U.S. patent number 3,565,068 [Application Number 04/797,631] was granted by the patent office on 1971-02-23 for breathing apparatus.
This patent grant is currently assigned to Automatic Sprinkler Corporation of America, Cleveland, OH. Invention is credited to Allan Morris Bickford.
United States Patent |
3,565,068 |
|
February 23, 1971 |
BREATHING APPARATUS
Abstract
A self-contained emergency breathing apparatus comprising a
chemical oxygen generator having an expandable casing, a delivery
tube, a filter in the tube, a carbon dioxide absorber having a
mouthbit, and a hood for covering the head of the user and
enclosing the carbon dioxide absorber to form a closed circuit
rebreathing system. The components of the system are encased in a
compact package form in a container which can be carried by the
user and readily opened in an emergency situation.
Inventors: |
Allan Morris Bickford (East
Aurora, NY) |
Assignee: |
Automatic Sprinkler Corporation of
America, Cleveland, OH (N/A)
|
Family
ID: |
25171380 |
Appl.
No.: |
04/797,631 |
Filed: |
February 7, 1969 |
Current U.S.
Class: |
128/201.25;
128/202.26; 422/120; 422/122 |
Current CPC
Class: |
A62B
7/10 (20130101); A62B 17/08 (20130101) |
Current International
Class: |
A62B
17/08 (20060101); A62B 17/00 (20060101); A62B
7/10 (20060101); A62b 007/08 () |
Field of
Search: |
;128/142,142.2,142.3,142.4,142.6,142.7,145.8,191,142--142.7
;23/281 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: L. W. Trapp
Assistant Examiner: G. F. Dunne
Attorney, Agent or Firm: Christel and Bean
Claims
I claim:
1. A breathing apparatus comprising a source of oxygen; a carbon
dioxide absorber assembly including a mouthbit; a hood adapted to
shroud the entire head of the wearer and cover said assembly; a
tube connecting said source of oxygen to the interior of said hood;
said hood having an opening and means closing said opening about a
wearer's neck when in use; and a container for housing said source
of oxygen, said assembly, said tube and said hood in compact kit
form prior to use.
2. A breathing apparatus according to claim 1 wherein said source
of oxygen comprises an oxygen generator having a canister and an
oxygen evolving body, said canister having a chamber connected to
said delivery tube.
3. A breathing apparatus according to claim 2 together with a
casing formed of a springy material connected to said canister
wrapped tightly thereabout when enclosed in said container, said
casing being adapted to expand radially outwardly when said
container is opened.
4. A breathing apparatus according to claim 1 wherein said
container is formed of two sections, one of said sections mounting
said oxygen generator, and means securing said sections
together.
5. A breathing apparatus according to claim 4 wherein said securing
means includes a wire encircling said sections, staples overlying
said wire and holding said sections together, and a strip of
material adhesively secured to said staples and said wire and
having a pull tab at one end thereof.
6. A breathing apparatus according to claim 1 wherein said assembly
comprises a canister, a chamber in said canister communicating with
said tube, and carbon dioxide absorbent material in said canister
on opposite sides of said chamber.
7. A breathing apparatus according to claim 6 together with at
least one port in said chamber, and valve means for opening said
port upon inhalation and closing said port upon exhalation to
direct exhaled air into the carbon dioxide absorbent material.
8. A breathing apparatus according to claim 7 together with spacer
means provided at the opposite ends of said canister for preventing
collapse of said hood against said opposite ends of said
canister.
9. A breathing apparatus according to claim 1 together with an
obstructor adapted to close the nose passages of the wearer.
Description
This invention relates to breathing apparatus and, more
particularly, to self-contained emergency escape breathing
apparatus.
It is known to provide emergency breathing equipment for use in
contaminated or oxygen deficient atmospheres. Very often,
environments which normally have adequate breathing air are
susceptible to contamination and depletion of sufficient oxygen for
breathing purposes so that it is necessary for such equipment to be
readily accessible. It is desirable that such equipment be carried
on the person of the user in the event of an emergency. However,
existing emergency breathing equipment often is heavy and
cumbersome and therefore awkward to wear or carry when not in
use.
