Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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FF-61~7
Decom~re sion and Toxic Fume P otection ADParatu~
Backaround of the Invention
A continuing concern for the airCa~t
indu~ry i8 apparatu~ for the protection o pa~sengers
again~ either decompre~ion in flight OL ~oxic fumes
r2sulting f lOm on-board fire~. Previously, oxygen
~asks and other apparatu~ have been p~ovided for
pa~enger use. However, previou~ apearatus do not
satisfy the need for individual smoke protection of 30
~inute~ o~ more, and the ~ize and weight o~ apparatu~
previou~ly available has liJni~ed its use in aircraft.
Typically the ratio of e~uipment poundage to minute~
of protection was on the order of 1:0.5 to 1:3. I~
additionO ~uch o~ the equiement previously available
for decompce~sion or toxic ~ume erotectio~ i8
~ ~omplicated to u~e and might be of limited value to an
: ~ ai~raft pa6senger i~ an eme~gency ~ituation.
Ac~ordingly, a contirauing need ~Xi6tE~ for an
un~om~licated, light-weight appara~u~ that will
: provide extended protection again~t toxic fume~ in an
aircraft environment. Si~ila ly, a need exi~ts for
uch a~ apparatu~ in a variety of other application~
` such as hotel~ and hospital~ in ~hich it may be
- ~ ~5 necsssary to e~cape from a ~moke-filled environment
with an appara~u6 that provides at least about 30
mihutes o~ breathable air for the user.
~ummarv Qf the Invention
The pr~6ent invention provides an improved
apparatus ~or protection again~t decompre~6ion and
. toxic fume~, particularly in an airc~aft environment,
which permit~ more complete uti~ization of available
: oxygen.
Specifically, the ~n~tant inventio~ provide~
a breathing device having an inner chamber and an
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inflatable outer chamber concantric with and
su~roundiAg the inner chamber, the inner and outer
chamberfi being adapted to ~urround the head o a
wearer;
a ga~ re~ervoir;
a ga~ inlet leading to the outer chamber and
a valve pe~itting ga~ to flow ~rom the vuter chamber
to the re~ervoir; and
-~ a ~a~ageway to pe~mît ~as to ~low betwee~
the re6ervoir and the inne~ cha~be~ ~hrough a C02
removal m2ans,
the outer chamber being inf latable to a rigidity
6ufficient to maintain subs~antially con6tant volume
:~: of the inner chamber while the wearer i~ breathinq.
Brief De~crie~ion of the Dra~in~
: Fig. 1 is a cro6s-~ectional view o~ a
~reathing device of the pr~ent ~llvention having a
C2 rel40val ~ean~ a eircumfereAtial configu~altio~
-~ ~urrounding the nec~ of the wearer.
Fig. 2 i~ a cro~ eetional view of a
breathing ~ev~ ce of a pre~en~c invention whe~ein the
C2 remo-tal D~lean6 iç~ po~itioned ad jaeent ~co the gas
.~ inlet.
Fig. 3 i~ a elanar viaw of the details of
con~truction that can be used for oche inflatable outer
eha~ber of the ~ ~re~en~c device~.
- ~ petailed De~criptiorl of the Inv ntion
; The pre6ent invention provide6 a breat~ing
device having concentric inner and outer chamber~.
The outer chamber i8 in~latable to a rigidity
~uffici0nt to maintain a ~ub~tantially con~ant volume
of the inner chamber while the wearer i~ breathing.
The device al~o includes a reservoir connec~ed to the
inner chamber by way of a carbon dioxide re~oval means.
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A ~ide variety of material~ can be used for
C2 re~oval. Thefie include, fo~ example, alkali
me~al hydroxides and oxides and ~odium carbonate. Of
the~e, ~he lîthium and ~odium ~alt~ are pfe~erred, and
lithium hydroxide in ear~iculate form is palticularly
preferEed. In addition, C02 ab60lbants in liquid or
gel ~oEm can be used. The quantity of C02 ab~orbant
~' used ~i~l vary according to ~he ab~orbant selected and
the capacity of the hood. In general, about ~rom 50
~o 500 grams can be u~ed in the pre~ent invention. It
has baen ~hown tha~ about fro~ 3 to 4 gram~ o$ lithium
hydroxide ara required fo~ re~oval of ca~bon dioxide
during each mim~te of closed circuit breathing in an
environment of ~ub~tantially pure oxygen. P~eferably,
about fcom 75 to 150 gram~ of C02 absorbant are used
~; in the pre~ent device~.
