IMPROVEMENTS IN SAFETY VALVES
Year: 1868

page_text: LETTERS PATENT to George Sanders, of Birmingham, in the County
of Warwick, Clerk in the Bank of England, for the Invention of
"IMPROVEMENTS IN SAFETY VALVES."-A communication from abroad
by Richard David Sanders, of Bombay, East Indies, Mechanical
Engineer.
Sealed the 12th March 1869, and dated the 19th September 1868.
PROVISIONAL SPECIFICATION left by the said George Sanders at the
Office of the Commissioners of Patents, with his Petition, on the
19th September 1868.
I, GEORGE SANDERS, of Birmingham, in the County of Warwick, Clerk
in the Bank of England, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN SAFETY VALVES," to be as follows, that is to
say:-
This Invention consists in the application of counteracting valves as
a means for balancing safety valves; with this view compound valves
are made use of and so arranged that one valve counteracts the other, .

page_text: the pressure upon cach acting in contrary directions. The valves rise
from their respective seats by virtue of their areas being different, and
also by the action of the escaping fluid upon an increased area of the
larger valve overhanging the valve seating. The valves are weighted in
order to counteract the different pressures upon them consequent upon
their different areas, by which means the required blow-off pressures arc
regulated.
SPECIFICATION in pursuance of the conditions of the Letters Patent,.
filed by the said George Sanders in the Great Seal Patent Office
on the 18th March 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
SANDERS, of Birmingham, in, the County of Warwick, Clerk in the Bank
of England, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by. Her
Letters Patent, bearing date the Nineteenth 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 George Sanders, Her special license that
I, the said George Sanders, my executors, administrators, and assigns,
or such others as I, the said George Sanders, my executors, adminis-
trators, 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 Esle of Man, an Invention for "IMPROVEMENTS IN SAFETY
VALVES," upon the condition (amongst others) that I, the said George
Sanders, by an instrument in writing under my hand and scal, 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 George Sanders, 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 tho
following statement, reference being had to the Drawings hereunto

page_text: say:-
.
.1.
This Invention consists in the application of counteracting valves as
a means for balancing safety valves. With this view compound valves.
are made use of and so arranged that one valve counteracts the other,
the pressure upon each acting in contrary directions. The valves rise
from their respective scats by virtue of their arcas being different, and
also by the action of the escaping fluid upon an increased area of the
larger valvo overhanging the valve seating. The valves are weighted in
order to counteract the different pressures upon them consequent upon
their different areas, by which means the required blow-off and pressures
are regulated.
The nature of the Invention will be more readily understood by
referring to the accompanying Drawings which represent a safety valve
fitted with the improved counteracting valves.
Figure 1 is a vertical section of the parts, and Figure 2 a plan of the
lower portion.
(a) and (b) are two valves each having separate seats in a valvo
box (c). The steam or other fluid upon being admitted through the
ports or openings (d) into the chamber (e) acts upon the two valves (a)
and (6) in contrary directions. By virtue of the area of the valve. (a)
being greater than that of the valve (b) the total amount of pressure
upon each valve is unequal; this difference of pressure is employed to
raise the valves from their scats. In order that, the pressure upon the
valve (a) may not overcome that upon the valve (6) before the limited
or required pressure is attained, weights or springs are placed upon the
valves, as at (9), by means of which the blow-off pressures may be
adjusted. Upon the valves rising from their seats the escaping steam or
other fluid acting upon the valve (a), as at (h), lifts the valves to the
required height to relieve the pressure; (f) are springs introduced to
counteract any vibration to which the valves may be subjected, as in
the case of locomotive and other moveable boilers; (j), are ports con-
ducting the escaping steam or other fluid from the lower valve (6) into
the funnel (i) which being perforated gives free exit therefor.
Having thus described the nature of the said Invention, and the
manner in which the same may be carried into effect, I do not confine
myself to the precise form of the parts shown, which represent the
Invention as applied to an ordinary locomotive steam boiler, but that

page_text: which I claim is, "the improvements in the construction of safety
valves" by the application of counteracting valves, for the purpose of
balancing such safety valves, substantially in manner as herein more
fully set forth and specified.
In witness whereof, I, the said George Sanders, have hereunto set
my hand and seal, this Sixteenth day of March, in the year of
our Lord One thousand eight hundred and sixty-nine.
GEORGE SANDERS. (L.S.)