Note: Descriptions are shown in the official language in which they were submitted.
CA 02343454 2001-04-06
BACKGROUND
The field of the present invention includes self contained breathing
apparatus, and
specifically, self contained breathing apparatus that may be worn by a user.
These types of
devices are known in the art, and are used for, among others, fire fighting,
emergency air
supply for workers in hazardous environments, or underwater use.
The disadvantages of previous air breathing apparatus include their weight,
bulk, the
restrictions they create in close confined spaces, their risk of explosion,
and the marginal
minutes of breathable air they provide in both emergency and continuous duty
situations.
Previous designs have often put the air supply either behind the user or in
front of the user,
causing the uses s centre of gravity to be shifted, thus creating strain on
the user when
wearing the apparatus and making continuous use of the apparatus difficult.
Further, in industry, emergency air supply apparatus typically only provide
five to ten minutes
of breathable air. This provides the user with a false sense of security,
since documented
evidence shows that in many cases more time is required. For miners, accidents
can require
that the miner have one to two hours of breathable air to allow for
evacuation. Construction
workers building additions beside operating gas plants and refineries have
found insufficient
evacuation routes in the past, and found a five to ten minute emergency air
supply was not
enough.
Other problems with self contained breathing apparatus include the fact that
they do not
compensate for the size of a user. It is well known that a larger person will
consume more
air per minute than a smaller person. Thus by providing the same emergency
device to both
individuals, the larger person will have less time to safely get out of the
hazardous situation.
SUMMARY OF THE INVENTION
The present air vest apparatus addresses all of the above problems for
existing self
contained breathing apparatus. This vest device is engineered to provide the
only self
contained air breathing apparatus option suited for close confinement
application in all of the
categories of fire, industrial, aqua-marine environments and aircraft
environments.
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The air vest device provides a compact design that increases the breathable
air time. The
vest device is calibrated to the size of users to allow a minimum of at least
one hour and
fifteen minutes of breathable air time in a preferred embodiment.
The air vest device uses high pressure flasks that increases the working
pressure to between
6000 and 9000 psi. This allows smaller flasks to provide the same amount of
air, making the
device less bulky and able to provide air for a longer period.
The high pressure of the flask is facilitated through the use of an innovative
containment bag
which creates a net around the flask and will confine each flask to a 2.5 cm
grid perimeter
containment. Also, a rubber bladder can be placed around the outside of each
flask before
the containment bag is installed to suppress flying fragments and to prevent
any chemical
or liquids from contaminating the integrity fo the composite material in each
flask.
Deflector plates are further secured between the high pressure flask and the
user to ensure
a user's safety. These plates are comprised of a new pure carbon fibre core
material.
The high pressure flasks are attached within pockets of the present vest
device. The flasks
are interconnected and situated both on the front and back of the vest. The
number of flasks
attached will depend on the size of the vest. These are then ultimately
attached to a
regulator to which a mask or SCUBA respirator can be affixed. This design
therefore is
compact, light weight, and easy to use.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a cross sectional view of the preferred embodiment of a high
pressure flask and
fitting.
Figure 2 is a cross sectional view of a second plate and nut arrangement that
may be
attached to the fittings of Figure 1.
Figure 3 is a cross sectional view of the flask of Figure 1, where the cross
section is taken
in a plain perpendicular to the cross section in Figure 1.
Figure 4 is a cross sectional view of the flask of Figure 1.
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CA 02343454 2001-04-06
Figure 5 is a detailed cross sectional view of the fittings for the flask of
Figure 1 including a
regulator means attached to it.
Figure 6 shows the various components of the fitting of Figure 5.
Figure 7 is a detailed cross sectional view of the fittings for the flask of
Figure 1.
Figure 8 is an end view of a wax module for creating the flask of Figure 1.
Figure 9 is a long view of a wax module for creating the flask of Figure 1.
Figure 10 is a top left isometric view of the flask of Figure 1 including a
"T" fitting.
Figure 11 is a top left isometric view of another embodiment of a flask,
including a regulator
means.
