AN IMPROVED METALLIC MANOMETER
Year: 1869

page_text: LETTERS PATENT to Ferdinand Delacroix, of Paris, Boulevard de
Strasbourg, 23, Mechanician, for the Invention of "AN IMPROVED
METALLIC MANOMETER."
Sealed the 16th May 1870, and dated the 16th November 1869.
PROVISIONAL SPECIFICATION left by the said Ferdinand Delacroix
at the Office of the Commissioners of Patents, with his Petition, on
the 16th November 1869.
I, FERDINAND DELACROIX, of Paris, Boulevard de Strasbourg, 23,
Mechanician, do hereby declare the nature of the said Invention for "AN
IMPROVED METALLIC MANOMETER," to be as follows:-
The important part which the manometer plays in the action of
boilers renders it an instrument of the highest importance. Since the
appearance of the first metallic manometer, of which M. Bourdon was
the inventor, many attempts have been made to contrive instruments
of this description which would avoid the faults of the first one, but I
know of none which will indicate correctly the slighter fluctuations of
the pressure.

page_text: In order to make an instrument as nearly perfect as may be the
following questions must be resolved:―
First. The construction of a metallic manometer of great simplicity
and at the same time of the greatest sensibility.
Secondly. To produce it at a low price and consequently to make its
parts few and simple.
Thirdly. To render it easy of repair and without requiring special skill
for that purpose.
Fourthly and lastly. To fix the needle by attaching it to one of
the rigid organs of the movement so that it may be free from all
vibration.
The manometer I have contrived fulfils all the above conditions. It
consists of a principal frame upon which a cock is screwed fix to the
interior surface of a box by means of two screws, the frame upon which
all the mechanism is hung is pierced throughout its length in order to
permit the steam to proceed to its upper part, and enter a chamber
formed in a box. Upon one of the faces of this box at and down to
the half of its length a large orifice is made which forms a bearing in
which a circular membrane or diaphragm which may be of metal or
simply of caoutchouc is fitted. This membrane is strongly pressed
upon its bearing by a screwed collar or ring which makes with it a
hermetic joint. The vertical arrangement of this membrane and the
facility of replacing it instantly are two essential points of my Invention.
A picce in the form of a piston enters frecly into the screw collar or
ring and presses on the one side upon the membrane and upon the
other upon a spring which may be considered the fundamental piece of
the new manometer. This spring lever, which is of a looped or bent
over form, is attached by one of its legs to the rear part of the box, the
other leg carries in line with the axis of the membrane an adjustable
screw, which should always be in contact with the piece, so that the
least effect exercised upon the membrane must necessarily act upon
the spring, the longer leg of which carries the adjusting screw and
terminates in a rigid lever arm attached to the rod which communicates
its movement to a sector and pinion intended to actuate the needle..
There results from the arrangement just described that it is sufficient
for a slight depression of the membrane to cause a complete revolution
of the needle or index hand.

page_text: A very simple mode of actuating the needle without a sector is as
follows: I attach the arm which is connected to the spring to work the
needle direct.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Ferdinand Delacroix in the Great Seal Patent
Office on the 16th May 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME; I, FERDINAND
DELACROIX, of Paris, Boulevard de Strasbourg, 23, Mechanician, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of November, in the year
of our Lord. One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors, givo
and grant unto me, the said Ferdinand Delacroix, Her special licence
that I, the said Ferdinand Delacroix, my executors, administrators, and
assigns, or such others as I, the said Ferdinand Delacroix, 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 MANO-
METER," upon the condition (amongst others) that I, the said Ferdinand
Delacroix, 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 Scal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Ferdinand Delacroix, 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 :-
The important part which a manometer plays in the action of boilers
renders it an instrument of the highest importance. Since the appearance

page_text: of the first metallic manometer, of which M. Bourdon was the inventor,
many attempts have been made to contrive instruments of this de-
scription, which would avoid the faults of the first one, but I know
of none which will indicate correctly the slighter fluctuations of
pressure.
In order to make an instrument as nearly perfect as may be the
following questions must be resolved:―
1st. The construction of a metallic manometer of great simplicity
and at the same time of the greatest sensibility.
2ndly. To produce it at a low price and consequently to make its
parts few and simple.
3rdly. To render it easy of repair and without requiring special skill
for that purpose.
4thly, and lastly. To fix the needle by attaching it to one of the rigid
organs of the movement, so that it may be free from all vibration.
The manometer I have contrived fulfils all the above conditions, and
I proceed to describe it with reference to the annexed Drawings. It
consists of a principal frame A upon which a cock R is screwed, fixed
to the interior surface of a box B by means of two screws V, V. The
frame A, Figure 1, upon which all the mechanism is hung is pierced
throughout its length in order to permit the steam to proceed to its
upper part C, and enter a chamber formed in a box. Upon one of the
faces of this box at and down to the half of its length a large orifice is
made which forms a bearing in which a circular membrane or diaphragm
which may be of metal or simply of caoutchouc is fitted. This
membrane is strongly pressed upon its bearing by a screwed collar or
ring E which makes with it a hermetic joint. The vertical arrangement
of this membrane and the facility of replacing it instantly, are two
essential points of my Invention. A piece P in the form of a piston
enters freely into the screw collar or ring E and presses on the one side
upon the membrane M and upon the other upon a spring R', which may
be considered the fundamental piece of the new manometer. This spring
lever R' which is of a looped or bent over form is attached by one of its
logs F to the rear part of the box C, the other leg G carries in line with
the axis of the membrane an adjustable screw V', which should always be
in contact with the piece P, so that the least effect exercised upon the
membrane M must necessarily act upon tlic spring R', the longer leg G

page_text: of which carries the adjusting screw and terminates in a rigid lever arm
attached to the rod H which communicates its movement to a sector
and pinion S intended to actuate the needle.
There results from the arrangement just described that it is sufficient
for a slight depression of the membrane M to cause a complete revolution
of the needle or index hand.
Figure 2 shows a very simple mode of actuating the needle without
a sector which is as follows:-I attach the arm which is connected to
the spring to work the needle direct. I may make the spring lever R¹
of one or several parts, and I may place it either to the right or to the left
of the box which carries the elastic membrane.
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 the
manufacture and employment of my improved metallic manometer,
substantially as herein-before described and illustrated in the accom-
panying Drawings.
In witness whereof, I, the said Ferdinand Delacroix, have here.
unto set my hand and scal, this Eighth day of May One thousand
cight hundred and seventy.
FERDINAND DELACROIX. (L.S.)
Witness,
CH. ARMENGAUD,
Eng. Civil,
Boulevard de Strasbourg, 23,
à Paris.