IMPROVE- MENTS IN SAFETY VALVES
Year: 1852

page_text: LETTERS PATENT to Richard Archibald Brooman, of the firm of
Robertson, Brooman, and Company, of 166, Fleet Street, in the
City of London, Patent Agents, for the Invention of "IMPROVE-
MENTS IN SAFETY VALVES." -A communication.
Scaled the 31st May 1853, and dated the 7th December 1852.
PROVISIONAL SPECIFICATION left by the said Richard Archi-
bald Brooman at the Office of the Commissioners of Patents,
with his Petition, on the 7th December 1852.
I, RICHARD ARCHIBALD BROOMAN, of the firm of Robertson, Broo-
man, and Company, of 166, Flect Street, in the City of London,
Patent Agents, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN SAFETY VALVES" (communicated to me by a
foreigner) to be as follows:-
The nature of the Invention consists in rivetting to the boiler an
apparatus with two steam ways, one closed by a simple valve kept
in place by a lever, which allows it to rise and thus let the steam
free when acted upon, as herein-after explained.
The other steam way leads into a chamber, one side of which is
fitted with a metal plate, so arranged as to yield to a given pressure.

page_text: To the outside of this chamber, at top, a support is fixed for
carrying one end of a lever; a rod projects from the back of the
pressure plate, and is connected with the lever. The lower end of
this lever carries an index pointer, which indicates on a scale
graduated to any given number of atmospheres. At the end of the
scale, or at any other convenient part, a small upright, centred on
a stud, is fixed; a screw passes through an aperture made in the
top of the upright, while the bottom of the upright terminates in
a catch, which fits into a corresponding catch fitted on the long
arm of the lever which commands the valve, before alluded to, for
allowing the escape of the steam.
The action is as follows: - Supposing the valve is calculated
to allow steam to escape after reaching the pressure of three atino-
spheres, the screw is turned forward in the upright till its inner
end comes exactly over the Figure 3, on the scale; and when the
pressure shall have exceeded that of three atmospheres, the index
lever, being pressed outwards by the pressure plate, will press against
the screw, the upper end of the upright will be pushed back,
while its lower end will make a corresponding motion forward, and
will thus liberate the valve lever. The valve being then free, will
rise and allow of the steam to escape. The steam may pass through.
a whistle, so as to call attention to its liberation. The whole may
be enclosed in a box and locked, so that the action of the valve
cannot be tampered with.
SPECIFICATION in pursuance of the conditions of the Letters 2
Patent, filed by the said Richard Archibald Brooman in the
Great Seal Patent Office on the 7th June 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
RICHARD ARCHIBALD BROOMAN, of the firm of Robertson, Brooman
and Company, of 166, Fleet Street, in the City of London, Patent 30
Agents, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of December, in-

page_text: the year of our Lord One thousand eight hundred and fifty-two,
in the sixteenth year of Her reign, did, for Herself, Her heirs
and successors, give and grant unto me, the said Richard Archi-
bald Brooman, Her special licence that I, the said Richard
Archibald Brooman, my executors, administrators, and assigns,
or such others as I, the said Richard Archibald Brooman, my
executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times there-
after 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 SAFETY VALVES" (commu-
nicated to me by a foreigner residing abroad), upon the condition
(amongst others) that I, the said Richard Archibald Brooman,
by an instrument in writing under my hand and seal, should parti-
cularly 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 Richard Archibald Brooman,
do hereby declare the nature of said Invention, and in what
manner the same is to be performed, to be particularly described
and ascertained in and by the following statement, reference being
had to the Drawings annexed (that is to say):
The Invention consists in constructing and arranging safety valves
for steam boilers, in the manner herein-after explained. Figure 1,
of the Drawings annexed, is a vertical section, and Figure 2, an end
elevation, of a safety valve, constructed according to the Invention.
A, is the shell of the boiler, to which the apparatus B, is rivetted,
or otherwise secured. This apparatus is provided with two steam
ways b, c, one of which 6, is closed by a simple valve d, kept in place
by a lever C, (centred in the standard c¹) which allows it to rise,
and thus let the steam free when acted on, as hercin-after explained;
the other steam way c, leads into a chamber D, in the interior

page_text: of which is fitted the corrugated spring plate E, which is capable
of yielding under the pressure of steam against it. To the outside
of the chamber D, near the top, is fixed a support F, from which is
suspended the lever G, the end of the lever being jointed to the
support. A rod e, is jointed to the back of the pressure plate E,
and, passing through an aperture in the back plate of the chamber
D, is jointed to the lever G, at g. The lower end of the lever G,
carries an index pointer h, which travels in front of the scale I, gra-
duated to any given number of atmospheres or degrees of pressure.
At the end of the scale I, or at any other convenient part, is fastened
the small upright K, which is centred on a stud k. A screw L,
with a milled head, passes through an aperture made in the top of
the upright K; while the bottom of the upright terminates in a
catch i, which fits into a corresponding catch m, fitted on the long
arm of the lever C, which commands the valve d, before mentioned,
for allowing the escape of the steam.
The action of the apparatus is as follows: - Supposing the
parts are to be arranged so that the valve shall allow steam to
escape after reaching the pressure of three atmospheres, the screw
L, is turned forward in the upright K, until its inner end comes
exactly over the Figure 3, on the scale; and when the pressure
shall have exceeded that of three atmospheres, the index lever G,
being pressed outwards by the pressure plate E, and rod e, will
press against the inner end of the screw L; the upper end of the
upright K, will be pushed back, while its lower end will make a
corresponding motion forward, and will thus disengage the catch i,
from the catch m, and liberate the valve lever, which will fall
into the position shewn by the dotted lines. The valve d, being
then free, will rise, and allow the steam to escape. A portion of
the steam will pass through the whistle N, so as to call attention
to its liberation. The whole apparatus may be enclosed in a box
and locked, so that the action of the valve may not be tampered
with.
Figures 3, and 4, are respectively a vertical section and end
elevation of a similar arrangement of safety valve, which differs

page_text: only from that described in the means adopted to give motion to
the lever G, for effecting the liberation of the valve d. In this case,
the pressure plate E, instead of being itself the spring, is a solid
piston, working in the chamber D, as in a cylinder. The pressure
plate E, is connected to the lever G, by a rod e, which has a coiled
spring, around it, and bearing against the back of the plate, in
order to bring it back to its position after having been moved by
the steam which is admitted to the chamber D, by a pipe c², leading
from the steam way c. The other parts of the arrangement are the
same as described with reference to Figures 1, and 2; and the ope-
ration of the parts is also the same as before described.
And having now described the nature of the said Invention, and in
what manner the same is to be performed, I declare that what I
claim in respect thereof, is, the construction of safety valves in such
manner that the valve shall be kept closed until the steam shall
have exceeded a given pressure; and that, when such pressure shall
have been exceeded, the valve shall be opened by the steam acting
on a plate or spring, and through it on a lever and catch, in the
manner herein-before described.
In witness whereof, the said Richard Archibald Brooman hath
hereunto set his hand and seal, the seventh day of June,
One thousand eight hundred and fifty-three.
R. A. BROOMAN. (L.S.)