IMPROVEMENTS IN GAUGES FOR INDICATING THE PRESSURE OF STEAM AND OTHER FLUIDS
Year: 1868

page_text: LETTERS PATENT to Alphonse Lafargue, of No. 13, Pine Street,
Newcastle-on-Tyne, Engineer, for the Invention of "IMPROVEMENTS
IN GAUGES FOR INDICATING THE PRESSURE OF STEAM AND OTHER
FLUIDS."
Sealed the 19th March 1869, and dated the 30th September 1868.
PROVISIONAL SPECIFICATION left by the said Alphonse Lafargue at
the Office of the Commissioners of Patents, with his Petition, on
the 30th September 1868.
I, ALPHONSE LAFARGUE, of No. 13, Pine Street, Newcastle-on-
Tyne, Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN GAUGES FOR INDICATING THE PRESSURE OF STEAM AND
OTHER FLUIDS," to be as follows:-
The object of the Invention is simplicity of construction and certainty
in the indications made under varying temperatures and pressures. For
this purpose the fluid, the pressure of which is to be indicated, acts in
a cylinder upon a piston or plunger, the rod of which by rack and
pinion, or otherwise, operates a pointer, and at the same time by arms

page_text: and pulleys or studs the piston rod acts on weighted levers, causing them
to move from a position vertical, or nearly so, to a horizontal one,
dependent on the pressure applied in relation to the weights of the
levers. I find it convenient for the studs or pulleys to move in slotted
openings in the weighted levers inclined inwards to the centre. An
extra indicating hand or dead pointer is moved forward with the one
pointer to indicate the pressure of steam when blowing off; it may also
be used when indicating water pressure.
Lalso only a whistle to give alarm at any desired pressure
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alphonse Lafargue in the Great Seal Patent
Office on the 29th March 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALPHONSE
LAFARGUE, of No. 13, Pine Street, Newcastle-on-Tyne, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of September, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Alphonse Lafargue, Her special licence that I,
the said Alphonse Lafargue, my executors, administrators, and assigns, or
such others as I, the said Alphonse Lafargue, 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 "IMPROVEMENTS IN GAUGES FOR INDICATING THE
PRESSURE OF STEAM AND OTHER FLUIDS," upon the condition (amongst
others) that I, the said Alphonse Lafargue, my executors or admi-
nistrators, 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.

page_text: NOW KNOW YE, that I, the said Alphonse Lafargue, do hereby declare
the nature of the 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, that is to say :-
The object of the Invention is simplicity of construction and certainty
in the indications made under varying temperatures and pressures. For
this purpose the fluid, the pressure of which is to be indicated, acts in a
cylinder upon a piston or plunger, the rod of which by rack and pinion,
or otherwise, operates a pointer, and at the same time by arms and
pulleys or studs the piston rod acts on weighted levers, causing them to
move from a position vertical, or nearly so, to a horizontal one, dependent
on the pressure applied in relation to the weights of the levers. I find
it convenient for the studs or pulleys to move in slotted openings in the
weighted levers inclined inwards to the centre.
An extra indicating
ad or dead pointer may be employed and moved forward with the
one pointer to indicate the pressure of steam when blowing off; it
may also be used when indicating water pressure.
I also in some cases apply a whistle to give alarm at any desired
pressure.
But that the Invention may be fully understood I will by the aid of
the accompanying Drawings proceed to describe means pursued by me
in carrying the same into effect.
DESCRIPTION OF THE DRAWINGS.
Figure 1 shows an internal front view, Figure 2 a transverse section,
and Figure 3 a front view of apparatus arranged according to my
Invention. In each of the Figures the same letters indicate corre
sponding parts wherever they occur.
a is the piston or plunger upon which the fluid, the pressure of which is
to be indicated, acts, but the form of the piston used may be varied; and
in place of a plunger closely fitting in a cylinder b, as shown, a piston
of the form of a flexible diaphragm may be used, or a flexible diaphragm
may be used for the fluid (the pressure of which is to be indicated) to
act upon with another fluid between that diaphragm and a piston or
plunger acting direct on the apparatus. The rod c of the piston or
plunger a is formed with arms d, d, with pins or studs and pulleys e, e,
which act in the slots f¹, f¹, formed in the lever arms f, f, which are
supported each at one end to turn on the axes or centres of motion f",

page_text: and at their other ends carry the weights f³, f³, which as pressure is
exerted on the under side of the piston or plunger a with a tendency
to raise it tend at the same time by their weight to keep it down. As
the pressure on the under side of the piston or plunger increases, the
weighted ends f* of the lever arms are raised until they arrive at a
horizontal position, or nearly so, as indicated by blue lines in Figure 1.
The axis of one of the lever arms fis formed with a segment or rack f4,
the teeth of which take into the teeth of a pinion i fixed to an axis or
spindle g, which is supported to turn in suitable stationary bearings j,
and upon which axis is also fixed the pointer hand h for indicating on
the dial the pressure for the time being exerted.
Having thus described my Invention, and means which I adopt in
carrying the same into effect, I would have it understood that what I
claim is, the arranging or combining parts of apparatus forming gauges
for indicating the pressure of steam and other fluids, substantially as
described.
In witness whereof, I, the said Alphonse Lafargue, have here-
unto set my hand and seal, this Twenty-fifth day of March, in
the year of our Lord One thousand eight hundred and sixty-
nine.
ALPHONSE LAFARGUE. (L.S.)