Improvements in Devices for Administering Anaesthetics.
Year: 1896

page_text: Date of Application, 14th Jan., 1896-Accepted, 15th Feb., 1896
COMPLETE SPECIFICATION.
Improvements in Devices for Administering Anaesthetics.
We, JOHN KNOX GAILEY of 702 Woodward Avenue, Detroit, Michigan,
Physician, and CLEMENT ALEXANDER DUNBAR of the Township of Southfield,
Oakland County, Michigan, Capitalist, both in the United States of America, do
hereby declare the nature of this invention and in what manner the same is to
he performed to be particularly described and ascertained in and by the following
statement:-
The invention consists in the construction of a device for administering
anaesthetics, and particularly in its construction whereby the strength of the
anaesthetic, or the proportion of the anaesthetic vapor and air can be varied as
desired.
The invention further consists in the construction of the respirator hood and
anaesthetic vessel in a single structure, whereby its construction and use is
simplified and its manufacture cheapened, all as more fully hereinafter described.
In the drawings,
Fig. 1 is a sectional elevation through an anaesthetic vessel embodying the
invention, showing the valves in position to admit air only to the patient, with the
hood attached to the vessel.
Fig. 2 is a vertical central section therethrough showing the valves adjusted to
admit a portion of air and a portion of anaesthetic air to the patient, and in dotted
lines the position of the valves to admit only anaesthetic vapor to the patient.
Fig. 3 is a section, similar to Fig. 2 of a modified form of valve.
Figs. 4, 5, 6 and 7 are sections showing different positions of the valve in
Fig. 3.
Fig. 8 is a section through one of the valves of the hood.
A is the anaesthetic vessel, preferably of glass, B is a detachable cap, C is a
cylindrical sleeve centrally in this cover, projecting above and below the same, as
shown in Fig. 1.
D is the supply pipe for the anaesthetic vapor to the patient, leading from the
sleeve C.
E is a tubular stem passing through the sleeve having a screw engagement with
a bearing F formed near the lower end of the sleeve.
G is a collar on the stem E within the vessel A which forms a valve to
control communication between the chamber D' within the sleeve and the
vessel A, by turning the stem E. This stem at its top has a suitable finger hold
for this purpose.
G' is a flange or collar on the stem E to control the opening to admit air into
the upper end of the chamber D'.
K is a tubular bushing in line with the stem E, adjustably secured in the top of
the sleeve, and which is a stop and closure for the stem in its upper position.
This bushing has a stopper K.
In the vessel A is a suitable wicking or other medium for holding the liquid
anaesthetic.
In Figs. 3, 4, 5, 6 and 7 is shown a three ported plug valve, A' being the plug,
B' being a port for admitting air into the vessel through pipe C, E being a port
to admit anaesthetic or air to the patient, or different portions of air and anaesthetic,
according as the plug is turned to the various positions shown, J' being an air port
and H a port to connect with the vessel and a port connecting to the patient
or the hood N placed over the patient's face.

page_text: The hood N is shaped to cover the nose and mouth of the patient. We
preferably fit the vessel A to it as shown in Fig. 1 and connect the outlet pipe from
the vessel A by a rigid tube as there shown, to form a handle by which it may be
held in position.
The inlet pipe is controlled by a check valve M and the hood has an exit
aperture controlled by a suitable check valve O (Fig. 1). These check valves are
disks O¹ supported by cords O2, connected to the middle of the disks and supported
at the ends in rings O³, secured to the hood. This makes a light, noiseless valve
with nothing to wear in use.
The operator puts the hood over the patient's face, the parts being in position
shown in Fig. 1. The flange G being away from its seat admits air freely into
chamber D so that the patient breathes only air. The operator gradually turns
down stem E to position shown in Fig. 2. This opens upper end of stem E to
admit air into the anaesthetic chamber, partly closes the air inlet into chamber D'
under flange G¹ and moves collar G from its seat to admit anaesthetic vapor
into chamber D. Thus chamber D' is charged with a mixture of anaesthetic vapor
and air, and this proportion may be varied at will by adjusting the valves. The
per cent. of anaesthetic is marked on the stem, as shown in Fig. 1. When the
stem is in its lower position, shown in dotted lines Fig. 2, the patient will inhale
only anaesthetic vapor.
Thus the strength of the anaesthetic may be varied, or the patient allowed to
breathe pure air or pure anaesthetic without removing the hood, and by turning a
single valve, and at all times maintaining substantially a uniform opening so as never
to impede the free breathing of the patient, no matter what adjustment of the
valve is made.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
1. The herein described valve arrangement for controlling the strength of
anaesthetic without changing the portage to the bood.
2. The combination of anaesthetic chamber, controlling hood secured together
and the connecting tube forming a handle, as and for the purpose described.
Dated December 1st 1895.
JOHN KNOX GAILEY.
CLEMENT ALEXANDER DUNBAR.
Haseltine, Lake & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicants.