U.S. patent application number 14/450863 was filed with the patent office on 2015-02-05 for helmet.
The applicant listed for this patent is SALOMON S.A.S.. Invention is credited to Stephane LATRUFFE.
Application Number | 20150033456 14/450863 |
Document ID | / |
Family ID | 49779958 |
Filed Date | 2015-02-05 |
United States Patent
Application |
20150033456 |
Kind Code |
A1 |
LATRUFFE; Stephane |
February 5, 2015 |
HELMET
Abstract
The invention relates to a helmet having an outer shell with an
apex and having an inner envelope demarcated by a lower edge, the
helmet further comprising an internal structure arranged within the
inner envelope, the internal structure including a plurality of
ribs, each rib extending from the apex to the lower edge.
Inventors: |
LATRUFFE; Stephane; (LA
BALME DE SILLINGY, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SALOMON S.A.S. |
Metz-Tessy |
|
FR |
|
|
Family ID: |
49779958 |
Appl. No.: |
14/450863 |
Filed: |
August 4, 2014 |
Current U.S.
Class: |
2/414 |
Current CPC
Class: |
A42B 3/125 20130101;
A42B 3/12 20130101; A42B 3/124 20130101; A42B 3/128 20130101 |
Class at
Publication: |
2/414 |
International
Class: |
A42B 3/12 20060101
A42B003/12 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 5, 2013 |
FR |
13 01883 |
Claims
1. A helmet comprising: an outer shell comprising: an apex; a lower
edge; and an inner envelope demarcated by the lower edge; an
internal structure positioned within the inner envelope of the
outer shell; the internal structure comprising a plurality of ribs,
each of the plurality of ribs extending between the apex to the
lower edge; and a bonding layer irremovably securing the internal
structure to the outer shell.
2. A helmet according to claim 1, wherein: the bonding layer is an
injected bonding layer.
3. A helmet according to claim 1, wherein: the plurality of ribs
includes a pair of laterally successive and spaced-apart pair of
ribs; and the bonding layer binds together at least the pair of
laterally successive and spaced-apart pair of ribs.
4. A helmet according to claim 1, wherein: the bonding layer has,
at least in a transverse cross section of the helmet, a height less
than a height of the ribs.
5. A helmet according to claim 1, wherein: the bonding layer and
the ribs are made of respectively different materials.
6. A helmet according to claim 1, wherein: the bonding layer and at
least some the plurality of ribs are made of materials having
respectively different densities.
7. A helmet according to claim 1, wherein: the plurality of ribs
and/or the bonding layer are made of EPP or EPS.
8. A helmet according to claim 1, wherein: the plurality of ribs is
made of a material having a density between 60 and 60 g/l.
9. A helmet according to claim 1, wherein: the bonding layer is
made of a material having a density between 10 and 100 g/l.
10. A helmet according to claim 1, wherein: all of the plurality of
ribs do not have an identical density and/or are not made of an
identical material.
11. A helmet according to claim 10, wherein: each of at least some
of the plurality of ribs has a surface having a shape of the inner
envelope of the outer shell, each of the surfaces extending along a
meridian extending through the apex.
12. A helmet according to claim 1, wherein: each of at some of the
plurality of ribs has a thickness (e) less than or equal to its
height.
13. A helmet according to claim 1, wherein: at least one of the
plurality of ribs has an inner profile designed to face a head of a
wearer in a use position when the helmet is worn by the wearer; the
inner profile comprises a plurality of cutouts extending between
the apex and the lower edge of the outer shell.
14. A helmet according to claim 1, wherein: the internal structure
comprises an assembly of separate pieces, each of the plurality of
ribs forming a separate one of the pieces.
15. A helmet according to claim 1, wherein: each of the plurality
of ribs has a first end and a second end; the first end is arranged
at the apex of the outer shell; and a connecting strip
interconnects all of the second ends.
16. A helmet according to claim 1, wherein: each of the plurality
of ribs has a respective free surface designed to face and to be
engageable with a head of a wearer in a use position of the helmet
when the helmet is worn by the wearer.
17. A helmet according to claim 16, wherein: the internal structure
is an innermost structure of the helmet.
