IMPROVEMENTS IN INSTRUMENTS FOR MEASURING. INDICATING. AND REGULATING THE PRESSURE OR FLOW OF FLUIDS
Year: 1861

page_text: LETTERS PATENT to Paul Cameron, of Glasgow, in the County of
Lanark, North Britain, Philosophical Instrument Maker, for the
Invention of "IMPROVEMENTS IN INSTRUMENTS FOR MEASURING. INDICATING.
AND REGULATING THE PRESSURE OR FLOW OF FLUIDS."
Sealed the 23rd November 1861, and dated the 31st May 1861.
PROVISIONAL SPECIFICATION left by the said Paul Cameron at the
Office of the Commissioners of Patents, with his Petition, on the
31st May 1861.
1, PAUL CAMERON, of Glasgow, in the County of Lanark, North
Britain, Philosophical Instrument Maker, do hereby declare the nature.
of the said Invention for IMPROVEMENTS IN INSTRUMENTS FOR MEASURING. INDICAT-
ING. AND REGULATING THE PRESSURE OR FLOW OF FLUIDS," to be as follows,
that is to say :-
This Invention relates to the arrangement and construction of
apparatus suitable for registering or indicating the pressure of the atmo-
sphere as well as of steam, gas, or water. Under certain modifications,
the instrument is also applicable as a means of regulating the pressure
and flow of steam, gas, or water so as to cause it to flow in a regular
and uniform manner, or to give an audible or visible signal upon a given
or predetermined pressure being exceeded.
Under one modification or arrangement, as adapted for indicating
the pressure of steam in boilers, the apparatus consists of a metal box

page_text: or case, which has a ring of metal either cast on or secured to a suitable
base plate. This ring has screwed to it a second and corresponding
ring, between which and the face of the lower ring is interposed a disc
of mica. This arrangement forms an air-tight chamber, which is, how-
ever, put in communication with the boiler by means of a pipe which
opens into the chamber. The disc of mica is connected by means of a
central universal joint with a lever extending across the chamber, and
centred on a pillar piece at the upper part of the case. The lower end
of the lever extends on cach side in a lateral direction, forming a T-
piece, the extremities of which are soldered to helical springs, which
are connected by end discs to the base plate. These springs serve to
keep the lever in a horizontal position, and the index to zero when there
is no pressure on the disc. Upon steam being admitted to the chamber,
the mica is pressed or bulged outwards, and being connected to the
lever, this motion is imparted to the indicating mechanism. A slot is
made in the T-end of the lever to admit of a traversing link being fitted
therein; this link is jointed to a projecting arm formed on a small metal
sphere, which traverses to and fro on a horizontal screw. This screw
is carried in a bracket piece fixed to the lower part of the base plate,
and it has fast to it. a milled head, the turning of which causes the little
sphere to traverse along the screw in either direction as required. The
sphere has fixed in the front part of its periphery a pin which passes
out through a slotted arm that forms a part of the spindle, on which
the quadrant for actuating the external index is fitted. This quadrant or
segmental wheel extends upwards towards the centre of the instrument,
where it gears into a pinion, the spindle of which projects out through
the graduated dial plate, and has fast to it the index or pointer. When
the steam presses on the mica it lifts the primary lever, which being
linked to the sphere, causes it to turn about its supporting screw; this
motion is imparted through the quadrant to the index. The arrange-
ment of the sphere on the screw admits of the pin which passes through
the slotted arm being moved to or from the spindle of the quadrant,
and thus imparting more or less motion to the spindle. In this way
the instrument may be adjusted so as to cause the indicator to traverse
nor of less over the dial, and thus admit of its ready adjustment to
suit dials graduated either for low or high pressures. The instrument
also forms a highly susceptible barometer; a thin film of mica is used
for the vacuum chamber, which is made air-tight and exhausted, so that
the atmospheric pressure of the exterior of the film is rendered visible
by the arrangement of the indicating mechanism.
Under another modification, the apparatus is adapted for regulating
or controlling the pressure or flow of fluids. A spring is arranged to