Accordingly, it is an object of the present invention to provide an
emergency breathing apparatus which affords complete respiratory
and eye protection with a minimum of equipment.
It is another object of the present invention to provide the
foregoing in a compact packaged form that can be conveniently
stored and carried by a user.
Generally speaking, the closed circuit emergency breathing
apparatus of the present invention comprises an oxygen generator
having a spring metal casing adapted to expand and protect the body
and garments of the user against the heat of the generator during
combustion, a delivery tube connecting the generator to a carbon
dioxide absorber having a mouthbit, a hood for covering the head of
the user and enclosing the carbon dioxide absorber to form a true
closed circuit rebreathing system, and spacer means mounted on the
absorber for preventing collapse of the hood against the outlet
ends of the absorber.
The foregoing and other objects, advantages and characterizing
features of the present invention will become clearly apparent from
the ensuing detailed description of an illustrative embodiment
thereof, taken together with the accompanying drawing wherein like
reference numerals denote like parts throughout the various
views.
FIG. 1 is a perspective view of an emergency breathing apparatus of
the present invention shown in use;
FIG. 2 is an exploded view of the container for packaging the
foregoing apparatus;
FIG. 3 is a sectional view illustrating the means for securing and
sealing the container;
FIG. 4 is a longitudinal sectional view of the oxygen generator of
the present invention;
FIG. 5 is a top plan view of the oxygen generator of FIG. 4;
FIG. 6 is a perspective view of the expandable casing for the
oxygen generator;
FIG. 7 is an elevational view, partially in section, of the carbon
dioxide absorber assembly of the present invention; and
FIG. 8 is a cross-sectional view of the carbon dioxide absorber
assembly, taken about on line 8-8 of FIG. 7.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in detail to the drawings, there is shown in FIG. 1 a
self-contained emergency escape breathing apparatus comprising a
sectional container 10 housing a source of chemically derived
oxygen in the form of an oxygen generator 12, a flexible oxygen
delivery tube 14, a filter 16, a carbon dioxide absorber assembly
18, a nose obstructor 20, and a protective hood 22 completely
covering the head of the wearer.
Container 10 (FIG. 2) comprises a pair of casing sections 24 and 26
connected together by means which permit easy separation of said
casings. A flat elongated strip 32, bent to the inside
configuration of casing 24 is fastened thereto as by means of an
adhesive and has a portion 34 extending axially outwardly from
casing 24 adapted to be snugly received within the peripheral walls
of casing 26. A clip 27 is fastened or other wise fixedly secured
to the outer surface of casing 24 and is adapted to be attached to
the belt or other wearing apparel of the user. Means are provided
for securing casings 24 and 26 together, such means comprising a
wire 36 encircling container 10 with wire 36 disposed between the
abutting edges of the respective casings. A plurality of staples 38
overlie wire 36 and have opposite legs positioned in openings 25 of
casings 24 and 26, respectively, and in openings 33 of strip 32. An
elongated adhesive tape 40, preferably of the pressure sensitive
type, is wrapped about wire 36 and staples 38 to secure them in
place with the free end of the tape folded over the free end of
wire 36 (FIG. 2). A short strip of tape 42 extending transversely
of tape 40 is folded over the free end thereof to form a gripping
tab 44 which can be grasped by the user's fingers to unwrap tape 40
from container 10 withdrawing along with it staples 38 and wire 36
to permit separation of casings 24 and 26.
A significant feature of this invention is that oxygen generator
12, delivery tube 14, absorber canister 18, nose obstructor 20, and
protective hood 22 encased in a disposable container 23, are
compactly stowed and enclosed within container 10, in the stored
condition thereof prior to use.
Thus, all the components required for a self-contained emergency
escape breathing apparatus are packaged within a small compact
container of approximately 8 inches in length, 4 inches wide and 2
inches deep. The above dimensions are exemplary to illustrate the
small size of the container and should not be taken as limiting the
scope of this invention, it being understood that various sizes of
containers may be employed within the purview of this
invention.
