Note: Descriptions are shown in the official language in which they were submitted.
This invention relates to respirator hoods. In
particular, this invention relates to a respirator hood to be
worn by persons escaping from fire and smoke.
PRIOR ~RT
~t is well known that many deaths occur in fires in
high-rise building and the li]ce as a result of poisoning from
combustion gases and smoke. Smoke poisoning and poor visibility
caused by thick, arrid smoke which is produced in many fires can
cause more difficulty than the combustion flames. Previous
attempts have been made to provide an escape-hood filter unit for
use by persons Eleeing a fire. In these known units, the air
inhaled is filtered in order to eliminate toxic combustion gases
and other units provide protection for the eyes and head of the
wearer.
In one known respirator hood which is used for fire
escape purposes, the hood has a knitted collar adapted to fit the
neck of the wearer. The collar is made of a resilient textile
material and must be expanded in order to pull it over the head
of the wearer. This makes the hood difficult to fit in the event
of panic and also gives the wearer a constricted feeling since,
- when the hood is fitted, the collar performs the function of a
seal around the neck. According to this known design, the hood
strapping which engages externally with the filter, presses the
inner mask against the wearer's face. As a result of this structure,
the seating of the inner mask on the face of the wearer is not
positive and the mask may, therefore, be displaced while it is
being worn. Furthermore, the sight-window in the hood is almost
flat and this restricts the field of vision.
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The respirator hood which will be described hereinafter
is constructed so as to be simple and easily fitted while providing
a complete se~l for widely different shapes of head and face. The
field of vision is also quite e~tensive as compared to known
~ designs of hoods.
According to one aspect of the present invention, a
respirator hood comprlses a hood having a sight-window and adjust-
able strapping and an external respirator filter. The hood has a
wide neck opening designed to accommodate heads of different sizes.
When the neck opening is in the open configuration, it extends
outwardly beyond the respirator filter. A seal is provided on each
side of the hood between an inner mask and the inside of the hood
for the purposes of sealing off the eye area from the neck opening.
The neck opening is open at its lower end and is in communication
with ambient air~ Straps are provided which pass around the back
of the head and are cor.nected to the hood for the purposes of
securing the hood to the head of the wearer. Retaining flaps are
formed in each side of the inner mask and merging from the body
of the mask towards the temples. The flaps constitute points of
application, recessed in relation to the varying surfaces, in the
form of a bead, on the inner mask, for the strapping running around
the outside of the hood. The sea~ is disposed below the strapping
to serve as a seal line for the eye area.
The invention will be more clearly understood after
reference to the following detailed specification read in conjunction
with the drawings wherein:
Figure 1 is a side view of a respiratox hood;
Figure 2 is a front view of the respirator hood;
Figure 3 is a front view of the head of a person
wearing a modified mask wi-thout the hood.
Figure 4 is a sectional view taken along the line A-B
of Figure l;
Figure 5 :is a section along t:he line ~-B o ri~ul-e 1
t~ithou-t the strapping; alld
Figure 6 is a plan vie~ O r a bl~ suiLablc ior ~.se in
forming the respirltor hood oE F:iclure 1.
The respirator hoocl illustrated in ~`i(,~lres 1 and 2
of the drawings consists of a flame-proof ancl heat-resistallt hood
1 ~ithin ~hich a viet~ing windot~ 2 is formed so as to be loc?ted
in the field of vision of the t~earer. The vie~ing ~indow 2 is
formed from a transparent foil material or ple~iglas, an inner
mask in the form of a half-mas}; 3 is also provided. A breathing
filter 4 is secured to the inner mask 3 and the hood 1 by means
of a clamp 5, an exhaling valve 10 and strapping 6. The strappin~
6 consists of a tension-strap 6a and an endless strip 6b ~hicll
passes around the back of the hood. The endless strip is secured
to the hood at the point ~ (Figure 1) and is guided througil a loo~
Y. This arrangement has -the advalltage of s?reading the strapping
and compensating for length for vrevelltillg the hood from slipping
on the ~earer's head.
Arranged laterally upon t}le inller mas~ 3, appro~imately
on a level ~ith the nostrils of a ~iearer, is a retainin~ flap 3~
(Figures ~l and 5) ~hich emerges from tnQ inller mask 3 and supports
a buckle 7 located on the outside of the hood for receiving the
stra?ping 6a. The strapping 6a is secured to the hood by ~uc~les
7 ~Jhich 2re fastened through the material of the hood 1 and
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the retaining flap 3a by means of screws or rivets 8.