18. A helmet according to claim 1, wherein: each of the plurality
of ribs has a respective free surface designed to face a head of a
wearer in a use position of the helmet when the helmet is worn by
the wearer; and no additional structure of the helmet extends
laterally across the free surfaces of the plurality of ribs at
respective lengthwise intermediate portions of the plurality of
ribs.
19. A helmet according to claim 1, wherein: each of at least some
of the plurality of ribs has a height that varies between the apex
and the lower edge.
20. A helmet according to claim 1, wherein: each of at least some
of the plurality of ribs has a greatest height at a lengthwise
intermediate portion between the apex and the lower edge.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon French Patent Application No.
13/01883, filed Aug. 5, 2013, 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 the Invention
[0003] The invention relates to the field of helmets, such as
sports helmets, including helmets intended for any of skiing,
mountaineering, climbing, and cycling.
[0004] 2. Background Information
[0005] Sports helmets typically comprise an outer shell and a layer
forming an internal structure. The outer shell defines an inner
envelope demarcated by a lower edge. The internal structure is
housed in the inner envelope and defines a volume within which the
user inserts his or her head. Generally, a comfort inner cap is
interposed between the internal structure and the skull of the
user.
[0006] The outer shell and internal structure combination protects
the head of the user. This combination is intended to absorb
impacts to the helmet and to prevent perforation or puncture of the
protective arrangement. In addition to impact resistance, weight is
an important factor affecting the performance of a helmet. Indeed,
user comfort is closely related to the weight of the helmet. Thus,
certain athletes do not use helmets because they find them to be
too heavy. The weight of the helmet supported by the head has
direct influence on the level of user fatigue, which is
proportional to the time the helmet is worn. Consequently, the
lighter the helmet, the better the sensations of the wearer and
his/her athletic performance will be. Moreover, a lightweight
helmet enables the user to have a greater sense of freedom and ease
in head movements. In this case, the user no longer has the feeling
of wearing a helmet.
[0007] Several solutions have been proposed to reduce the weight of
helmets; such solutions generally providing to reduce the weight of
the layer forming the internal structure. However, to maintain a
satisfactory impact resistance, the material density cannot be
overly reduced with a conventional construction, which consequently
limits the reduction in weight.
[0008] Thus, there is a need for a construction that makes it
possible to reduce the weight of a sports helmet significantly
while maintaining satisfactory strength, particularly for impact
absorption. Such is an object of the present invention.
SUMMARY
[0009] To this end, the invention provides a helmet comprising an
outer shell having an apex and defining an inner envelope
demarcated by a lower edge. The helmet also comprises an internal
structure arranged within the inner envelope. The internal
structure includes a plurality of ribs, each rib extending from the
apex to the lower edge.
[0010] Because of this construction, shock absorption is largely
provided by the ribs of the internal structure. Indeed, during
impacts, the ribs deform by compressing or bending, which makes it
possible to reduce the impact energy that is transmitted to the
head of the user. By extending from the apex to the lower edge, the
ribs have good damping properties.
[0011] A number of internal structures form a layer of the same
material. This layer does not necessarily have a constant thickness
but substantially covers the surface of the skull. By being formed
of ribs, the internal structure is more recessed than conventional
structures, which makes it possible to reduce the mass of the
internal structure and therefore to limit the weight of the helmet.
Alternatively, the space between two ribs may be filled with a
material having very low density compared to the material of the
ribs.
[0012] The arrangement of the ribs makes it possible to evenly
distribute both the weight of the helmet during use and the energy
transmitted to the head during impact.
[0013] In addition, the internal structure defines a free space
between each pair of adjacent ribs for air flow, thereby improving
ventilation and user comfort.
[0014] Optionally, the invention may have any of the following
optional features, taken alone or in combination: [0015] the ribs
extend along a first direction, from the apex to the lower edge
and, along a second direction, from the outer shell inward of a
volume defined by the inner envelope; [0016] each rib extends in a
plane such that, at any point of the rib, this plane is
perpendicular to another plane that is tangent to the inner
envelope, at a right angle with that point; [0017] each rib extends
in a vertical plane when the helmet is worn normally, without
tilting of the head. Each rib has a main direction of elongation
extending from the apex to the lower edge; [0018] at least some,
and in a particular embodiment all, of the ribs conform to the
shape of the inner envelope along a meridian portion, a pole of
which is the apex of the inner envelope; [0019] at least some, and
in a particular embodiment all, of the ribs have an outer profile
shaped to conform to the shape of the inner envelope, and an inner
profile shaped to conform to the shape of the skull of the user.