Oxygen generator 12 comprises a canister 46 having an oxygen
generating unit, hereafter referred to as an oxygen candle body 48,
encased therein and capable of evolving oxygen upon burning. Oxygen
candle 48 consists of a consolidated body having uniformly
distributed therethrough an alkali metal chlorate or perchlorate
which generates oxygen upon combustion, a finely divided oxidizable
material such as iron powder for burning and supplying part of the
heat needed for combustion, a binder such as inorganic glass fibers
or steel wool for holding the mass together and aiding in the even
decomposition of the chlorate or perchlorate, and barium peroxide
or like chlorine fixes for chemically eliminating traces of
chlorine gas released during thermal breakdown of the chlorate or
perchlorate. Such oxygen candle compositions are known and per se
form no part of the present invention.
Candle body 48 is encased within a heat insulating envelope 50 of
filter medium with candle body 48 and envelope 50 comprising a
self-contained candle unit which can be handled and stored as such.
Envelope 50 can be formed, for example, of fiberglass impregnated
with a silicate or other hardening agent in an amount sufficient to
make the envelope shape sustaining in the desired form which, in
the illustrated embodiment, generally corresponds to the interior
dimensions of canister 46.
A bottom cap assembly 58 is attached to the bottom of generator 12
and defines a chamber 60 into which filtered oxygen is collected.
One end of a tube 62 communicates with chamber 60 for conveying
oxygen therefrom and is adapted to be connected at its other end to
delivery tube 14. Mounted on the top of generator 12 is a bracket
64 having an aperture therethrough for receiving a primer 66. A tab
member 68 is mounted on top of bracket 64 and is provided with an
offset portion 70 having an aperture 72 therethrough for receiving
tube 62.
In order to secure the top of oxygen generator 12 to casing 24, an
internal casing reinforcing bracket 63 is adapted to receive a
chain or a heat resistant cord (not shown) for encircling the upper
end of oxygen generator 12.
A filter screen 47 is fitted against the apertured bottom wall 45
of the canister 46. A flanged nut 43 receives a screw 41 which
holds cap 58 against a seal washer, thereby providing a gas tight
assembly.
Combustion of oxygen candle 48 is initiated by an igniter
composition 74 which comprises the foregoing oxygen evolving
composition enriched with a metal powder, such as iron, to provide
a concentrated area of the intense heat when ignited by primer 66.
A firing mechanism, generally designated 76, comprises a bracket 78
mounted on tab member 68 and a shaft 80 extending therethrough. A
firing pin 82 has an extension 84 mounted on shaft 80. A coiled
spring 86 mounted on shaft 80 has a portion 88 biasing firing pin
82 in a counterclockwise direction as viewed in FIG. 4. Normally,
pin 82 is held in the cocked position shown in FIG. 4 by means of a
cotter pin 90 inserted in openings in the sides of bracket 78 and
disposed in a groove 92 on the underside of extension 84. When
cotter pin 90 is withdrawn, the force of spring 86 drives firing
pin 82 into contact with primer 66 which initiates ignition of
oxygen candle 48.
An important feature of the present invention is that the outer
cylindrical wall of canister 46 is encased in a coiled sheet 94 of
spring metal which is formed at its inner end to tightly engage
about canister 46. That portion of sheet 94 which engages about
canister 46 is dimensioned to fit between the crimped ends thereof.
The remainder of sheet 94 extends below canister 46 and fits into
bracket 61. Sheet 94 is held in its coiled condition within
container 10 when the latter is closed, and is released to its
expanded condition when casings 24 and 26 are separated as shown in
FIG. 1. The expanded coiled sheet serves as a spacing barrier to
protect the user against burning contact with oxygen candle 48
while providing ventilating passages permitting cooling air to
communicate with the heated peripheral surface of canister 46 and
with the heat exchange surface provided by sheet 94, to dissipate
the heat therefrom. The extension of sheet 94 below canister 46
provides additional protection against accidental contact
therewith.
The carbon dioxide absorber assembly 18 comprises a corrugated
canister 100 having a chamber 102 defined by a pair of spaced
screens 104. Chamber 102 is connected to delivery tube 14 by means
of an inlet bleed fitting 106. A mouthbit 108 is provided on
canister 100 and communicates with chamber 102. Spacer means in the
form of a pair of conical springs 110 are provided at opposite ends
of canister 100 and bear against end screens 112 disposed in the
endmost grooves of corrugated canister 100. The smaller ends of
springs 100 are adapted to engage hood 22 upon inhalation to
prevent hood 22 from collapsing against end screens 112. The spaces
between screens 104 and 112 are filled with a suitable mixture of
carbon dioxide absorbing granules 114. Upon exhalation, exhaled air
is directed through the carbon dioxide absorbing material outwardly
through end screens 112 into the interior of hood 22.
