Year: 1887

page_text: Date of Application, 30th Sept., 1887
Complete Left, 26th Apr., 1888
Complete Accepted, 25th May, 1888
I, EDWARD GEORGE BLOOMFIELD BARLOW, manufacturer of compressed gases, o
54 Poland Street, Oxford Street, London, in the county of Middlesex, do hereby
declare the nature of this invention to be as follows:-
According to the method of administering Nitrous Oxide gas, either alone, or in
combination with Ether, or other vapours, introduced by Dr. Hewitt, the administrator
requires an apparatus attached to the face piece which will enable him-
First. To shut off the nitrous oxido gas, and at the same time admit air.
Secondly. To shut off the air and open a valve for inhaling the nitrous oxide gas,
and also a valve for exhaling it into the atmosphere.
Thirdly. To open a free communication with the nitrous oxide gas bag and shut all
other openings so that nitrous oxide gas is inhaled, and exhaled again into the bag.
My Invention is designed to meet these requirements in a more convenient manner
than has hitherto been attained.
It consists of a cylindrical case or valve-box of metal, having one, or both ends
closed, and three openings or apertures in the circumference, one at the side, with a
tube to connect with the facepiece, one at the bottom, with a tube to connect with
the bag containing the nitrous oxide gas, the other at the top covered externally by an
expiratory valve. In one of the ends are small apertures for the admission of the air.
Inside this cylindrical case is another metal cylinder or drum, closed at the ends, and
made to fit exactly in the outer case, so as to be airtight, and is capable of being
revolved by means of a handle. In the interior of this inner drum an inspiratory
valve is fixed over an opening, similar to the opening in the lower part of the outer
case. There are also openings in the circumference, and air holes in one end.
When this inner drum is moved by means of the handle into position I, the air
holes in the end exactly correspond in position to the air holes in the outer case,
here is also an opening in the circumference corresponding in position to the opening
in the outer case leading to the facepiece, and at the same time the apertures in the top
and bottom of the outer case, are closed by the solid part of the drum. Thus the
nitrous oxide gas is shut off, and at the same time air is admitted.

page_text: When the drum is moved into position II the aperture leading to the facepiece still
remains open, but the inspiratory valve in the interior of the drum has now come into
a position exactly over the opening in the outer case leading to the nitrous oxide gas
bag, and at the same time the expiratory valve at the top of the outer case is also open
and the air holes are closed.
The free communication with the air is thus closed and the nitrous oxide gas may
be inhaled through the inspiratory valve and exhaled through the expiratory valve
into the atmosphere.
When the drum is moved into position III, the inspiratory valve in the interior is
moved away from the lower opening leading to the gas bag, but the openings in the
circumference of the drum are now in such a position that free communication is open
to the gas bag, and all other apertures closed. Thus the nitrous oxide gas may be
inhaled and exhaled again into the bag.

page_text: COMPLETE SPECIFICATION.
An Improvement in Apparatus for Inhaling Nitrous Oxide Gas.
I, EDWARD GEORGE BLOOMFIELD BARLOW manufacturer of compressed gases of
54 Poland Street Oxford Street London 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 :-
For the administration of nitrous oxide gas either alone or in combination with
Ether or other vapours to produce anesthesia, the administrator requires an apparatus
attached to the facepiece which will enable him-
First. To shut off the nitrous oxide gas and at the same time admit air.
Secondly. To shut off the air and opon a valve for inhaling the nitrous oxide gas
and also a valve for exhaling it into the atmosphere.
And some administrators require
Thirdly. To open a free communication with the nitrous oxide gas bag and shut all
other openings so that the gas is inhaled and exhaled again into the bag.
The apparatus hitherto used for this purpose consists of a facepiece made of india-
rubber, or other suitable material, fitted with an inspiratory and expiratory valve, a
gas bag is connected with the facepiece by means of a tube fitted with a two-way
stop cock, that is, a cock or tap which when turned in one position shuts off the nitrous
oxide gas and admits air to the patient and when turned in another position, it opens
the passage to the nitrous oxide gas bag and shuts off the air.
Sometimes instead of the facepiece being fitted with valves they are placed in a
valve-box apart from the facepiece.
My Invention combines the valve-box and two way stop cock in one apparatus apart
from the facepiece, and is designed to meet the requirements of administrators in a
moro convenient manner than has hitherto been attained.
In the accompanying drawing figure shows the apparatus attached to the face-
piece, and figures 2, 3, and 4, are sections of the same. It consists of a cylindrical
case of metal A figures 2, 3, and 4, which may or may not have one or both ends
closed, having the following apertures or openings one at the side a, with a tube to
connect with the facepiece, another at the bottom b, with a tube to connect with
the bag containing the nitrous oxide gas, another at the top covered externally by
the expiratory valve c, and another for the admission of air d, situated nearly opposite
the passage leading to the facepiece.
Inside this cylindrical case is another metal cylinder, or drum, B, closed at the
ends, and made to fit exactly in the outer case, so as to be airtight, and is capable
of being revolved by means of a handle C.
In the interior of this inner drum is a partition having an opening or aperture e,
covered with an inspiratory valve also an aperture f, in the segment of the circum-
ference behind the partition, and the large aperture 9, 9, 9, in the segment of the
circumference in front of the partition.

page_text: When the inner drum B. is moved by means of the handle into position 1 (figure 2)
the passage leading to the facepiece is open, also the air hole d, and the expiratory
valve c, but the aperture 6 leading to the nitrous gas bag is closed.
When the drum is moved into position 2, (figure 3) the passage leading to the
facepiece still remains open but the aperture f, in the circumference of the drum has
now come into a position exactly over the aperture 6 leading to the nitrous oxide gas
bag, and the air hole is now closed; the nitrous oxide gas may now be inhaled through
the inspiratory valve f and exhaled through the expiratory valve c.
When the inner drum is moved into position 3, (figure 4) the inspiratory valve fis
moved away from the aperture b, and by means of the opening g, 9, 9, in the inner
drum, there is now free communication between the bag and the facepiece, but the
air hole d, and the expiratory valve c, are both closed.
Some administrators object to patients breathing and robreathing the gas from
the bag.
In that case only the first two positions are required, or the apparatus may be made
with the inspiratory valve in the tube leading to the gas bag, instead of in the
moveable drum, as shown in figures 6 and 7 in section, and figure 5 in elevation.
The valves shown in the drawings are flap valves," but any kind of valves adapted
to the purpose may be used such as "spring valves" &c.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what I
claim is
1. The simplification of the apparatus ordinarily used for the administration of
nitrous oxide gas, by means of the pieces of mechanism hereinbefore described for
controlling the admission of air and gas to the patient.