IMPROVEMENTS IN APPARATUS FOR PREVENTING ACCIDENTS TO STEAM BOILERS, AND FOR DRAWING OFF STEAM THEREFROM, OR REDUCING THE PRESSURE OF SUCH STEAM; ALSO IN APPARATUS POR DRAWING OFF WATER PRODUCED BY THE CONDENSATION OF STEAM FROM PIPES OR VESSELS CONTAINING STEAM UNDER PRESSURE
Year: 1868

page_text: LETTERS PATENT to William Leatham, of Brooksfield Works, Hunslet
Road, Leeds, in the County of York, Mechanical Engineer, for the
Invention of "IMPROVEMENTS IN APPARATUS FOR PREVENTING ACCIDENTS
TO STEAM BOILERS, AND FOR DRAWING OFF STEAM THEREFROM, OR REDUCING
THE PRESSURE OF SUCH STEAM; ALSO IN APPARATUS POR DRAWING OFF
WATER PRODUCED BY THE CONDENSATION OF STEAM FROM PIPES OR VESSELS
CONTAINING STEAM UNDER PRESSURE."
Sealed the 16th March 1869, and dated the 22nd September 1868.
PROVISIONAL SPECIFICATION left by the said William Leatham at
the Office of the Commissioners of Patents, with his Petition, on
the 22nd September 1868.
I, WILLIAM LEATHAM, of Brooksfield Works, Hunslet Road, Leeds,
in the County of York, Mechanical Engineer, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN APPARATUS FOR PRE
VENTING ACCIDENTS TO STEAM BOILERS, AND FOR DRAWING OFF STEAM THEREFROM;
OB REDUCING THE PRESSURE OF SUCH STEAM; ALSO IN APPARATUS FOR DRAWING
[Price 8d.]

page_text: OFF WATER PRODUCED BY THE CONDENSATION OF STEAM FROM PIPES OR VESSELS
CONTAINING STEAM UNDER PRESSURE," to be as follows:-
In order to prevent accidents to steam boilers in consequence of the
supply of water being insufficient I mount on the top of the boiler a
chamber which near the bottom is connected by two pipes with the
interior of the boiler. These pipes are of different lengths; one of them
opens into the boiler at such a level that its mouth becomes uncovered
as soon as there is too little water in the boiler, the other descends lower
into the boiler. At the top of the chamber is an opening closed by a
valve and spiral spring attached to a float within the chamber. When
there is a proper quantity of water in the boiler so that both the con-
necting pipes dip into the water the pressure of the steam forces water
up the connecting pipes into the chamber and fills it until the float is
raised so as to raise the valve with the assistance of a spring to its seat,
preventing any escape from the chamber. Directly however the water
in the boiler sinks so as to leave uncovered the mouth of one of the
connecting pipes steam rises up this pipe, displaces the water from the
chamber, and the float being no longer supported falls, opening the
valve; immediately steam rushes through the opening and is led by a
pipe to a whistle, which it sounds. There is also a branch pipe leading
some of the escaping steam into the ash-pit beneath the fire-bars of the
furnace so that should the sound of the whistle be neglected the steam
rapidly extinguishes the fire. In some cases it is required to draw off
steam from a steam boiler at a much lower pressure than that at which it
is contained in the boiler, and to provide that whatever be the variations
of pressure in the boiler the steam shall be drawn off from it at a uniform
pressure. For this purpose I admit the steam from the boiler under-
neath a valve balanced by connecting it with a piston of equal area on
which the high-pressure steam also presses, so that in the result the
pressure of the steam in the boiler has no tendency to move the valve
either way. By means of weights however acting through a lever on
the stem of the valve a tendency is given to the valve to open, and the
steam passes
the valve and enters the pipe into which its supply at
low pressure is required. Directly however that the steam in this pipe
rises to the required pressure its back pressure on the valve becomes
sufficient to close the valve, lifting the weights by which it was kept
open, and so the further passage of steam from the boiler is prevented
until the pressure in the steam supply pipe again falls so as to allow the
weights to overcome the back pressure. The pressure at which the

page_text: steam is drawn off is thus kept quite uniform, and this pressure can of
course be adjusted by altering the weights. The same apparatus may
also serve as a check valve to cut off the steam altogether by the
addition of a screw with a hand wheel upon it so arranged that by
turning the hand wheel the screw is brought down on the valve and
locks it in its seat. The piston has a small valve inserted beneath, so
that if any water should accumulate beneath the piston the small valve
would open and allow the water to ascend into the chamber of the piston.
In order to draw off automatically condensed water from pipes or
vessels containing steam under pressure I connect with the pipes or
vessel a close chamber so placed that the condensed water accumulates
in it. Within the chamber is apparatus so arranged as to open a valve
at the bottom of the chamber when the temperature in it falls, and to
close the valve when the temperature rises. It will be seen that so long
as the chamber is filled with steam the temperature of the vessel will be
that of the steam and the valve will remain closed, but as soon as water
displaces the steam the temperature falls, for there is now no compensa-
tion for the loss of heat conducted away and escaping through the sides
of the chamber, consequently the valve is opened, the water runs out,
and the chamber again fills with steam.
The apparatus within the chamber consists of a double bow formed of
two metals having different rates of expansion, and which bow tends to
straighten itself and so to elongate as its temperature is increased. One
end of the double bow is fixed at the bottom of the chamber, the other
end is connected to this valve rod by a serises of levers to multiply the
motion. The first lever to which the double bow is connected has as its
fulcrum an iron link connecting it with the bottom of the chamber, so
that the position of this fulcrum does not materially vary with the
changes of temperature. Then as the double bow expands the part of
the first lever attached to it rises, whilst the end of the lever which is
beyond the fulcrum is depressed, and this end forms the fulcrum of a
second lever, which at its outer and is attached the valve rod.
The
motion given to the valve consists in part of the motion of the fulcrum
of the second lever as above described, and in part of a motion given to
the second lever about its fulcrum by means of a third lever connected
with its other extremity. The fulcrum of the third lever is upon the
first lever, but on the same side of its fulcrum with the double bow,
hence the fulcrum of the third lever rises, and as its outer end is
prevente rising by an iron link attaching it to the bottom of the

page_text: chamber, its inner end connected with the second lever rises, and its
outer end which is connected with the valve rod is depressed. In this
way a further downward movement is given to the valve rod. The valve
may consist of two tubes sliding the one on the other, and with openings
or ports in them which coincide or otherwise according to their positions
the one on the other. In place of these arrangements I sometimes
employ within the chamber a metal coil, by preference a coiled metal
tube; it is fixed at one end to the interior of the chamber, and at the
other end is connected with the valve. The chamber is made cylindrical
and the coil fits its interior. The expansion and contraction of the coil
at a different rate from the containing chamber causes the free end of
the coil to move through a sufficient space to work the valve; or a coiled
metal pipe filled with mercury may be similarly used.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Leatham in the Great Seal Patent Office
on the 16th March 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
LEATHAM, of Brooksfield Works, Hunslet Road, Leeds, in the County
of York, Mechanical Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-second day of September, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-second year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said William Leatham, Her
special licence that I, the said William Leatham, my executors, admi-
nistrators, and assigns, or such others as I, the said William Leatham,
my 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 APPARATUS FOR PREVENTING ACCIDENTS TO STEAM BOILERS AND
FOR DRAWING OFF STEAM THEREFROM OR REDUCING THE PRESSURE OF SUCH
STEAM: ALSO IN APPARATUS FOR DRAWING OFF WATER PRODUCED BY THE CON-