Alternatively, at least some, and in a particular embodiment all,
of the ribs have an outer profile shaped to conform to the shape of
the inner envelope, and a discontinuous inner profile having
cutouts and shaped to take support on the head of the user only
between two successive cutouts; [0020] at least some, and in a
particular embodiment all, of the ribs have a support zone adapted
to be in support against the head of the user. This support zone is
a surface support zone. However, a comfort inner cap can be
interposed between the skull and the shaped inner profile. The
comfort inner cap can be formed of a cushion, foam, and/or fabric;
[0021] the ribs are configured to take support on the head of the
user, on the one hand, and on the outer shell, on the other hand.
The ribs are thus arranged in the propagation path of the shocks
generated on the helmet; [0022] the thickness (e) of at least some,
and in a particular embodiment all, of the ribs is less than or
equal to its height (h), the height (h) at a point of the rib being
taken perpendicular to the inner envelope in that point, and the
thickness (e) being taken along a direction perpendicular to the
height and perpendicular to a dimension along which the rib extends
mainly. In a particular embodiment, the thickness of the rib is
less than 0.8 times or, in a particular embodiment, less than 0.6
times its height; [0023] each rib has a height (h) between 1.0 cm
and 5.0 cm or, in a particular embodiment, between 1.0 cm and 3.5
cm, the height (h) at a point of the rib being taken perpendicular
to the inner envelope and passing through that point. Each rib has
a thickness (e) between 0.5 cm and 3.0 cm or, in a particular
embodiment, between 0.6 cm and 1.0 cm, the thickness (e) at a point
of the rib being taken perpendicular to the main direction of
elongation of the rib. The thickness (e) of a rib corresponds to
the distance separating the two lateral surfaces of the rib; [0024]
each rib has a substantially constant thickness; [0025] the helmet
comprises a bonding layer affixing the internal structure to the
outer envelope. According to an embodiment, the bonding layer
connects two adjacent ribs of the internal structure to one
another. This keeps the ribs affixed to the outer shell in the
event of an impact. The ribs then absorb the compression
deformations over their entire height. In this case, the helmet may
have the following characteristics: [0026] the bonding layer
extends along each rib over a dimension at least equal to half or,
in a particular embodiment, at least equal to two thirds, of the
length of the rib, the length of the rib being taken along the main
dimension along which it extends, that is to say, along the curve
extending from the apex towards the lower edge. According to an
embodiment, the bonding layer extends partially along each rib,
from the lower edge to the apex. According to an embodiment, the
bonding layer extends along each rib, over the entire length of the
rib; [0027] the bonding layer conforms to the shape of the inner
envelope; [0028] the bonding layer is continuous. According to a
particular embodiment, it covers the inner envelope in its
entirety, except for the ribs; [0029] the bonding layer and the
ribs define an outer envelope shaped to conform to the shape of the
inner envelope of the outer shell. According to an embodiment, the
outer envelope forms a continuous surface, without relief, shaped
to be continuously in contact with the inner envelope. This enables
a better transmission of forces to the internal structure during an
impact; [0030] the bonding layer has a smaller height than that of
the ribs. According to an embodiment, the height of the bonding
layer is then less than 0.8 times or, in a particular embodiment,
less than 0.6 times the height of the ribs. It can be greater than
eight millimeters, at any point; [0031] the bonding layer is made
of a material having different properties than the constituent
material of the ribs. It may be a material of the same family, or a
different material. According to an embodiment, the bonding layer
is made from a material whose density is less than that of the
material forming the ribs. This makes the helmet lighter. According
to an embodiment, the density of the ribs is between 60 grams and
100 grams per liter. According to an embodiment, the density of the
bonding layer is between 10 grams and 100 grams per liter, and can
be less than 60 grams per liter. [0032] the material forming the
ribs and/or the material forming the bonding layer is expanded
polystyrene, for example, which is usually designated by the
acronym EPS. It may also be expanded polypropylene, which is
usually designated by the acronym EPP. [0033] at least one rib is
formed by shaping a sheet between the two lateral surfaces of the
rib. For example, in the thickness of the rib, the sheet may form
corrugations, slots, zigzags, or other repetitive patterns. The
