Note: Descriptions are shown in the official language in which they were submitted.
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~WO 94/02206 PCT/EP93/01916
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BREATHING DEVICE
The invention relates to a breathing device, for example for
use in an emergency situation. It is well known that exhaled breath
still contains sufficient oxygen for a person to breathe in and out
several times the same breath. In an emergency situation it can be
of vital importance for such person to have a breathing device at
his disposition, which device allows the person to exhale and
subsequently inhale his breath several times until conditions are
safe for normal breathing. Such an emergency situation can for
example occur when a person in an aircraft cast in the sea
following an accident is carried underwater before being able to
free himself from the aircraft, or in case of a fire when a person
has to escape through smoke which prevents normal breathing.
A known breathing device consists of a bag to which a flexible
hose provided with a mouthpiece is connected. During normal
circumstances the bag is empty, whereas in case of an emergency the
wearer uses the bag to exhale and inhale the same breath several
times by breathing through the mouthpiece. A problem of the known
device is that during a submerged position of the wearer the
flexible hose can become shut-off at the connection to the bag due
to the water pressure acting on the bag. Another problem of the
known device is that water which has entered the bag can block
fluid communication between the air in the bag and the mouthpiece.
It is an object of the invention to provide a breathing device
which overcomes the problems of the known device and which allows a
wearer to breath in and out the same breath several times.
In accordance with the invention there is provided a breathing
device comprising a bag of flexible material and a flexible hose in
fluid communication with the interior of the bag, the flexible hose
being provided with a mouthpiece so as to allow a wearer of the
device to exhale into the bag and to inhale from the bag via said
mouthpiece and said flexible hose, wherein the hose is in fluid
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communication with the interior of the bag at a plurality of
locations mutually spaced across the bag. The feature that the hose
is in fluid communication with the bag at said plurality of
locations ensures that an amount of air present in the bag remains
in fluid communication with the mouthpiece even when the bag
becomes partially flattened due to external pressure, or when water
has entered the bag.
Preferably, the flexible hose is in fluid communication with
the interior of the bag via a manifold having a plurality of
passages, each passage being in fluid communication with the
interior of the bag at a respective one of said locations mutually
spaced across the bag.
In a preferred embodiment of the breathing device, the
manifold extends externally from the bag and comprises a main
conduit which is at one end thereof connected to the flexible hose
and which is at the other end thereof closed, and a plurality of
branch conduits, each branch conduit extending from the main
conduit to the bag and forming a respective one of said passages.
In another preferred embodiment of the breathing device, the
manifold includes a conduit extending within the bag, said passages
of the manifold being formed by a plurality of openings provided in
the wall of said conduit.
The invention will now be described by way of example in more
detail with reference to the Figures in which:
Figure 1 shows schematically a cross-section of an embodiment
of the breathing device according to the invention; and
Figure 2 shows schematically a plan view of another embodiment
of the breathing device according to the invention.
The breathing device of Fig. 1 includes a flexible watertight
bag 1 arranged at the interior of an immersion suit 3 of a wearer
(not shown). The bag 1 is attached to the immersion suit by
attachment means (not shown) which keep the bag 1 close to the lung
centroid position of the wearer. The maximum air volume in the bag
a
1 when inflated is limited to approximately the lung capacity of
the wearer.
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WO 94/02?Ob PGT/EP93/01916
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A flexible watertight- hose 4 is at one end thereof connected
to the bag 1 via a manifold '~ and at the other end provided with a
mouthpiece 6. The mouthpiece 6 is in fluid communication with the
interior of the bag 1 via the flexible hose 4 and the manifold 5.
The manifold ,~ includes a main conduit 7 arranged exterior
from the immersion suit 3, which main conduit is at one end ~
connected to the flexible hose 4 and at the other end provided with
a relief valve 9. Three branch conduits 10, 11, 13 extend from the
main conduit 7 through the immersion suit 3 into the bag 1 at
mutually spaced locations thereof. The immersion suit 3 as sealed
with respect to each branch conduit 10, 11, 13 to prevent seawater
entering the immersion suit 3 at the locations of the branch
conduits 10, 11, 13. Each branch conduit 10, 11, 13 has an end part
15, 17, 19 extending in the bag, the end part 15, 17, 19 having an
open end 21, 23, 25 and a plurality of openings 27, 29, 31 in the
wall thereof. Each end part 15, 1'7, 19 is provided with an annular
shoulder in the form of a primary ring 33, 35, 37 adjacent said
open end 21, 23. 25 and a secondary ring 39, 41, 43 adjacent the
wall of the bag I, each ring 33, 35, 37, 39, 41, 43 extending
around the end part, the rings being located such that the openings
27, 29, 31 are arranged between the primary ring 33, 35, 37 and the
secondary ring 39, 41, 43.
The mouthpiece 6 is provided with a directional valve (not
shown) which can be aperated 'by means of a handle S4 to switch the
valve between a first and a second mode of operation. In the first
mode of operation the valve provides fluid communication between
the breathing opening (not shown) of the mouthpiece 6 and the
flexible hose 5 so as to allow the wearer' to exhale into the bag 1
and to inhale from the bag 1, and in the second mode of operation
the valve provides fluid communicatian between the breathing
opening and atmosphere.
