Fire Extinguisher.
Year: 1896

page_text: Date of App-ication, 31st Mar., 1996-Accepted, 16th May, 1896
COMPLETE SPECIFICATION.
Fire Extinguisher.
I, HENRY AUGUSTUS MANSFIELD of 47 Canon Street Bridgeport State of
Connecticut U.S.A. Inventor do hereby declare the nature of my said invention
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
My invention relates to fire extinguishers and has for its object to provide a
vessel or reservoir, which shall be absolutely fluid, gas and air-tight, in which no
opening or joint appears, except a small discharge nipple located in the bottom of
the reservoir and projecting below the same, having a small horizontally arranged
tube connecting said nipple with the discharge nozzle attached to the skirt of the
reservoir, which nozzle and connection are entirely outside of the same, It further
consists in providing a soft metal seat for the plug of the nozzle, so that a tight
joint will always be maintained, and to so construct such seat that no leakage can
take place.
To enable others to understand my invention, reference is had to the accompanying
drawings, in which:
Figure 1 represents a front elevation of a shell whose sides and dome are made
of one piece of drawn metal.
Figure 2 is a view showing the manner of compressing the air in the reservoir.
Figure 3 is a central sectional side elevation of the shell or reservoir, showing
the manner of attaching the bottom and skirt; also sectional view of the filling
and discharging nipple in said bottom; broken view of the discharge nozzle
screwed into the skirt of the reservoir and the conduit tube connecting such nozzle
with the nipple.
Figure 4 is a detail view partly in section of the nozzle in the first steps of its
manufacture.
Figure 5 is a detail longitudinal central sectional view of the nozzle with the
plug removed.
Figure 6 is a view similar to Figure 5 with the addition of the plug or key.
Its construction and operation are as follows: 1 represents the shell or reservoir
and this it is absolutely necessary should be made of drawn metal, i.e. formed in
this shape by being drawn through a die large enough for the purpose. It is not
enough that this shell be made simply of one piece of metal as sheet iron, steel or
cast iron, glass, or any other known metal or substance that has not been drawn
through a die, as this operation will effectually close the pores so as to prevent the
escape of compressed air within the reservoir. Compressed air being one of the
most difficult of all substances to retain for any length of time, no metal has yet
been found sufficiently non-porous to prevent its escape. This, however, I have
only successfully accomplished by selecting metals possessing great ductility, like
copper, and drawing it through a die in the form of a shell, as shown. This
drawing process solidifies the metal by closing all the pores, so that it will stand
a strain of several hundred pounds without loss or diminution of the internal
pressure.
The bottom 2 (Figure 3) should, in practice, be more crowning than shown, so
as to resist more effectually the internal pressure. This bottom I prefer to draw
or cup out, so that the sides 2* thereof shall have a prolonged bearing on the inner
wall of the reservoir, as shown. This arrangement will carry said bottom up far
enough to form the open chamber 3 at the lower end of the extinguisher, the

page_text: purpose of which will presently be explained. 4 is a U-shaped sheet metal ring
adapted to receive the end 2 of the cup-shaped bottom 2 firmly embracing the
inner walls of this cup and the outer surface of the shell or reservoir 1, in which
position it is further secured by soldering or brazing.
The nipple 5, having the small passage-way a, is firmly screwed into the
bottom 2 and close to the rear part of the reservoir, the ring of solder b effectually
preventing any escape of fluid or air around the threaded connection. This nipple
serves a three-fold purpose, viz.; as an aperture through which the liquid is
admitted to the interior of the reservoir; means whereby connection is had with
the discharge nozzle outside of the reservoir; and by its position enabling all the
liquid in the reservoir to be discharged through the nozzle. 6 is a removable cap
on the end of said nipple. 7 is a horizontally arranged tube or conduit pipe, one
erd of which is screwed into the nipple 5, and the other end into the threaded
end of the nozzle 8. A threaded hole is formed through the skirt of the
reservoir, which skirt consists of the U-shaped ring 4; end of the reservoir 1, and
sides 2 of the cup-shaped bottom 2 into which is firmly screwed said threaded end c
of the nozzle, and it is further secured by the nut 9. The internal bore of the
tube 7 is about one-quarter of an inch in diameter, which corresponds to the size
of the passage-way d of the nozzle, (see also Figures 5 and 6).
