AST HARDING STRE NEAR FLEET STREET
Year: 1852

page_text: LONDON:
PRINTED BY GEORGE E. EYRE AND WILLIAM SPOTTISWOODE,
PRINTERS TO THE QUEEN'S MOST EXCELLENT MAJESTY:
PUBLISHED AT THE QUEEN'S PRINTING OFFICE, EAST HARDING STRE
NEAR FLEET STREET.

page_text: LETTERS PATENT to Joseph Hopkinson the younger, of Hudders-
field, in the County of York, Engineer, for the Invention 'of
"IMPROVEMENTS IN STEAM BOILERS.":
Sealed the 5th January 1858; and dated the 15th October 1852.
ww
PROVISIONAL SPECIFICATION left by the said Joseph Hopkinson
1
at the Office of the Commissioners of Patents, with his Petition,
on the 15th October 1852...
.I, JOSEPH HOPKINSON the younger, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN STEAM BOILERS" to be as
follows:-
My first improvement in steam boilers consists in forming the sides
of the furnace of cylindrical water chambers constituting a portion of
the boiler. A furnace of the ordinary construction is placed between
two or more such chambers, and above these the main part of the
boiler is situate, which may also consist of one or more cylindrical
vessels; the side chambers may, if desired, be furnished with a number
of small tubes constituting flues, through which the products of com-
bustion pass after leaving the furnace. The boiler so constructed
affords a large amount of heating surface, and. is, free from outward

page_text: biMy second improvement consists in peculiar arrangement of safety
valve. The valve is pressed to its scat by a weight within the "boiler,
as now sometimesi practised; and mylinprovenient has reference to a
method of raising it by the action of a float immersed in the "water";
within atlio boiler ¡therelisa déver turning upon a centre. one end' of it
carrying the immersed float and the other a counterweight; the 'rod
which carries the loading of the valve is provided with 'a slot; within
which is situate a pin projecting from. the float lever;"upon the water
sinking below its proper levelt the float will fall; in order to displace an
amount of water according to its bulk;which action will turn the
lever upon its centre, and raise the valve so as to allow. the steam to
escaped op,
Y WORD WOR
Anothera improvementiin the Isafetyn valve" is the adaptation of a
chain,.instead of a rigid fodffor. raising the valve from the outside of the
boiler, by which means the necessary: lifting action may be accom-
plished, but if the lever be depressed by an attempt to attain an undue
pressure the links will giveaway; and thus prevent any extra loading.
four quizzo di solaw aroundy,

page_text: and at all times thereafter, during the term therein expressed, should
and lawfully might make, use, -exercise,anda vend, within the United
Kingdom of Great Britain and Ireland,.the-Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN STEAM BOILERS," upon
the condition (amongst others) that I; tlie said Joseph Hopkinson:the
younger, by an. instrument in writing under. my hand and seal, 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.
pub wore bar
**
"
NOW KNOW YE, that T, the said Joseph Hopkinson the younger, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described-and-ascer-
tained in-and by the following statement and accompanying Drawing
(that is to say): .
In all t
My improvements consist, firstly; in forming the sides of the furnace
of steam boilers of cylindrical water chambers constituting portions of
the boiler. Secondly, in an arrangement of apparatus constituting a
safety, valve, one peculiar feature of which consists in the employ
ment of an immersed stone or other float, which float, upon the water
sinking below its proper level, will become heavier and fall in order to
displace its proportionate amount of water, by which action the safety
valve is raised and the Steam allowed to escape. Another feature of
novelty in the safety valve isi the adaptation of a chain or other
flexible medium, instead of a rigid rod, 'for raising such valves as aré
loaded from.. the interior of tlic boiler, by which means the required
lifting action may be acconiplished, but if the lever be'depressed by an
attempt to obtain an under pressure the links will give way, and this
prevent any extra loading.And in order that my Invention' may be
fully understood I have appended to this my Specification' one Sheet f
Drawings, which I will now proceed to 'describe:
sonoil
Fig. 1, is a sectional view of a boiler constructed according to the
first part of my Invention. Upón "suitable masonry are placed
circular chambers a, a, in this case provided with a number ofbšimali

page_text: tubes.constituting flies; above the chambers a, and resting upon them,
is the minin part of the boiler b, and in order to make the junctions at
c, c, perfect apply a requisite thickness of fire clay or brick; according
to the arrangement shown the products of combustion pass from the
furnace d, to the back part of the boiler, return through the tubes of
the vessels a, a, at the front end of which they turn downward into
flues e, e, and from thence to the chimney; such arrangement, however,
constitutes no part of my Invention, for the flues may be disposed
according to a variety of ordinary methods.. I have in the. Drawing
shown the upper or main part of itho: boiler as one vessel; two or more,
however, may be applied, if desired.
.' 1.
The second part, of my improvenients is shewn at Fig. 2, which is a
sectional view of the vaive attached to a boiler top. The valve f. is
placed upon the seat g, and loaded there by the direct action of an
interior weight h, according to the pressure. required, or a loaded lever
may be employed. if desired; the rod i, which connects the weight to
the valve passes through a slot formed within a lever j, and upon it are
screw nuts, for the purpose of enabling the lever to lift the valve.
The lever j, turns upon a fixed centre. at 4, and carries at one end a
float m, which is borne upwards's by a counterbalance weight n.
suspended from the lever j; the float m, however, is kept immersed by
the part o; of the lever arriving in contact with the top of the boiler.
According to the possition. shewn in the Drawing the valve is retained
to his sent by the direct action of, the weight h, but should the level of
the water sink and become below the surface of the float m, or below a
portion thereof;-as-may-be-determined, then-by-sinking -in-order-to
displace its proportionate quantity of water. it will overcome the
counterbalance n; and cause the lever to turn upon its centre
to arrive in contact with the nuts
seat..
as
and thereby left the valve from its
My other improvement in the safety valve is also shewn in Fig. 2.
where 9 is a chain attached to the valve and connected to a rod
which passes through the case r; this rod is jointed to a levers, by
means of which the valve may be raised from its seat by hand, but
cannot be forced downward thereby, the flexible connection formed by!

page_text: the chain preventing such operation. In order to admit of the boiler
being worked at any desired pressure below that effected by the direct
action of the weight I mount the levers, so as to be suitably arranged
for receiving a weight on one side of its centre of motion, and of being
connected to the valve on the other side thereof; by applying such weight,
therefore, at any position according to the graduations shewn, a tendency
to raise the valve will be imparted, and the working pressure diminished
accordingly. Thus it will be seen by my. improved arrangement, of
valve that upon the water becoming too low steam will be allowed to
blow off so as to remove the whole of the pressure, and that an undue
pressure cannot be attained by overloading; for, as the only connection
with the outside of the boiler is flexible, the valve cannot be depressed.
Having thus described and ascertained the nature of the said Inven-
tion, and the manner in which the same is to be performed, I desire it to
be understood that.I.claim as secured to me,-Firstly, the adaptation
of cylindrical water chambers constituting the sides of the furnace..
Secondly, the.application of a submerged float, which by the sinking of
the water level in the boiler raises the valve or the weight by which it
is loaded. Thirdly, the application of a chain or other flexible medium
for connecting the safety valve with the outside of the boiler.
hai
...'
"In witness whereof, I, the said Joseph Hopkinson''the younger,.
have hereunto 'set my hand and seal, this Twelfth' day of April,
One thousand eight hundred and fifty-three."
* Jur,
“‍JOSEPH HOPKINSON, Ƒª. *(L´S.)
'JOSEPH HOPKINSON, Jª. *(L´S.)