ribs may be made of paper or cardboard; [0034] the ribs of the
internal structure have different materials and/or densities;
[0035] the ribs of the internal structure have dimensional
variations and in particular different thicknesses or local cutouts
in their height. According to an embodiment, the ribs have an inner
profile with inner cutouts. The support line between the head and
the rib is therefore not continuous. This enables the ribs to
deform in bending and/or in rotation and to improve ventilation of
the helmet; [0036] the ribs are evenly distributed around the
periphery of the lower edge; [0037] the internal structure forms a
plurality of sectors demarcated by two adjacent ribs, the sectors
being open in the area of the lower edge; [0038] the internal
structure is a unitary, monolithic structure, and, in a particular
embodiment, obtained by injection of a material forming the ribs;
[0039] the internal structure is an assembly of a plurality of
separate elements including the ribs and a common support, in which
each rib is assembled on a common support arranged in the area of
the apex. According to an embodiment, each rib includes a fixing
member adapted to cooperate with a complementary fixing member
carried by the support, the cooperation of the fixing members
carried by the rib and the support ensuring the affixing of the rib
on the support; [0040] each rib extends between a first end
arranged in the area of the apex and a second end, a connecting
band connecting all of the second ends to one another. This enables
good retention of the free ends of the ribs. According to an
embodiment, the second ends extend to the lower edge, and the
connecting band extends over the entire periphery of the lower
edge; [0041] the inner envelope is a solid/continuous surface and
has no openings. According to another embodiment, the inner
envelope has openings for ventilation.
[0042] Other objects, features and advantages of the present
invention will become apparent upon reviewing of the following
description and accompanying drawings. It is understood that other
advantages may be incorporated.
BRIEF DESCRIPTION OF DRAWINGS
[0043] The objects and characteristics, as well as the advantages
of the invention will become more apparent from the detailed
description of an embodiment thereof, which is illustrated by the
following annexed drawings, in which:
[0044] FIG. 1 is a perspective view of an exemplary embodiment of a
helmet according to the invention;
[0045] FIG. 2 is a perspective view of an internal structure
portion for a helmet as that illustrated in FIG. 1, with a
disassembled rib being shown;
[0046] FIG. 3 is a perspective view of an outer shell and an
internal structure portion before assembly to form a helmet as that
illustrated in FIG. 1;
[0047] FIG. 4 is a bottom view of the helmet of FIG. 1, before
assembly of the straps.
[0048] FIG. 5 is a cross-sectional view of the helmet of FIG. 4
along the cross section V;
[0049] FIG. 6 is a cross-sectional view of the helmet of FIG. 4
along the cross section VI;
[0050] FIG. 7 is a cross-sectional view of the helmet of FIG. 4
along to the cross section VII;
[0051] FIG. 8 is a cross-sectional view of the same section as FIG.
7, of a helmet according to another embodiment, in which the ribs
have particular shapes.
DETAILED DESCRIPTION
[0052] The drawings are given by way of examples and are not to be
considered to limit the invention.
[0053] The helmet 1 according to the invention comprises an outer
shell 100 having an apex 102, an outer surface turned outwards, and
an inner surface 104 defining an inner envelope 101. The inner
envelope 101 extends from the apex 102 to the lower edge 103 of the
outer shell, and defines a volume for receiving an internal
structure 200. FIG. 3 clearly illustrates the internal structure
200 prior to being inserted into the inner envelope 101. As
described in detail below, the invention is not limited to the
embodiments of the helmet in which the internal structure 200 is
obtained separately from the outer shell 100 prior to being
assembled in the latter.
[0054] Indeed, the invention extends to manufacturing methods in
which the internal structure 200 is injected directly within a
previously produced outer shell 100.
[0055] The internal structure 200 comprises a set of ribs 201. When
the internal structure 200 is located in the outer shell 100, the
ribs 201 extend between the apex 102 and the lower edge 103, that
is to say, from the apex 102, or from a region of the apex, to the
lower edge 103 or substantially to the lower edge. Each rib 201 has
an outer profile 202 shaped to conform to the inner surface 104. In
a particular embodiment, the outer shell 100 and internal structure
200 are shaped so that the outer profile 202 of each rib 201 is in
contact with the inner surface 104 over the entire dimension along
which the rib 201 extends.