This outside arrangement of the nipple, conduit tube and nozzle enables them
to be easily removed when obstructed with sediment and cleaned, without defacing
or otherwise injuring the outer surface of the shell reservoir.
Formerly it has been the custom to tap a hole in the side wall and near the
bottom of the reservoir, which made it necessary to solder the nozzle firmly
thereto to prevent leakage, and when its passage-way was obstructed by the
sediment incidental to all extinguishers, or the nozzle became injured by accident
or from whatever cause made it necessary to remove the nozzle, the solder had to
be melted off, which operation destroyed the japan finish, nickel or polish on the
exterior of the shell, so that it was cheaper to throw away the extinguisher than
to incur the expense incidental thereto. Locating the nozzle, as shown, in the
skirt of the extinguisher and having all its connections upon the outside where
they can readily be removed and replaced without defacing the shell, is of great
advantage. When, therefore, the tube 7, Figure 3, nipple 5 or nozzle 8 becomes
clogged with sediment, or the nozzle becomes damaged, the nut 9 is simply loosened
and the nozzle unscrewed, which operation will also unscrew the tube 7, when the
parts can readily be cleaned or replaced, as the case may require.
A serious drawback to the use of fire extinguishers of this class is the difficulty
experienced in keeping the nozzle fluid-tight, as the pressure of the compressed air
or gas would force the liquid by an ordinary hard plug and its ground seat.
Therefore, no such plug and seat have yet been found that could be freely opened
and closed and long remain tight under these conditions. This result I have
successfully accomplished by the use of a soft metal seat, of Babbitt-tin or other
like substance, combined with a taper plug or key sufficiently hard to be forced
into the softer metal of the seat and, notwithstanding inequalities exist in the plug,
the softer metal by conforming thereto, will make a tight seat. But this
advantage gained is of no account unless the inferior metal composing the soft seat
is firmly and closely united to the harder metal of the nozzle.
In Figure 4 is shown one of the stages in the construction of the nozzle I use in
my extinguisher, in which is first formed the large circular chamber e, whose walls
are finished so as to take a coating of solder or other like substance. Then the
said chamber is filled with molten metal for the soft seat 10, the cooling of which
will cause it to shrink away from the walls of the chamber and thus leave a space
for the escape of liquid under pressure. To counteract this, after the seat has
become cooled, a metal like bismuth or other like substance that will melt at a
lower temperature than the babbitt of the seat, or metal of the same kind that was
used in the tinning or coating the walls of the chamber, is poured over the Babbitt
seat and flowing between the two metals will effectually seal them together, making a

page_text: solid joint that cannot otherwise be secured. The soft metal seat 10 is allowed to.
overflow the said chamber and fill the annular openings in the top and bottom of
the body of the nozzle to form the neck portions f, and thereby produce a more
extended bearing surface for the plug or key. The taper hole g, Figure 5, for the
plug 11, Figure 6, is then formed through the seat 10, and also the channel-way d
at right angles thereto.
The threaded hole h in the threaded extension c is for the threaded end of the
pipe or tube 7, before mentioned, while the interior threaded hole in the front
end of the nozzle is intended to receive the threaded end of an air pump presently
to be described. The hole j, which opens communication between the threaded
seat and the chanuel way d, is considerably smaller in diameter than such
channel-way, so as to make the labor of filling the reservoir with air much less,
besides, this narrow opening will so compress the outgoing stream that it will be
thrown with greater force. To assist in this latter purpose, I prefer to gradually
taper the end of the channel-way d to the size of the outlet j, as shown at m.
The plug 11 is provided with the elongated hole k which always coincides with
the channel-way d regardless of the changed vertical position of said plug. Nut 12.
and washer 13 are mounted on the lower end of the plug, as provided in such cases,
for the purpose of setting, adjusting and taking up the wear.
