IMPROVEMENTS IN STEAM BOILERS, AND IN VALVES AND PARTS CONNECTED THEREWITH
Year: 1855

page_text: LETTERS PATENT to Thomas Cowburn and George Walker Muir, both
of the City of Manchester, in the County Palatine of Lancaster, En-
gineers, for the Invention of "IMPROVEMENTS IN STEAM BOILERS, AND IN
VALVES AND PARTS CONNECTED THEREWITH."
Sealed the 18th March 1856, and dated the 24th December 1855.
PROVISIONAL SPECIFICATION left by the said Thomas Cowburn and
George Walker Muir at the Office of the Commissioners of Patents,
with their Petition, on the 24th December 1855.
We, THOMAS COWBURN & GEORGE WALKER MUIR, both of the City of
Manchester, in the County Palatine of Lancaster, Engineers, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN STEAM BOILERS,
AND IN VALVES AND PARTS CONNECTED THEREWITH," to be as follows:-
The improvements relate to forming steam boilers with vertical
passages uniting the outer shell and external flue with the internal flues,
the latter being formed of cells or chambers, separated from each other
by water partitions, having openings by tubes or. flues for the passage of
the products of combustion through them.
Also, to the application of bladed or fan shafts, either hollow or solid,

page_text: placed under the internal flues, and passing through the whole or part
of the boiler, which, when set in motion, will cause the water in the
lower parts to pass towards the upper parts of the boiler.
Also, to forming the supply pumps to the boiler with a hollow ram,
permitting the passage of water into and through them, the valves of
the pumps being segments of a sphere, with the weight placed below the
surfaces in contact. The pump is formed in connection with a column
of water in an air vessel, through which the exhaust steam may be
passed.
Also, to forming the float wheel water indicator, for indicating the
height of water in the boiler, with an equilibrium valve connected by a
sliding tube with a float in the boiler.
Also, to forming the glass water guages, for indicating the height of
water in the boiler, with adjustable parts, so as to suit various lengths
of glass tube used therewith.
Also, to constructing the feed and overflow valves to the boiler with a
float attached to the feed valve, and applying the overflow in a chest
capable of being placed on the summit of a stand feed pipe.
Also, to the construction of the stop valves with spherical surfaces,
having spindles applying pressure at a point below the seating, the
spindle passing through a nut secured into the valve.
Also, to forming the valves for the discharge of mud from boilers of
a ram shape, the foot being convex.
The side of the ram closing one
opening and the convex foot another opening.
Also, to forming a fusible plug cup, the bottom of which screws on to
the sides. The cup is fixed over a hole upon the top of the flue in an
inverted position. The bottom is perforated with holes, which holes
are filled with lead or other fusible substance.
Also, to constructing the safety valve to boilers of a convex form, and
with a hollow or tubular spindle passing clear through. The spindle
is carried into the boiler and connected to a swivel valve actuated by a
lever and float.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Cowburn and George Walker Muir in the Great
Seal Patent Office on the 24th June 1856.

page_text: COWBURN and GEORGE WALKER MUIR, both of the City of Manchester,
in the County Palatine of Lancaster, Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of December, in the year*
of our Lord One thousand eight hundred and fifty-five, in the nineteenth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto us, the said Thomas Cowburn and George Walker Muir, Her
special licence that we, the said Thomas Cowburn and George Walker
Muir, our executors, administrators, and assigns, or such others as we,
the said Thomas Cowburn and George Walker Muir, 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 "IMPROVEMENTS IN STEAM BOILERS,
AND IN VALVES AND PARTS CONNECTED THEREWITH," upon the condition (amongst
others) that we, the said Thomas Cowburn and George Walker Muir,
our executors or administrators, by an instrument in writing under our
or their hands and seals, or under the hand and seal of one of us or them,
should particularly describe and ascertain the nature of the said Inven-
tion, 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 Thomas Cowburn and George Walker
Muir, 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:
The improvements relate to forming steam boilers with vertical
passages uniting the outer shell and external flue with the internal flues,
the latter being formed of cells or chambers, separated from each other
by water partitions, having openings by tubes or flues for the passage
of the products of combustion through them.
Secondly, our improvements relate to the application of bladed or fan
shafts, either hollow or solid, placed under the internal flues, and pass-
ing through the whole or part of the boiler, which, when set in motion,
cause the water in the lower parts to pass towards the upper parts of
the boiler.
Thirdly, our improvements relate to forming the supply pumps to the
boiler with a hollow ram, permitting the passage of water into and
through them, the valves of the pumps being segments of a sphere, with
the weight placed below the surfaces in contact. The pump is formed

