IMPROVEMENTS IN AND RELATING TO SAFETY VALVES FOR STEAM BOILERS
Year: 1877

page_text: LETTERS PATENT to John Addy Hopkinson and Joseph Hopkinson, both of
the Firm of J. Hopkinson & Co., of Huddersfield, in the County of York,
Engineers, for the Invention of "IMPROVEMENTS IN AND RELATING TO
SAFETY VALVES FOR STEAM BOILERS."
Sealed the 13th March 1877, and dated the 3rd January 1877.
PROVISIONAL SPECIFICATION left by the said John Addy Hopkinson and
Joseph Hopkinson at the Office of the Commissioners of Patents on the 3rd
January 1877..
JOHN ADDY HOPKINSON and JOSEPH HOPKINSON, both of the Firm of J.
Hopkinson & Co., of Huddersfield, in the County of York, Engineers. "IMPROVE-
MENTS IN AND RELATING TO SAFETY VALVES FOR STEAM BOILERS."
.
Our said Invention relates to safety valves and apparatus connected there-
with, and is designed to render the same more efficient for the protection of steam
boilers than heretofore.
We have formerly obtained Letters Patent, dated 10th November, A.D. 1870,
No. 2954, in the Specification of which we have described an apparatus consisting
of a lever and low water float connected with the peculiarly constructed safety
valve described in the said Specification, and known as Hopkinson's low water
safety valve apparatus. And the said Joseph Hopkinson has obtained Letters
Patent, dated the 28th August, A.D. 1875, No. 3036, for improvements relating to
safety valves for steam boilers, and in the Specification thereof describes the
employment of a vessel containing mercury and a mercurial column as an auxiliary
device for opening the safety valve.
Now, one part of our present Invention consists in the combination of the aforesaid
low water apparatus described in our said former Specification with a safety valve,
which is controlled or assisted in its action by a mercurial column or a float or
weight in mercury or other arrangement by which the weight and fluidity of the
mercury may be made available in connection with or as an auxiliary to a safety
valve.
Our Invention also consists in the combination of the aforesaid low water
apparatus described in our former Specification with the special safety valves and
apparatus described in the said former Specification of the said Joseph Hopkinson.
ID 577

page_text: Our said Invention also consists in the novel construction and arrangement of
apparatus comprising a safety valve and low water apparatus as follows:-We
employ a hollow valve of any suitable dimensions fitted upon a seat, and which is
held with the required pressure thereon by a weight or spring. The said valve has
a tubular stem which connects it with a vessel containing mercury. Inside the said
hollow valve we fit another valve; this inner valve is inverted, that is to say, is
placed below its seat, and it has attached to it a rod or stem which is connected
with a float partially or entirely immersed in the mercury in the said vessel. The
said hollow valve and its tubular stem have apertures, through which the steam has
access to the small or inner valve. Across the top of the said valves we arrange a
bridge or bar provided with a rod or pin which projects downward and forms a
stop for the said inner valve, as herein-after described.
The aforesaid yessel containing mercury has extending from its lower end a rod
or spindle, on which is suspended the weight of the hollow valve, and which has
an adjustable collar on which the lever acts, as described in the said former
Specifications.
It will be obvious that this arrangement of the safety valve in connection with
the lever of the low water apparatus leaves the said safety valve quite free to open
by the pressure of steam in the boiler independently of the said low water
apparatus, but the action of this apparatus in the manner described in our said
former Specification when there is a deficiency of water in the boiler will also open
the said safety valve and discharge the steam from the boiler.
By the peculiar construction of the said valve, that is to say by having one valve
fitted within the other, as above described, we obtain a double discharge of steam.
The outer or large valve opens a large area between its lower surface and its seat,
and at the same time the inner valve, whose seat is on the top of the large valve,
and which is kept up to its seat by the buoyancy of its float in the mercury, is held
immovable by the aforesaid stop while the outer valve rises, and thus presents an
additional area for the discharge of the steam.
We modify this part of our Invention by constructing and arranging the said
valve and apparatus as follows, that is to say:-The larger or outer valve is inverted
or placed below its seat, while the small or inner valve is seated upon the top of
the said outer valve. The outer valve has a tubular part which extends down, and
is connected to the float lever. The said float lever preferably consists of two bars
united at their ends, and between which is placed another lever. The stem of the
inner valve projects down through this tubular part of the outer valve, and has on
it the adjustable collar, upon which the said inner lever acts in the manner above
described. These levers have their fulcrum at the same point, within the boiler.
The part of the lever which acts on the said collar and the float are both on one
side of the said fulcrum.
