IMPROVEMENTS IN SAFETY VALVES FOR STEAM BOILERS
Year: 1873

page_text: LETTERS PATENT to Charles Stuart, William Jagger, John Smith,
and John Pilling, all of Halifax, in the County of York, for the.
Tusaution of is Turnatuhuma TW CADDY Viruno DAD SAY ROZEDDe "
PROVISIONAL SPECIFICATION. left by the said Charles Stuart, William
Jagger, John Smith, and John Pilling at the Office of the Com-*
missioners of Patents, with their Petition, on the 3rd December
.1873.
We, CHARLES STUART, WILLIAM JAGGER, JOHN SMITH, and JOHN
PILLING, all of Halifax, in the County of York, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN SAFETY VALVES FOR
STEAM BOILERS," to be as follows:-
This Invention consists in an improved construction of safety and
relief valves, and has for its object a safe method or manner of weighting
and easing them, also the combination of a low water indicator.
The Invention relates to and is an improvement upon that class of
valves whereby steam is held or used as an opposite medium in retaining

page_text: "
the main valve upon its "seat" to that medium which tends to elevate it,
and consists in having a main annular valve of one or more "seatings
of any size, whereby an annular opening is obtained and which forms a
ready means for the escape of steam or other fluids, and which is con-
structed and arranged so that regulating or auxiliary valves are used and
weighted according to the desired pressure to be maintained, the weight
or weights being protected by a lid or covering, so that tampering with
them is avoided.
For the easing of the main valve, which is held down by the pressure
of the steam, we employ a suitable valve cock or their equivalent,
thereby dispensing with the use of levers or other appliances commonly
used for the purpose of clevating this main valve when escape of steam
is desired or required.
For the indication of low water in the boiler we construct a chamber
formed in the lid of the main valve, and communicating with this
chamber we have a passage constructed in the casing of the valve (or
we may employ a pipe outside the valve to communicate with the
chamber) with a pipe or connection to the water in the boiler, the above
chamber and passage or pipe being always filled with water when the
proper quantity or desired level of water is in the boiler; on the top of
the chamber we fix or adjust a fusible plug, which we apply in a new
and novel manner, viz., we insert the fuze in a hole formed in the spindle
or valve of an ordinary alarm whistle or similar appliance when the same
is "shut" or "closed." After we have inserted the fuze we turn the valve
or spindle of the alarm whistle to "open "the alone, being the means of
preventing the alarm, and also at the same time locking or preventing
the valve from turning to "shut."
L
It will be readily seen that when the water gets below the pipe which
extends to the proper level of the water in the boiler an indication to
that effect will be made, as steam will rise up the passage or pipo into
the chamber, and so cause the fusible plug to drop from its position, the
steam being of greater intensity of heat than the water heretofore con-
tained in the passage or pipe and chamber.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Stuart, William Jagger, John Smith,
and John Pilling in the Great Seal Patent Office on the 2nd June
1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, wc, CHARLES
STUART, WILLIAM JAGGER, JOHN SMITH, and JOHN PILLING, all of
Halifax, in the County of York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of December, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Charles Stuart, William Jagger,
John Smith, and John Pilling, Her special licence that we, the said
Charles Stuart, William Jagger, John Smith, and John Pilling, our
executors, administrators, and assigns, or such others as we, the said
Charles Stuart, William Jagger, John Smith, and John Pilling, our
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 "IM-
PROVEMENTS IN SAFETY VALVES FOR STEAM BOILERS," upon the condition
(amongst others) that we, the said Charles Stuart, William Jagger, John
Smith, and John Pilling, our executors or administrators, by an
instrument in writing under our, 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 we, the said Charles Stuart, William Jagger,
John Smith, and John Pilling, do hereby declare the nature of our said
Invention, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement
and accompanying Sheet of Drawings (that is to say) :-
-:
This Invention consists in an improved construction of safety and

page_text: In order that our Invention may be more clearly understood we have
hereunto annexed one Sheet of Drawings illustrative thereof, giving
reference to the same by letters and figures, the same letter referring to
the same part in both the views or Figures.
Fig. 1 is a longitudinal section of a safety valve constructed according
to our Invention and Fig. 2 is a plan view of the same taken through
the line C, D, in Fig. 1.
A is the main annular valve which rests upon two "seatings” a¹, a¹,
between which is formed the annular opening B for the escape of the
steam from the boiler; C and D are the auxillary valves formed on the
spindle E, and which are weighted to the desired pressure required by
means of the weights D' which rest upon the valve C, and it will be
observed that these weights being within the valve A are prevented from
being tampered with, and that the valve itself is so constructed that it
prevents the action of the steam on the top side of the valve spindle E.
F is the valve or cock which we employ, but which may be of other
forms as desired for the easing of the valve A when required.
The action of the valve A and the auxillary valves C and D is as
follows: The steam upon entering the cavity or space G of the valve H
acts simultaneously upon the valvé A. and the auxillary valve D, and
passes up the space or cavity 6 on to the top of the main valve A,
whereby it is retained on its "seatings" a¹, a³, until the pressure in the
boiler exceeds the gravity of the weights D¹ when the auxillary valve D
is raised, thereby closing the space b, and so preventing any further
action of the steam on the top of the valve A and allowing the same to
rise for the purpose of the escape of the steam from the boiler through
the annular opening B. The steam heretofore contained on the top of
the valve A is now allowed to pass back through the space by the
opening of the valve C, thence through the passages or openings J into
the main annular opening or outlet B.
We have shewn weights for the adjustment of the auxillary valves,
but a spring or springs may be applied for the purpose.
For the indication of low water in the boiler we have here shewn a
pipe I communicating with the chamber K, the other end of which

page_text: communicates with the water in the boiler, but we may make a passage
for this purpose in the casing of the valve H, the pipe I (or passage in
the casing of the valve when such is used) and chamber K being always
filled with water when the proper quantity or desired level of water is
in the boiler. On the top of the chamber we fix or adjust a fusible plug
or fuse L in the spindle M of an ordinary alarm whistle in such manner
that when the same is turned to " open "the fuse alone is the means of
preventing the alarm and at the same time locking or preventing the
same from turning to "shut."
It will be readily seen that when the water gets below the end of the
pipe I an indication to that effect will be made, as the chamber and pipe
will at once be emptied of the water before contained therein, and steam
will rise up the passage or pipe into the chamber, and being of greater
intensity of heat will cause the fuse L to dissolve and drop from its
position and so cause the whistle or alarm to give the indication.
Having now described and shown by Drawings how our Invention
may be carried into practise, we would have it understood that what we
claim and believe to be new is the general construction, combination,
and arrangement of the parts as comprised and set forth as our improve-
ments in manner and for purposes substantially as herein described and
shewn in the Drawings.
In witness whereof, I, the said Charles Stuart, for and on behalf of
myself and the said William Jagger, John Smith, and John
Pilling, have hereunto set my hand and seal, this Twenty-
ninth day of May, in the year of our Lord One thousand eight
hundred and seventy-four.
Witness,
WN. WHITEHEAD,
Patent Agent,
Halifax & Sheffield.
CHARLES STUART. (L.S.)