[0056] Each rib 201 has an inner profile 203, or free surface,
shaped to face and to conform to the shape of the skull of the
user. A comfort inner cap, not shown, may be inserted between the
ribs and the head of the user, thereby improving the wearing
comfort.
[0057] Each outer 202 and inner 203 profile is curved.
[0058] Thus, the assembly formed by the laterally successive
spaced-apart ribs 201 defines a hollow volume for receiving the
head. This assembly thus forms a hollow dome or skeleton. Each rib
201 is in the form of an arch substantially extending from the apex
102 to a lower edge 103, thus forming a meridian, a pole of which
is the apex 202 of the inner envelope 101.
[0059] According to a particular embodiment, at least some, and
possibly all of the ribs 201, extend to the lower edge 103.
[0060] Each rib 201 extends mainly along a longitudinal curve
following the curvature of the inner envelope 101. The rib 201 is
characterized by a height "h" and a thickness "e".
[0061] The height "h" may vary along the rib. It is defined along a
direction perpendicular to the inner envelope 101 in the area of
the measurement.
[0062] The thickness "e" is defined along a direction perpendicular
to the height and the length of the rib corresponding to the
longitudinal curve.
[0063] According to an embodiment, the thickness "e" is less than
the height "h" of the rib 201. Thus, each rib 201 can easily deform
in compression or in bending along its height in the event of an
impact. The effective dimension for impact absorption is primarily
its height. Its thickness may be reduced to limit the weight of the
helmet 1, while enabling the helmet to maintain good overall impact
resistance.
[0064] The cross section of the rib 201 along a plane perpendicular
to the longitudinal curve is characterized by the height and
thickness. The cross section may be rectangular, square,
trapezoidal, or more generally polygonal.
[0065] According to an embodiment, the rib 201 extends along a
vertical plane when the helmet 1 is worn on a non-tilted head. This
orientation of the ribs provides good damping in the main impact
configurations.
[0066] In the illustrated embodiment, the internal structure 200
comprises seventeen ribs 201. The geometry of the ribs varies,
depending upon their location, so as to follow the inner envelope
101 and the morphology of the skull. In this example, the thickness
of the ribs is constant and ranges between 0.5 cm and 3.0 cm or, in
a particular embodiment, between 0.6 cm and 1.0 cm. The height
varies between 1.0 cm and 5.0 cm or, in a particular embodiment,
between 1.3 cm and 3.0 cm along each rib. Locally, the height
depends on the shape of the outer shell. Therefore, these height
values are not fixed. The smallest height can be close to the lower
edge 103. The greatest height can be close to the middle of the
length of the rib.
[0067] According to an embodiment, all of the ribs 201 have the
same thickness. This makes it possible to facilitate the
manufacture of the internal structure 200, because the ribs 201 can
then be obtained by making a cutout 207 in the same plate, as
descried in detail below.
[0068] According to another embodiment, the ribs 201 have different
thicknesses. For example, greater thicknesses are provided in zones
requiring reinforcement, or to ensure adequate strength of the
helmet. The other ribs 201 may smaller thicknesses to reduce the
weight of the helmet 1. The sizing of the ribs is important because
it affects the impact absorption. Therefore, the ribs are sized so
as to be able to damp either by direct compression or by
bending/buckling of the rib, or by a combination of both phenomena.
The sizing is adapted in the zones often that are biased during
impacts, such as the forehead, the back of the head, or in
particularly fragile zones such as the temples. The thickness
should not be too small in order not to cause wearing
discomfort.
[0069] Similarly, the distribution of the ribs 201 may be adapted
to optimize the weight of the helmet 1, while maintaining
satisfactory impact resistance. For example, the ribs 201 may be
arranged so as to be closer to one another in sensitive zones
(forehead, back of the head, temples) and more spaced apart in the
other zones.
[0070] Alternatively, the ribs 201 are distributed evenly over the
entire periphery of the lower edge 103.