Four flapper valves 116 are mounted about openings or ports 118 in
canister 100 and permit flow of breathing air from the interior of
hood 22 into chamber 102 upon inhalation. Valves 116 close ports
118 upon exhalation to direct the exhaled air into the carbon
dioxide absorbing material.
Hood 22 completely encloses the head of the wearer and is
preferably formed of a transparent flexible plastic material. If
desired, hood 22 may be formed of a generally opaque flexible
plastic material having a transparent window portion for providing
visibility. Hood 22 is fitted with a cord 25 for securing the lower
open end around the neck in a manner to provide a closing which is
not necessarily a gas tight seal but offers resistance to the free
flow of gas from the hood.
In use, tab 44 is grasped by the user'fingers and pulled to unwrap
tape 40 from about container 10. Staples 38 and wire 36 adhere to
the adhesive side of tape 40 and are removed therewith to permit
separation of casings 24 and 26. Casing 26 is removed and discarded
permitting the coiled sheet of spring metal 94 to expand as shown
in FIG. 1. Carbon dioxide absorber 18 is removed from casing 24 and
the mouthbit 108 is placed in the mouth of the user. Nose clip or
nose obstructor 20 carried by absorber assembly 18 is used to
prevent inadvertent exhalation through the nostrils. The assembly
canister has molded portions engaging the nose clip wire. Hood 22
is removed from disposable container 23, placed over the wearer's
head and tightened about the neck by means of cord 25.
To initiate the oxygen evolving process, cotter pin 90 is withdrawn
to release firing pin 82 and allow the force of spring 86 to drive
firing pin 82 into contact with primer 66 thereby initiating
ignition of oxygen candle 48. Oxygen is supplied through delivery
tube 14 and is bled into chamber 102 of carbon dioxide absorber 18
at a rate sufficient to meet the oxygen consumption of the user.
Thus, pure oxygen is supplied through delivery tube 14 to
supplement the oxygen contained in the breathing air within the
hood which flows through openings 118 upon inhalation. Upon
exhalation, gas is directed through the carbon dioxide absorbent
material outwardly through end screens 112 and into the space
within the interior of the hood. Excessive gas pressure within the
hood, such as when oxygen flow is greater than that consumed, is
discharged by leakage at the neck closure. Thus, a true closed
circuit rebreathing system is formed with duration determined by
the carbon dioxide absorbing capacity and the capacity of oxygen
evolving candle 48. Eyes are protected from toxious fumes and smoke
and a full field of vision is provided by the transparent material
of the hood. Heat generated by the carbon dioxide absorption
reaction is dissipated to the atmosphere through the large surface
area presented by the plastic hood so that the resulting
temperature of inhaled gas is relatively low and comfortable. Where
resistance to external ambient heat is desired, the hood may be
made from a heat transparent material, such as a polimide film for
example. Added heat resistance can be provided by applying a
reflective coating to the surface of the hood, leaving only enough
transparent surface for visibility.
From the foregoing, it is seen that the objects of the present
invention have been fully accomplished. As a result of this
invention, an improved closed circuit breathing apparatus is
provided for use in escape from toxic atmospheres. The apparatus
affords complete respiratory and eye protection with a minimum of
components and is contained in a relatively small pocket-sized
package. Although the apparatus of this invention can be used with
other means for supplying oxygen, such as compressed or liquified
oxygen or air, it is preferably used with a chemically derived
oxygen supply, as herein described, because only a minimum of
components are required to control the flow of oxygen thereby
making possible a lighter, smaller and less complicated apparatus.
Also, the package can be kept sealed for an indefinite period with
no inspection and maintenance required.
A preferred embodiment of the principles of this invention having
been described and illustrated, it is to be realized that
modifications thereof can be made without departing from the broad
spirit and scope of this invention as defined in the appended
claims.
* * * * *