Year: 1887

page_text: Date of Application, 3rd May, 1887
Complete Left, 3rd Mar., 1888
Complete Accepted, 20th Apr., 1888
EDWARD GEORGE MAXWELL 54 Gresham Street E.C. City of London Agent, do
hereby declare the nature of this invention to be as follows:-
This invention relates to that class of hand fire extinguisher in which a plunger or
piston is employed to expel or eject any suitable liquid contained in a convenient
receptacle and consists of various improvements upon and modifications of previous
extinguishers of this class.
In carrying this invention into effect a convenient sized reservoir or receptacle pre-
ferably of cylindrical or tubular shape through the centre of which a plunger or
piston works is employed-The cylindrical or tubular reservoir is provided at each end
with a suitable cap to hermetically seal the contents, but instead of being screw
threaded as in the case of former extinguishers of this class and thus requiring to be
unscrewed at the cost of great waste of time when there is no time to spare.
Each cap is locked and unlocked by a simple half turn similar to a bayonet joint
thus rendering the piston rod and piston free to work with the least possible delay and
trouble.
Another feature of this invention consists in dispensing with or considerably reducing
in length the usual lateral inlet tube for the extinguishing fluid which (as hitherto
employed militates against the effective use of the extinguisher when partly empty)
and in providing the instrument with more than one automatic valve so as to render it
immaterial in what position the extinguisher is held in the hand instead of as heretofore
being compelled to hold it in one position.
The other details of this instrument are substantially similar to those in general use
in instruments of this kind.
In witness whereof I the said Edward George Maxwell have hereunto set my
hand and seal this Second day of May, in the year of our Lord, One thousand

page_text: COMPLETE SPECIFICATION.
An Improved Hand Fire Extinguisher.
EDWARD GEORGE MAXWELL of 55 Gresham Street E.C. 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, reference
being had to the accompanying sheet of drawings and letters and figures marked
thereon:-
This invention relates to Hand Fire Extinguishers.
Figure 1 is a sectional. side elevation showing the internal construction and
arrangement of the pump etc. inside the reservoir A.
Figure 2 is a plan.
Figure 3 is an end view with the end cover B removed.
Figure 4 is also an end view at B showing the positions of the charging orifice U
and catch or hook G for securing the handle F".
Figures 5 and 6 is a detail of the nozzle piece L or jet showing the manner in
which the winged cap N is secured by the inclined bayonet fastener.
The same letters refer to corresponding parts in the several figures.
A. is the main shell of the extinguisher constructed of tin or other suitable material
forming the reservoir for the liquid, it being closed by the end plates B and C. D is
the pump
barrel made of brass tube or other suitable material. E is the pump piston
or plunger. F the pump piston rod bent at the opposite end to the piston to form the
handle F G the hook or catch to secure the handle F¹ when not in use. H, and
Hare the suction valves of the pump, J and J' the delivery valves, these can be con-
structed, with ball valves as shown or any other form of valve that may be suitable, of
brass or any other suitable material. K, K is the delivery pipe common to both
delivery valves. L is the nozzle through which the liquid jet is forced. M is the air.
inlet passage. N is the cap with inclined "bayonet" fastener, constructed with wings.
so that it can very readily be removed by one quarter turn, when it is necessary to
bring the extinguisher to work. P is the leather packing to prevent leakage when
the extinguisher is not in use. R is a loop in which to insert the thumb when using
the extinguisher so as to insure it being held the right way up. The handle FI
(Fig. 1) is shown in a position ready for use, but in Figs. 2 and 4 it is shown secured
by the catch G as when not in use." The cover B can be constructed of a light brass
casting or other suitable metal, that at the other end C can be made of tin.
S is a
diaphragm soldered into the pump barrel forming the chamber T between it and the
nozzle piece L into which the pipe K delivers the liquid. U is the orifice, with a
wing screw cap, through which the reservoir A can be filled.
When using the extinguisher the barrel or reservoir A should be taken in the left
hand inserting the thumb in the loop R. The cap N is then detached by giving it a
one quarter turn to the left. The handle F¹ is then grasped by the right hand and
brought from the position shown in Figs. 2 and 4 to the position shown in Fig. 1,
clear of the catch G, then the extinguisher is ready for use.

page_text: The action of the apparatus when in use is (the reservoir A being fully charged
with the liquid chemical compound as also is the pump barrel D) thus, say in the first
instance it is held perfectly horizontal, the piston or plunger E is drawn from the
valve H up to the valve H' by so doing the liquid in the pump barrel D at the back
end of the piston is forced through the delivery valve J¹ into the pipe K thence to the
nozzle L. When the piston is thus travelling from H to H¹ the liquid flows through
the suction valve H following up the piston thus filling the pump barrel D in front of
the piston, on forcing the piston back to its original position, that is, from H' to H
the liquid flows through the delivery valve J into the pipe K and thence to the
nozzle L, at the same time the liquid is flowing through the suction valve H¹, filling
the barrel D at the back of the piston. This double action of the pump will continue
so long as the apparatus is held in a horizontal position and until the reservoir A is
emptied. The channel M is for the purpose of allowing air to entre the reservoir as
the liquid is pumped out.
Should the nozzle end L of the extinguisher be elevated and the liquid fall to the
level as shown by the dotted line W the suction valve H and the delivery valve J will
no longer act but the valves H' and J¹ will continue in action thereby making the
pump single acting but still effective. Let the reverse be the case, the nozzle end L be
depressed and the level of the liquid fall to the dotted line W₁ then the valves H and J
will only act.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is performed, I declare what I claim is.
First. In hand fire extinguishers. The construction or general arrangement and
combination of the parts of the hand fire extinguisher appliances, the pump and the
valves, the nozzle and cap, and the fittings substantially as herein described in reference
to and shown on the accompanying drawings.
Second. In a hand fire extinguisher that the valves H & J and H¹ & J¹ of the pump
are so arranged and constructed that the pump is capable of acting whether the nozzle
end of the extinguisher is elevated or depressed.
Third. In a hand fire extinguisher, the arrangement of the nozzle L and the air
channel M.
Fourth. In a hand fire extinguisher, the construction of the cap N, in combination
with both the nozzle or jet pipe L and the air channels M whereby they are both closed
and made tight at one and the same time so that the liquid cannot leak out from
either opening.
Fifth. In a hand fire extinguisher, the means of securing the cap N on the nozzle L.
viz., by the inclined "bayonet" joint, whereby the cap can be readily removed by one
quarter turn to the left see Figs. 5 & 6.
Sixth. In a hand fire extinguisher, the loop R in which the thumb is inserted,
to ensure the extinguisher being held in the right position.
Seventh. In a hand fire extinguisher, the catch or hook G for securing the handle F
when the extinguisher is not in use.
In witness whereof I the said E. G. Maxwell. have hereto set my hand and