AN IMPROVED METALLIC MANOMETER
Year: 1855

page_text: LETTERS PATENT to Paul Eugène Charton, Watchmaker, of Troyes,
Town in the French Empire, for the Invention of "AN IMPROVED
METALLIC MANOMETER."
Sealed the 12th February 1856, and dated the 30th August 1855.
'
PROVISIONAL SPECIFICATION left by the said Paul Eugène Charton at
the Office of the Commissioners of Patents, with, bis Petition, on the
30th August 1855.
I, PAUL EUGENE CHARTON, Watchmaker, of Troyes, Town in the French
Empire, do hereby declare the nature of the said Invention for "AN IMPROVED
METALLIC MANOMETER" to be as follows:-
My improved manometer is worked by the direct action of steam or other
motive agent (the pressure of which is to be ascertained) without the employ-
ment of tubes, condensation water, or other intermediate means. It consists
of a dial fixed to one end of a cock or tap, the other end of which opens into
the generator. Between the dial and the body of the tap I fix a dish, and in
it a spiral spring, to the end of which is fitted a second spring, in the form of a
thin blade of steel; the further end of this steel blade is connected to the inner
end of the index needle. A recess is made under the dish, into which the
steam or other motive agent is admitted from the generator direct, and, pressing
against the bottom of the dish, raises or lowers the spiral spring, which exerts

page_text: a corresponding action on the second spring, and thereby moves the under
needle on its fixed centre, so as to indicate the pressure. A third spring blade,
fixed at one end on a stationary arm inside the dial, is connected at the other,
also to the lower end of the needle, and serves to bring the index needle back
to its original position. Or the spiral spring may be dispensed with, and the
dish may then be made to impart the action direct to the spring, which causes
the index needle to play round its centre.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Paul Eugene Charton in the Great Seal Patent Office on the
29th February 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PAUL
EUGENE CHARTON, Watchmaker, of Troyes, Town in the French Empire, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of August, in the year of our Lord One
thousand eight hundred and fifty-five, in the nineteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Paul Eugene Charton, Her special licence that I, the said Paul Eugene
Charton, my executors, administrators, and assigns, or such others as I, the
said Paul Eugene Charton, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "AN IMPROVED
METALLIC MANOMETER," upon the condition (amongst others) that I, the said
Paul Eugene Charton, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said Paul Eugene Charton, do hereby
declare the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement thereof, reference being had to the Drawings hereunto annexed,
that is to say-

page_text: The object of my Invention is to obtain an indication of the degrees of
vacuum and pressure in any kind of apparatus. I cause steam or gases to act
directly upon and depress or raise, as the case may be, a diaphragm or plate
of any suitable material, plane, convex, or concave, the motions of which are
conveyed and multiplied by a spring constructed specially for the purpose to an
indicating needle.
I collect the whole motion of the diaphragm at its centre, or at the inner
end of the concentrating spring, to transmit it from thence to an indicator of
any approved kind, by differently arranged levers and springs, based upon the
principle of a differential motion.
My manometer may be applied directly upon every description of steam and
motive power generator, upon cylinders, &c.
I will now proceed to describe the manner in which my Invention may be
carried into effect.
Figure 1, Sheet 1, is a sectional elevation, and Figure 2 a transverse
section, of an arrangement of a metallic manometer for locomotive engines,
stationary engines, and marine engines. A is a dial plate, of which Figure 3
is a front elevation on a smaller scale, fixed by bolts through a flange, or by
other suitable means, to the short flanged pipe B, as shewn by the plan,
Figure 4. The bottom flange of this pipe B is connected to a cock. The
flanges of A and B hold between them a thin copper plate a, dished, as shewn
at Figure 1, or nearly flat, as in Figure 6. This latter plan is economical, and
works easily. In or upon the plate a I place what I call a concentrating or
accumulating spring b, shewn separately in Figure 5. The spring 6 is in cast
or tempered steel, copper, or other metal, or other suitable substance; it is
arranged spirally, and tapers off from near its outer to its inner end, where it
terminates in a connecting piece f, upon which I fix a rod e, to the upper end
of which is fitted one end of a steel spring 9; the other end of this spring fits
into the needle d; another spring his held at one end in a fixed block i,
while its other end is also fitted into the needle d; the springs are held by
pins, screws, or keys. The needle d is free to oscillate between the degrees
marked on the scale (Fig. 3) under the influence of the spring g; but as soon
as this working action ceases, the fixed spring h comes into play, and restores
the needle to the zero point on the scale. Thus this needle oscillates according
to the difference of the position of the springs h, 9, (which are independent
of each other.)
Steam or other fluid passes from a generator or cylinder into the pipe B,
where it acts directly upon the plate a, from the bottom of which condensation
water falls as quickly as it is formed. The steam elevates the diaphragm a to

