IMPROVEMENTS IN PRESSURE GUAGES
Year: 1858

page_text: LETTERS PATENT to Charles Henry Chadburn, of Liverpool, in the
County of Lancaster, Optician, for the Invention of "IMPROVEMENTS IN
PRESSURE GUAGES."
Sealed the 12th October 1858 in pursuance of an Order of the Lord Chancellor,
1105
PROVISIONAL SPECIFICATION left by the said Charles Henry Chadburn
at the Office of the Commissioners of Patents, with his Petition, on
the 6th April 1858.
I, CHARLES HENRY CHADBURN, of Liverpool, in the County of Lancaster,
Optician, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN PRESSURE GUAGES," to be as follows (that is to say) :-
This Invention is applicable to guages which are used to measure the
internal or external pressure to which they are exposed, such as pressure or
vacuum guages for steam engines, &c., barometers, thermometers, and other
like instruments.
A pressure or vacuum guage constructed according to this Invention,
consists of a box or chamber formed of brass or other suitable elastic material,
being in plan a parallelogram, or approaching thereto, and in cross section
partaking of the oval or flattened oval, the extremities being enclosed by stout
pieces of metal, serving to keep the instrument in shape when not acted upon
by pressure. This chamber or box is connected by the centre of one of its
broad or flatted sides to, say, a steam boiler, by means of a pipe which forms

page_text: a passage between the interior of the boiler and the interior of the elastic box.
On the outside of the chamber, and immediately opposite to where the steam
passage opens into the box, a small rod, arm, or crank, is placed, which abuts
against or is fixed to the surface thereof at a right angle to the axis of the
chamber, which carries a rack or other mechanical equivalent, which works an
index hand travelling on the surface of a suitably graduated scale. Steam
from the boiler being allowed to enter the chamber by its expansive power,
causes the broader or flattened elastic sides of the chamber to separate from
each other, forming arcs in the direction of the length of the box, the edges
and ends being drawn slightly towards each other, by which motion the pro-
jecting rod or arm which works the index pointer is forced forward, and
lenotes the steam pressure within the boiler. Should this instrument be
attached to the condenser of a steam engine, &c., a vacuum or partial vacuum
being formed within the elastic chamber, the broad sides will be pressed
towards each other by the external pressure of the atmosphere; the projecting
arm working the index hand will recede, causing the index pointer to take a
backward direction from the resting point on the index dial, a graduated scale
being marked thereon to show the amount of vacuum in the condenser.
When this Invention is applied to a barometer, the only difference between
its construction and the pressure or vacuum guage, herein-before described, is
that in place of being fitted to a pipe connecting it with the boiler or con-
denser, the elastic chamber having the air exhausted therefrom is hermetically
sealed, care being taken to place the chamber in such a position that the
elastic sides will have liberty to expand and contract freely. A thermometer
may be constructed in the same way, except in place of exhausting the air from
the elastic chamber it is filled with alcohol, or any of the various liquids now
used to fill thermometer tubes. The instrument may also be rendered
applicable to indicate the amount of pressure of solids as well as fluids.
SPECIFICATION filed in pursuance of the conditions of the Letters Patent,
and of an Order of the Lord Chancellor, by the said Charles Henry 3
Chadburn in the Great Seal Patent Office on the 20th October 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
HENRY CHADBURN, of Liverpool, in the County of Lancaster, Optician, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters 3.
Patent, bearing date the Sixth day of April, in the year of our Lord One

page_text: thousand eight hundred and fifty-eight, in the twenty-first year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Charles Henry Chadburn, Her special licence that I, the said Charles
Henry Chadburn, my executors, administrators, and assigns, or such others
as I, the said Charles Henry Chadburn, 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 PRESSURE GAUGES," upon the condition (amongst others)
that I, the said Charles Henry Chadburn, 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 on or before the Twentieth day of
October, One thousand cight hundred and fifty-eight.
NOW KNOW YE, that I, the said Charles Henry Chadburn, do hereby
declare the nature of my said Invention, and in what manuer the same is
to be performed, to be particularly described and ascertained in and by the
following statement (that is to say):-
This my said Invention is applicable to gauges which are used to measure
the internal or external pressure to which they are exposed, such as pressure
or vacuum gauges for steam engines, &c., barometers, thermometers, and
other like instruments, as well as to the weighing of solids.
A pressure or vacuum gauge constructed according to this Invention
consists of a box or chamber formed of brass, or other suitable elastic material
(which may be electro-plated to prevent oxidation, if preferred), being in plan
a parallelogram, approaching thereto, and in cross section partaking of the
oval or flattened oval, the extremities being enclosed by stout pieces of metal,
serving to keep the instrument in shape when not acted upon by pressure.
This chamber or box is connected the centre of one of its broad or flatted
sides to, say, a steam boiler, by means of a pipe, which forms a passage
between the interior of the boiler and the interior of the elastic box. On
the outside of the chamber and immediately opposite to whero the steam
passage opens into the box, a small rod, arm, or crank is placed, which abuts
against or is fixed to the surface thereof, at a right angle to the axis of the
chamber, which carries a rack or other mechanical equivalent, which works
an index hand, travelling on the surface of a suitably graduated scale. Steam
from the boiler being allowed to enter the chamber, by its expansive power