When we use mercury in connection with this modification of our Invention the
inner lever is provided with a cup containing mercury, and is arranged in connec-
tion with the mercurial column or otherwise, as described in the former Specifica-
tion of the said Joseph Hopkinson. The float being suspended from the end of the
outer lever, to which the large valve is connected, this valve will open and close
as the said float descends or rises. The inner valve has a weight or spring which
keeps it down upon its seat while the outer valve is closed, but the inner lever
forms a stop, or we provide a special stop which prevents its following the outer
valve as the latter descends; consequently when there is a deficiency of water in
the boiler there will be a double discharge of the steam, as above described.
When there is an excess of pressure in the boiler the same is relieved by the
rising of the small or inner valve.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Addy Hopkinson and Joseph Hopkinson in the Great Seal
Patent Office on the 19th June 1877.
JOHN ADDY HOPKINSON and JOSEPH HOPKINSON, both of the Firm of J.
Hopkinson and Co., of Huddersfield, in the County of York, Engineers. "IMPROVE-
MENTS IN AND RELATING TO SAFETY VALVES FOR STEAM BOILERS."
Our said Invention relates to safety valves and apparatus connected therewith,
and is designed to render the same more efficient for the protection of steam boilers
than heretofore.
We have formerly obtained Letters Patent, dated 10th November, A.D. 1870,
No. 2954, in the Specification of which we have described an apparatus consisting
of a lever and low water float connected with the peculiarly constructed safety
valve described in the said Specification, and known as "Hopkinson's Low Water
Safety Valve Apparatus." And the said Joseph Hopkinson has obtained Letters
Patent, dated the 28th August, A.D. 1875, No. 3036, for "Improvements relating
to Safety Valves for Steam Boilers," and in the Specification thereof describes the
employment of a vessel containing mercury and a mercurial column as an auxiliary
device for opening the safety valve.
Now, one part of our present Invention consists in the combination of the afore-
said low water apparatus, described in our said former Specification, with a safety
valve which is controlled or assisted in its action by a mercurial column or a float
or weight in mercury or other arrangement by which the weight and fluidity of
the mercury may be made available in connection with or as an auxiliary to a
safety valve for the purpose herein set forth.
Our Invention also consists in the combination of the aforesaid low water
apparatus, described in our former Specification, with the special safety valves
and apparatus described in the said former Specification of the said Joseph
Hopkinson
Figure 1 is a longitudinal section of a portion of a steam boiler provided with a
safety valve controlled by a mercurial column and a low water apparatus
according to one part of our Invention.
Figure 2 is a plan of part of the said apparatus.
Figure 3 is a longitudinal section of a part of a boiler provided with a safety.
valve controlled by a mercurial column and low water apparatus according to
another part of an Invention. Figure 4 is a plan of a portion of this apparatus.
Figure 5 is a longitudinal section of part of a boiler provided with a safety valve
and low water apparatus according to another modification of our said Invention,
Like letters indicate the same parts throughout the Drawings.
The part of our Invention illustrated in Figures 1 and 2 is carried into practice
as follows:-The mercurial apparatus by which the said valve is controlled and
assisted may be constructed and arranged as set forth in the Specification of
said former Letters Patent of Joseph Hopkinson. A is the boiler; B is the valve
block attached to the boiler; i is the safety valve placed upon the valve seat.
The said valve is made of any suitable diameter, and is weighted internally to the
required pressure, as shewn at j. On the valve spindle j¹ is a collar ², which can
be adjusted to any required height. The lever k is suspended in the boiler upon a
joint or fulcrum ; m is a cup containing a quantity of mercury sufficient to fill the
column pipe n (which varies in length according to the pressure of steam), and also to
balance the weight o. It will be seen that the said valve is free to act in the same
manner as an ordinary dead weight valve until the steam attains a pressure to
which the column pipe n and the receiver n² are adjusted; then the mercury being
displaced by the pressure and forced from the suspended cup m into the receiver n³,

page_text: the end carrying the weight o becomes the heavier end of the lever. When this
happens the tips k¹ on the lever act on the collar of the valve spindle, and raise
the valve from its seat, discharging the surplus or excess of steam as it is generated
until the normal maximum pressure in the boiler is restored, then the lever returns
to a state of equilibrium and rest, and the valve closes again quite tightly, and is as
free as an ordinary valve. The screws q are provided to regulate the position and
traverse of the said lever. The various modifications of the above apparatus
described in the said Specification are applicable to our present Invention. We
combine with this valve and mercurial apparatus a low water apparatus which
opens the safety valve and discharges steam when the said float descends below its
proper level. The rod j³ is not only provided with a collar 2 to be acted on by the
lever k but also with a similar collar to be acted on by the lever p, so that the
turning of either of these levers on their fulcrum will lift the valve i from its seat
and discharge steam. The float p¹ is kept submerged so long as the water does not
sink below its proper level. It is rather more than counterbalanced by the weight
p and kept from rising too high by the pin or rod p³; but when the water sinks
and begins to uncover the said float the increased weight of the latter causes it to
overbalance the weights ; and p², thereby raising the valve i and discharging steam
freely until the float's normal position is restored or the steam is all discharged.