page_text: DENSATION OF STEAM FROM PIPES OR VESSELS CONTAINING STEAM UNDER
PRESSURE," upon the condition (amongst others) that I, the said William
Leatham, my executors or administrators, 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 William Leatham, 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 in and by the
following statement thereof, that is to say :-
In order to prevent accidents to steam boilers in consequence of the
supply of water being insufficient, I mount on the top of the boiler a
chamber which near the bottom is connected by two pipes with the
interior of the boiler. These pipes are of different lengths; one of them
opens into the boiler at such a level that its mouth becomes uncovered as
soon as there is too little water in the boiler, the other descends lower into
the boiler. At the top of the chamber is an opening closed by a valve
attached to a float within the chamber. When there is a proper quantity
of water in the boiler, so that both the connecting pipes dip into the
water, the pressure of the steam forces water up the connecting pipes
into the chamber and fills it until the float is raised so as to raise the
valve to its seat, preventing any escape from the chamber. Directly
however the water in the boiler sinks so as to leave uncovered the mouth
of one of the connecting pipes steam rises up this pipe, whilst the
longer pipe acting as a syphon displaces the water from the chamber,
and the float being no longer supported falls and so opens the valve.
Immediately steam rushes through the opening and is led by a pipe to
a whistle which it sounds. There is also a branch pipe leading some
of the escaping steam into the ash-pit beneath the fire-bars of the
furnace, so that should the sound of the whistle be neglected the steam
rapidly extinguishes the fire.
Figure 1 on Sheet 1 shows a vertical
structed as above described; Figure 2 on
section of an apparatus con-
Sheet 2 shows a side view of
an ordinary cylindrical boiler with such an apparatus applied to it;
Figure 3 is a plan view, and Figure 4 an end view of the same.

page_text: In these Figures a is the metal chamber applied to the top of the
boiler; b is a pipe descending from the bottom of the chamber into the
interior of the boiler; this pipe is divided into two passages 61, 62, by a
central division 63, as shown, the lower ends of both passages being open
to the boiler. Both pipes or passages are led down into the boiler
below the ordinary water level which it is desired to maintain in it; the
passage terminates at the level at which it is desired to sound an
alarm if the water in the boiler descends below such level, the
passage b2 descends lower into the boiler so as that its lower end shall
always be covered by the water therein. The advantage of dividing the
pipe 6 into two passages, one descending lower into the boiler than the
other, is that should the opening in the passage bl get stopped up by any
means the passage 62 would act to give the alarm, so rendering the
apparatus doubly safe; the passage 62 by acting as a syphon also aids
the steam to empty the chamber a of water when the end of the
passage becomes uncovered.
c is a float within the chamber a; this
float may either be made of sufficient strength to withstand the pressure
of steam in the boiler or it may have a pipe descending from it into
the boiler and rising up into the steam space therein, as shewn,
the pressure within the float may be the same as on its exterior.
tubular passage is formed through the centre of the float, through which
passes a tube d which descends down from the top of the chamber a; this
tube forms a guide upon which the float may rise and fall. The upper
end of the tube d is screwed on to a short brass tube e, which tube is
itself screwed into the top of the chamber a, as shown. At the lower end
of the tube is formed a seat for the valve e to close against; this valve
is formed at the upper end of a rod f, which passes down through the
tube d and carries at its lower end a collar f' on to which the float drops
when the vessel a is emptied of water; the rod f has also arms f² pro-
jecting from it; these arms pass through slots in the tube d, and the top
of the float comes against them and thereby lifts the rod f to close the
valve when water again enters the vessel a and the float is buoyed up
by it. fare arms projecting from the rod f near its upper end and
forming guides to guide the valve into its seat. A spiral spring may
be placed around the rod f with its lower end resting on a ring fixed
within the tube d, whilst its upper end bears against the arms 3 and
holds the valve against its seat until the float falls on to the collar at
the lower end of the rod f, the weight of the float will then open the
so that
A