The C02 removal mean~ can be integrated
~::. into the pre~ent breathing device in a wide variety of
onfigurations. The C0~ re~oral mean~ can be
:~ 20 oon~ained in a 6epa~ate chamber positioned, ~or
~: example, a~ a ring around the neck of the ~earer. In
i~ another embodi~ent, the C02 removal ~ean~ can be
exterior to the remainder of the hood ~tructure, fo~
~: example, in a compa~t~ent, cani~ter or hose adjacent
~: 25 to the inlet. ~he positioning of the C02 removal
~ean~ exterior to the hood pezmit~ the replace~ent or
~enewal of the C02 ~emoval mean~ for reuse of the
hood.
In aacordance with:a prefer~ed embodiment of
the present i~vention, a brea~hing device i6, provided
: which aonsi6t2 of thrae concent~ic chambers, the
chambers ~eing de~ignated a~ an inner chamber, an
inflatable oute~ chamber and a re~ervoir. The inner
chamber i~ ne~ted within the inflatable cha~ber which
i~ ne6ted within the re6ervolr. In the operation of
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.. the breathing device, gas i8 ~a~ed from an outside
source, such as the fresh air and/or oxygen ~upply on
an aircraft, to ~he inflatable outec chamber of the
brea~hi~g dev~ce. The outer chamber i8 in~latable to
a rigidity ~uf~icie~t to maintain substantially
constant volume of the inner chamber within the
: breathing device while ~he wearee i~ bLeathing.
A ~alved mechani6m i8 provided to per~it
pas6age of the ga6, whether freRh air, oxygen enriched
air, or pure oxygen, f rom the outer chamber to the
re~ervoir. A passage i~ al60 provided f rom the
re~ecvoir, through a C02 re~oval mean~0 to the inner
-~ chamber. Accordingly, with the breathing of the
~earer, oxygen and~oe air ~8 deawn only,fEom the
rsservoir. In thig ~arlner, the inflatable outer
:~ ~ char~ber ~ ~ kept at ~ub~antially constant volume while
the wearer i~ breathing.
~: In the breathi~g cycle, inhala~ion by the
:~ wearer draw~ air ~Lom ~he reserYor, throush the C02
removal mean~ and into the inner chamber. ~he
:~ exhaling pre~6ure o~ the wearer focce6 exhaust air
through the carbon dioxide ab~orber, and back to the
reservoir.
The invention can be more clearly unde~6tood
.-: 25 by ceference to the drawings, in w~ich l~ke numbers
: are u~ed ~or like elements in ~he f igures .
In ~igure 1, ga~ ig ~upplied through inlet 1,
from a ~ource, not ~ho~n. of re~h air, oxygen, or
both, to inflatable outer chamber 2, surrounding the
head of the wearer. When the inflatable outer chamber
i8 sub6tantially fully inflated, the ga6 pas~e6
through valve 3 into re6er~0ir 4, he~e ~hown a6 an
~ addit~onal outer concentric chamber. Inhaling o~ the
: wearer causes flo~ ~rom the reservoir through C02
:; 35 eemoval ~ean~ 5 to inner cha~ber 6. ~xhaling by tAe
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. wearer cau6e~ pas~age of exhaufit brea~ back through
the C02 removal meang and to the reserYvir. The
C2 removal ~ean~ is hers illus~rated a~ an annular
Ling, containing C02 ab~orbant 7, through which the
- 5 air is cir~ulated in it~ pas~age between the reGervoir
and the inner chamber. The hood is also provided wi~h
annular nec~ ~eal 8.
Another e~bodiment of the invention i~
- illu6tr~ted in Pigure 2, in ~hich the C02 r2moval
~ean~ i~ exterior to the lnner, outler and re~ervoic
element~ ~urrounding the head of the wearer, and i6 ~ n
the form of cani~ter 21 containing C02 absorbant 22.