page_text: in connection with a column of water in an air vessel, through which the
exhaust steam may be passed.
Fourthly, our improvements relate to forming the float wheel water
indicator, for indicating the height of water in the boiler, with an
equilibrium valve connected by a sliding tube with a float in the boiler.
Fifthtly, our improvements relate to forming the glass water guages,
for indicating the height of water in the boiler, with adjustable parts,
so as to suit various lengths of glass tube used therewith.
Sixthly, our improvements relate to constructing the feed and over-
flow valves to the boiler with a float attached to the feed valve, and
applying the overflow in a chest capable of being placed on the summit
of a stand feed pipe.
Seventhly, our improvements relate to the construction of the stop
valves with spherical surfaces, having spindles applying pressure at a
point below the seating, the spindle passing through a nut secured into
the valve.
Eighthly, our improvements relate to forming the valves for the dis-
charge of mud from boilers of a ram shape, the foot being convex. The
side of the ram closing one opening and the convex foot another opening.
Ninthly, our improvements relate to forming a fusible plug cup, the
bottom of which screws on to the sides. The cup is fixed over a hole upon
the top of the flue in an inverted position. The bottom is perforated
with holes, which holes are filled with lead or other fusible substance.
Tenthly, our improvements relate to constructing the safety valve to
boilers of a convex form, and with a hollow or tubular spindle passing
clear through. The spindle is carried into the boiler, and connected to
a swivel valve actuated by a lever and float.
But that the nature of our said Invention, and in what manner wo
carry the same into effect, may be more fully understood, we will pro-
ceed to describe the Drawings annexed.
DESCRIPTION OF THE DRAWINGS.
We would, however, first state, that formerly it was usual to have
the furnaces of steam boilers constructed externally of their outer cir-
cumference and under them. This system was faulty, inasmuch as the
whole mass of water of several feet in depth being above the fire, it was
necessary, before obtaining the steam of the pressure required, to have
the whole mass of water within the boiler heated to boiling heat.
Of late it has become more general to construct the boilers with one
or more flues within the outer circumference of the boiler, and to place

page_text: the furnace or furnaces within the said flue or flues. But by this latter
arrangement only a small portion, comparatively, of the water in the
boiler is above the fire, and thus steam of the pressure required can be
obtained in a much shorter time from the lighting of the fire than was
the case when the furnace was placed under the boiler. It has, how-
ever, been found, that although steam of the required pressure can be
more quickly obtained by this arrangement, that it is open to serious
objection, inasmuch as although the water above the fire may be boiling
and producing steam, that greater portion under the line of fire is kept
at a comparatively low temperature, indeed is seldom at a temperature
high enough to produce steam. A loss of capital is thus caused by the
expenditure on boiler plate, which is not available for steam raising;
while the different temperature of the upper and under portions of the
boiler has a tendency to lessen its durability by loosening the rivets
and joints, leading in some cases to disastrous consequences.
Our improvements then relate to constructing boilers of a form which
will admit of the application of a fire both under the boiler, as was
formerly the case, and within the boiler, as has of late been the general
custom, by which arrangement the advantages of both systems are
secured, and the defects avoided.
Figure 1 shows a longitudinal vertical section of a steam boiler and
parts arranged according to the first part of the Invention; Figure 2 is
a transverse section, Figure 3 a front view, and Figure. 4 sectional
plan view, of the seating of the same. In each of these Figures the same
letters indicate similar parts.
a is the outer casing of the boiler; and b, a fire or furnace chamber
within it, the flame and particles of combustion from which pass by the
internal flue c, c, to the side flues d, d. And it will be seen that the
internal flue c is formed in several parts or compartments to admit of
water space and consequent increased heating surface between them,
whilst they are connected together by passages c', c', which we find
it desirable to arrange in such manner that the succeeding ones may
not be in the same line, in order thereby to break the direct current of
the flame and heated particles in passing from one to a succeeding com-
partment. The arrangement of these connecting passages c¹ which we
have found best to answer is, with one on the top row and two to the
bottom row, connecting the fire or furnace chamber 6 with the adjoin-
ing chamber c; two to the top row and one to the bottom row, connect-
ing that chamber c with the next chamber c; two in each row next,
and so on; but these numbers, as may also the diameters and lengths of
the passages c', may be varied to a considerable extent. These chambers

