AN IMPROVED MECHANICAL APPARATUS FOR INDI- CATING BY CLOCKWORK THE EXCESSIVE PRESSURES OF LIGHTING GAS
Year: 1874

page_text: PROVISIONAL SPECIFICATION left by Eugéne Henri Hache at the
Office of the Commissioners of Patents, with his Petition, on the
16th July 1874.
I, EUGENE HENRI HACHE, of the firm Hache et Cie., of Boulevard
de Strasbourg, 23, at Paris, Manufacturers, do hereby declare the nature
of the said Invention for "AN IMPROVED MECHANICAL APPARATUS FOR INDI-
CATING BY CLOCKWORK THE EXCESSIVE PRESSURES OF LIGHTING GAS," to be as
follows:-
It is well known in all establishments lighted by gas the closing of
some burner or their extinction in neighbouring establishments causes
sudden increase in the pressure of gas in the burners which remain
lighted. These burners begin to shoot out or produce a disagreeable:
hissing sound, and the light which they furnish ceases to be in-
proportion to the supply of gas which is considerably augmented with
the pressure. It is rare that this improper condition is at once perceived;
and before the remedy is applied, time sufficient has elapsed to allow of
a considerable waste of gas, which repeated daily, amounts at the end of
a month or so to a considerable sum to be needlessly paid to the
supplying company. All these inconveniences and waste would be

page_text: obviated if by some
means one could be warned in time of the
alteration in the pressure of the gas, and if it could be at once corrected
by turning the cock which commands the supply throughout the
establishment. It is this object which I propose to attain with
the apparatus which forms the subject of my Invention, and which
may be called
"the mechanical bell warner." The idea of drawing
attention to the variations of the pressure of gas by means of bells has
already been put in practice on several occasions, but the apparatus
employed, either alone or in combination with electric regulators,
require a too delicate handling and have a too trifling action to succeed
practically. In the new system on the other hand recourse is only
necessary to mechanical action in order to transmit the variation in the
elastic force of the gas to the bell apparatus. Such is the combination
which characterizes the present Invention.
The apparatus consists of three principle parts, a manometer, a
clock movement with a bell put in communication by a balanced lever
or float the whole enclosed in a case from whence only the bell with its
hammer is excluded.
:
The manometer is arranged as follows: It comprises a receiver of
glass which is held within the apparatus by a little partition and is
provided externally with a graduated band. In its cover is fixed
invariably at the middle of the receiver a long glass tube which descends
nearly to the bottom of the latter. To the lower end of this tube is
fixed an armature or metallic case carrying a tube which debouches at
the top in order to receive a flask or bottle, intended to maintain the
constant level corresponding to zero in the graduated scale upon the
receiver. The flask consists of a glass gauge provided with the
armatures, the lower one of which serves it as a bottom and is in a piece
with the tube, while the other is provided with a loop piece with the
grooved holes constituting a sort of bayonet closing very easy to open
and shut. The tube descends nearly to the bottom of the other tube,
and contains a small rod or triangle, which carries at its top the closing
valve, which abutting against the closing stock and against the bottom of
the branch of the tube maintains the valve open. By this arrangement
the constant level of the liquid is assured, and the mounting and dis-
mounting of the flask is effected with great facility without the escape
of even a drop of water. The float is formed by a long metallic hollow,
cylinder which is provided exteriorly with little fingers, intended to

page_text: prevent it from rubbing against the partition of the tube, which would
diminish its sensibility. This float is provided at its top with a handle,
by the aid of which it is attached to the rock lever already mentioned.
This rock lever is supported at the place of its articulation upon a cap
forming a body with a square piece, which is adapted upon the metallic
armature of the top of the tube. At its hinder part the lever is curved
upwards, and is closed in a sort of case in which a lining of leather,
caoutchouc, or other convenient flexible material is embedded. The
lever carries a counterweight by the aid of which the movement for the
action of the bell is regulated with all desirable precision.
It is unnecessary to describe the clockwork movement which presents
no peculiarity. It is arranged so as to actuate the hammer which
produces the sounding, by striking with successive blows upon the
bell.
From the preceding description it is easy to understand the simple
and certain action of the apparatus. As soon as in the establishment
where it may be placed the pressure of gas rises above what is usual
and necessary the level of the coloured water rises in the manometer
tube and draws the float in its ascending movement. As soon as tho
float mounts the lever moves upon its axis, and descending permits the
escape of the disc. Immediately the mechanism causes the sounding of
the bell, and by hearing it one is warned that it is necessary to go to the
key of entrance cock and turn it, so as to diminish the delivery of
the gas. This will occur every time when in the establishment or outside
there is an extinction of a sufficient number of burners to give rise to an
injurious or useless excess of pressure.
The apparatus will be easily regulated for a given excess with the aid
of a counterweight. As to the liquid of the manometer, the waste pro-
ceeding from the evaporation will be found compensated by the water of
the little reservoir or flask.