: The outer chamber i6 inflatable to a ~igidity
- ~ufficient to ~aintain ~ubstantially con~tant inte~nal
volume while the wearer i~ breathing. A typical
con~truction whi~h can be used f or this ~unctio~
~llustrated in Figure ~ which the re6ervoir i6
~abricated from two lay~rs o~ ther~oplastie ~aterial
31 and 32, ~he ~wo layer~ being heat sealed at ~eam6
~: 20 33 ~o provide a plurality of pockets 34 having upper
and lo~er poction~ 34A and 34B. Alternat~vely, the
. ~heet~ can be adhe~ively bonded a~ eequiced. The area
between the upper and lo~e~ portions i~ ~ealed
together to provida ~i6ibility band 35. The
2S vi~ibility band i~ interrupted by full leng~h air
pDckets 36 which in~rease the rigidity of the
structure when in~lated.
A wide va~iety of con~truct~on materials can
be used for the breathing device~ of the present
in~ention. Particularly ~atisfactory are polymer~c
films, ~uch as polyethylene, polypropylene, nylon,
polyvinyl chloride, polyurethane, fluoLopolymer~ and
~olyethylene terephthalate. Such film~ a~e
paeticularly ufieful in forming the in~latable outer
chamber. Heat re~i~tant ~ater~als such as polyimide
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~ilm6 are preferably used for the exterlor wall of the
breathing de~ice. Tho6e film~ commerc~ally availa~le
from E. I. du Pont de Nemour6 and Company a~ ~apto~*
~olyi~ide films have been found to be particularly
sa~isfactory. The e~terior surface o~ the breathing
devic~ san be metalized ~or further h~a~ reflectivity,
using technique~ well known ~n the art.
~he breathing de~ice~ of t~e pre~e~t
invention provide ~everal advantageæ over similar
~- 10 device~ previoufily known in the art. The present
deviceæ per~it, through the inflatable outer cha~ber,
a con~tant volu~e while the wearer i~ breathing.
Moeeover, with ~he carbon dioxide re~oval ~eans
~: integrated into the breathing device, upon
; 15 discsnnecti~g the device fro~ th~ ga~ ~upply, ~axi~um
util~zation of the oxygen ~ the ga~ contained within
the h~od can be obtained. ~ithout the CO ~e~o~al
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eans, ~he available oxyge~ ca~ be ut~lized to a
su~6tantially les6er eYtent, with increa~ing build-up
of ~ar~on dioxide.
. The b~eathing deviees o~ t~e pre~ent
invention ca~ be u~ed in a ~ide variety of
application~, includi~g ai~craft cabi~ interior~,
hoseital~, ana residential and commercial interio~6.
~- 25 When u~ed i~ con3unction ~ith a ga~ ~ource, ~uch a~
:. tho~e available on an aircraft, the user can ~reathe
in a toxic ~ume environment or in a decompre~sion
ieuation for virtually un~i~ited period~ of ti~e.
Upon di~connection from a ga~ ~ourse, u~ to about 45
~nute6 of breathable and u~able ai with the carbon
dioxide Eemoval ~eans, are available.
The p~Q~ent hood~ can be ~afely storQd for
~xtended period~ without deterioration of their
: operatin~ capabil3t~. However, it ~ pr~ferred tha~
$he hood~ be 6tored in a sealed containe~ to i~sulate
the devices fro~ changes in ~nvi~onmenta} conditio~s.
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The E?~e~en~ appa~atu~ makes mo~e effective
u~e of the oxygen sllpply ~y8tem8 sur~ently in place on
commercial aiccra~t for deco~p~e~sion ~rotection. The
oxyge~ ma~ks pre~riou~ly provlded on airc~af e p~ovide
5 the u~ec with a mixture of oxygen and ambient air,
~hile the ~re~en~ device~ provide the user with a
~ub~tantially pure oacygen îo~ deco~pre63ion a~ ~ell as
~moke protection. ~Poreover, ~che present in~ren~cion
does r~o~c requile a pump OE pressure ~ource Sor
operation of the C02 removal mean~ once the hood ha~
been f itted.
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