IMPROVEMENTS IN GAS PRESSURE REGISTERS."
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by the said Ernest Pierre Brouardel at
the Office of the Commissioners of Patents on the 31st January 1880.
ERNEST PIERRE BROUARDEL, Merchant, of Paris, France. IMPROVEMENTS IN
GAS PRESSURE REGISTERS."
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This Invention has for its object the construction of gas pressure registers in such
a manner that while ensuring efficiency they may be made much smaller, more
portable, and less expensive than is now ordinarily the case.
The Invention consists of a hollow cylinder mounted upon a base, and free to
turn upon a vertical axis. Within the cylinder and at its lower part there is fixed
a metal plate, between which and the bottom of the cylinder a piece of clockwork
to give motion to the cylinder and mark time is placed. Externally and on each
side of the cylinder rises a hollow column, the tops of which are connected together
by a transverse bar or plate. To this bar or plate is fixed the gas inlet pipe, which
depends therefrom and supports at its lower end the pressure chamber, which
consists of a cylinder closed at the bottom, and of a somewhat smaller diameter
than the cylinder first mentioned. The top of the pressure chamber is covered by
a flexible diaphragm of ample dimensions, so that it, together with a plate fixed to
its centre, is free to rise and fall with the pressure of the gas admitted to the
chamber. The flexible diaphragm, besides being fixed to the top edge of the
chamber, is suspended by a strong silken or other suitable thread, which passes
through the transverse bar or plate, and is wound round a reel or pulley, upon the
axis of which is another and larger reel or pulley placed immediately over the
centre of one of the columns. Between the transverse bar or plate, and the plate
fixed to the centre of the diaphragm is attached a spiral spring. To the largest of
the two pullies is fixed another strong silken or other suitable thread, one extremity
of which passes into the interior of the column, and is fastened to a weight, while
the other extremity is attached to a little carriage that is free to rise and fall upon
a suitable guide on the outside of the column. Pivotted to this carriage is a pen,
which presses against the cylinder, and is supplied with non-drying ink. The
cylinder first mentioned has wrapped round and secured to it a sheet of paper

page_text: printed with vertical lines, representing the hours, half hours, and quarters, while
similar lines ruled horizontally indicate the pressure in tenths of an inch of water.
The whole instrument may be enclosed in a case furnished with a handle for con-
venience in carrying it about, or a suitable handle may be otherwise fixed to it for
the same purpose.
The action of the instrument is exceedingly simple, and is as follows:-The
clock work being wound up by a knob or button placed in the thickness of the base
is made to revolve once in twenty four hours. On gas being admitted to the
pressure chamber it causes the plate that is fixed to the flexible diaphragm to rise,
and by virtue of the weight fixed to the thread within the column the pullies are
made to revolve, the small pulley taking up the slack of the thread attached to the
plate, while the other larger pulley winds up the carriage and with it the pen until
it attains a height corresponding to the pressure marked on the paper surrounding
the cylinder. It will be seen therefore that as the paper revolves a continuous line
will be marked thereon corresponding with the variations of pressure during the
twenty-four hours, and this record showing the exact pressure at any particular
time may then be taken off and preserved for future reference.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Ernest Pierre Brouardel in the Great Seal Patent Office on the 30th July
1880.
ERNEST PIERRE BROUARDEL, of Paris, France.
PRESSURE REGISTERS."
"IMPROVEMENTS IN GAS
Pressure registers are employed to represent definitely the variations of the
pressure of gas, either in the works at different points of and during different
phases of the manufacture, or at a point or points in the course of the distributing
mains. Those which are actually in use are hydraulic ones, heavy and inconvenient,
and practically impossible to transport from place to place either in the works or
along the route of the mains.
The object of my Invention is the construction of an apparatus reduced in size,
easily transportable, and at a very slightly increased price. The distinct represen-
tations of the pressures are made upon a cylinder which encloses within its interior
some of the principal moving parts or organs of the pressure register. The details
of construction may be modified and applied to any kind of pressure register, but I
prefer the form of apparatus represented in the Drawings attached.
The dry apparatus is shown in part sectional elevation. Fig. 1 and Fig. 2 is a
section following the line from M to N of the right hand column which supports
the apparatus. My pressure register consists of a principal cylinder A made of
metal, and furnished interiorly towards its lower part with a shoulder a used to
support the plate Z, which is attached to a clockwork movement H. This plate Z
takes the place of the hands of a clock, and makes one revolution within a given