Figure 12 is a schematic view of a containment bag of the present invention.
Figure 13 is a cross sectional view of a suppression device used in the
containment bag of
Figure 12.
Figure 14 is a prior art configuration of an "I-beam" balsa wood core
composite.
Figure 15 is a cross section showing a new pure carbon fibre composite
material .
DETAILED DISCLOSURE
The present invention consists of a compact, lightweight, self contained air
breathing
apparatus in the form of multiple, high pressure vessels or flasks that are
contained within
a body vest and in a preferred embodiment are designed to provide a user with
at least 1
hour and 15 minutes of breathable air.
The construction of the vest apparatus in the present invention consists of a
series of distinct
components that are interconnected in order to provide the functionality of
the apparatus.
These components include a series of high pressure flasks or vessels that are
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CA 02343454 2001-04-06
interconnected, a containment bag or device to protect a user in the case of a
rupture of one
of the high pressure vessels, an explosion shield placed within the vest and
between a user
and the high pressure flasks in order to further protect a user in the case of
an explosion or
rupture of one of the flasks, a breathing respirator, and a vest structure
comprised of a
material suited to the envisioned use of that particular vest apparatus.
Further features such
as pressure monitoring sensors and alarms, straps for securing the vest
apparatus more
securely to a user, regulators, T fittings, etc... may also be included in the
vest. Each of
these components will be described in more detail below.
The functional aspect of the vest centres around the use of a series of
interconnected high
pressure flasks. These flasks are illustrated in Figures 1 to 11, and in a
preferred
embodiment are comprised of an entirely non-metal structure to reduce their
weight. These
preferred flasks are discussed below. Other metal embodiments of the flasks
could also be
used in the present invention, and this disclosure is not intended to limit
the type of flask that
may be used within the present vest apparatus.
The preferred embodiment flasks are changeable to extremely high pressures as
compared
with flasks available today. In this embodiment, the flasks will be changeable
to a working
pressure of 6000 PSI and will be tested at 15000 PSI. This is compared to the
present air
flasks which are currently charged to around 3000 PSI on average.
The flasks are comprised of a carbon fibre epoxy body portion which has a
rubber or nylon
coating on both or alternate sides. Carbon fibre and epoxy were chosen due to
strength and
weight considerations. New millennium carbon fibre and epoxy technology
incorporating an
axis filament winding processing provides this high strength. The shape of the
flask can be
a traditional cylinder, or can be flatter to more closely fit a user, and can
range in size from
small up to the size of conventional air tanks similar in diameter and 16 to
18 inches in
length, or larger. These configurations are best seen in Figures 10 and 11.
The inner rubber or nylon coating or bladder is used to provide some strength
and to avoid
corrosion. This acknowledges and corrects the problem of corrosive aluminum
liners used
currently in the art. The use of the liner further eliminates the need to
tumble the flasks in
order to remove any corrosion and ensures that the engineered strength of the
flask will
never be dangerously diminished from its original design values. The inner
rubber bladder
is created through the use of a wax module, as can be seen in Figures 8 and 9.
This wax
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CA 02343454 2001-04-06
module contains the air fittings described below, and is dipped in liquid
rubber and allowed
to cure. An inner nylon liner can be formed by rotomoulding.
Once cured, the wax module and inner bladder are mounted on a lathe and the
carbon
filament is wound onto the bladder. This is then heated in an oven at between
200 and 450
degrees Fahrenheit, depending on the epoxy. The heating further melts the wax.
The core and bladder are then x-rayed for imperfections and quality assurance.
Once this
is done, the outer rubber layer is created by dipping the assembly into liquid
rubber. This
outer rubber layer provides strength and prevents hazardous materials from
contacting the
carbon fibre core. This prevents chemical spills from compromising the
integrity of each
flask. The use of other fluid and corrosion resistant outer layers such as
nylon is also
contemplated.
One side of each flask contains an inlet portion, as can be seen in Figure 1.
