FIELD OF THE INVENTION
[0001] The present invention relates to safety or protective helmets for cyclists heads.
BACKGROUND OF THE INVENTION
[0002] Conventional safety helmets comprise an impact resistant, hard external shell and
an inner shock-absorbent liner which is contoured to fit and protect the head of the
wearer. Usually, the shock-absorbent portion of the helmet is made of a low-density
soft material, such as expanded polystyrene foam, which is easily damaged and soiled
during handling.
[0003] U.S. Patent 4,996,724 dated March 5, 1991 and entitled: PROTECTIVE RIM CONFIGURATION
FOR HARD SHELL SAFETY HELMET - inventor: Serge Dextrase, partially overcomes the above-noted
disadvantage, by providing a rim configuration made of the same hard material as the
external shell and covering the lower periphery of the external shell. However, in
such a helmet, the polystyrene foam is still left exposed inside the helmet.
[0004] In order to have sufficient impact resistance, the liner of such a helmet must be
relatively thick or the foam material of said liner must have a relatively high density,
for instance 6 pounds per cubic foot.
[0005] Another problem with existing safety helmets is that, once they have sustained a
first major blow, they tend to fracture, become fragmented and to fall apart - the
fragmented parts thereof release one another -. This is to say, the helmet disintegrates.
This is unfortunate, since in high-speed cycling accidents, multiple ground impacts
of the head are not uncommon. If the helmet has already fragmented and disintegrated
after the first ground impact, it becomes useless in preventing head injuries for
the following ground impacts of the behelmeted cyclist.
OBJECTS OF THE INVENTION
[0006] It is the general object of the present invention to provide a safety helmet of the
character described, which is provided with an internal shell as well as an external
shell, the internal shell being made of hard material and substantially covering the
inner surface of the shock-absorbent liner.
[0007] Another object of the present invention is to provide a safety helmet of the character
described, in which all the surfaces of the shock-absorbent liner, including those
at the ventilation openings, are covered and coated by the hard internal and external
shells.
[0008] Another object of the present invention is to provide a safety helmet of the character
described, of minimum weight and yet of maximum resistance to impact.
[0009] An important object of the invention is to provide an alternate embodiment of such
helmet, having means to capture and retain to the helmet fragments of impacted parts
thereof, wherein a major portion of the internal shell is embedded into the soft-bodied
insert part of the helmet.
SUMMARY OF THE INVENTION
[0010] The safety helmet of the invention is especially designed for cyclists and comprises
a hard external shell, a hard internal shell, and an intermediate shock-absorbing
insert. The internal shell defines a bottom rim portion formed by an outwardly-extending
web and a flange projecting upwardly from the web, the bottom rim portion thus defining
an upwardly-opening trough, said insert conforming with and adhering to the outer
surface of said internal shell and filling said trough, said external shell intimately
conforming with, and adhering, to the external surface of said insert and having a
bottom edge forming a joint with the top edge of the flange, and ventilating opening
extending through the internal shell, the insert and the external shell.
[0011] Preferably, the internal and external shells form tube-like extensions surrounding
their respective portions of the ventilating openings and protruding from the inner
surface of the external shell, and from the outer surface of the internal shell, respectively,
the extensions of the external shell butting the extensions of the internal shell,
said extensions thus forming a liner coating the surfaces of the insert which would
otherwise be exposed in said ventilation openings.