page_text: time, say once in 24 hours for example. The movement H thus occupies the lower
part of the cylinder, and is wound up by means of a knob or button B placed
underneath in the thickness of the socle D, which is hollowed out at this part.
On each side of the cylinder A the columns C, C³, rise, and are united at their top
extremities by a transverse plate E, which at the same time covers the top opening
of the cylinder A, but without touching it, in order to avoid impeding its rotation.
The upper part of the cylinder contains an inner cylinder X, which is placed in
communication with the outside with the gas inlet pipe or any point of the works
by means of a tube b, which is furnished if necessary with a cock G. Near the
upper part of the cylinder X a circular membrane or diaphragm J of ample dimen-
sions is fixed all round by its outer edge, and so closes the cylinder hermetically.
This diaphragm takes the form of a basin after having been first blown out or inflated.
In the middle of the diaphragm is placed a small plate K suspended by a strong
silk cord x. A spiral spring R is supported from below by the plate K, and from
above by the plate E. This spiral spring is large enough in diameter to prevent the
rubbing of the cord x against the guide. It will be seen that a pressure coming
from the outside, from a gas pipe for example, by the tube b will operate upon
the diaphragm J, which raises the plate K and compresses the spiral spring in
proportion to the pressure.
The pressure is indicated outside by the following means:-The cord x which
suspends the plate K traverses the plate E, and is wound upon a small pulley L
which is fixed upon the same arbor as another larger pulley M placed above the
column C¹. Upon this latter pulley M another silk thread y is fixed towards its
middle. One of the extremities enters into the interior of the column C¹, while
the other hangs outside and in front. To the extremity which hangs inside the
column is suspended a little weight P intended to counterpoise the weight of K and
that of the carriage which is attached to the front extremity of the cord y. The
carriage is composed of two cross pieces c, c¹, united by the legs or shanks d, d, and
guided by the vertical rod f. The cord y is attached to a ring 9, and the upper
cross piece carries a gudgeon h, which serves to support a writing pen. This pen,
shown at i, is attached to a shank ; terminated by a hook k, so that the pen simply
suspended tends to descend and consequently leans or presses lightly upon the
surface of the cylinder A. The pen i is conveniently supplied with a special ink
that does not dry.
It will be seen now that if there is any pressure in the cylinder X the silk
thread x which supports the bell K will roll itself upon the pulley L under the
influence of the counterpoise which is in the column C', and that the carriage will
rise, at the same time it will also rise in the proportion of the difference between
the two pulleys L and M. This very simple arrangement necessitates only one
axle being employed for the transmission of motion.
To make use of the apparatus there is applied to the exterior cylinder A a sheet
of paper, upon which has already been printed a number of vertical divisions
indicating the hours, and horizontal divisions representing tenths or hundredths of
an inch of water or mercury, according to the use to which the apparatus is applied
in practise. After each revolution of the cylinder the paper is taken off and shows
the exact pressure exerted at any moment during the day.
In place of the membraneous or flexible diaphragm a movable bell working in
liquid, such as water, oil, or mercury, can be used. Also in lieu of the spring a
special curb fixed upon the axis of the transmission pullies, and of which the lever
arms increase with the variations of the height of the movable plate fixed to the
diaphragm.
Fig. 3 in the Drawings represents a vertical section of a liquid pressure register.
The revolving cylinder A, upon which is rolled the sheet of paper, is divided into
two compartments by a partition c, in which is placed a tube d that opens into
one of the compartments. It is by this tube d that the gas coming from the pipe e
enters, and by its pressure upon the liquid in the first compartment causes it to
rise in the other, for the two compartments communicate at the lower part at f. The

page_text: variations of level are transmitted to a float g, to which is fastened a cord k that
passes round the return pulley 1, descends in the tube m placed in the centre of the
drum A, and is wound upon the pulley N. The movement is transmitted to the
pen, as in the preceding apparatus. The clock work is placed horizontally above
the drum, but it could be equally well placed below it.
In the fixed dry pressure registers the button for winding up the clock can be
attached to the side of the instrument.
These instruments recommend themselves particularly for the following
advantages:-Greatly reduced volume, especially in comparison with analagous
apparatus made up to the present time; also by means of the handle S they can be
removed and carried about easily; great lightness, the total weight.not exceeding about
six and a half pounds; security for the moving parts J, K, R, which being enclosed
are not liable to be touched or to dust; the pullies L and M can be protected by a
cover; absence of all liquid in the dry pressure register, which makes the apparatus
always ready for use, and always regulated as to level, since the spring is constant;
the employment of ink instead of pencil, which renders impossible the accidental or
fraudulent disfiguration of the records; and, lastly, they can be supplied at a price
which no other analagous apparatus can approach.
This system of apparatus can be adapted to measure the pressure of water, steam,
or gas by simply modifying the resistance and dimensions of the organs.
Having now described and particularly set forth the nature of this Invention,
and the manner in which the same is or may be used or carried into effect, I would
observe in conclusion that I do not confine or restrict myself to the precise details
or arrangements which I have described or referred to, as variations may be made
therefrom without deviating from the principles or main features of this Invention ;
but what I consider to be novel and original and therefore claim as the Invention
secured to me by the hereinbefore in part recited Letters Patent is,―
First. The arrangement of the drum or cylinder, upon which is rolled the sheet
of paper which receives the tracing from the organs of the pressure register, and
of the clockwork which permits of the apparatus being made in a reduced and light
form, as herein described and shown on the Drawings, Figs. 1 and 2.
Second. The arrangement of the membrane or flexible diaphragm and spiral
spring in the interior of the dry pressure register, as herein described and shown on
the Drawing, Fig. 1.
Third. The horizontal arrangement of the clockwork within the movable drum,
as herein described and shown on the Drawing at Fig. 1.
Fourth. The arrangement of the carriage, guide, and pen and their connection
with the pressure gauge inside, as herein described and shown on the Drawings at
Figs. 1 and 2.
Fifth. The general details of the construction of the apparatus, as herein described
and shown on the Drawings at Figs. 1 and 2.
In witness whereof, I, the said Ernest Pierre Brouardel, have hereunto set
my hand and seal, this Twenty seventh day of July, in the year of our Lord
One thousand eight hundred and eighty.
Witness,
ERNEST PIERRE BROUARDEL. (L.S.)
JULES ARMENGAUD JEUNE,
of Paris,
Boulevard de Strasbourg, No. 23,
Civil Engineer.