IMPROVEMENTS IN APPARATUS FOR SIGNALLING AN EXCESS OR DEFICIENCY OF WATER IN STEAM BOILERS
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the Office of
the Commissioners of Patents on the 8th April 1879. A communication from
abroad by Juan Vila y Jove, of Barcelona, in the Kingdom of Spain.
"
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. IMPROVEMENTS IN APPARATUS FOR SIGNALLING AN EXCESS OR
DEFICIENCY OF WATER IN STEAM BOILERS." A communication from abroad by
Juan Vila y Jove, of Barcelona, in the Kingdom of Spain.
This Invention relates to an improved apparatus for giving notice by means of a
steam whistle of an insufficient or excessive supply of water in boilers, the said
apparatus being fixed at the upper part of the boiler in such a manner that
movement may be imparted to it when necessary by a horizontal lever connected
to a float. The positions of the parts are adjusted in such a manner that the whistle
is silent so long as the water in the boiler is at a proper level, but commences to
sound gently when the level of the water falls below or rises above certain limits,
the sound increasing continuously and proportionately to the ascent or descent of
the level of the water until the said water has returned to its normal level.
In carrying out this Invention a pipe is fixed to the upper part of the boiler,
communicating at one end with the steam space, and at the other end with a steam
whistle. This pipe is provided with a stop cock, the plug of which is formed with
two ways or passages at right angles the one to the other, and of unequal area in
cross section. When the boiler is filled with water to the proper level the whistle
is silent, as neither of the passages in the plug of the stop cock then communicates
with the pipe leading to the boiler, and the steam is thereby prevented from acting
upon the whistle.
The plug of the stop cock is provided with a square end carrying an arm or lever
jointed to the lower end of a connecting rod, the latter being attached at its upper
end to another rod, which is jointed at its upper end to a horizontal lever by a pin.
This lever, which is suspended at or near its centre on a fulcrum placed above the
boiler is connected by a suitable connecting rod with a float of stone (for example)
inside the boiler at one end, and is provided with a suitable counterweight at the
other end. When the water in the boiler sinks below its normal level the float
consequently descends at the same time, drawing with it one end of the horizontal
lever hereinbefore referred to, and also depresses the rods by which the said lever is
connected to the lever carried by the plug of the stop cock herein before described.
This plug is thereby caused to describe a portion of a revolution, and the larger of

page_text: the two passages is gradually brought into, communication with the pipe leading
from the boiler to the whistle, which then emits a sound indicating a deficiency of
water in the boiler, the said sound increasing in intensity in proportion to the
descent of the float and consequent extent of opening of the passage in the stop
cock.
When the water in the boiler rises above its normal level the movements herein-
before described are reversed, the float rises raising the end of the horizontal lever,
and, consequently, the end of the lever on the plug of the stop cock causing the
latter to turn in the opposite direction, thus bringing the smaller passage in the
plug into communication with the pipe leading from the boiler to the whistle,
thereby causing the latter to emit a sound of less intensity than that hereinbefore
described, so as to give a signal indicating an excess of water in the boiler.
The plug of the stop cock may be adjusted in the proper relative position by
means of the connecting rods, the rod jointed to the horizontal lever at its upper
end, as herein before described, being provided with a socket at its lower end, in
which the upper end of the rod, jointed at its lower end to the arm or lever on the
plug of the stop cock, is free to slide, the said rod being capable of being main-
tained in any required position by means of a set screw.
Stops may be provided for retaining the cock in its extreme positions.