[0071] According to an embodiment, the helmet 1 includes a binder
provided for affixing the various ribs 201 to the outer shell 100.
This binder forms a bonding layer 211 joining two adjacent ribs 201
as shown in FIGS. 1 and 4-8. This makes it possible to maintain the
ribs 201 in position in relation to one another and on the outer
shell 100. This also prevents the ribs from sliding or collapsing
during impact, for example.
[0072] The bonding layer 211 irremovably fixes at least one rib 201
to the outer shell 100. This anchoring makes it possible to keep
the internal structure continuously affixed to the outer shell. The
helmet then has a monolithic, i.e., one-piece, construction. The
internal structure is then non-removable.
[0073] Moreover, by being fixed, the ribs deform during impact so
as to provide damping that is adapted to the normative need.
[0074] According to an embodiment not shown, the height of the
bonding layer 211 is identical to those of the ribs 201. Thus, the
ribs 201 and the bonding layer 211 define a second inner envelope
adapted to conform to the shape of the skull of the user. In this
embodiment, the bonding layer 211, along with the ribs, also
participates in absorbing the impact.
[0075] According to an embodiment illustrated in FIGS. 1 and 4-8,
the height of the bonding layer 211 is less than that of the ribs
201. Thus, the ribs 201 provide a space 214 between the ribs 201
and the skull of the user, which reduces the weight of the helmet 1
and improves ventilation.
[0076] According to this embodiment, the bonding layer 211 extends
over the entire space between two adjacent ribs 201. Thus, this
bonding layer 211 extends along the entire length of each rib 201.
Thus, the inner surface 104 of the outer shell 100 is not visible
when the internal structure 200 is located in the inner envelope
101. This makes it possible to reinforce the outer shell 100 and
improve the helmet resistance to impact or perforation.
[0077] The height of the connecting layer 211 between the ribs is,
in a particular embodiment, greater than eight millimeters at any
point in order to ensure good retention and cohesion of ribs with
respect to one another. Below this value, the ribs may
collapse.
[0078] According to an embodiment, there may be zones with no
bonding layer locally, in zones not likely to be biased and not
affecting the strength of the internal structure. This makes it
possible to further lighten the helmet.
[0079] According to an embodiment, the bonding layer 211 extends to
the lower edge.
[0080] As illustrated in the drawing figures, in the immediate
vicinity of a rib 201, the bonding layer 211 is provided to have an
increasing height towards that rib 201. Thus, the bonding layer 211
forms a relief that can be also termed a weld seam 212. This makes
it possible to reinforce the position of the rib 201 and the
cohesion between ribs 201 and binder 211 by limiting the weight of
the helmet 1. The weld seam 212 appears clearly in FIGS. 5 and
6.
[0081] According to an embodiment, and as illustrated in FIG. 5,
the height of the bonding layer 211 varies along the rib 201. Thus,
the height h1 in the vicinity of the lower edge 103 is greater than
the height h2 located in the upper portion of the helmet 1. This
makes it possible to limit the quantity of material and therefore
the weight of the helmet 1, while reinforcing the zones that need
to be reinforced. Moreover, this distribution remains compatible
with an embodiment of the helmet by injection of the binder.
[0082] Alternatively, the height of the bonding layer 211 is
uniform between the apex 102 and the lower edge 103.
[0083] According to an embodiment, the ribs 201 are made of EPS.
This makes it possible to reduce the cost of the helmet 1.
Alternatively, the ribs are made of EPP, a material having a higher
elastic yield than EPS, which therefore enables the helmet to
absorb stronger impacts before being altered. The helmet can thus
be reused after sustaining certain limited impacts.
[0084] EPP and EPS also have the advantage of being hydrophobic.
Therefore, they can be used without the addition of a sealing
envelope.
[0085] A density between 60 g/l and 100 g/l can be selected for the
ribs 201 made of EPS or EPP.
[0086] Alternatively, in particular embodiments, corrugated
cardboard or paper, or rubber, is selected for the ribs 201. A
watertight protection can also be provided for these embodiments to
protect the ribs 201 from water.
[0087] Alternatively, rubber is selected for the ribs 201.
[0088] According to a particular embodiment, all of the ribs 201
are made of the same material and have the same density.