page_text: Having now described the manner in which I prefer to construct the
apparatus, I would have it understood that I do not confine myself to
the precise details herein-described; what I claim as regards this part
of my Invention is, the combining apparatus for preventing accidents to
steam boilers substantially as herein described, such combined apparatus
consisting essentially of a chamber containing a float which when it
rises acts on a valve to close an exit orifice from the chamber, and also
of a pipe descending from the lower part of the chamber into the boiler
and opening into it, so that if the water level in the boiler rises above
the opening into the pipe water is forced up into the chamber and the
float by rising closes the exit orifice; but if the water level in the boiler
descends below the opening into the pipe steam passes up the pipe and
the water in the chamber being displaced by the steam flows back into
the boiler, so that the float falls, the exit orifice is opened, and the steam
escaping therefrom gives an alarm by sounding a whistle or otherwise.
In some cases it is required to draw off steam from a steam boiler at a
much lower pressure than that at which it is contained in the boiler,
and to provide that whatever be the variations of pressure in the boiler,
the steam shall be drawn off from it at a uniform pressure. For this
purpose I admit the steam from the boiler underneath a valve balanced
by connecting it with a piston of equal area on which the high-pressure
steam also presses, so that in the result the pressure of the steam in the
boiler has no tendency to move the valve either way. By means of weights,
however, acting through a lever on the stem of the valve a tendency is
given to the valve to open, and the steam passes the valve and enters
the pipe into which its supply at low pressure is required. Directly
however that the steam in this pipe rises to the required pressure, its
back pressure on the valve becomes sufficient to close the valve, lifting
the weights by which it was kept open, so that the further passage
of steam from the boiler is prevented until the pressure in the steam
supply pipe again falls so as to allow the weights to overcome the back
pressure. The pressure at which the steam is drawn off is thus kept
quite uniform, and this pressure can of course be adjusted by altering
the weights. The same apparatus may also serve as a check valve to

page_text: cut off the steam altogether by the addition of a screw with a hand
wheel upon it so arranged that by turning the hand wheel the screw
is brought down on the valve and locks it in its seat. The piston has
a small valve inserted beneath, so if any water should accumulate
beneath the piston a small valve would open and allow the water to
ascend into the chamber of the piston.
Figure 5 shews a longitudinal section, Figure 6 an end view, and
Figure 7 a plan view of an apparatus constructed as above described.
a is the valve underneath which steam from a boiler is admitted through
the pipe b. On the valve stem a¹ is a piston c working in a cylindrical
chamber. Below the valve d is a lever acting at one end on a collar on
the valve stem and at the opposite end acted on by a rod e on which
are placed weights f, so that the lever tends constantly to raise the valvo
until the back pressure of steam upon the top of the valve is sufficient
to close it. The piston c is not rigidly connected to the valve stem a¹,
but the valve stem passes through it and at its lower end carries a
valve a² upon which the piston rests, so that if any water accumulates
under the piston c to prevent it descending when the valve a is closed
by the pressure of steam above it the valve a² moves away from the
piston, and the water passes up through the centre of the piston and
allows the piston to descend on to the valve; or in place of this
arrangement for getting rid of any accumulation of water from beneath
the piston it might be drawn off through apparatus such as herein-after
described, or by other suitable apparatus. 9 is a screw with a hand
wheel upon it, by turning which the end of the screw can be brought
down on to the valve to hold it down and prevent steam passing
through it.
What I claim as regards this part of my Invention is, combining
apparatus for drawing off steam from a steam boiler substantially in the
manner herein described, such combined apparatus consisting of a valve
balanced by a piston of equal area, so that the steam from a boiler shall
have no tendency to open it, but which valve is acted on by a weighted
lever or by equivalent means to keep it open until the back pressure on
the valve is sufficient to close it.
In order to draw off automatically condensed water from pipes or
vessels containing steam under pressure I connect with the ning aruncat

