Improved Respirator for Firemen, Divers, and others.
Year: 1890

page_text: Date of Application, 27th May, 1890-Accepted, 23rd Aug.,
1890
COMPLETE SPECIFICATION.
Improved Respirator for Firemen, Divers, and others.
We, GEORGE HILL HURD, of 426 Tiffin Street, Fostoria, Inventor, and FREDERICK
HENRY BRETT, of 221 Newell Street, in the City of Cleveland, both in the State of
Ohio, in the United States of America, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
The object of our invention is an improved apparatus to enable fireman to enter
burning buildings and rooms filled with smoke and noxious gases and to work therein
with impunity. It may also be used by divers to enter water and carry with them
their own supply of air which will enable them to work continuously for some time
without the necessity of rising to the surface or having attendants who will furnish
them with a new supply of air.
Referring to the accompanying drawing:
Fig. 1 is a perspective view of the figure of a man protected with our improved
armour; and
Fig. 2 is a detail view of the double valve.
A is a metal cylinder filled with compressed air, which may be compressed into one
twelve hundreth its original bulk, if necessary. Strap c¹ passes over the shoulder of
the wearer, and is secured at its respective extremities to the cylinder A. Tube B is
secured to one end of said cylinder from which the air may issue; the connection
between said tube and cylinder being governed by valve b¹, adapted to prevent
entirely the emission of air from chamber A or to regulate the outflow of air
therefrom. Expanding tube E connects with said tube B and passes partially around
the body of the operator and connects at its outer extremity with the bag or air
expanding chamber E¹, that is secured in any suitable manner to the back of the
operator. Tube e connects air expanding chamber E¹ with the helmet, said chamber
has no communication with the outer air.
The said helmet is made preferably of rubber adapted to stretch to a greater or less
degree and its free edges to tightly inclose the head and face of the wearer. It is
furnished with eye holes h provided with isinglass coverings h. A compound valve J
is secured in the lower front portion of said helmet; said valve being formed as
follows. A primary seat k is formed at the outer extremity of the valve, a pin j
extending downwardly from the outer shell of the valve into close proximity to said
seat. Resting on said seat is the isinglass disc j³. As the wearer exhales, the disc is
forced outwardly and permits the exhalations to pass out, the pin preventing the
whole of the disc from moving outwardly, but affording ample opportunity for the
discharge of the exhalations. The lower portion of the valve is practically a duplicate
of the outer portion and consists of a seat k and pin k¹ and a disc. It will be
understood that we in no wise confine ourselves to a disc made of isinglass, for any
other suitable substance may answer the purpose, whether opaque or transparent.
For instance, aluminium would answer as well as isinglass.
As the wearer inhales, the discs, being very light, are drawn tightly against the
seats and prevent any ingress of the smoke or other fluids or gases by which the
wearer may be surrounded; and the duplex or compound formation of the valve
renders it practically impossible for any portion of outside gases to pass into the
helmet. This formation of valve we regard as a very considerable importance in
the use of our invention. For we have found, by practice, and experiment, that the
usual and common forms of valves, as heretofore used, are inefficient and worthless
after a few minutes use.
Moistened sponges have been used, but the dense smoke usually found in a burning
building and the noisome and mephitic gases frequently met with in such places soon

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render the sponges useless, as they become gummed and clogged and render danger
of suffocation extremely imminent.
Another feature of our invention which renders it of practical use, is the expanding
air chamber or bag located intermediate of the cylinder and the helmet. The
necessity of this intermediate-expansion of the condensed air has not heretofore been
thoroughly understood. The result has been that apparatus of this character have
been extremely dangerous in use. For, if the highly condensed air contained within
the cylinder, is allowed to be breathed without proper intermediate expansion, before
it enters the lungs of the wearer of the helmet, there is extreme, not to say certain,
danger of suffocation. But by means of our apparatus we can regulate the amount of
air issuing from the cylinder to a nicety and provide for its expansion in the sack to
its original bulk: so that, by the time it reaches the wearer of the helmet, it is in
condition to be breathed without danger or distress.
Another advantage of our form of apparatus is that the lower portion of the
expanding tube passes under the arm of the wearer, whereby he is enabled, at all times,
by merely dropping his arm, to be thoroughly conversant with the amount of air
contained in said tube, and thus there can be no danger that the air supply can
become exhausted without his knowledge.
This is of the highest importance for two reasons; First, a fireman when working in
a burning building, becomes very forgetful of himself and is very apt to be unmindful
and negligent of the condition of his air supply. Second, if he merely depends on his
sight, for his knowledge of the amount of air contained in the bag, he would frequently
be at a loss, for the rooms being filled with smoke, his sight is obstructed and the
helmet also impedes considerably the acuteness of his sight.
As we make no claim to the manner of securing the eye holes in the helmet, nor of
the details of construction of connecting the cylinder with the tube and the sack with
the helmet, we do not more particularly describe them, as this may be done in any
suitable manner.
It is to be understood that we in no wise confine the use of this apparatus to
burning buildings, as it may be as well used for operation under water, or in any
place where gases or fluids are encountered that are harmful to the life of man.
The foregoing description and accompanying drawings set forth in detail, mechanism
embodying my invention; changes may be made therein provided the principles of
construction respectively recited in the following claims are retained and employed.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The combination of a condensed air chamber wovided with a valve adapted at
will of the operator to regulate the emission of air from said chamber, a helmet, and
an air chamber located intermediately of said condei sed air chamber and said helmet,
and wherein the air issuing from the former may expand to atmospheric pressure
before passing to said helmet, said expanding air chamber connected with said
condensed air chamber and helmet, and having no connection with outer air, said
helmet provided with an expiratory valve, substantially as set forth.
2. The combination of condensed air chamber A provided with hand valve 6¹
adapted to prevent entirely the emission of air from chamber A or to regulate the
outflow of air therefrom, helmet G having its free edges formed of rubber adapted
tightly to clasp the head of the wearer, said helmet provided with double expiratory
valve J provided with primary and secondary discs, and seats and pins with which
said discs respectively engage, and an air expanding chamber located intermediately
of and connected with helmet G and chamber A and having no connection with the
outer air, substantially as set forth.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicants.