IMPROVE- MENTS IN DEAD WEIGHT SAFETY VALVES FOR STEAM BOILERS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said Joseph Sheldon Stubbs
at the Office of the Commissioners of Patents on the 2nd January 1882.
JOSEPH SHELDON STUBBS of the City of Manchester Engineer.
"IMPROVE-
MENTS IN DEAD WEIGHT SAFETY VALVES FOR STEAM BOILERS."
The objects of my Invention are -To provide a safety valve with a large
escape area, and to combine therewith an automatic contrivance for opening the
safety valve when the water within the steain generator has become reduced to
a determined depth. In constructing the safety valve, I employ a centre hollow
pillar fixed to the shell of the generator or boiler having at its lower end free
communication with the steam space within the same. At the top of this pillar
is a valve seating-In the centre of the corresponding valve is a perforation of
sufficient size to permit the escape of steam into a transverse chamber which has
at each end an opening, and into such are fitted spherical valves having attached
thereto a fork which is loaded with cake or other adjustable weights proportioned
to the total number of pounds at which it is desired to fix the blow-off.
When this pressure is attained, these two openings are simultaneously but
independently lifted up and permit steam to escape.
By this action, the burden of the two sets of weights together with that of the
two side valves themselves are lifted from the centre or large valve, which thus
lightened opens and permits the steam to escape from a large escape area.
I prevent the side or smaller valves from lifting too high by means of the
checking action of the clutch of the weight carrying fork closing upon the respective
under exterior surfaces of the transverse chambors.-I prevent the larger or centre
valve from rising more than requisite by set screws through the outer casing,
which act against a projecting part of the hollow pillar formed to correspond.

page_text: In combination with this arrangement I employ an apparatus which will
automatically open the side valves immediately the water within the boiler or
steam generator has become reduced to a depth previously determined. This
I accomplish by placing within the water space of the generator a lever turning on
any suitable fulcrum, having at one end a float of fire brick or other material, and
at the other a balance weight. This lever is attached by suitable mechanisin to
the valve arrangement already described in such manner as to cause the valve
to open for the escape of steam, whenever the float falls to a determined point.
The improvements in a modified form are also applicable to steam economisers
bath and domestic boilers and other water heaters with low pressure.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said Joseph Sheldon Stubbs in the Great Seal Patent Office on
the 1st July 1882.
JOSEPH SHELDON STUBBS, of the City of Manchester, Engineer,
MENTS IN DEAD WEIGHT SAFETY VALVES FOR STEAM BOILERS."
"IMPROVE
The objects of my Invention arc,-To provide a safety valve with a largo
escape area, and to combine therewith an automatic contrivance for opening the
safety valve when the water within the steam generator has become reduced to a
deterinined depth.
In constructing the safety valve, I employ a centre hollow pillar fixed to tho
shell of the generator, or boiler, haying at its lower end free communication
with the steam space within the same. At the top of this pillar is a valvo
seating.
In the centre of the corresponding valve, is a perforation of sufficient size to
permit the escape of steam into a transverse chamber which has at each end an
opening, and into such are fitted spherical valves, having attached thereto, a fork
which is loaded with cake or other adjustible weights, proportioned to the total
number of pounds, at which it is desired to fix the blow off.
When this pressure is attained, these two openings are simultaneously but
independently lifted up, and permit steam to escape. By this action the burden
of the two sets of weights, together with that of the two side valves themselves;
are lifted from the centre or large valve; which thus lightened, opens, and permits
the steam to escape from a large escape area. I prevent the side or smaller valves
from lifting too high, by means of the checking action of the crutch of the weight
carrying fork, closing upon the respective under exterior surfaces of the transverse
chambers. I prevent the larger or centre valve from rising more than requisite
by set screws through the outer casing; which act against a projecting part of the
hollow pillar formed to correspond.
In combination with this arrangement, I employ an apparatus which will auto-
matically open the side valves immediately the water within the boiler or steam
generator has become reduced to a depth previously determined.