Alternatively, certain ribs do not have the same density and/or are
not made of the same material as other ribs. This makes it possible
to adapt the strength and weight of the internal structure 200. The
characteristics of the helmet can thus be adapted locally, for
example by reinforcing the sensitive portions. This also makes it
possible to optimize the weight of the helmet.
[0089] According to a particular embodiment, the material of the
binder 211 is also made of EPP or EPS, without this being
limiting.
[0090] Although the material of the ribs 201 and the material of
the binder 211 are of the same type, a difference in density
between these elements may be provided. For example, the ribs 201
can have a higher density than the binder 211 to ensure good impact
absorption and good retention of the helmet 1 on the skull. In
contrast, a binder 211 of lower density makes it possible to reduce
the weight of the helmet 1. In this case, the density of the binder
211 is between 10 g/l and 60 g/l so as to be lower than the density
of the ribs 201.
[0091] Alternatively, identical densities, between 60 g/l and 100
g/l, and, in a particular embodiment, identical materials are
selected for the ribs 201 and the binder 211. In this embodiment,
the bonding layer 211 can have a height significantly less than
that of the ribs 201 to make the helmet 1 lighter.
[0092] Typically, the height of the bonding layer 211, on at least
half of the length of the rib, is less than 70% of the height of
the rib 201.
[0093] The invention has the advantage of being compatible with two
techniques for manufacturing helmets.
[0094] The first technique, known as "in-mold" construction,
includes the following. First, the outer shell 100 is made. For
example, a plate made of polycarbonate or an equivalent material is
heated. It can be a copolymer of acrylonitrile butadiene styrene
(ABS), flax, carbon fibers or glass fibers. The plate is then
deformed along a curvature. Then, the edges are cut. This outer
shell is soft, very light, and resistant to perforation or
puncture. Second, the outer shell 100 is inserted in a mold, and
the same material is then injected within the outer shell to form
both the internal structure 200 comprising the ribs 211 and the
bonding layer 211. In this case, the internal structure 200 and the
binder 211 form a molded monolithic element having great cohesion
and strength. The helmet thus produced has a very good integrity
between its constituent elements and is particularly light.
Moreover, this embodiment makes it possible to reduce the assembly
steps. One can provide to add a coating on the inner surface of the
shell, before the second step, in order to improve the adhesion
between the latter and the internal elements.
[0095] Alternatively, the inner portion is made by bi-injection,
which enables use of a different material between the ribs and the
binder.
[0096] According to an alternative embodiment, the previously made
internal structure 200 is inserted into the outer shell 100 in the
second step, as illustrated in FIG. 3. This subassembly 100
comprised of the outer shell and 200 and the internal structure is
then inserted into the mold. Then, the binder 211 is injected to
affix the internal structure 200 to the outer shell 100. Again, the
helmet produced has very good integrity between its constituent
elements and is particularly light. This embodiment includes an
additional assembly step, compared to the previous embodiment.
However, it allows for more possibilities in making of the internal
structure 200, as described below.
[0097] A compatible second technique involves making the outer
shell by injection rather than by deformation in in a first step.
The outer shell is then more rigid, a little heavier, and has good
strength and resistance to perforation or puncture. In a particular
embodiment, the material used is acrylonitrile butadiene styrene
(ABS). Alternatively, the other materials mentioned above can be
provided for the outer shell 100.
[0098] The internal structure can be affixed to the outer shell by
injection, in a manner similar to the previously described
assemblies. Alternatively, the internal structure can be assembled
to the inner shell by bonding or another technique, the binder
being the adhesive element between the internal structure and the
outer shell.
[0099] The internal structure 200 can be made separately.
[0100] According to an embodiment illustrated in FIG. 2, the
internal structure 200 is made by the assembling of various ribs.
Each rib has a first end 204 adapted to be arranged in the area of
the apex 102. This first end 204 comprises a fixing member 206 for
fixing the rib 201, either directly to other ribs or to an element
forming a common support 210 for connecting all of the ribs 201 (as
shown in FIG. 2).
