deformation, the height "h" of the pads is greater than the
thickness "e" of the first layer.
[0060] Furthermore, to obtain an even more efficient additional or
alternative deformation, certain pads positioned in deformation
zones have a height "h" greater than the smallest dimension
characterizing the average cross section of these pads. The
smallest dimension can be a side of a square or rectangular cross
section, the smallest height or length of a parallelogram-shaped
cross section, the diameter of a cylinder. The greater the height
in relation to this dimension, the easier the desired additional
deformation will be. The pads can then more easily deform along a
non-axial direction.
[0061] According to an embodiment having good damping, the cross
section of the base of the pads is substantially the same as the
cross section of the top of the pads. Therefore, pyramidal or
overly tilted cone-shaped pads can be avoided so that the pad does
not essentially become deformed in compression, which is not the
desired behavior.
[0062] Unexpected, compared to conventional "solid" caps, that is
to say, caps without pads, are that the damping properties of a cap
comprising such pads are significantly better for equivalent total
thickness. For example, the acceleration measured in the area of
the head, following an impact on the crown portion, is lower by at
least 15% between a cap with pads and a cap without pads.
[0063] Thus, the pads 133 act as impact absorbers (crash box) in a
manner similar to car bumpers. The kinetic energy generated by the
impact is thus dissipated by these pads in addition to the inherent
absorption in the material of the cap. This double dissipation
improves damping, compared to a cap with no pads of equivalent
thickness.
[0064] Therefore, the damping mainly results from the deformation
of the pads 133 and slightly via the thickness of the first layer
132. The first layer is primarily used to create a unitary
structure by connecting the pads to one another.
[0065] In these examples, the height "h" to thickness "e" ratio is
greater than one. Good damping results are obtained with a
thickness "e" between 1.0 and 17.5 millimeters and/or with a height
"h" between 10 and 35 millimeters, it being necessary to follow the
previously defined ratio. For comfort, the total thickness "T" of
the cap can be less than 40 millimeters.
[0066] Similarly, the average cross section of the pads is
advantageously between 0.5 and 5.0 square centimeters. With a small
cross section, the pad deforms more easily along a non-axial
direction. With a larger cross section, the pad deforms less along
a non-axial direction. However, the top 1331 of the pad has a
greater surface of contact with the skull, which is more
comfortable because the stress transmitted is less. A good
compromise is a cross section between 1.0 and 4.0 cm.sup.2.
[0067] According to a particular embodiment, the first layer 132
has a small thickness "e" of less than 10 millimeters. This small
thickness makes it possible to easily conform the shape of the cap
to that of the outer shell, while favoring damping pads having
substantial height. In addition, the reduced thickness of the first
layer and the spacing of the pads make it possible to reduce the
amount of the efficient and necessary damping material.
Consequently, this makes it possible to lighten the helmet, which
is a very important, even fundamental, element for a sports helmet.
It has been noticed that, contrary to conventional helmet
constructions, it is not necessary to have a continuous thickness
over the entire surface of the cap to obtain a good level of
protection.
[0068] The cap is a "monolithic" element in the sense that the
first layer 132 and the pads 133 form a single unitary piece.
However, the cap can be constructed in several portions, each
comprising a first layer and projections. By being made of a single
piece, the implementation of the cap is greatly simplified.
Furthermore, the number of constituent elements of the helmet is
reduced, compared to a helmet provided with a number of attached
pads.
[0069] To further simplify the construction of the cap, the pads
are designed so that the cap can be removed from the mold by a
simple movement of the tooling. This means, in this example, that
the pads are oriented such that their height extends substantially
along a vertical direction.
[0070] Due to the invention, the cap can be made using an
economical material, such as EPS and/or EPP, taking advantage of
its damping properties. Due to the recess of the inner envelope of
the cap, resulting from the use of pads, the volume of the material
of the cap and, therefore, the weight of the helmet, are reduced.
This reduction in weight provides wearing comfort to the user
without sacrificing the required safety. The reduction in the
damping material is then compensated for by the potential
deformation of the pads.
[0071] In this example, the top 1331 of the pads 133 is designed to
be in contact with the head or an inner cap covering the head.
Generally, helmets incorporate an inner cap forming the interface
between the head of the user and the cap. This provides greater
comfort because the cap can be made of a material more pleasant to
the touch. Moreover, this enables the inner cap to easily be
replaced if damaged, for example, by prolonged contact with
perspiration.
[0072] In the illustrated embodiment, the pads are solid.
Alternatively, one can provide to recess the pads to further
lighten the structure. In this case, the cap would be comprised of
hollow pads.
[0073] In summary, the pads 133 of the upper portion 131 of the cap
fulfill two main functions, including impact absorption, on the one
hand, and ventilation of the skull, on the other hand.
[0074] The invention is not limited to these particular
embodiments. And it is possible to combine these embodiments.
[0075] Also, the invention is not limited to the embodiment
described above, but extends to all embodiments covered by the
following claims.
[0076] Further, at least because the invention is disclosed herein
in a manner that enables one to make and use it, by virtue of the
disclosure of particular exemplary embodiments of the invention,
the invention can be practiced in the absence of any additional
element or additional structure that is not specifically disclosed
herein.
* * * * *