CA2090347C

CA2090347C - Protective headgear with a hard, flexible outer shell, a soft insert anda hard, flexible inner shell embedded in the insert

Info

Publication number: CA2090347C
Application number: CA002090347A
Authority: CA
Inventors: Louis Garneau
Original assignee: 9001 6262 Quebec Inc
Current assignee: 9001 6262 Quebec Inc
Priority date: 1993-02-25
Filing date: 1993-02-25
Publication date: 1997-11-18
Anticipated expiration: 2013-02-25
Also published as: CA2090347A1

Abstract

The safety helmet comprises hard internal and external shells and a shock-absorbent insert. The internal shell forms at its lower edge and on the outside thereof an upwardly-opening trough in which the insert is inserted. The free edge of the trough joins with the lower edge of the external shell above the bottom of the trough. The two shells, together with the insert, form ventilation openings which are lined by portions of the two shells. The main portion of the internal shell is embedded into the soft-bodied insert, so that it is mainly the insert that contacts the wearer's head, but for the rim portion thereof where the internal shell still surrounds the bottom edge of the insert.

Description

' 2~3~
FIELD OF THE INVENTION

The present invention relates to safety or protective helmets for cyclists heads.
BACKGROUND OF THE INVENTION

This patent application is being filed pursuant to the filing of co-pending Canadian patent application No 2,043,725-1 filed 31 May 1991 in the name of the present a]pplicant, and laid-open on 1 December 1992. Canadian application No 2,043,725-1 is hereby incorporated by way of reference to the present patent 10 application.
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 15 material, such as expanded polystyrene foam, which is easily damaged and soiled during handling.
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 20 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.
In order to have sufficient impact resistance, the liner 25 of such a helmet must be relatively thick or the foam material of said liner must have a relatively high density, for instance at ~ 2~r.~3~7 least 6 pounds per cubic ~oot.
Another problem with existing safety helmets is that, once they have sustained a first major blow, they tend to fracture, bec~me fragmented and to fall apart - the fragmented parts thereof 5 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 10 following ground impacts oE the behelmeted cyclist.
OBJECTS OF THE lNv~;N~ oN
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 15 internal shell being made of hard material and substantially covering the inner surface of the shock-absorbent liner.
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, includin~ those at the ventilation 20 openings, are covered and coated by the hard internal and external shells.
Another object of the present invention is to provide a safety helmet of the character described, of minimum weight and yet of ~ resistance to impact.
An important object of the invention is to provide an alternate embodiment of such helmet, having means to capture and 3 ~ 7 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.
SUM~RY OF THE INVENTION
The safety helmet of the invention is especially designed for cyclists and comprises 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 10 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 15 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 20 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 25 and having a bottom edge forming a joint with the top edge of said :~
flange; and further including ventilation openings, each extending : :

3 ~-f~ 3'~'7 ' ::
.;
through said internal shell, insert and external shell.
Preferably, said internal she:Ll i5 substantially thinner relative to said external shell, and its flexibility, accordingly greater.
Advantageously, 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.
lo Pro~itably, said joint is a lap joint. Moreover, it is envisioned that 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 15 of thQ 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.
Preferably, said internal shell main portion further includes a number of transverse fingers spaced from one another, at .
20 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.
BRIEF DESCRIPTION OF THE DRAWINGS
25 figure 1 is a top plan view of the preferred embodimsnt of the helmet internal shell part; ~ ~

4 ~- -,:.:
; ~

.. . ...

~3~3~ /

figure 2 is a side elevational view of the internal shell of figure l;
figures 3 and 4 are sectional views of the internal shell taken along lines 3-3 and 4-4 respPctively of figures 1 and 2; and 5 figures 3a and 4a are views similar to figures 3 and respectively, but showing the helmet in full including the insert and the external shell thereof.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the co-pending Canadian patent application No 10 2,043,725-1 filed 31 May 1991, and laid-open on 1 December 1992, the protective headgear, or more commonly named safety helmet, was said to comprise an external shell, an internal shell, and a shock-absorbing lnsert. Both shells and are made of hard yet resiliently flexible material, such as ABS, or similar thermoplastic material.
15 Preferably, each shell has a thickness of about 0.3 millimeter~.
The insert is made of light weight, soft yet substantially rigid, shock-absorbing material, preferably expanded polystyrene foam.
The insert preferably has a non-uniform thickness averaging about 30 millimeters. Instead of the usual density of 6 pounds per cubic 20 foot, found in the foam portions of prior art safety helmets, the helmet of this co-pending application has been provided with the insert having a density of only 3.5 pounds per cubic foot.
Such a lower density helmet insert has recently been certified (in August 1991) by the Snell Memorial Foundation, inc.
25 (St. James, NY) as having demonstrated compliance with the performance requirements under the B-90 standard for protective - : , . .. .

3'~
headgear. It therefore meets safety standards for cyclists, even though its density is almost half that of conventional helmet inserts.
From this, it is clear that, providing a full internal 5 shell considerably increases the helmet resistance to impact.
Therefore, providing an internal shell, 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.
The internal shell is provided at its lower periphery 10 with a bottom rim portion, formed by an outwardly-extending web and a flange projecting upwardly from the web. Thus, the rim portion forms an upwardly-opening trough surroundinq internal shell and which is completely filled by the bottom portion of the insert. The external shell terminates downwardly short of the bottom portion of 15 the insert, and its lower edge forms a joint with the top edge of the flange.
In this co-pending application, the joint is preferably a lap joint, but can be a butt joint. In both cases, the joint is preferably covered, for aesthetic purposes, by a strip adhered to 20 the flange and to the adjacent portion of the external shell. Strip completely surrounds the helmet.
The internal shell conforms with, and is adapted to cover, the wearer's head, including part of thP forehead and the back of the head just above the neck.
Still in this co-pending application, the rear section of the rim portion and the corresponding part of the insert is thicker ~9~3~7 than the front section of rim portion and corresponding part of the insert. The rear section of the rim portion is provided with a central orifice defined by an upwardly-extending tubular extension, at the top of which is exposed the insert. The orifice, with its 5 tubular extension, is formed in an upwardly-recessed central section of the rim portion.
Elongated cushioning patches are adhered to the inside surface of the internal shell and are adapted to contact the wearer's head while maintaining the internal shell spaced from said 10 head. Each patch includes velours or terry-like fabric.
To further reinforce the helmet, ~he external shell is provided with a pair of longitudinally-extending ribs, which protrude inwardly from the inner surface of the external shell, ~hereby ~orming grooves at the outer surface of the latter.
15 Similarly, the internal shell is provided with a pair of longitudinal grooves, which protrude outwardly from the external surface of the internal shell toward external shell. The ribs are longitudinally registering and are preferably diverging from back to front of the helmet.
In this co-pending application, ventilation openings are formed through the helmet, more specifically through the external shell, the insert, and the internal shell. Ventilation openings are located through the ribs, while ventilating openings are disposed along the central plane of the helmet, and also forwardly 25 of the ribs. Obviously, additional ventilation openings could be provided. These ventilation openings are characterized by the fact 3 ~ 7 that their portions formed in the ihternal shell and external shell are surrounded by tubular extensions, respectively. The extensions inwardly protrude from the external shell, while the extensions outwardly protrude from the internal shell. The two extensions 5 abut against each other approximately mid-way of the thickness o~
the insert to form a butt joint. Thus, the tubular extensions completely line the surfaces of the insert which would otherwise be exposed in the ventilation openings.
The helmet is provided with retention straps of known 10 construction, and including length-adjusters and chin straps. At the back of the helmet, the retaining strap extends through a portion of two transversely-aligned ventilation openings underneath the external shell through a passage formed by a transverse groove, made a~ the outer surface of the insert, and communicating with the 15 two ventilation openings. Similarly, a pair of transversely-spaced strap-receiving orifices are formed at the front of the helmet for the passage of the retaining strap. The two orifices communicate with a transverse passage formed by a groove at the outer surface of the insert.
The internal and external shells are separately molded;
the internal shell is inserted in a mold in which is injected the material of the insert, the polystyrene then expanding within the mold to its final shape and adhering to the outer surface oE the hot internal shell. The resulting assembly, once cured, is covered 25 with the external shell which is adhered to the insert after the positioning of the retaining straps. The patches are finally .
, .~

2~,3~ 3 ~r 7 positioned on the internal shell. ~he resulting helmet is verv light; it has a minimum of thickness and fully complies with the regulations governing the resistance to impact oE such helmets.
Now, according to the present preferred embodiment of the 5 invention, there is provided a helmet as illustrated at 110 in figures 3a and 4a. Internal shell 114 is rnade of a hard yet resiliently flexible material. Preferably, shell 114 could have a thickness, e.g. 0,1 mm. Moreover, shell 114 has preferably a large number of ventilation openings 140 formed therethrough.
Still another novel feature of the present internal shells is in the way the internal shell 114 is mounted to the insert 116. Indeed, as best seen in figures 3a and 4a, the main portion of shell 11~ is thicknesswisely embedded into insert 116, while the rim portion 118 of shell 114 is not - rim portion 118 15 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 tha internal shell 114, that will come in contact with 20 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 ~ortions of the wearer's head in the known fashion.
~ -A marginal annular portion 115 is thus defined on the --25 inside face of the helmet 11o, adjacent the rim portion 118, where -the internal shell 114 transversely engages through the soft body ,.
,'''~'''' '"''' ~ "' ~

,' ".