This I accomplish by placing within the water space of the generator, a lever or
levers, turning on any suitable fularum, having at one end a float of firebrick or
other material, and at the other a balance weight. This lever or levers is attached
by suitable mechanism to the valve arrangement already described, in such manner
as to cause the valve to open for the escape of steam, whenever the float falls to a
determined point. The improvements in a modified form are also applicable to
steam economisers, bath and domestic boilers; and other water heaters with low
pressure.
But that the improvements may be better understood, I will by the aid of tho
accompanying Drawings, proceed more fully to described means employed by me.
DESCRIPTION OF DRAWINGS:-
Fig. 1 shows an elevation, Fig. 2, a part section, and part clevation, and Fig. 3
Fig. 1 shows an elevation, Fig. 2, a part section, and part clevation, and Fig. 3
shows a vertical section of portions of apparatus arranged according to my
Invention.
The same letters indicate corresponding parts wherever they occur.
aa is the central hollow pillar attached to the shell of the boiler or steam
generator, and having free opening into the steam space thereof.
At the upper end is a large valve c c, with corresponding seating B B perforated
to afford communication with a transverse chamber, at each end of which is a small
valve seating d, d; covering the apparatus is a saddle vv, which is connected with

page_text: the valves e e corresponding to the seatings d d. A crutched fork is attached to
each of these valves, having pendulous weights proportioned to the determined
pressure of blow-off and prevented from rising too far by the fork, being checked
by the under exterior surface of the transverse chamber.
On the upper inner surface of the boiler, is suspended a bracket oo, which carries
two eccentric sheaves or cams, which have attached thereto, a lever or levers con-
nected with the float u u, in such manner, that when the water sinks below the
determined point the float, or floats following it turn the eccentric sheaves or cams,
thereby raising the lifter P P. In the upper part of this lifter, is a socket, in which
works the lower end of a rod m m. This rod is so proportioned in length that
when the float reaches the low water point previously determined, the rod m m is
forced upwards against the saddle vv, which lifts up the valves e e allowing steam
to blow-off, and continuing to do so, until the deficiency of water is rectified ;
whether the water is heated or cold.
It will be seen that the whole of the upper part of the apparatus together with
the side valve loadings rests on the large valve cc: the weight of the whole is
proportioned to the pressure at which the blow-off is to take place; and consequently
when the steam rises to the determined pressure, this valve opens giving, a large
escape area; should this pressure be attained while the water is too low, the whole
of the valves will remain blowing, until the pressure is reduced, when the central
valve will at once return to its seating, while the side valves continue blowing.
In all cases, this central or larger valve is prevented from rising too high, by set
screws in the outer casing, which act upon corresponding projections on the central
pillar.
A portion of the apparatus may be used as a safety valve alone, as shown in
Fig. 1, or in combination with the blow off arrangement for low water as shown in
Figs. 2 and 3.
Having now described my improvements, and means I adopt in carrying the
same into effect, I would have it understood, that I do not confine myself to the
precise details shown and described, as variations may be made, without departing
from the peculiar character of my Invention.
But what I do claim is
First. The combination and application of apparatus to steam boilers and other
generators, forming a dead weight safety valve, exterior to the shell of such steam
boiler or generator, substantially as shown and described.
Second. The combination and application of apparatus within such boiler or
generator or safety valve, for the purpose of automatically relieving pressure by
opening the valves, upon the water falling to a determined level substantially, as
shown and described.
And third. The combination of a dead weight safety valve and apparatus for the
purpose of a low water blow-off, substantially as shewn and described.
In witness whereof I the said Joseph Sheldon Stubbs have hereunto set
my hand and seal, this Twenty-ninth day of June in the year of our Lord
One thousand eight hundred and eighty two.
Witness:
WILLIAM GADD
Consulting Engineer
64 Barton Arcade
Manchester.
JOSEPH SHELDON STUBBS. (L.S.)