page_text: press on the mica disc in such a manner that its pressure can be regulated.
to any required force by means of a screw or other equivalent. The
disc of the chamber is so arranged that the bulging of the mica shall
cause the valve which controls the flow of the fluid to be more or less
closed. Thus, when the pressure of the Huid from the source of supply
exceeds the predetermined ammount, the bulging of the mica actuates
the controlling valve, and partially closes it, so that the pressure or flow
of the fluid is rendered uniform. By modifying this arrangement, the
pressure of the fluid on the disc may be caused to open a suitable jet or
orifice, and so give either a visible or audible signal.
Another mode of arranging the pressure chamber is to form both the
sides of films of mica, which are arranged in the retaining frame with a
certain degree of curvature. Upon admitting the fluid to this chamber,
its pressure tends to straighten the mica, the motion of which is com-
municated to the index or other moveable detail.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Paul Cameron in the Great Seal Patent Office on
the 30th November 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PAUL
CAMERON, of Glasgow, in the County of Lanark, North Britain,
Philosophical Instrument Maker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirty-first day of May, in the year of
our Lord One thousand eight hundred and sixty-one, in the twenty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Paul Cameron, Her special license that
I, the said Paul Cameron, my executors, administrators, and assigns.
or such others as I, the said Paul Cameron, my executors, admini-
strators, or 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 INSTRUMENTS
REGULATING THE PRESSURE OR FLOW OF
FOR MEASUBING. INDICATING.
FLUIDS," po
upon the condition (amongst others) that J, the said Paul
Cameron, my executors or administrators, by an instrument in writing
under my hand and seal, or under the hand and scal of one of them.

page_text: should particularly describe and ascertain the nature of the said Inven-
tion, 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 Cameron, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings,
and to the letters and figures marked theron, that is to say:-
My said Invention relates to the arrangement and construction of
apparatus suitable for registering or indicating the pressure of the
atmosphere, as well as of steam, gas, or water. Under certain modifi-
cations the instrument is also applicable as a means of regulating the
pressure and flow of steam, gas, or water, so as to cause it to flow in a
regular and uniform manner, or to give an audible or visible signal upon
a given or predetermined pressure being exceeded.
Under one modification or arrangement as adapted for indicating the
pressure of steam in boilers, the apparatus consists of a metal box or
case, which has a ring of metal either cast on or secured to a suitable
base plate. This ring has screwed to it a second and corresponding ring,
between which and the face of the lower ring is interposed a disc of
mica. This arrangement forms an air-tight chamber, which is however
put in communication with the boiler by means of a pipe which opens
into the chamber. The disc of mica is connected, by means of a central
universal joint, with a lever extending across the chamber, and centred
on a pillar piece at the upper part of the case. The lower end of the
lever extends on each side in a lateral direction, forming a T-piece,
the extremities of which are soldered to helical springs, which are con-
nected by end dises to the base plate. These springs serve to keep the
lever in a horizontal position, and the index to zero when there is no
pressure on the disc. Upon steam being admitted to the chamber, the
mica is pressed or bulged outwards, and being connected to the lever
this motion is imparted to the indicating mechanism. A slot is made
in the T-end of the lever to admit of a traversing link being fitted
therein; this link is jointed to a projecting arm formed on a small metal
sphere which traverses to and fro on a horizontai screw. This
carried in a bracket piece fixed to the lower part of the base plate, and
it has fast to it a milled head, the turning of which causes the little
'sphere to traverse along the screw in either direction as required. The
sphere has fixed in the front part of its periphery a pin which passes
out through a slotted arm, that forms a part of the spindle on which the
quadrant for actuating the external index is fitted. This quadrant or
is

page_text: segmental wheel extends upwards towards the centre of the instrument
where it gears into a pinion, the spindle of which projects out through
the graduated dial plate, and has fast to it. the index or pointer. When
the steam presses on the mica it lifts the primary lever, which being
linked to the sphere causes it to turn about its supporting screw; this
motion is imparted through the quadrant to the index. The arrange-
ment of the sphere on the screw admits of the pin which passes through
the slotted arm being moved to or from the spindle of the quadrant,
and thus imparting more or less motion to the spindle. In this way the
instrument may be adjusted as to cause the indicator to traverse more
or less over the dial, and thus admit of its ready adjustment to suit
dials graduated either for low or high pressures. The instrument also
forms a highly susceptible barometer; a thin film of mica is used for the
vacuum chamber, which is made air-tight and exhausted, so that the
atmospheric pressure on the exterior of the film is rendered visible by
the arrangement of the indicating mechanism.
Under another modification the apparatus is adapted for regulating.
or controlling the pressure or flow of fluids. A spring is arranged to
press on the mica disc in such a manner that its pressure can be regulated
to any required force by means of a screw or other equivalent. The
disc of the chamber is so arranged that the bulging of the mica shall
cause the valve which controls the flow of the fluid to be more or less
closed. Thus when the pressure of the fluid from the source of supply
exceeds the predetermined amount, the bulging of the mica actuates the
controlling valve, and partially closes it, so that the pressure or flow
of the fluid is rendered uniform. By modifying this arrangement, the
pressure of the fluid on the disc may be caused to open a suitable jet.
or orifice, and so give either a visible or audible signal.
Another mode of arranging the pressure chamber is to form both the
sides of films of mica, which are arranged in the retaining frame with
a certain degree of curvature. Upon admitting the fluid to this chamber,
its pressure tends to straighten the mica, the motion of which is com-
municated to the index or other moveable detail.
And in order that my said Invention of improvements in instruments
for measuring, indicating, and regulating the pressure or flow of fluids
may be property understood. I shall now proceed to describe the several
Figures on the explanatory Sheet of Drawings, which I have hereunto
appended for the purpose of showing certain modifications under which
my improvements may be judiciously carried out in practice, that is
to say:
Figure 1 is a front external elevation of one arrangement of a steam
gauge constructed according to my improvements; Figure 2 is a corre-