page_text: a close chamber so placed that the condensed water accumulates in it.
Within the chamber is apparatus so arranged as to open a valve at the
bottom of the chamber when the temperature in it falls, and to close the
valve when the temperature rises. It will be seen that so long as the
chamber is filled with steam the temperature of the vessel will be that
of the steam and the valve will remain closed, but as soon as water
displaces the steam the temperature falls, for there is now. no compensa-
tion for the loss of heat conducted away and escaping through the sides
of the chamber, consequently the valve is opened, the water runs out,
and the chamber again fills with steam.
The apparatus within the chamber consists of a double bow formed of
two metals having different rates of expansion, and which bow tends to
straighten itself and so to elongate as its temperature is increased. One
end of the double bow is fixed at the bottom of the chamber, the other
end is connected to the valve rod by a series of levers to multiply the
motion. The first lever to which the double bow is connected has as its
fulcrum an iron link connecting it with the bottom of the chamber, so
that the position of the fulcrum does not materially vary with the
changes of temperature. Then as the double bow expands the part of
the first lever attached to it rises, whilst the end of the lever which is
beyond the fulcrum is depressed, and this end forms the fulcrum of
a second lever, which at its outer end is attached to the valve rod. The
motion given to the valve consists in part of the motion of the fulcrum
to the second lever as above described, and in part of a motion given to
the second lever about its fulcrum by means of a third lever connected
with its other extremity. The fulcrum of the third lever is upon the
first lever, but on the same side of its fulcrum with the double bow,
hence the fulcrum of the third lever rises, and as its outer end is
prevented rising by a link attaching it to the bottom of the chamber its
inner end connected with the second lever rises, and its outer end which
is connected with the valve rod is depressed. In this way a further
downward movement is given to the valve rod. The valve may consist
of two tubes sliding the one on the other, and with openings or ports in
them which coincide or otherwise according to their positions the one on
the other, or a conical or other valve may be employed.
Figures 8 and 9 shew two sections of an apparatus such as is above

page_text: the
rates of expansion. One end of the bow is fixed to the bottom of the
chamber b, and the other is connected by a pin to the lever c the
fulcrum c¹ of which is carried by a rod d of iron from the bottom of the
chamber, the opposite end of the lever of which is beyond the fulcrum.
c¹ carries a pin e which forms the fulcrum of a lever f, which at one end
is connected to the valve rod g, and at its other extremity is acted on by
one end of the lever h, the fulcrum of which is carried on the same side
of the lever as that to which the double bow a is connected ;
opposite end of the lever his connected by the iron rod k to the bottom
of the vessel b, so that as above stated when the double bow a expands
the valve rod will be depressed both by the downward motion of the end
of the lever c to which it is connected, and also still further by the
movement of the lever f. The valve is composed of a tube / sliding
over the end of the exit tube m, which projects up somewhat into the
vessel, as shewn. There is a side opening through the tube m and also
through the tube l, which when brought opposite to one another form a
passage from the chamber into the exit tube m, but when these
openings do not coincide the passage into the exit tube is closed.
In place of these arrangements I sometimes employ within the
chamber a metal coil, by preference a coiled metal tube; it is fixed
at one end to the interior of the chamber, and at the other end is
connected with the valve. The chamber is made cylindrical, and the
coil fits its interior. The expansion and contraction of the coil at a
different rate from the containing chamber causes the free end of the
coil to
move through a sufficient space to work the valve; or a coiled
metal pipe filled with mercury may be similarly used, or a
containing other metals may be used.
tube
Figure 10 shews a vertical section of an apparatus thus constructed.
a is a cast-iron case containing the coil of copper or brass tube b, fixed
at its upper end by the bolt c to the top of the case, and at its lower end
formed into a plate d, which by the contraction and expansion of the
tube is caused to cover and uncover the exit opening e formed at the
bottom of the vessel.
What I claim as regards this part of my Invention is, combining
apparatus for letting off condensed water substantially in the manuer
herein described, such combined apparatus consisting of a case con-

page_text: aining a valve actuated as herein described by metal bows or by coils
of metal contained within the case..
In witness whereof, I, the said William Leatham, have here-
unto set my hand and seal, this Third day of March, in
the year of our Lord One thousand eight hundred and sixty-
nine.
WILLIAM LEATHAM. (L.S.)
Signed, sealed, and
sealed, and
delivered
by the said William Leatham,
in the
presence of
WILLIAM HOMER COWLEY,
EDWARD WHITELEY,
Clerks to Messrs. Richardson & Turner.
Solrs.
Leeds.