Improvements in and Relating to Chemical Fire Extinguishers.
Year: 1899

page_text: Date of Application, 13th June, 1899-Accepted, 15th July, 1899
COMPLETE SPECIFICATION.
Improvements in and Relating to Chemical Fire Extinguishers.
I, WILLIAM HARVEY DOUGLAS, a Citizen of the United States of America,
residing at 1210 E Street Northwest, in the City of Washington, District of
Columbia, United States of America, Brass Founder, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:-
This invention relates to that class of portable fire extinguishers comprising a
main reservoir containing a liquid and which when combined with a proper acid
held in a normally sealed bottle contained within said reservoir, forms a fluid which
will most quickly extinguish fires, said acid being liberated automatically when
the apparatus is inverted, and the object of the invention is to provide a most
simple and cheap means for sealing the acid bottle, which is operated by gravity
to liberate the acid when the apparatus is inverted, which will cause the acid
to mix slowly with the solution in the main receptacle, thereby overcoming the
danger of explosion incident to constructions wherein there is a high pressure
within the main receptacle created instantaneously by the rapid union of the
acid with the alkaline solution, and to this end my invention consists in the
parts and combinations of parts hereinafter shown and described and more par-
ticularly pointed out in the claims.
Referring to the drawings:
Figure 1 is a vertical section of the apparatus in its normal position,
Figure 2 is a detail plan view,
Figure 3 is a vertical section of one half of the apparatus showing the same
inverted for use,
Figure 4 is a detail perspective view of the acid bottle and its plug, separated;
and
Figure 5 a detail sectional view of the bottle showing a modification.
Similar letters refer to similar parts throughout the several views.
The reservoir A is preferably made of metal of such thickness as to withstand
the great pressure exerted thereon by the gases generated by the mixing of the
acid contained in the reservoir. The neck surrounding the opening in the
reservoir is screw threaded to receive a correspondingly threaded cap E for
closing the opening, the said cap being preferably formed with handles, a,
whereby the apparatus may be moved or carried from place to place. Within
the cap is arranged a flexible washer, b, resting on a shoulder, c, formed on the
cap, which is adapted to engage the rim or edges of the neck of the reservoir
in order to form an air-tight joint between the cap and the reservoir.
washer b, is made sufficiently wide to engage the lugs formed on the acid bottle,
as will be hereinafter described, for the purpose of holding the latter firmly in
position in the reservoir. Within the neck of the reservoir an inwardly pro-
jecting flange F is formed on which is supported the acid bottle B and between
which flanges and the washer the lugs, of the bottle B are held. The bottle
is of sufficiently less diameter than the mouth or the opening in the reservoir
077
The

page_text: to provide a space i therebetween for the free passage of the fluid from the body
of the reservoir into the neck thereof so as to meet and mix with the acid
discharged from the bottle B.
G represents a tube arranged upright in the reservoir at one side thereof and
which extends nearly to the top of said reservoir and is held by an elbow
joint secured in the side of said reservoir. The outer end of the elbow joint
has connected thereto in any desired manner a flexible tube I which is to be
provided with any desired or suitable nozzle for discharging the fluid from the
reservoir when the apparatus is being used.
The acid bottle B, is preferably made of glass and is formed with lugs d which
are arranged, preferably, at equal distance apart around and project both
laterally and vertically from the upper end of the bottle. These lugs serve the
double purpose of engaging the flange of the reservoir in order to support
the bottle therein and also to prevent the latter dropping or moving when the
apparatus is inverted, and they are arranged as described for the purpose of
permitting of the free passage of the fluid between them to mix with the acid
escaping from the bottle as will now be described.
The plug for the bottle B is formed with a flange e adapted to rest closely on
the top or rim of said bottle, and its body f, is formed of a hollow cylinder whose
diameter is such that a space or opening g, is left between it and the mouth or
opening in' said bottle into which it extends in order to form a vent for the acid
bottle when the apparatus is inverted as shown best in Figure 3, and thus enable
the acid to flow more freely through the series of openings or perforations h
formed around the cylindrical body of the plug at a point adjacent the flange c.
Thus, it will be observed, upon inverting the apparatus the plug will drop
until arrested by the cap, as shown in Figure 3, in which position the perfora-
tions are uncovered and the acid in the bottle flows or escapes therethrough
in order to meet and mix with the fluid in the reservoir, the latter flowing freely
through the space i between the opening in the reservoir and the body of the
bottle B.
Owing to the space or passage g the bottle B is vented and the steady and
uniform flow of acid therefrom is thereby attained.
It is evident that the washer b may be dispensed with and shoulder c on the
cap enlarged to engage the lugs, d, or that the latter may be made longer so
as to engage the cap itself without departing from the scope of my invention
and therefore I do not desire to be limited to the exact construction of the parts
named as herein described and shown.
Also it is evident that the body of the plug may be increased in diameter so
as to loosely engage the opening in the bottle B and practically, close the space g
as shown in Figure 5, in which a series of perforations s are shown as formed in
the constricted neck of the bottle m, to form a vent therefor, which perforations
would be covered by the flange of the plug when the apparatus was not in use.
The bottle, m, is formed with the lugs, n, and a plug o having discharge
openings is provided therefor.
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 combination in a chemical fire extinguisher of an alkali reservoir A,
an acid bottle B having a vent and immovably mounted with reference to said
reservoir, and a movable plug for said bottle provided with discharge openings h
and adapted to close and disclose said vent according to the position of the plug.
2. The combination, in a chemical fire extinguisher, of a bottle B, a plug
having a hollow cylindrical body, f, formed with openings h, and adapted to
enter the mouth of said bottle so as to provide a vent space thereabout, and a
flange c, formed on said plug to support the same in position and to close said
vent space.

page_text: 3. The combination, in a fire extinguisher, of an alkali reservoir A. formed
with a flange, F, in its mouth, an acid bottle, B, having lugs d, extending
laterally from and projecting above the mouth of said bottle, and a cap, E, for
the mouth of the reservoir adapted to close the same and engage said lugs,
whereby the bottle is held firmly in position.
4. The combination in a chemical fire extinguisher of an acid bottle B and a
plug for said bottle provided with discharge openings and a flange, e, the said
bottle having a vent situated contiguous to said flange and adapted to be closed
thereby.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.