page_text: sponding elevation, but with the front index plate removed; Figure 3
is a vertical section of the gauge taken at right angles to Figures 1 and 2,
and Figure is a sectional view of the steam chamber to show its
arrangement; Figure 5 is a partially sectional elevation, and Figure 6
is a plan of a lubricator, constructed according to my improvements.
The mechanism of the guage delineated in Figures 1 to 4 is contained
in a circular or other shaped box A, to the lower part of which is
attached the cock B, which is connected to the steam pipe C. The
lower extremity of the pipe C communicates with the boiler, and conveys
the steam up through the tubular passage of the cock B to the tube D,
which is arranged within the gauge box A. To the back of the box A
is attached the metal plate E, and to the face of this plate is screwed
a brass ring F, which is more clearly shown in Figure 4. The face of
the ring F is made with an annular groove, in which is fitted the ring G,
before screwing down the ring G a leather washer is put in the annular
recess-of-the-part-F, and upon this washer is placed a film or disc of
mica H. A second washer or ring of leather is put on the mica and
the ring G is screwed down, the arrangement now forms a steam-tight
chamber, into which the steam pipe D opens. It follows from the con-
struction of this part of the apparatus that when steam or other similar
clastic fluid is admitted to the chamber formed by the ring F and the
parts connected thereto, that its pressure acting upon the film of mica H
will cause it to bulge outwards more or less. If, therefore, the film
be connected to suitable indicating mechanism, this varying motion will
correctly indicate the pressure on the dial plate. To the centre of the
dise of mica H is attached by means of a nut the stud piece I, the outer
part of which is shaped to a wedge-like figure, as shown in profile in
Figure 3. The edge of the stud piece I is in contact with the lever J.
which is jointed at one end to the elbow piece K, so that the lever is
free to move up and down with the motion of the mica disc H. Near
the lower end the lever J is connected to the helical spring L, by means
of which the lever is brought back to the normal position when the
pressure on the dise is removed. The extremity of the lever J is bent
inwards towards the back of the box A, and this part carries a down-
wardly projecting pin, which takes into a curved slot which is formed
in the hollow cynder M. The journals of this cylinder are carried in
the plates E and N, the latter of which is supported on bracket pieces O
screwed to the back plate E. The front part of the spindle of the
cylinder M carries the fine spiral spring P, and also the segmental rack
Q, which gears with the pinion R. The spindle of the pinion Ri
carried in the front plate N, and in the overhanging bracket piece S
the extremity of the spindle projects out through the graduated dial

page_text: plate T, and has attached to it the index or pointer U. A circular
opening is left in the centre of the dial plate T, which shows a portion
of the internal mechanism as delineated in Figure 1 of the accompanying
Drawings. Upon admitting steam or other similar elastic fluid to the
chamber F, its pressure upon the mica H causes the lever to be moved
outwards, and this motion is communicated through the cylinder M to
the pointer U, and in this manner the pressure of the steam is accurately
indicated on the graduated plate T. The front part of the box A is
enclosed by means of a plate of glass in the ordinary manner. The helical
spring is shown in the Drawings as of the same diameter throughout, but
it is preferred in most cases to make it of a conical figure, the smaller part
being in front next the lever J. This arrangement admits of a kind of
differential compensation for the range of movement of the lever .J. so
that, when the mica is acted upon by high pressures the spring acts with
a uniform resistance in place of the resistance gradually increasing as
the lever is moved outwards. In arranging this apparatus as a vacuum
gauge the same general arrangement of the parts is observed; the pipe C
is connected with the vacuum chamber to be indicated. In this way the
pressure of the external atmosphere upon the disc of mica causes it to
be pressed inwards, the concavity of the disc being proportioned to the
amount of vacuum obtained in the chamber formed by the ring F and
its connected parts. The motion of the disc is imparted to the cylinder
M, and thence to the pointer U. the index plate T being suitably
graduated for the purpose. The apparatus is also equally adapted for
indicating the diurnal variations of the atmospheric pressure. For this
purpose the chamber formed within the ring F is completely sealed,
and is carefully exhausted of air, so that as the atmosphere presses with
more or less force upon the surface of the mica it is more or less
depressed, and the pointer indicates the same upon a dial plate
graduated to correspond practically with the inches of the ordinary
mercurial column. A barometer formed upon this principle may be
constructed to be as sensitive as the best example of the aneroid form,
but having great advantages over those instruments as being much less
liable to injury either in travelling or when otherwise exposed to
rough usage.
So also in steam or vacuum gauges there are corre-
sponding advantages; the mica is a non-oxidisable material, and it is not
liable to injury from any amount of reciprocatory motion imparted to it.
The gauge, from the simplicity of its construction, is readily taken
asunder and re-adjusted by any ordinary mechanic, should any derange
ment from an extraordinary or any unforeseen cause arise.
In applying the principle of this Invention to the purpose of a lubri
cator for the purpose of lubrication the interior of a steam cylinder,