~ ~ '3 ~ X
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.
Thus, the helmet still retains two hard shells 112, 114 and one shock absorbing insert, 116 (as in said co-pending patent application). However, while in this co-pendi~g application, all of the inner (concave) face of the helmet was lined with the internal shell 14, in the present invention 110, only the marginal 10 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 15 110. Indeed, with the present 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 20 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 for the embodiment disclosed in said co-pending application.
Maintaining together these variou~ fragments of helmet 110 after impact, even if in non-integral fashion, is critical in " 10 providing post-impact sustained protectio2 ~ e~Xead 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 5 control of his vehicle and falls to the ground. If the helmet becomes shattered and disintegrates after t:he 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 10 fall. ~ ~
Preferably, and as best illustrated in figure 2, 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 pro~eating cavities 170. Such cavities 170 define on 15 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 ' -20 includes an outturned cylindrical finger 170'' with a conical tip, extending in a direction opposite fingers 170', for the same purpose as the latter.
Preferably and as suggested in figures 3a and 4a, the apices of outturned fingers 170' project through the inner face of - ~ -25 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 ~f~

11 ,: . .:
: :..' .

2~3~7 . ~
. .
: - , .. :..
..

with a number of small discs 170' made of hard material and spaced from each other. -The invention also concerns a process for manufacturing such a helmet. The process includes the following steps~
5 (a) providing a first, dome-shaped ABS sheet shell, said first shell including a number of apertures therethrough joining inner ~ -and outer opposite convex faces defined by said dome-shaped shell;
(b) inserting said first shell into a female part of a male-female composite mould;
lO (¢) closing a male part of said composite mould over said ~emale part ther~o~, whereby said first shell becomes confined and enclosed into the enclosure defined within said composite mould;
(d) injecting expanded polystyrene granules into said composite mould enclosure, through said mould, whereby said granules cover at 15 least a substantial portion of said first shell inner face and -extends through said shell apertures to ~eep therethrough and cover at least a sub~tantial portion of said first shell outer face;
(e) submitting said mould enclosure, for a period ranging between approximately 5 to 15 seconds, to the heating action of boiling 20 water vapour, through a plurality of noz~les opening into said mould enclosure, wherein said expanded polystyrene granules will set into a dome~shaped cap and said first shell will become fixedly ! e hed~ed thicknesswisely of said polystyrene cap;
(f) coolin~ said mould, for a period ranging between approximately 25 5 to 15 seconds, through the action of ambient temperature water sprays;
(g) stabilizing said integral first shell and polystyrene cap, for a period ranging between approximately 3 ~o 4 minutes;
(h) withdrawing said integral first shell and polystyrene cap from 30 the mould enclosure;
~i) providing a second, dome-shaped ABS sheet shell; and (j) glueing a second, dome-shaped ABS shell against the inner dome-shaped face defined by said polystyrene cap, wherein said first and second shells becomes integral to one another via said ~ -35 polystyrene cap.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR
PRIVILEGE IS CLAIMED, ARE DEFINED AS FOLLOWS:

1. 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.

2. A safety helmet as in claim 1, wherein said internal shell is substantially thinner relative to said external shell, and its flexibility, accordingly greater.

3. A safety helmet as in claim 1, 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.

4. A safety helmet as defined in claim 1, wherein said joint is a lap joint.

5. 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.

6. A safety helmet as in claim 1, 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.

7. A process for manufacturing a safety helmet, including the following steps:
(a) providing a first, dome-shaped ABS sheet shell, said first shell including a number of apertures therethrough joining inner and outer opposite convex faces defined by said dome-shaped shell;
(b) inserting said first shell into a female part of a male-female composite mould;
(c) closing a male part of said composite mould over said female part thereof, whereby said first shell becomes confined and enclosed into the enclosure defined within said composite mould;
(d) injecting expanded polystyrene granules into said composite mould enclosure, through said mould, whereby said granules cover at least a substantial portion of said first shell inner face and extends through said shell apertures to seep therethrough and cover at least a substantial portion of said first shell outer face;
(e) submitting said mould enclosure, for a period ranging between approximately 5 to 15 seconds, to the heating action of boiling water vapour, through a plurality of nozzles opening into said mould enclosure, wherein said expanded polystyrene granules will set into a dome-shaped cap and said first shell will become fixedly embedded thicknesswisely of said polystyrene cap;
(f) cooling said mould, for a period ranging between approximately 5 to 15 seconds, through the action of ambient temperature water sprays;
(g) stabilizing said integral first shell and polystyrene cap, for a period ranging between approximately 3 to 4 minutes;
(h) withdrawing said integral first shell and polystyrene cap from the mould enclosure;
(i) providing a second, dome-shaped ABS sheet shell; and (j) glueing a second, dome-shaped ABS shell against the inner dome-shaped face defined by said polystyrene cap, wherein said first and second shells becomes integral to one another via said polystyrene cap.