To charge the reservoir the cap 6 is removed from the nipple and the interior
partially filled with a suitable fire extinguishing liquid. Then the reservoir is laid
upon its side, as shown in Figure 2, and the air pump 14 attached to the nozzle,.
the handle 15 raised to open the port of the nozzle and sufficient air forced into
the reservoir to furnish the pressure required. When, therefore, the extinguisher
is placed in an upright position, as shown in Figures 1 and 3, the compressed air
will be in the upper part or dome, which, containing no seams or joints and being
drawn metal, as before mentioned, it will remain for an indefinite length of time
without suffering any diminution of pressure. There is a decided advantage to be
gained in forcing the air through the nozzle, as described, as otherwise a special
aperture would be required for that purpose, making one more joint to guard
against; besides, with the extinguisher lying on its side (Figure 2) and between
the feet of the operator, gives him both hands for manipulating the air pump.
The machine is operated by simply opening the nozzle 8 through the medium of
the handle 15, whereupon the fluid is driven out with great force and the reservoir
partially or fully exhausted, the position of the discharge nozzle 8, conduit 7 and
nipple 5 with respect to the reservoir being such that all of the contents may be
expelled.
To insure an instantaneous opening of the nozzle, the lug n is formed on the
plug 11 to engage with the projection o on the body portion of the nozzle, which
will bring the elongate hole in line with the channel or port d.
p are wire rings encircling the outer surface of the shell 1 and soldered thereto,.
and serve simply as means to prevent the carrying strap placed about the can from
slipping.
From the foregoing description it will be seen that my peculiar construction
embraces all the advantages that a fire extinguisher should possess, it being
cheaply and easily refilled, as a pump accompanies each extinguisher, and being
perfectly air-tight is always ready for use. This latter feature is of the utmost
importance when one considers the liability, in the majority of cases, for fire
extinguishers to be set one side and forgotten until the very moment that they are
wanted and then to realize that they have deteriorated in pressure to such an
extent as to render them useless.
Having thus described my invention, what I claim as new and desire to secure-
by Letters Patent is;
1. A fire extinguisher, consisting of a seamless metal shell forming the top and.
side walls thereof, substantially as shown, a bottom sealing the lower end and
placed far enough within the shell so that the lower side walls of said shell will.

page_text: form a skirt enclosing the open chamber, a filling and discharging nipple attached
to said bottom and projecting downward within said chamber, a discharging nozzle
projecting through said skirt, a conduit pipe connecting said nipple and nozzle
outside the reservoir, as set forth.
2. In a fire extinguisher, the seamless shell 1 having closed bottom 2, receiving
and discharging nipple 5 projecting below said bottom and protected by a skirt
formed by the projecting sides of said shell, discharge nozzle 8 attached to said
skirt, as shown, conduit tube 7 connecting said nipple and nozzle, and outside the
reservoir said nozzle provided with the soft metal seat 10 constructed and
attached thereto as described and set forth, hard plug 11 engaging therewith to
make a tight joint so as to prevent the escape of liquid from the reservoir, as set
forth.
3. In a fire extinguisher, in combination with the reservoir for holding
compressed air and fire extinguishing liquid and a discharge nozzle, of means,
substantially as shown for attaching the air pump for recharging the reservoir to
said nozzle, and thereby dispense with an extra air inlet, as set forth.
4. In a fire extinguisher, of the character described, of a nozzle constructed
with a view to prevent the leakage of the contents of said extinguisher, consisting
of the body 8, large chamber e therein, a tinning coat on the walls of said chamber,
soft metal seat 10 within said chamber, combined with a metal that will fuse at a
lower temperature than either the seat 10 or the tinning metal spread over the
walls of said chamber, so as to effectually seal such seat and tinning substance
together, as set forth.
5. In a fire extinguisher, the reservoir constructed of a single piece of metal
drawn in the form of a tube or shell whose sides and closed top are without seam
or joint, combined with a sealed bottom at the lower end and a discharge nozzle,
for the purpose set forth.
Dated this 30th day of March 1896.
GEORGE BARKER,
77 Colmore Row, Birmingham, Agent for Applicant.