The inlet portion
in the preferred embodiment consists of two stainless steel plates, each with
a circular hole
in the centre. A cylindrical stainless steel air fitting whose outer diameter
fits concentrically
within the hole in the steel plates is placed within this hole and the steel
plates are then
welded in place. In the final configuration the steel plates are arranged
parallel to each other
with the gap between them corresponding to the width of the carbon fibre core
of the flask.
When the carbon fibre is placed within this gap, its strength will ensure the
air fitting will not
be blown out of the flask due to the pressures involved. This is further
tested after the
manufacture of the flask by charging the flask to considerably higher than the
working
pressure and ensuring that the flask does not rupture and the air fitting
remained in place.
The steel plate disposed towards the inner surface of the flask further
includes two flanges
welded to it, these flanges protruding substantially perpendicularly to the
steel plate and into
the flask, thereby directing air.
The end of the steel air fitting is threaded to allow a fixture to be added to
the fitting in an air
tight manner. An extended threaded portion is also considered whereby the
option exists to
secure a second plate with a nut like washer to the outer steel plate. The nut
would be a lock
tight washer in a preferred embodiment.
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The second plate is shaped to accommodate the regulator body housing, as is
illustrated in
Figure 2. As can be seen from this figure, the second housing has downwardly
extending
side portions which have screw holes in them. Screws can thus pass through
this hole and
connect the regulator body to the second plate.
In operation, the flasks are charged with'high pressure air through a
regulator or valve
attached to the steel air fitting. A series of high pressure lines connects
all of the flasks
together through the use of stainless "T" fittings, and these lines are
connected to a
regulator. These lines are made of high pressure flexible pneumatic hose with
a 'make before
break' threaded connection. The lines are further designed to withstand the
pressure under
which the vest is to be tested.
The regulator of the present vest apparatus is constructed to withstand the
pressure under
which the flasks are to be tested. In a preferred embodiment the regulator
will be of a "quick
coupling mechanism" type and shall allow for the connection of multiple face
masks - ie one
for a rescuer and one for the person being rescued. The regulator is further
placed on the
vest in a location that allows easy and rapid connection of the face masks.
The location
should also allow a user to easily be able to read a pressure gauge on the
regulator. In a
preferred embodiment the regulator will also have an alarm to signal to the
user when the
pressure falls below a certain level.
A respirator is designed to easily attach to the regulator. Various types of
breathing
apparatus are contemplated, including a mask to fit over a users nose and
mouth, or a
SCUBA regulator such as those currently used in the art.
Due to the high pressure of the flasks, the vest apparatus further includes
several safety
features. The first is a containment "bag" that is secured to the outside of
the flask. A
preferred embodiment of the containment bag can be seen in Figure 12.
In a preferred embodiment, the containment bag consists of braided stainless
steel aircraft
cable woven to resemble a fish net with approximately 2.5 cm squares. The
dimensions of
this containment bag allow virtually no clearance between the cable and the
exterior rubber
bladder of the flask. This confines the flask, and in the case of an explosion
or rupture, any
propelled fragments are limited in size to a 2.5 cm fragment. Further, the
rubber or nylon
bladder on the outer surface of the flask will act to further suppress any
flying fragments.
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The braided steel wire of the containment bag is held in place through the use
of special
suppression lugs, a cross section of one of which is shown in Figure 13. These
suppression
lugs are crimped at strategic points on the cable to hold and tighten the
containment bag in
place. As can be seen in Figure 13, the suppression lug includes three lead
cones and a
stainless cable end anchor plug to hold the cable within the lug. In the event
of a rupture,
the anchor plug compresses and flattens the cones to absorb energy. The other
end of the
cable is permanently secured to the lug, thus creating a closed loop.
The strength of the cable wire, along with the rubber bladder and the energy
absorption
provided by the suppression lugs, should act to prevent any fragments from
escaping from
the flask. If, however, a fragment does escape, the present vest apparatus is
further
provided with a novel deflection shield disposed between the user and the
flask.
