Improvements in Fog or Audible Signaling Apparatus for Lighthouses and the like.
Year: 1896

page_text: COMPLETE SPECIFICATION.
Improvements in Fog or Audible Signaling Apparatus for
Lighthouses and the like.
1, JOHN FRANCIS BARKER, of No. 86 Sherman Street, of the City of Spring-
field, County of Hamplen, State of Massachusetts, United States of America,
Manufacturer, 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 aud
by the following statement:-
My invention relates generally to the operation of that class of signaling
devices used in light houses and similar situations, known as fog horns or sirens.
The means heretofore employed for operating such signals have been expensive
to construct and operate, and require constant attention while in operation, and
the object of my improvements is to provide an apparatus which, while capable of
giving a sound of sufficient volume, shall be inexpensive, simple and automatic in
operation.
The apparatus is illustrated in the drawings in which Fig. I shows a vertical
elevation partly in section of a form of apparatus for carrying my invention into
effect, and Fig. 2 shows the details of a pump employed therein.
Referring to the drawings A indicates an engine, such as a gasoline engine of
any usual or suitable form of construction, by means of which is operated a
pump B. The pump B is connected by a small pipe a with a receptacle con-
taining gasoline, which may be the same tank 6 from which gasoline is supplied to
the engine in case a gasoline engine is used, and is also provided with an air
port p through which air is drawn into the pump B at the same time with the
gasoline from the pipe a.
From the pump B
pipe C, in which is a check valve e closing toward the
pump, leads to a chamber D, which I call the explosion chamber, and which is
provided with walls of sufficient strength to resist the effects of the explosions
which take place therein.
The explosion chamber D is connected by a pipe d with a cylinder E, within
which is a piston and piston head F. Normally the piston head is held at the end
of the cylinder E nearest to the chamber.D by a spring G, which also operates to
drive the piston head back into its normal position when it is driven away there-
from by gas pressure, or the force of an explosion. An elastic buffer, such as the
springs e e, may be interposed between the piston head and the end of the cylinder
to prevent shock from impact when the piston head is drive. back into position by
the spring G.
From such a point in the cylinder E, that it is shut off from the chamber D by
the piston head F when in its normal position, an opening f leads to a vibratory
sounding device such as an ordinary siren or fog horn H. Into the explosion
chamber D project two contact points g g of carbon or other suitable material,
which are normally in contact with each other and are respectively connected with
the terminals of an electric battery indicated at I. One of the contact points g 9
is connected with a lever h, from which it is insulated in any suitable manner, and
which is arranged to be moved by a cam i, operated by a train of clock work K,
so as to separate the contact points gg.
The operation of the device is as follows: On operating the pump B by means
of the engine A, liquid gasoline is drawn into the pump. barrel through the pipe a
(its return being prevented by a check valve o) and at the same time air is drawn

page_text: in through the port p. The relative capacities of the pipe a and the air port,
should be such that about ten thousand parts of atmospheric air will be drawn into
the pump barrel for each part of liquid gasoline. This, when the gasoline is
vaporized, will give a mixture of about ninety-eight parts of atmospheric air to two
parts of gasoline vapor, which is a highly explosive mixture.
The gasoline vaporizes as it is drawn into the chamber of the pump B, and with
the return stroke of the pump is forced together with the air through the pipe C
into the chamber D. The return of the gas through the pipe C is prevented by
the check valve c, and its escape through the cylinder E and opening fis
prevented by the piston head F, so that it accumulates under pressure in the
chamber D.
An excess of pressure at any time is relieved by the forcing back of the piston
head F and the escape of the gas through the opening f
The relative speeds of the pump B and clock work K are so regulated that, at
such times as it is desired to sound the signal, a sufficient quantity of gas is
accumulated in the chamber D, and the electrodes or contact points g g are
separated by the action of the clock work so that a spark passes between them.
The gas in the chamber.D is thus ignited and exploded, and the piston head Fis
driven backward in the cylinder E leaving the opening f free, through which the
products of combustion pass with much force, causing the signaling device to. be
loudly sounded. As the pressure decreases the piston head F is driven back to its
original position, by means of the spring G, thus forcing out more of the products
of combustion through the opening and prolonging the sound given, by the
sounding device. By varying the length of the cylinder E or the length of the
throw of the piston head in the cylinder, the length of the sound produced may be
varied, so that different specimens of the apparatus can be made to produce notes
or sounds of different lengths..
So long, as the pump B and the clock work K. continue to operate, the
chamber D will be filled with gas which will be exploded and the signal sounded
at regular intervals.
It will be evident that an explosive gas or mixture of gases other than a
mixture of gasoline vapor and atmospheric air, may be employed with the same
result, and I do not limit my invention in this respect to any particular gas or
mixture of gases.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I. declare that what I
claim is :
1. In an apparatus for producing audible signals the combination of an exploding
chamber and means for admitting explosive material thereto, a source of electricity
and electrodes connected therewith and projecting into such exploding chamber,
means for automatically separating the electrodes, a cylinder connected with such
exploding chamber, a spring actuated. piston in such cylinder, an opening from
such cylinder normally disconnected from the exploding chamber by said piston
and a sounding device connected with such opening, substantially as and for the
purposes set forth.
2. In an apparatus for producing audible signals, the combination with an
exploding chamber of a cylinder connected therewith, an: opening in the cylinder
leading to a sounding device, a piston head in the cylinder normally closing such
opening from the exploding chamber. and adapted to be driven backward past such
opening by the force of an explosion in. said "chamber, and a spring operating to
drive such piston head in the opposite direction, substantially as and for the purposes
set forth..
3. In an apparatus for producing audible signals, the combination of a gasoline
engine, a pump operated thereby, pipes.connecting such pump with a gasoline
supply tank and with an exploding chamber, a.check valve in the pipe connecting
the, pump, with such tank and an opening from the pump barrel. to. the outer air

page_text: provided with an outwardly closing valve, whereby liquid gasoline is drawn into
the pump barrel and therein vaporized and mixed with atmospheric air and the
gasoline product forced into the exploding chamber, means for igniting the vapor
in the exploding chamber and a sounding device adapted to be opened to the
exploding chamber by the force of the explosion therein, substantially as and for
the purposes set forth.
Dated this 25th day of May 1896.
CRUIKSHANK & FAIRWEATHER,
Chartered Patent Agents,
62 St. Vincent Street, Glasgow, Agents for the Applicant...