The fact that the location at which the strapping 6a
is secured to the hood is set back from the front of the hood,
by reason of the position of the retaining flaps 3a of the inner
mask, the hood can be correctly and stabley positioned on the
user's face withou~ any slippage. Moreover, as a result of the
special arrangement of ~he strapping and, in particular, the
configuration of the blank used for the hood, the viewing window
2 which is sewn into the hood ac~uires a curved shaped when the
hood is being worn. This eliminates the need for the usual curved
frame to provide this curvature.
The inner mask 3 is formed with a bearing surface 3b
in the form of a bead which presses against the face of the wearer
when it is being used to act as a seal extending about the breathing
area. This feature is illustrated in Figure 5 of the drawings.
Located on each side of the hood, between the inner mask 3 and the
inside of the hood is a seal 9 which seals off the eye area from
the neck opening in the hood which is open at its lower end and is
in communication with the ambient air.
The seal 9 may either be in the form of lip integral with
the body of the inner mask 3 or it may be provided in the form of
a part made-of rubber, foam material or an elastomer which is ~lued,
snap-fastened into or buttoned to the body of the mask in any suit-
able manner. The seal thus provided may be secured to the inner
mask and the-inside of the hood on one or both sides thereof.
As shown in Figures 4 and 5, the seal 9 is secured to
the inner mask 3 on one side of the vicinity of the retaining
~f~
~la? 3a and is in tI1C -O~ o a ~a(~ 3~ oamcd ~aJ;erial ar.d is
shaped in such ~ar!lcl: .c to ~pl~ sealillg pressure to the
inside OL tI1e }100d.
The seal 9a ~a~ also be in a -orm in wllich it projects
beyond tlle body o- t]le l1aSI~ ovcr ta cheeks of the ~earer to
e.~tend to the tcmples a silo:ll in l`i(3ure 3 of the clrawings. The
desicJn of this s.al i sucll t:h;lt oll side is ~ a~)ted to t'e sba?
of the cheek ~hile tile O~hC?l:` ~id~e ~o;lEo~llls t-o .Illd iil.ls Up all~'
cavities or depressiolls bet~eell t}l~ bod~v o tile ini~er masl~ and
the inside of the hoocl . The 5~;!;I1 j IIg aCtiOl1 may be i;nproved by
locating a seal, at least in ~art under the strappincJ 6a so that
pre~ssure is applied thereto whell the strappillg is tightelled.
According to a further aLternative construction the
seal 9 ~La~ pass over the cheeks toward the wearer s eyes such
that it runs around the inner edge o~ the window of the hood.
In this construction the design of the seal itself is such that
when the hood is fitted and the strapping is tightened the seal
is pressed to the wearer s face thus sealing off the eye area.
Figure 6 illustrates a blallk suitable for use in the
forming of a hood in accordance witll an embodilllellt of the present
invention. The blank is formed with an aperture 12 for receiving
the viewing window 2 and a further aperture 1l for receiving the
fil-ter 4. A U-shaped notch 11 is formed at the front of the hood
with the side edges and inner ecqe oi tlc notcil conver inCJ at
2~ points ~ hen the blank is SeWn togetiler this produces a
T-shaped seam at the front and top of the hood ~hich provides
that the fron-tal area is arched as sho~ll in Figure 1. In this
marner tne sewn-in ~:indo~ is clrawn to the required curved con-
iguration to afforc~ a panoramic line of vision to the wearer.
From the foregoing, it will be apparent that the
respirator of the present invention provides the advantages of
a wide neck-opening to allow it ~o be fitted quickly and easily
over the head of the wearer without imposing a restriction on
the wearer. In addition, the eye area of the wearer is completely
sealed by means of a sealing pad so that the hood is comfortable
to wear. Furthermore, exhaled air passes downwardly through an
exhaling valve out of the open lower end o the hood thereby
providing the re~uired flushing of exhaled air from the hood.
Furthermore, by reason of the fact that the internal mask is
secured to its mounting straps rearwardly from its point of contact
with the face of the wearer, the inner mask is securely seated on
the wearer's face. In addition, the structure of the hood provides
that the viewing window which is formed therein will extend in an
arcuate curve to provide a panoramic line of vision. These and
other advantages of the present invention will be apparent to
those skilled in the art.