The defection shield is comprised of a material that will withstand and absorb
the impact of
a high speed fragment hitting it. In order to ensure that the weight and bulk
of the vest
apparatus is minimized, it is further desirable to ensure this deflection
shield is as thin and
light weight as possible. The compromise between absorption and deflection
strength, and
the weight and bulk of the vest is solved through the use of a new composite
material.
Prior art for carbon composite materials includes the "I-beam" configuration
as shown in
Figure 14. This type of core is referred to as "End-Grain-Balsa", wherein the
vertical portion
of the I-beam is balsa wood, and the horizontal portions above and below the
"I" are applied
carbon fibre fabric.
The new composite deflection shield is comprised of a pure carbon fibre and
high quality
epoxy, providing the highest possible impact resistance when compared with
existing core
materials. For this improvement, the balsa wood core of previous composites is
replaced
with vertical carbon fibre strands. This core, in the preferred embodiment,
measures
between one-eighth of an inch to more than two inches. These carbon fibres are
continuous-
roving, pre-impregnated tow, meaning the fibres have been previously
impregnated in an
epoxy-bath with epoxy which will begin its cure process with the introduction
of heat and light.
The core of the present composite is created by placing fibres in a trough 6-
inches wide by
6 inches deep by three feet in length. The trough has a plastic liner allowing
the fibres to
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move without friction in the trough. The material has a consistency similar to
cookie dough,
and can be cut to a predetermined thickness through the use of a computerized
laser cutter.
The cut slices are placed on a sheet of pre-impregnated carbon fibre fabric. A
second layer
of the fabric is placed on top of this cut slice, creating a pure carbon fibre
core material. The
material is then placed in refrigerated storage until ready for delivery. The
present invention
further contemplates using this new core for other higher strength and/or wear
resistant uses
besides the deflection plates. An example will be brake components.
All of the above components are placed within a vest. The vest is constructed
in a
compartmentalized fashion such that the components are of sufficient capacity
to allow for
the easy insertion and removal of the containers. The number of container is
dependant
upon the physical size of a user's vest, where a child's vest may only have
four flasks, and
an extra large vest may include up to twelve flasks. Each compartment further
allows a
deflector plate to be installed behind the flask, protecting the user in case
the flask explodes
or ruptures.
The compartments of the vest are evenly distributed between the front and the
back. This
allows the centre of gravity to be centred on the shoulders, chest and back of
a user. Further,
the bulk of the vest due to the air flasks is distributed around the user
instead of behind the
user, as is the case with most fire fighting breathing apparatus used
presently.
In one embodiment of the present invention the vest is constructed to
incorporate a "quick
connect" strap under the buttocks of a user to prevent the vest from riding up
and interfering
with the face mask. The vest further includes a drawstring at its bottom which
can be used
to tighten the bottom of the vest. The vest can also be constructed in a
double walled
configuration consistingn of an inner and outer layer to enclose the air
flasks and provide the
user with better thermal insulation against both heat and cold. The two layers
can be
zippered or VelcroedT"" together for greater flexibility.
The vest also includes the regulator. As described above, the regulator is
placed in a
location that is easily accessible to a user to allow for both the connection
of a respirator and
to facilitate the checking of the amount of air left in the flasks.
The vest can further include storage compartments into which the respirator
fits, such that
the respirator can easily be accessed in the case of an emergency.
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The material the vest is made of will depend on its intended application. If
the vest is to be
used in a fire rescue situation, the material will be the same as that
presently used in fire
fighting clothing. It will thus be fire resistant. Conversely, if the vest is
to be used in
mountaineering or aqua situations, it can be constructed of a waterproof
fabric.
The air vest device thus provides a compact system with a considerably longer
air supply
than current self contained breathing apparatus on the market. It is
envisioned that the vest
may be used for a number of applications by different users including: fire
departments, oil
fields and gas plants, mining operations, underwaterdiving environments,
search and rescue
units, industrial chemical processing plants, NASA, passenger aircraft
personnel, police
tactical units, and armed forces world-wide.
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