page_text: a height varying with its pressure, and the diaphragm conveys its rising
motions to the spring b, and this spring transmits these motions multiplied to
the needle d through the connecting piece f, the rod c, and spring g.
Figure 7 is a front view of a direct metallic manometer arranged as a pres-
sure or vacuum indicator: It is specially applicable to the cylinders of steam
engines, to shew the effect of the steam at the moment of its acting upon the
piston. Figure 8 is a side view of Figure 7, partly in section. The lower end of
the short junction pipe B is threaded, as at C, instead of being formed with a
flange for being fitted to a cock. The thread is intended to be screwed directly
into a cylinder or generator. This manometer is constantly under the influence
of the pressure, which it indicates continuously. In order to mark correctly
the effect of vacuum, I have made an opening in the inner end f of my con-
centrating spring, into which the rod centers. The part of the spring b is
held between the plate a and a nut k, which works upon the threaded portion
of the rod f. All the other arrangements. before described remain the same,
and the needle & works according to the difference in the curves of the springs
hand g, the one fixed and the other transmitting the variable indications of
pressure. To obtain as great susceptibility as possible the arrangement shewn
at Figure 9 may be adopted. Here the plate a is subjected to the influence of
the spring b, which receives directly the action of the steam. There is a
similar spring on each side of the flexible plate.
Figures 10 and 11 shew another arrangement of my Invention, with the
spring and flexible plate placed vertically instead of horizontally. I thus
obtain a manometer with a vertical diaphragm occupying a very small space.
As seen at Figure 10, the dial plate A is united to the steam channel B by a
joint, consisting of two pieces m, m, of cast iron, having a V groove to hold the
projecting parts n, n', of the dial A, and the steam pipe or chamber B. To fix
the two pieces m, m, and obtain a perfect joint, I heat a cast or wrought iron
or other metal hoop o, and shrink it round the pieces m, m, so as to occupy
the position shewn at Figures 12 and 13. The transmission of the oscillations
of the plate a is effected by the inner end f of the spiral spring b. The end f
acts upon a plate or piece p, fitted on the end of a spring g, fixed upon a
stationary block r. The lever s describes oscillations, and transmits them by
a blade v to a crank v¹, oscillating about a fixed axis u; upon the outer end
of this axis the needle d is also fixed.
Figures 14, 15, & 16 represent respectively a vertical section, side view,
partly in section, and front elevation, of a vacuum indicator, in which the
transmission of the movement of the diaphragm a to the indicating needle as
slightly modified.
The spring b is placed under the diaphragm a, held, as

page_text: before described, between the flange of the indicating dial A and the top of the
pipe B. A tube D, united to the pipe B by a nut F, opens a communication
between the chamber G, in which the spiral spring is placed, and the pneumatic
machines or other apparatus, in which the degree of vacuum is to be indicated..
The diaphragm a is made strong in its centre, is slightly dished, and has con-
nected to it a rod W, to the upper end of which is fixed one end of a spring z.
The other end of this spring is attached to the lever y, which oscillates round
a pin e, and by its motion causes a toothed quadrant to oscillate, which works.
a toothed pinion 2. This pinion is fixed on an axis 3, which also carries a
needle 4. The needle indicates the degree of vacuum upon the dial A. A
counterpoise 5 is fixed opposite to the tooth quadrant on the axis e, tends con-
stantly to equipoise the toothed quadrant, and acts in a direction opposite to
that of the spring 2.
I have also arranged my Invention as a steam indicator. Figure.17 is a
section, Figure 18 a plan, and Figure 19 a section, on the line A, B, of such
an indicator. a', 6', are two tubes, which allow of the apparatus being placed
vertically, laterally, or horizontally. The plate or diaphragm c', held by a hoop
joint, similar to that herein-before described, acts upon the spiral spring d.
A blade e¹ is fixed by a screw to the inner end of the spiral spring. The
opposite end of the blade is attached to a connecting piece 9', which causes a
lever h¹ to move to and fro. The upper end of this lever carries a tracer,
while its lower end is centred on a pin i on an axis j', which carries a vertical
table L', and is held by a fixed support M. The table L' is moveable upon
the axis j', and is caused to slide by a toothed rack m³, worked by a pinion u¹,
(see the detached view, Figure 20.) This pinion is moved by the pulley M,
which receives motion from any suitable moving part of the machine, and is
mounted upon the same axis as the pinion. The rod h¹ describes a curve,
varying with the pressure exerted by the fluid upon the flexible diaphragm c¹.
The pulley M is fitted in such manner as to turn loosely, and carry with it the
axis N only when revolving in a given direction.
Instead of a spiral spring, concentric rings of varying thicknesses, united
by a blade of steel or other metal, to accumulate at the centre the action of
all the rings, might be employed in any of the arrangements herein-before
described, though not with so great advantage as the spiral, concentrating,
5 or accumulating spring.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim,-
First, the employment in manometers of a thin diaphragm or plate of metal
or other suitable substance, resting upon or connected with a spiral spring of

page_text: metal or other substance, capable of modifying its curves to the degree of
pressure exerted by fluids, or the degree of vacuum.
Second, the employment in manometers of two springs acting differentially,
the one fixed to the case of the instrument, and acting as a resistance, the other
connected to the centre of the diaphragm, and representing the power, and
both connected to the needle in order to transmit the motion of the diaphragm
to and regulating the motion of the needle, as herein-before described.
Third, the general arrangement of the manometer, represented in Figures
1 and 2.
Fourth, the modifications thereof, represented at Figure 6, at Figures 7,
8, and 9, at Figures 10 and 11, at Figures 14, 15, and 16, and at Figures 17,
18, 19, and 20, and herein-before described.
In witness whereof, I, the said Paul Eugène Charton, have hereunto set
my hand and seal, this Twelfth day of February, One thousand
eight hundred and fifty-six.
Witness,
CH. ARMENGAUD, Ing" Civil,
Rue des Filles du Calvaire, 6, à Paris.
P. E. CHARTON. (L.S.)