page_text: c are also connected by passages with the flue è for the passage of the.
flame and particles of combustion from a fire-place or furnace f placed
under the boiler. By these passages c², not only will the flame and pro-
ducts of combustion from the two fire-places or furnaces mingle together,
and a greatly increased heating surface to the boiler thereby be obtained,
but they serve to prevent an accumulation of dirt and matters in the
chambers c, as well as to facilitate ingress thereto for repairs or other-
wise. Such application of passages to connect chambers c with a flue
under the boiler is also applicable to other arrangement of internal flue
than that shown. The dirt and other matters falling in the flue e are
by the inclined form of the bottom thereof caused to accumulate at e',
where they may readily be removed by an opening provided for the pur-
pose. fare the bars of the fire-place or furnace f, and it will be seen
that they incline upwards on each side so as to aid the heat therefrom
in acting more directly upon the boiler; are furnace doors to the parts
of the furnace or fire-place f. The heat and products of combustion
from the flues having mingled together, pass by the passage d on one
side of the boiler back towards the front thereof, where that passage
descends, and rises again to a similar flue on the other side of the boiler.
conducting to the stack.
.
We will now proceed to describe the second part of our improvements,
which is shewn applied by the longitudinal and transverse sections of a
boiler at Figures 5 and 6. In steam boilers with internal fire-places
only, it is well known that the direct heat is given off mainly to the upper
surface of the water therein; consequently, whilst steam may be generat-
ing from the upper surface of the water, the lower surface thereof may
be comparatively cold, and this is especially the case with boilers in
which two internal fire-places are employed, arranged side by side, by
reason of the increased water space produced at the lower part of such
boiler; and the object of this part of the improvements is to give cir-
culation to this water to cause it to rise and mingle with that in the upper
portion. h, h, are axes, of which we have shown two; but this number
may be varied. Upon each of which are formed or affixed blades or
vanes h', as also screw wheels h², which are taken into and driven by the
worm wheel h³ upon the axis h', which passes through the stuffing box
h formed in the boiler, and has affixed to it the drum or pulley he to
receive a band or strap, set in motion by the steam engine or other power,
thereby to give rotary motion to the axes h, h, in order that the blades
or fans thereon may give the desired motion to the water.
We will now proceed to the describe the third part of our Invention,
which is shewn by sectional view at Figure 7, by external view at

page_text: Figure 8, and by plan view at Figure 9. i is a steam cylinder, to which
steam is supplied in any way desired. At the lower part of this cylinder
i is formed a chamber j, having in connection therewith the hollow
rod j. This hollow rod j', which is stationary, is embraced by the
hollow moveable plunger, to which motion is given from the piston of
the engine by its being affixed to the cross head ', which by the rods k³
is connected to the upper end of the piston rod i'. The hollow plunger /
moves up and down in the cylinder 1, which with the chamber j is
formed with inlet and outlet passages and valves, in order that, in the
to and fro motion of the hollow plunger k, water may be alternately
drawn into and forced out from those chambers ; and l. The passages
and valves to the chamber are clearly shewn in one of the Figures of
the Drawings. The valves to the chamber j are only shewn in the plan
view, and are of a similar character. The valves m, it will be seen,
are of the form of segments of spheres, and rest in seatings of a similar
form. They have also stems m' which act as pendulous weights to keep
them properly in their seatings, whilst they are prevented rising too
high by the projections n from the covers n¹. The water raised is
forced from the chambers j and by suitable passages into the lower
part of the chamber o, and thence by a suitable passage to the boiler.
The chamber o serves as an air vessel to render the supply uniform.
We will now proceed to describe the fourth part of our Invention,
which is shewn by Figure 10. p represents a portion of a boiler; and
q, a float resting upon the surface of the water therein, whilst q' is the
counterbalance weight affixed to the end of a. chain or band q, which
passes over the wheel q", supported upon the standard q' from the boiler;
but in place of this chain or band being connected to the float by means
of a solid rod sliding through a stuffing box, we form such rod tubular
(r), with openings (¹), at the lower end to steam way of the boiler, so
that when steam is generated it may pass therein; and we also form
other openings at the upper end of the tube, which are under ordinary
circumstances closed, by being surrounded by the cap. But in the
event of the water in the boiler descending below a given level, the tube
7 in descending with the float will bring the cap upon the stationary
ring s, by which that cap will be removed from over the passages,
admitting the escape of steam through them to indicate the want of
water; and, if desired, these openings may be formed so that the escape
of steam therefrom shall produce a whistle or other sound.
We will now describe the fifth part of our Invention, which is shewn
applied by sectional and external views at Figures 11 and 12. t is a
portion of a boiler, and u, u, passages therefrom, with taps by which