page_text: causes the broader or flattened elastic sides of the chamber to separate from
each other, forming arcs in the direction of the length of the box, the edges
and ends being drawn slightly towards each other, whereby the section of the
centre of the box assumes a more circular form, by which motion the pro-
jecting rod or arm which works the index pointer is forced forward, and
denotes the steam pressure within the boiler. When this instrument is
attached to the condenser of a steam engine, and a vacuum or partial vacuum
being formed within the elastic chamber, the broad sides will be pressed
towards each other by the external pressure of the atmosphere, and the pro-
jecting arm working the index hand will recede, causing the index pointer to
take a backward direction from the resting point on the index dial, a graduated
scale being marked thereon to show the amount of vacuum in the condenser.
When I apply this my said Invention to a barometer, the only difference
between its construction and the pressure or vacuum guage herein-before
described is, that in place of the elastic box or chamber described being
fitted to a pipe connecting it with a boiler or condenser, I exhaust the air
from the box or chamber; then I hermetically seal it, taking care to place
the chamber in such a position that the elastic sides will have liberty to expand
and contract freely. A thermometer may be constructed in the same way,
except in place of exhausting the air from the elastic chamber. I fill it with
alcohol or any of the various fluids now used to fill thermometers tubes.
When I apply this my said Invention to indicate the weight of solids, I use
the elastic sided box or chamber herebefore described in combination with a
cylinder or other suitably shaped vessel, fitted with a piston, plunger, or ram,
which works up and down therein, and which elastic sided box I connect to
the cylinder by means of a pipe or other suitable passage which extends from
the bottom of the cylinder (or other suitable vessel), and enters the elastic
sided box at the centre of one of its flatted sides. I then fill with water or
other suitable fluid the cylinder (below the piston), the elastic sided box, and
the passage which communicates between them. By this arrangement it will
be readily seen that any pressure applied to the piston, plung, or ram working
within the cylinder will immediately be communicated to the clastic sided box,
which actuates an index pointer which works on the face of a suitably gra-
duated index dial, as herein before described. When this my said Invention is
used as a steam gauge, two, four, or any number of cylinders with their
appurtenancies may be used in place of one, by connecting them to one of the
elastic sided box by pipes or other convenient passages, so as to act on the
gauge box collectively. If preferred, a second elastic sided box, or diaphragm,
or other suitably shaped gauge may be used to receive and communicate

page_text: pressure to the elastic sided box used to actuate the index pointer in place of
the cylinder, and so forth, as herein-before described.
That this my said Invention may be the more readily seen and understood,
I have hereunto annexed Drawings in partial illustration of the practical
application of the same when applied to a steam vacuum gauge, and as
instruments for weighing ponderables, like letters marked thereon having
reference to similar parts.
Figure 1 (Sheet A) is a front elevation of my Invention applied to a
pressure or vacuum gauge showing the instrument at rest; Figure 2 (Sheet A)
is a front clovation of the elastic sided box as it would appear when acted upon
by internal pressure; Figure 3 (Sheet A) is a plan of the elastic sided box.
The internal dotted lines (G) show the profile of the box when acted upon by
internal pressure, and the external dotted lines (H) show the form the box
will take when acted upon by external pressure; Figure 4 (Sheet A) is a
perspective view of the elastic sided box; Figuro 5 (Sheet A) is a vertical cross
section of ditto; Figure 6 (Sheet B) shows a front elevation of a pressure and
vacuum gauge, having two of the elastic sided oval boxes used in its con-
struction to give a greater motion to the rod or arm which actuates the index
pointer; Figure 7 (Sheet B) shows a front elevation of my Invention applied
to an instrument for weighing ponderables, which consist of a cylinder fitted
with a solid ram upon which the articles to be weighed are placed, and the
weight of which is communicated to the clastic sided oval box by the water
pressed from the cylinder by the down action of the ram; Figure 8 (Sheet B)
is a front elevation of a weighing machine constructed according to my Inven-
tion, having four cylinders which collectively communicate with the elastic
sided box by pipes which diverge into one before entering the gauge box.
A, an oval clastic sided box, or chamber form, of brass or other suitable
elastic material; a, hoops used to securo and strengthen the ends of ditto;
B, a pipe communicating with the the steam boiler or condenser when used as
in ordinary pressure or vacuum gauge, or with the interior of a cylinder con-
taining water when used to indicate the weight of ponderables when acting
upon a piston working within the cylinder; C, a small arm or rod which is
attached to or rest upon the elastic sided chamber, which is forced upwards
when the chamber is acted upon by internal pressure, and gives motion to D,
a rack quadrant, which works on d, a fixed axis, and gives motion to E, a
pinion wheel on the axis of F, the index pointer; f, a small spring to bring
back the index pointer when the elastic box assumes its normal position; G,
dotted lines showing the form the box will assume when acted upon by internal
pressure; and HI, dotted line show the form the chamber assumes when acted

page_text: upon by external pressure; I, Fig. 6, Sheet B, is a pipe connecting the two
elastic sided boxes A, A, which are coupled together for the purpose of
giving a longer action to the rod or arm C, which communicates the motion of
the boxes A, A, to the index pointer F through the quadrant D and pinion E;
K, hydraulic cylinder; K, cylinder cover; L, hydraulic ram, upon the top of
which is placed M, a platform to receive the articles to be weighed; N, pipe
which forms a connecting passage between the interior of the hydraulic
cylinder and the interior of the elastic sided box.
Having now fully described and ascertained the nature of this my said Inven-
tion, and how the same may be carried into effect, what I claim is, the use and
application of the oval & elastic sided box or chamber herein-before
described, or any mere modification of the same, when applied to or used for
a pressure gauge, vacuum gauge, barometers, theremometers, or other like
instruments for indicating internal or external pressure; and the application
of pressure gauges, as herein-before described, for indicating the weight of
ponderables when pressure is is communicated thereto through the medium
of confined water or other fluids.
In witness thereof, I, the said Charles Henry Chadburn, have hereunto
set my hand and affixed my seal, this Nineteenth day of October, in
the year of our Lord One thousand eight hundred and fifty-eight.
CHARLES HENRY (L.s.) CHADBURN.
Witness,
WILLIAM WALKER,
of 44, Castle Street,
Liverpool.