[0012] In an alternate embodiment of the invention, the major portion of the inner face
of the internal shell is embedded thicknesswisely into the soft-bodied insert of the
insert, rather than being applied against the outer face thereof as in the first embodiment,
so as to provide increased capability of maintaining together impact fragments of
the shattered helmet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013]
Figure 1 is a top plan view of the safety helmet according to a first embodiment of
the invention;
Figure 2 is a side elevation of the helmet of figure 1;
Figure 3 is a longitudinal section, taken along line 3-3 of Figure 1;
Fig 4 is a partial cross-section taken along line 4-4 of Fig 2;
Figure 5, on the second sheet of drawings, is an enlarged view of the area circumscribed
by circle 5 in figures 3 or 4, and particularly showing the joint between the internal
and external shells;
Figure 5a is a partial section similar to Figure 5 but showing another type of joint;
Figure 6 is an enlarged view of the area circumscribed by circle 6 of figures 3 or
4;
Figure 7 is an enlarged, partial cross-section, taken along line 7-7 of Figure 2;
figure 8 is a top plan view of a second embodiment of the helmet internal shell part;
figure 9 is a side elevational view of the internal shell of figure 8;
figures 10 and 11 are sectional views of the internal shell taken along lines 10-10
and 11-11 respectively of figure 9; and figures 10a and 11a are views similar to figures
10 and 11 respectively, but showing the helmet in full including the insert and the
external shell thereof.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0014] The protective headgear, or more commonly named safety helmet 10 of the invention,
comprises an external shell 12, an internal shell 14, and a shock-absorbing insert
16. Both shells 12 and 14 are made of hard yet resiliently flexible material, such
as ABS, or similar thermoplastic material. Preferably, each shell 12, 14 has a thickness
of about 0.3 millimeters. The insert 16 is made of light weight, soft yet substantially
rigid, shock-absorbing material, preferably expanded polystyrene foam. The insert
16 preferably has a non-uniform thickness averaging about 30 millimeters. Instead
of the usual density of 6 pounds per cubic foot, found in the foam portions of prior
art safety helmets, the helmet of the invention has been provided with the insert
having a density of only 3.5 pounds per cubic foot.
[0015] Such a lower density helmet insert has recently been certified (in August 1991) by
the Snell Memorial Foundation, inc. (St. James, NY) as having demonstrated compliance
with the performance requirements under the B-90 standard for protective headgear.
It therefore meets safety standards for cyclists, even though its density is almost
half that of conventional helmet inserts.
[0016] From this, it is clear that, providing a full internal shell considerably increases
the helmet resistance to impact. Therefore, providing an internal shell 14, which
covers the wearer's head, provides a structural function for the helmet in that it
has a synergistic effect with the external shell and insert.
[0017] The internal shell 14 is provided at its lower periphery with a bottom rim portion,
indicated at 18, formed by an outwardly-extending web 20 and a flange 22 projecting
upwardly from the web 20. Thus, the rim portion 18 forms an upwardly-opening trough
surrounding internal shell 14 and which is completely filled by the bottom portion
of the insert 16. The external shell 12 terminates downwardly short of the bottom
portion of the insert 16, and its lower edge forms a joint 24 with the top edge of
the flange 22.
[0018] The joint 24 is preferably a lap joint, as shown in Figure 5, but can be a butt joint,
as shown at 24a in Figure 5a. In both cases, the joint is preferably covered, for
aesthetic purposes, by a strip 26 adhered to the flange 22 and to the adjacent portion
of the external shell 12. Strip 26 completely surrounds the helmet 10.
[0019] Internal shell 14 conforms with, and is adapted to cover, the wearer's head, including
part of the forehead and the back of the head just above the neck.
[0020] Referring to Figure 3, the rear section of the rim portion 18 (at the left side of
the figure) and the corresponding part of the insert 16 is thicker than the front
section of rim portion 18 and corresponding part of the insert 16. The rear section
of the rim portion 18 is provided with a central orifice 28 defined by an upwardly-extending
tubular extension 30, at the top of which is exposed the insert 16. The orifice 28,
with its tubular extension 30, is formed in an upwardly-recessed central section 32
of the rim portion 18, as shown in Figure 4.
[0021] Elongated cushioning patches 34 are adhered to the inside surface of the internal
shell 14 and are adapted to contact the wearer's head while maintaining the internal
shell 14 spaced from said head. Each patch 34 includes velours or terry-like fabric.
[0022] To further reinforce the helmet, the external shell 12 is provided with a pair of
longitudinally-extending ribs 36, which protrude inwardly from the inner surface of
the external shell 12, thereby forming grooves at the outer surface of the latter.
