IMPROVEMENTS. IN CHEMICAL FIRE-ENGINES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by John Gibbs and David Fotheringham
at the Office of the Commissioners of Patents on the 7th August 1883.
JOHN GIBBS and DAVID FOTHERINGHAM, both of Glasgow, in the County of
Lanark, "IMPROVEMENTS. IN CHEMICAL FIRE-ENGINES,"
"
This Invention relates to improvements in chemical fire-engines or "extincteurs."
Such apparatus usually consists of a close cylindrical vessel containing a solution
of an alkaline carbonate, and having fixed within it a bottle of acid which has to
be broken or canted, to cause admixture of the liquids when the apparatus is to be
used. The main object of the prosent Invention is so to construct and fit the
bottle or vessel containing the acid that its contents can be disharged by simply
turning a handle outside without breaking the bottle, that it can be re-charged at
any time, and that the apparatus may be ready to operate in any position in which
it may be placed.
The improved fire-engine or "extincteur" is made of the usual form externally, but
is fitted with a screwed cap or cover, through which passes a central stein fitted at
its inner end with a socket in which the neck or upper end of the bottle or vessel
carrying the acid is gripped or held. The bottle or vessel containing the acid is by
preference made in the form of a hollow sphere, which is provided at the upper
end with a ring or close neck by which it is held, and has a circular or other
opening in its lower side through which the bottle is filled and dischargod. This
opening forms a valve seat for a ball or conoidal valve which is held against it by
a light spring or holder fixed to the inside of the cover. When the extincteur is
to be used, the central stem is turned partly round by means of a hand wheel or
handle fitted outside the apparatus, so that the opening in the bottle is moved
away from the fixed spring valve, and the bottle is discharged into the solution
with which the apparatus is filled. The bottle can be re-filled with acid, and the
opening again brought round under the valve, when the cap or cover of the
extincteur is unscrewed to charge that vessel afresh. The stem by which the
bottle is held is formed with a bevilled collar or conical valve which fits and closes
outwards against a corresponding valve seat in the cap or cover through which it
passes; and a spiral spring or equivalent device is provided to cause the valve to
bear lightly on its seat. When the apparatus is in use, the pressure of the gas
within forces the valve againt its seat and keeps it closed. This device may be

page_text: with advantage used in substitution of the stuffing box which is fitted on the stem
of ordinary extincteurs.
In another modification, the bottle or vessel containing the acid, is made in the
form of a hollow plug, similar to that of an ordinary tap or crane, with its lower end
slightly tapered and ground to fit an annular valve seat which is secured by a set of
prongs fixed to the cap or cover of the extincteur. A hole is formed towards the
lower end of the hollow plug or bottle, by which it is filled and discharged, and a
corresponding hole is formed in the valve seat. The bottle when filled is fitted in
the seat which keeps it closed, and it is discharged by turning it in its seat until
the hole formed in the plug comes opposite that cut in the seat, the action being
similar to that of turning on a tap or cock. The upper end of the hollow plug or
bottle is by preference formed with a square which fits into a corresponding socket
at the inner end of the turning stem (or a square end on the stem may fit a socket
in the plug) and a volute or other spring is fitted between them to keep the plug
tightly pressed in its seat.
In a further modification, the bottle containing the acid is fixed at one side of
the central turning stem, and is fitted with a discharge tap or crane which is in
line with and is opened or closed by turning the stem.
The shell of the extincteur is provided with the usual devices by which it can be
strapped on the back of the person using it, and in addition it is fitted with
supporting legs on which it may be laid in a slightly inclined position when in use,
or by which it may be suspended. The usual discharge pipe is provided with a
cock or valve, which may be opened or closed to start or stop, or to regulate the
discharge of the liquid; and the pipe-is- carried-within--the vessel-towards the
bottom to such a position that the entire contents of the vessel can be discharged
when it is carried upright or on the back, or when it rests on the supporting legs.