[0101] In the latter embodiment, the support 210 has a body 213 in
the form of a tube providing a space 214 to make the helmet 1
lighter. The tube cross section can be circular or oval to enable
good distribution of forces on the ribs. Alternatively, the cross
section is polygonal and/or solid. The drawing figures show that,
once positioned, the ribs 201 define a housing 209 for receiving
the support 210. This body 213 also comprises fixing members 215
complementary to the members 206 of the ribs 201. On the example
shown, these complementary fixing members 215 form slots each
shaped to receive a stud 216 carried by the first end 204 of the
rib 201. In a particular embodiment, the upper and lower ends of
the support 210 have slots over their entire periphery, and each of
the first ends 204 of the ribs 201 has two studs or projections
216. The studs 216 of the same rib 201 are configured so that each
is inserted into a slot cut in the upper and lower ends,
respectively, of the body 213.
[0102] FIGS. 7 and 8 clearly illustrate the support 210 forming a
common fixing element for all of the ribs 201. In these drawing
figures, the thickness of the body section 213 appears in cross
section in the recess formed between the two studs 216 of each rib
201. The common support 210 thus forms a keystone for the entire
internal structure 200.
[0103] This embodiment has the advantage of being particularly easy
to carry out because it does not require an injection mold. It
suffices to cut ribs 201 using laser or water jet, and then
assemble them to one another or to the common support 210. This
type of cut is very easily modifiable and makes it possible to
customize the shape of the ribs 201 easily and at low cost.
[0104] Therefore, the volume receiving the head of the user can
easily be customized, for example to provide a broad range of
helmets to fit a number of skull morphologies. Alternatively, or in
combination, the outer profile can also easily be customized to
offer a wide range of shapes for the shell.
[0105] Furthermore, this embodiment enables easy use of various
materials to optimize the weight and strength of the helmet. For
example, different materials may be used for the support 210 and
the ribs 201. Also, different materials may be used for the ribs,
typically depending upon their positioning around the skull, as
mentioned above.
[0106] The binder is then positioned between the ribs 201 to form
the bonding layer 211.
[0107] In particular embodiments, a structure or a resorbable
material is provided to maintain the ribs 201 in position before
and during injection of the bonding layer 211 between the ribs
201.
[0108] According to an embodiment illustrated in FIG. 8, openings
208 are provided in the ribs. In this example, these openings 208
are located in the vicinity of the inner surface 104 of the outer
shell 100. They are typically located at a distance between 1.0 mm
and 10 mm therefrom. Their diameter is greater than 3.0 mm, so that
during injection, the bonding material 211 penetrates into the
openings 208. When the bonding material 211 solidifies, it
reinforces the cohesion between the ribs 201 and the bonding layer
211 located therebetween, thereby improving the strength of the
helmet 1.
[0109] Furthermore, and irrespective of the helmet manufacturing
technique, cutouts 207 can be provided on the inner profile 203 of
the ribs 201. Thus, the inner profile 203 of the ribs does not form
a line in continuous support with the skull. This makes it possible
to increase the ventilation of the helmet 1; in particular, this
enables the portions of the ribs 201 located between the cutouts
207 to deform in bending and/or in translation in order to improve
the absorption of the forces transmitted from the outer shell 100
to the skull.
[0110] Typically, the depth of the cutout 207, measured along the
same direction as the height "h" of the rib 201, is greater than
30% of the height of the rib in a zone with no cutout 207.
[0111] Once the internal structure has been made in the outer
shell, the helmet is finalized by adding a strap. In a particular
embodiment, a comfort inner cap is added between the skull and the
ribs.
[0112] According to an embodiment, the helmet includes a connecting
band connecting the ribs in the vicinity of their second ends 205,
such as, in a particular embodiment, a connecting band having a
width the same as the heights of the second ends 205 of the ribs.
This ensures a better retention of the internal structure 200 on
the outer shell 100. This also makes it possible to avoid lateral
collapse of the second ends 205. In a particular embodiment, the
connecting band is applied over the entire circumference of the
inner envelope 101, and in a particular embodiment, in the area of
the lower edge 103. In a particular embodiment, it is formed by the
bonding material, during the same step for making of the bonding
layer 211.
[0113] The invention is not limited to the embodiments described
above and extends to all of the embodiments covered by the
claims.
[0114] Lastly, at least because the invention is disclosed herein
in a manner that enables one to make and use it to achieve various
ones of the characteristics mentioned above in 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.
* * * * *