During normal travelling circumstances the bag 1 is attached
to the interior of the immersian suit of the wearer irr a ~cieflated
state. The flexible hose 5 and the mouthpiece b are attached to the
exterior of the immersion suit. The rings 39, 41, 43 prevent the
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WO 94/02206 PGT/EP93/OI~
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manifold 5 from being accidentally pulled out of the immersion
suit. When the wearer becomes cast in the sea, for example
following an accident to an aircraft in which he is travelling and
is carried underwater before being able to free himself from the
aircraft, he will apply the mouthpiece 6 to his mouth, switch the
directional valve to the first mode of operation thereof, and
starts breathing through the mouthpiece 6. By inhaling and exhaling
the same breath from the bag 1 several times, the wearer is able to
breathe while he escapes to the water surface. In case the bag 1
becomes partially flattened by the pressure of the water acting
thereon, one or more of the openings 21, 23, 25 may become shut-off
by the wall of the bag opposite the branch conduits 10, 11, 13. In
such case the wearer is able to breathe in and out from the bag via
the openings 27, 29, 3I provided in the branch conduits 10, 11, 13.
The rings 33, 35, 37 serve to prevent shut-off of the openings 27,
29, 31 by the wall of the bag 1 opposite the branch conduits 10,
11, 13. In case an amount of water has entered the bag 1 and partly
fills the bag 1, the wearer is still able to breathe since the
spaced arrangement of the branch conduits 10, 11, 13 ensures that
the remaining air in the bag 1 is still in fluid communication with
the mouthpiece 6. When the pressure in the bag 1 exceeds a
predetermined magnitude, the relief valve 9 opens automatically and
thereby allows some of the contents of the bag 1 to escape. When
the wearer reaches the water surface and floats with his face clear
from the water surface he can operate the handle 50 to switch the
two way valve to the second mode of operation thereby providing
fluid communication between the breathing opening of the mouthpiece
6 and atmosphere.
In Fig. 2 is shown another embodiment of a breathing device
according to the invention, including a flexible watertight bag 60
having along its outer circumference a seam which is provided with
openings 64 for attaching the breathing device to an immersion suit
of a wearer. A flexible watertight hose 66 is at one end 68 thereof
sealingly connected to the bag 60 and at the other end 70 to a
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mouthpiece 72 which is similar to the mouthpiece 6 described with
reference to Fig. 1.
A manifold in the form of a conduit 74 extends through the
interior of the bag 60, said conduit 74 being provided with a
plurality of openings 76 at mutually spaced locations along the
conduit 74. The conduit 74 is at one end thereof connected to the
end 68 of the flexible hose 66 via an opening (not shown) in the
wall of the bag 60, and rests in an elastically deformed state
against the inner surface of the wall of the bag 60.
Normal operation of the breathing device shown in Fig. 2 is
similar to normal operation of the breathing device described with
reference to Fig. 1. When the bag 60 becomes partially flattened by
the pressure of the water acting thereon, some of the openings 76
of the conduit 74 may become shut-off by the wall of the bag being
pressed against the conduit. In such case the wearer is able to
breathe in and out from the bag via remaining openings 76 which are
not shut-off. Equally, when an amount of water has entered the bag
and partly fills the bag, breathing is still possible via openings
76 in a part of the conduit 74 which is not in contact with the
water.
In view of the foregoing it will be clear that the breathing
device according to the invention allows the wearer to breathe
during an emergency situation whereby overpressuring of the bag is
prevented by the limited internal volume of the bag and by the
position of the bag as close to the lung centroid position of the
wearer as possible. Furthermore, shut-off of the air passage
between the mouthpiece and the interior of the bag due to partial
flattening of the bag is prevented. When used in water, the
hydrostatic pressure acting on the bag is well within physiological
limits with regard to breathing resistance and lung overpressure.
The above described breathing device can suitably be combined
with an enclosed respiratory system including a substance which
reacts with carbon dioxide and water present in the exhaled air to
liberate oxygen therefrom.
WO 94/02206 ~ PCT/EP93/O1~
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Since the breathing device is of relatively small size, it can
suitably be combined with an inflatable life jacket to provide
buoyancy to the wearer. Suitably, a life jacket is applied which is
asymmetrically shaped by being provided with a small lobe and a
large lobe, the lobes being interconnected by a collar which fits
around the neck of the wearer. The lobes and the collar enclose a
common buoyancy chamber so that upon inflation of the jacket, the
lobes and the collar are inflated simultaneously. During normal use
of the life jacket, the collar is arranged around the neck of the
wearer, and the lobes are located substantially in front of the
wearer and at opposite sides of an imaginary line of symmetry of
the wearer. Since in the inflated state of the jacket the small
lobe and the large lobe provide unequal buoyancy forces to the
wearer when said lobes are submerged, the wearer rotates until the
lobes float substantially on the water surface so that the wearer
becomes in a face-upward position.