AN IMPROVED COMPENSATING SPRING BALANCE FOR SAFETY VALVES
Year: 1873

page_text: LETTERS PATENT to Alfred Vincent Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Mechanical
Draughtsman, for the Invention of "AN IMPROVED COMPENSATING
SPRING BALANCE FOR SAFETY VALVES." A communication from
abroad by Valdemar Frederik Lassoe and George Frederick
Meyer, both of Brooklyn, in the State of New York, United
States of America.
-
PROVISIONAL SPECIFICATION left by the said Alfred Vincent Newton
at the Office of the Commissioners of Patents, with his Petition,
on the 3rd June 1873.
I, ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery
Lane, in the County of Middlesex, Mechanical Draughtsman, do hereby
declare the nature of the said Invention for "AN IMPROVED COMPENSATING
SPRING BALANCE FOR SAFETY VALVES," to be as follows:-
This Invention has for its object to provide a spring balance for
safety valves with means for adjusting and regulating the power of the

page_text: spring, s
the valve.
On locomotives and steam ships where the application of a weight
to the safety valve is not practicable, owing to the jarring motion of
the engine or the rolling of the vessel, and the consequent injurious
effect which the weighted lever would exert upon the valve, springs have
been introduced in place of the weights. These spring balances were
however very defective in one particular, that is, as the valve was
raised off its seat by pressure of steam the spring being thereby effected
increased its resistance to the action of the steam upon the valve, and
therefore it required a greater steam pressure to keep the valve open
than it did to open the same, consequently the increased power of the
spring sufficed immediately after the opening of the valve to re-close
the latter, and thus the chief object of a safety valve was defeated.
Various attempts have been made to counteract this injurious effect
of the increase of the spring power, but none that were successful.
The present Invention aims at such a compensation of the spring
balance that the power of the spring will remain nearly the same,
or perhaps even become decreased as the valve is being lifted off its
seat. This object is partly attained by connecting the off end of
the spring balance with a vibrating bell-crank lever or quadrant in
such manner that the distance between the valve lever and the point
of connection of the spring with the afore-mentioned quadrant lever
will be less increased during the upward motion of the valve lever
than if the spring was secured to a stationary point, owing to the
consequent vibration of the quadrant towards the valve lever. It is
evident that this circumstance will only partly contribute to compensate
the increased force of the spring because the latter surely elongates to
make up for the balance, the valve lever and quadrant or bell cranķ
are connected by a link which transmits back to the former, a fraction
of the strain exerted upon the spring by the pressure of the valve, thus
leaving the difference of these two items as effectual resistance to the
steam pressure.
:
The lever, quadrant, or bell crank is slotted or perforated, or other-
wise so arranged as to permit the point of its connection with the
spring balance, and also with the connecting link to be varied at
pleasure, so that the apparatus can be set at any suitable decrease

page_text: of steam pressure. This adjustment can also be effected by moving
the fulcrum or supporting bracket of the quadrant to and fro in a
line parallel to the valve lever.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alfred Vincent Newton in the Great Seal Patent
Office on the 3rd December 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Mechanical Draughtsman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of June, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alfred Vincent Newton, Her special
licence that I, the said Alfred Vincent Newton, my executors, admi-
nistrators, and assigns, or such others as I, the said Alfred Vincent
Newton, 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 Inven-
tion for AN IMPROVED COMPENSATING SPRING BALANCE FOR SAFETY VALVES,"
being a communication to me from abroad by Valdemar Frederik
Lassoc and George Frederick Meyer, both of Brooklyn, in the State of
New York, United States of America, upon the condition (amongst
others) that I, the said Alfred Vincent Newton, my executors or ad-
ministrators, 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.
NOW KNOW YE, that I, the said Alfred Vincent Newton, 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

page_text: in and by the following statement, reference being had to the Drawing
hereunto annexed, and to the letters and figures marked thereon (that is
to say) :-
This Invention has for its object to provide a spring balance for
safety valves with means for adjusting and regulating the power of the
spring, so that such power will not be increased with the opening of
the valve.
On locomotive and marine engines where the application of a weight
to the safety valve is not practicable, owing to the jarring motion of
the engine or the rolling of the vessel, and the consequent injurious
effect which the weighted lever would exert upon the valve springs
have been introduced in place of the weights. These spring balances
were however very defective in one particular, that is, as the valve
was raised off its seat by the pressure of the steam, the spring being
thereby affected increased its resistance to the action of the steam upon
the valve, and therefore it required a greater steam pressure to keep
the valve open than it did to open the same, consequently the increased
power of the spring sufficed immediately after the opening of the valve
to re-close the latter, and thus the chief object of a safety valve was
defeated. Various attempts have been made to counteract this in-
jurious effect of the increase of the spring power, but hitherto without
success.
The present Invention aims at such a compensation of the spring
balance that the power of the spring will remain nearly the same,
or perhaps even become decreased as the valve is being lifted off its seat.
This object is partly attained by connecting the off end of the spring
balance with a vibrating bell-crank lever or quadrant in such manner
that the distance between the valve lever and the point of connection
of the spring with the afore-mentioned quadrant lever will be less
increased during the upward motion of the valve lever than if the
spring was secured to a stationary point, owing to the consequent
vibration of the quadrant towards the valve lever. It is evident that
this circumstance will only partly contribute to compensate the in-
creased force of the spring, because the latter surely elongates. To
make up for the balance the valve lever and quadrant or bell crank
are connected by a link which transmits back to the former a fraction
of the strain exerted upon the spring by the pressure of the valve,