Similarly, the internal shell 14 is provided with a pair of longitudinal grooves 38,
which protrude outwardly from the external surface of the internal shell toward external
shell 12. The ribs 36 and 38 are longitudinally registering and are preferably diverging
from back to front of the helmet.
[0023] Ventilation openings 40, 42 are formed through the helmet, more specifically through
the external shell 12, the insert 16, and the internal shell 14. Ventilation openings
40 are located through the ribs 36, 38, while ventilating openings 42 are disposed
along the central plane of the helmet, and also forwardly of the ribs 36 and 38. Obviously,
additional ventilation openings could be provided. These ventilation openings are
characterized by the fact that their portions formed in the internal shell 14 and
external shell 12 are surrounded by tubular extensions 44 and 46, respectively. The
extensions 44 inwardly protrude from the external shell 12, while the extensions 46
outwardly protrude from the internal shell 14. The two extensions abut against each
other approximately mid-way of the thickness of the insert 16 to form a butt joint
50, as shown in Figure 6. Thus, the tubular extensions 44 and 46 completely line the
surfaces of the insert 16 which would otherwise be exposed in the ventilation openings
40 and 42.
[0024] The helmet is provided with retention straps 52, 52a of known construction, and including
length-adjusters 54 and chin straps 56, the latter only being partially shown. At
the back of the helmet, the retaining strap 52 extends through a portion of two transversely-aligned
ventilation openings 40 and underneath the external shell 12 through a passage formed
by a transverse groove 58, made at the outer surface of the insert 16, and communicating
with the two ventilation openings 40. Similarly, a pair of transversely-spaced strap-receiving
orifices 60 are formed at the front of the helmet for the passage of the retaining
strap 52a. The two orifices 60 communicate with a transverse passage formed by a groove
62 at the outer surface of the insert 16.
[0025] The internal and external shells 14 and 12 are separately molded; the internal shell
14 is inserted in a mold in which is injected the material of the insert 16, the polystyrene
then expanding within the mold to its final shape and adhering to the outer surface
of the hot internal shell 14. The resulting assembly, once cured, is covered with
the external shell 12 which is adhered to the insert 16 after the positioning of the
retaining straps 52, 52a. The patches 44 are finally positioned on the internal shell
14. The resulting helmet is very light; it has a minimum of thickness and fully complies
with the regulations governing the resistance to impact of such helmets.
[0026] The second embodiment of helmet is illustrated at 110 in figures 10a and 11a, and
referenced with the 100-series reference numerals corresponding to those of the first
embodiment. Namely, the alternate internal shell 114 - figures 8-11 - is made of a
hard yet resiliently flexible material, similar to that of shell 14 of the first embodiment;
however, its relative hardness will be substantially smaller. Preferably, shell 114
could then have a reduced thickness, e.g. 0,1 mm (about one third the thickness of
shell 14).
[0027] A second difference between the two internal shells is that shell 114 has preferably
a much larger number of ventilation openings 140 formed therethrough.
[0028] The third and main difference between the internal shells is however in the way the
internal shell 114 is mounted to the insert 116. Indeed, as best seen in figures 10a
and 11a, the main portion of shell 114 is thicknesswisely embedded into insert 116,
while the rim portion 118 of shell 114 is not - rim portion 118 forms an upwardly
opening trough completely filled by the bottom edgewise portion of the insert 116.
Thus, the main, generally concave wall of internal shell 114 is concealed within the
thickness of the insert 116, so that it is the inner wall of insert 116, and not the
internal shell 114, that will come in contact with the top portion of the cyclist's
head - except at the rim portion where internal shell portion 118 will project outwardly
from the thickness of the insert 116 to engage around the side portions of the wearer's
head in the known fashion.