Our said Invention also consists in the novel construction and arrangement of
apparatus comprising a safety valve and low water apparatus, as illustrated in
Figures 3, 4, and 5 of the Drawing.
In the arrangement of our Invention, illustrated in Figures and 4, i is an
inverted hollow safety valve; is the seat thereof; p is a tubular rod or stem
which connects this hollow valve i with the lever p of the low water float p¹. This
float is submerged in the water in the boiler, and rises and falls with the same; it
is maintained nearly in a state of equilibrium by the counterweight p². As the
water sinks or descends in the boiler and begins to leave or uncover the float the
increased weight of the float causes the lever p to turn on its fulcrum and draw the
valve i down from its seat i¹, thereby discharging the steam.
According to this part of our Invention we combine with this low water
apparatus the valve 4, which is seated upon the hollow valve i and pressed upon
its seat by the dead weight which is suspended from the said valve by the rod
j. This valve j will be raised by excess of pressure in the boiler, and will relieve
the same like an ordinary dead weight safety valve, but this valve is controlled and
assisted by the mercurial apparatus m, n, n¹, acting as above described.
'
And by the combination of the two valves i and j', with the low water apparatus,
as above described, we obtain the following result, namely,-when the valve i is
drawn down from its seat by the action of the float and lever the valve is kept
from following it by the arrangement of the parts j, k, and q, and a double dis-
charge of steam is thereby obtained.
If desired in this form of our apparatus any other mercurial apparatus which will
serve the purpose of our Invention may be substituted for that above described, or
the mercurial apparatus may be dispensed with.
.
In the modification of our Invention illustrated in Figure 5 we employ a hollow
valve of any suitable dimensions, as shewn at r, fitted upon a seat, and which is
held with the required pressure thereon by a weight j. The said valve has a
tubular stem which connects it with a vessel ? containing mercury. Inside the
said hollow valve we fit another valve s; this inner valve is seated in the top of
the outer valve and inverted, that is to say, it is placed below its seat, and it has
attached to it a rod or stem 8¹ which is connected with a float s², partially or
entirely immersed in the mercury in the said vessel 2³.
The hollow valve ? and its tubular stem 72 have apertures, through which the
steam has access to the small or inner valve s. Across the top of the said valves
we arrange a bridge or bar t provided with a rod or pin t, which projects down-
ward and forms a stop for the said inner valve, as shewn in the Drawings and as
berein-after described..

page_text: The vessel containing mercury has, extending from its lower end, a rod or
spindle j, on which is suspended the weight of the hollow valve, and which has
an adjustable collar 2, whereon the tips p* of the lever p act as above described.
By the peculiar construction of the said valve, that is to say, by having one
valve fitted within the other, as above described, we obtain a double discharge of
steam in case of a deficiency of water in the boiler. The outer or large valve r
opens a large area between its lower surface and its seat, and at the same time the
inner valve s, whose seat is on the top of the large valve, and which is kept up to
its seat by the buoyancy of the float 2 in the mercury is held immoveable by the
aforesaid stop t¹, while the outer valve » rises, and thus presents an additional area
for the discharge of the steam.
Having thus fully described our said Invention and the manner of performing
the same, we wish it understood that we claim,-
First. The combination of the apparatus herein-above described as "Hopkinson's
Low Water Safety Valve Apparatus" with any suitable safety valve which is con-
trolled or assisted in its action by a mercurial apparatus or by mercurial action.
according to the first part of our said Invention, and for the purpose specified.
Second. The combination of the above described safety valve and mercurial
apparatus with the low water apparatus, as shown in Figures 1 and 2 of the
Drawings, and as above set forth and for the purpose specified.
Third. The compound or double dicharging safety valve, shewn in Figures 3 and
4 of the Drawings, constructed and operating in combination with the low wator
apparatus, and with or without the mercurial apparatus, as above set forth, and for
the purpose specified.
Fourth. The compound or double discharging safety valve, as shewn in Figure 5
of the Drawings, constructed and operating in combination with the low water
apparatus, as above described, and for the purpose specified.
In witness whereof, we, the said John Addy Hopkinson and Joseph Hop-
kinson, have hereunto set our hands and seals, this Fourteenth day of
June, in the year of our Lord One thousand eight hundred and seventy-
seven.
Witness,
ALFRED J. LIVERSEDGE,
Draughtsman,
Huddersfield.
JOHN ADDY HOPKINSON. (L.S.)
JOSEPH HOPKINSON.
(L.S.)