page_text: thus leaving the difference of these two items as effectual resistance
to the steam pressure. If, for example, the safety valve is set to
obey a steam pressure of thirty pounds, and the spring properly
adjusted to represent such power of thirty pounds, the effect of an
excess of steam pressure will be the elevation of the valve. But
upon its elevation and consequent transmission of motion to the spring
balance the latter will still retain its resisting power of thirty pounds,
and will, with the use of this Invention, not increase in power, thereby
allowing the steam, as long as there is an excess of pressure, to keep
the safety valve open.
The adjustment of the parts may be such that the spring pressure
may be brought down, say, to twenty-nine pounds perhaps when the
valve is raised to facilitate the keeping open of the valve by the least
excess of steam pressure.
The lever, quadrant, or bell crank is slotted or perforated or other-
wise so arranged as to permit the point of its connection with the
spring balance and also with the connecting link to be varied at
pleasure, so that the apparatus can be set at any suitable decrease
of steam pressure. This adjustment can also be effected by moving
the fulcrum or supporting bracket of the quadrant to and fro in a
line parallel to the valve lever, and the arrangement will yield the
same result if the quadrant is turned, so that the spring connection
will come between the link and valve instead of having the link placed
between the valve and the spring.
In the accompanying Drawing Fig. 1 is a side view of the improved
compensating spring balance applied to the safety valve of a loco-
motive boiler, and Fig. 2 is a horizontal section of the same on the
line c, c, of Fig. 1.
A, Fig. 1, represents a safety valve of suitable construction placed
upon an appropriate seat B of the steam dome C or other part of a
boiler. The valve A is by a link a connected in the ordinary or
suitable manner with a beam or lever D which is at 6 pivotted to a
fixed post or standard d. The outer end of the lever D is connected
with a spring balance E, the latter being of the customary construction,
that is to say, one end of the spring contained in such balance is con-
nected with the rod e that is secured in the beam D, while the other
end of such spring is connected with the lower end of the balance,

page_text: ".
so that the more the end ƒ is drawn away from D the more will
the power of the spring within E be increased. The lower end f
of the spring balance is by a rod 9 connected with a lever quadrant
or bell crank F that is at h pivotted to a fixed frame or standard G.
The pin which connects the rod g with the quadrant F is beneath the
pivot of F, as shewn. A link H connects the beam D with the upper
part of the quadrant F, as shewn.
In the Drawing the valve A is represented as being closed upon its
seat. Whenever, by an excess of steam pressure within the dome or
boiler C, the valve is raised off its seat the beam D will be swung up
in the direction of the arrow on its pivot b. By such motion of the
beam and the connection of the same with the quadrant the latter
will be caused to swing on its pivot h in the direction of the arrow m.
By such movement of the quadrant the connecting point i of the spring
balance with the quadrant will be elevated, and therefore the extension
of the spring within E and its consequent increase of power would be less
than it would be were the lower part of the spring balance E fixed
instead of moveable. In consequence of the motion of the quadrant F
a back pressure is exerted by the link H upon the lever D, which
pressure increases as the rod g moves away from the fulcrum h. Hence
the more the valve is lifted off the seat the more effectual will be the
action of the link H%; this is a very important point of the con-
struction.
By adopting suitable relations between all the dimensions the effect
of the spring on the valve may be kept nearly uniform, or may be even
made to decrease while the valve is raised.
For permitting of the proper adjustment of the parts the quadrant F
may be perforated, as shewn, or it may be slotted or otherwise con-
structed to allow the pins and n to be set in the desired manner, for
it is evident that the further down the pin i is originally set on the
quadrant or bell crank F the larger will be its proportion of motion
during the raising of the valve, and the larger therefore the counter-
acting influence of such motion upon the increased spring power. It is
also evident that the nearer the pin n is set to the pivot h the greater
will be the power exerted by the link connection upon the lever D.
The upper pivot o of the link H may also be adjustable upon the
beam D by perforating or slotting the latter or otherwise, so that the

page_text: power of the link connection may be increased the further o is set away
from 6, and decreased the nearer o is set to b.
Having now set forth the nature of the Invention of "An Improved
Compensating Spring Balance for Safety Valves," as communicated to me
by my foreign correspondents, and explained the manner of carrying the
same into effect, I wish it to be understood that under the above in part
recited Letters Patent I claim,―
First. The quadrant or bell-crank lever F connected by a link H with
the lever D of a safety valve and combined with the spring balance E
which connects with both levers D and F, substantially as and for the
purpose herein shewn and described.
Second. The spring balance E of a safety valve when connected and
combined with a vibrating quadrant or bell-crank lever F to reduce
the extension of the spring during the raising of the valve, substantially
as described.
In witness whereof, I, the said Alfred Vincent Newton, have here-
unto set my hand and seal, the Third day of December, in the
year of our Lord One thousand eight hundred and seventy-
three.