[0029] A marginal annular portion 115 is thus defined on the inside face of the helmet 110,
adjacent the rim portion 118, where the internal shell 114 transversely engages through
the soft body of the insert 116 to become thicknesswisely embedded therein. Preferably,
this marginal portion 115 will come flush with the internal wall of the insert 16,
so as to define a smooth, non-irritating, inner surface joint for comfort of the wearer.
[0030] Thus, as in the first embodiment of helmet 10, there are in the second embodiment
of helmet 110 two hard shells 112, 114 and one shock absorbing insert, 116. However,
while in the first embodiment 10, all of the inner (concave) face of the helmet was
lined with the internal shell 14, in the second embodiment 110, only the marginal
rim portion 118 of the helmet is lined by the internal shell 114 while the major portion
of its inner face is lined by the insert proper 116. The advantage of having the internal
shell 114 partially embedded into the soft bodied, yet substantially rigid insert
116, is in the impact absorbing capabilities of the helmet 110. Indeed, with the second
embodiment of helmet 110, what will be enhanced is the capability of maintaining together
a number of structural fragments of external shell 112 and/or internal shell 114 and/or
insert 116, following impact fracturing of the helmet 110. Obviously, internal shell
114, which is embedded into the insert 116 (the latter covering the wearer's head),
still provides a structural function for the helmet 110, in that it has a synergistic
effect with the external shell 112 and insert 116, in providing very high impact resistance,
as in the first embodiment of the invention.
[0031] Maintaining together these various fragments of helmet 110 after impact, even if
in non-integral fashion, is critical in providing post-impact sustained protection
to the head in view of eventual secondary ground impacts of the cyclist's head following
the initial impact. Indeed, the purpose of the helmet is to prevent head injuries,
which usually occur when the cyclist loses control of his vehicle and falls to the
ground. If the helmet becomes shattered and disintegrates after the initial ground
impact, it will not help prevent head injuries if the cyclist's head strikes the ground
for a second or third time - which could occur of course when the cyclist speed is
relatively high before fall.
[0032] Preferably, and as best illustrated in figure 9, the outer face of the main concave
wall portion of internal shell 114 is poked at a plurality of random locations, to
define a plurality of inwardly projecting cavities 170. Such cavities 170 define on
the internal face of the internal shell 114, full convex "fingers" 170' (the mirror
image of the cavities 170). Cylindrical fingers 170' are destined to sink into the
soft body of the insert 116 so as to more firmly anchor the shell 114 into the insert
116. The apex of the internal shell 114 preferably also includes an outturned cylindrical
finger 170'' with a conical tip, extending in a direction opposite fingers 170', for
the same purpose as the latter.
[0033] Preferably and as suggested in figures 10a and 11a, the apices of outturned fingers
170' project through the inner face of the insert 116, so as to come flush with the
inner face of insert 116. Hence, the inner face of soft-bodied insert 116 is dotted
with a number of small discs 170' made of hard material and spaced from each other.
1. A safety helmet for cyclists, comprising a hard external shell, a hard internal shell,
and an intermediate shock-absorbing insert, said internal shell conforming with and
adapted to fit the head of a wearer, and defining a bottom rim portion formed by an
outwardly-extending web and a flange projecting upwardly from said web, said bottom
rim portion thus defining an upwardly-opening trough, said insert conforming with
and adhering to the outer surface of said internal shell and filling said trough,said
insert having an external surface which is substantially flush with said flange, said
external shell intimately conforming with, and adhering, to the external surface of
said insert and having a bottom edge forming a joint with the top edge of said flange,
and ventilation openings extending through said internal shell, insert and external
shell.
2. A safety helmet as defined in claim 1, wherein said external and internal shells form
tube-like extensions surrounding their respective portions of said ventilation openings
and protruding inwardly of said external shell and outwardly of said internal shell,
respectively, the extensions of the external shell butting the extensions of the internal
shell, said extensions forming a liner coating the surfaces of the insert which would
otherwise be exposed in said ventilation openings.