page_text: preference is given to the arrangement delineated in Figures 5 and 6
of the accompanying Drawings. The grease cock V is screwed into
the cylinder cover or other part in the usual way, and to this is attached
the grease cup W, which is supplied from time to time with oil or grease
that is poured into the hopper feed X. The aperture which opens into
the cup W from the hopper is closed by a vertical slide Y, when the
cup is properly supplied. The upper part of the lubricator is fitted
with a mica disé Z in manner similar to the corresponding part in the
steam gauge herein-before described. Extending across the disc Z is
a blade spring a, the ends of which are passed into lateral slots formed
below the face of the graduated ring b. The valve spindle c passes up
through the disc Z, to which it is connected by the double nuts d; tho
upper extremity of the spindle projects out above the spring a, and
carries on its screwed end the pointer c. By turning this pointer round
the spring a is depressed, and a greater amount of force is required to
raise the dise Z, so that the engineer regulates its position according
to the pressure required. At the lower part of the spindle a are arranged
the duplex valves f and g, the seats of which are formed on the tubular
part of the cup W. When the steam is admitted to the cylinder, the
cock V being open, its pressure on the valve g shuts the tubular passage;
the grease now flows below the valve f, and fills the space between the
valves. Upon the steam being exhausted the valve g opens, and the
valve is closed, which allows the oil contained in the tubular part to
flow into and lubricate the cylinder and piston. In this way a suitable
and predetermined quantity of oil is admitted at each stroke of the
engine.
A modification of this apparatus may also be used for regulating and
controlling the passage of steam from the safety valves of steam engines.
In this arrangement the spindle c and valves and gare dispensed with;
the steam from the boiler having free access to the chamber W presses
upon the disc Z. To a snug or projecting part on the ring is jointed
a lever, which extends across and beyond the ring, so as to admit of
its being connected to the slide Y. A pointer e is connected by means
of a screwed stud to the transverse lever, so that by turning this pointer
round any required amount of pressure is exerted on the mica to prevent
its rising. When, however, the pressure of the steam exceeds that of
the lever, the mica is pressed upwards, which motion lifts the lever
and raises the slide Y; this allows the steam to escape laterally into
a chamber in which the safety valve is fitted. With this arrangement
the safety valve is more easily adjusted, and is operated with greater
certainty and effect, than by the ordinary means.
Although I have named the mineral substance mica as the most suit-

page_text: able material for the flexible discs of the several instruments I have
herein-before described, yet I do not confine myself solely to that
material, but I give it the preference on account of its having advantages
not possessed by any other suitable material with which I am at present
acquainted.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe, in conclusion, that what I consider
novel and original, and therefore claim as the Invention secured to me
by the herein-before in part recited Letters Patent, is,-
First, the general arrangement and construction of apparatus for
measuring, indicating, and regulating the pressure or flow of fluids, as
herein-before described and shown in the accompanying Drawings.
Second, the use and application of mica in the construction of
apparatus for measuring, indicating, and regulating the pressure or flow
of fluids, or any mere equivalent for the said flexible mineral substance.
Third, the combination of parts forming the several mechanical
arrangements, by means of which the reciprocatory movement of the
mica or other disc is imparted to the external index or pointer, as herein-
before described and shown in the accompanying Drawings, or any mere
modification of the said arrangements.
In witness whereof, I, the said Paul Cameron, have hereunto set
my hand and seal, this Twenty-eighth day of November, Onc
thousand eight hundred and sixty-one.
PAUL CAMERON. (..s.)