3. A safety helmet as defined in claim 1, wherein said joint is a butt joint and further
including a strip covering said butt joint and adhering to said flange and to said
external shell all around said helmet.
4. A safety helmet as defined in claim 2, wherein said joint is a butt joint and further
including a strip covering said butt joint and adhering to said flange and to said
external shell all around said helmet.
5. A safety helmet as defined in claim 1, wherein said joint is a lap joint.
6. A safety helmet as defined in claim 2, wherein said joint is a lap joint.
7. A safety helmet as defined in claim 2, wherein said internal shell and said insert
have two transversely-spaced, helmet retaining, strap receiving orifices, said insert
being provided at its outer surface with a transversely-extending groove, communicating
at its ends with said orifices, said groove and orifices defining a continuous passage
inwardly of said external shell for a helmet retaining strap.
8. A safety helmet as defined in claim 1, wherein said rim portion has a front and a
rear section adapted to extend across the forehead and the back of the head of the
wearer, respectively, said insert being thicker at said rear section than at said
front section, the web of said rear section having an orifice defined by a tubular
extension upwardly extending in said trough and said insert being exposed in said
orifice at the upper end of said tubular extension.
9. A safety helmet as defined in claim 1, further including cushioning patches adhering
to and protruding from the inner surface of said internal shell and adapted to space
said internal shell from the head of a wearer when in contact with said head.
10. A safety helmet as defined in claim 1, wherein said internal shell forms longitudinally-extending
internal shell ribs outwardly protruding therefrom and said external shell forms longitudinally-extending
external shell ribs inwardly protruding therefrom.
11. A safety helmet as defined in claim 10, wherein each external shell rib registers
with an associated internal shell rib thicknesswisely of the helmet, at least some
of said ventilation openings being elongated and located through said ribs.
12. A safety helmet for use with chin retention straps on a cyclist's head, comprising:
(a) a hard, resiliently flexible, external shell;
(b) a hard, resiliently flexible, internal shell, defining a main portion and a rim
portion, the latter rim portion formed by an outwardly extending web and a flange
projecting upwardly externally from said web, the latter rim portion thus constituting
an upwardly-opening trough; and
(c) a soft, substantially rigid, shock absorbing insert, also defining a main portion
and a rim portion, said insert main portion defining an external surface generally
conforming with and adapted to fit onto the top of said cyclist head;
wherein said insert rim portion conforms with and adheres to the outer surface of
said internal shell rim portion, and fills said trough; said internal shell main portion
is thicknesswisely embedded into said insert main portion; said internal shell rim
portion surroundingly conforming with and adapted to fit around the sides of said
cyclist head; said insert rim portion having an external surface, substantially flush
with said flange; said external shell conforming with and adhering to the external
surface of said insert and having a bottom edge forming a joint with the top edge
of said flange; and further including ventilation openings, each extending through
said internal shell, insert and external shell.
13. A safety helmet as in claim 12,
wherein said internal shell is substantially thinner relative to said external shell,
and its flexibility, accordingly greater.
14. A safety helmet as in claim 12,
wherein a generally annular marginal portion is defined between said rim portion and
main portion of said internal shell, said marginal portion being flush with the adjacent
areas of said insert main portion so that the whole internal face defined by said
helmet be smooth, for comfort of said cyclist.
15. A safety helmet as defined in claim 12,
wherein said joint is a lap joint.
16. A safety helmet as defined in claim 12,
wherein said external and internal shells form tube-like extensions, surrounding their
respective portions of said ventilation openings and protruding inwardly of said external
shell and outwardly of said internal shell, respectively, the extensions of the external
shell butting the extensions of the internal shell, said extensions forming a liner
coating the surfaces of the insert which would otherwise be exposed in said ventilation
openings.
17. A safety helmet as in claim 12,
with said internal shell main portion further including a number of transverse fingers
spaced from one another, at least some of said fingers extending toward the inner
face of said insert main portion and therethrough, so that the free end defined by
each of said at least some of said fingers comes substantially flush with said insert
main portion inner face.