page_text: communication is maintained, as is well understood, through a glass
tube between the upper and lower portion of the boiler; the height of
the water in the boiler being indicated by the height of the water in
the glass tube. But it often happens that the glass tube at hand when
required is not sufficiently long for the particular case; and this part
of our improvements consists in applying adjustable means, so that
tubes of different lengths may be used in any one case. vis a glass tube,
which is held at its lower end in the ordinary way; but at its upper end
it is fitted to the end of a metal tube v¹, which is capable of sliding
through the stuffing box u¹ in the chamber us, formed upon the end of
the upper passage u. This chamber u also serves as a means of using
various lengths of glass tube independently of the lengthening tube v¹.
We will now describe the sixth part of our improvements, which is
shewn by a sectional view at Figure 13. w is part of the upper
portion of a steam boiler; and x, a float at the end of the lever ¹,
resting upon the surface of the water in such boiler. The lever x¹ turns
upon the fixed axis x³, and at its other end a³ it is connected to one
end of the rod x', the other end of which is connected to the valve x,
opening into the water chamber ; by which, when the water descends
below a given level, the valve will be raised to admit water from the
reservoir, to give the desired supply. y is another passage to the
chamber a, closed by a weighted valve y', for the escape of steam
thereto when its pressure in the boiler exceeds the weight on the
valve y¹. The valve y¹ is connected to the lever arm y, whose outer
end is connected by the chain y³ to the valve x, in order, when steam
escapes from the valve y', it may be the means of admitting cold water
into the boiler by the valve 25, to reduce the temperature of the water
in the boiler. z is another passage to the chamber x, closed by a
weighted valve 2', in order that when the quantity of water forced into
the reservoir exceeds that required by the boiler, the surplus may escape
by the passage 22.
In order to give strength to the floats we form them of two dissimilar
hollow chambers, the one being capable of sustaining and giving strength
to the other, and the forms which we prefer are a sphere within an oval
figure.
We will now describe the seventh part of our improvements, which
is shewn by a sectional view at Figure 14. A is the valve, the surface
of which for resting on the seating is of a spherical form, and the part
of it which receives the pressure of the spindle B, for lifting and lower-
ing it, is continued below such bearing surface, whereby, when pressure

page_text: is applied to the valve, the tendency will be to draw it correctly into its
seat.
We will now proceed to describe the eighth part of our Invention,
which is shewn by sectional view at Figure 15. We would here state,
that it is common to apply slide valves, as also convex or conical valves,
but we are not aware of the two forms being combined to operate together
as one. C is the passage from the boiler, which is closed by the side
surface D of the valve, which it will be seen is formed hollow as a ram,
and is operated for closing by the spherical end E of the screw E' acting
upon the lower part of the interior of the ram. And this lower part D'
of the ram is formed externally of a convex figure, capable of closing
tightly the passage F, by which it will be seen that by one operation a
double sealing will be effected. The end E of the screw E' is con-
nected to the valve D by a pin E, as shewn, in order that it may raise
that valve in the rising of the screw by the rotation of the spindle G.
G' is a fixed stop moving in a slot in the valve, to prevent that valve
rotating.
We will now describe the ninth part of our improvements, which is
shewn applied in plan and sectional views at Figures 16 and 17. H is
a screw cap screwed on to a rim fitted over a hole in the flue of the boiler.
This cap is perforated with several small holes, which are filled with lead
or other soft metal, capable of being readily fused when uncovered with.
water. We would here state, that we are aware that it is not new to
apply lead or other soft metal fusible at a low temperature to the flues
of steam boilers when separately considered; and this part of our
improvements consists simply in employing several small surfaces of
such metal in a screw cap, capable of being replaced, in lieu of one
larger surface, by which greater strength is obtained with facility of
replacement.
And we will now describe the last part of our improvements, which
is shewn by Figure 18. I is a spherical valve for the escape of the
steam when the pressure thereof exceeds that of the weights I', applied
to the valve I. The stem I of the valve I is tubular, forming a passage
through it to the chamber J, from which there are openings K, K, to
the interior of the cylinder J', forming the inner surface of the chamber
J, which openings K are capable of being closed, as shewn, by the
surfaces of what we have called the swivel valve L, and we have called
it a swivel valve, because it is simply supported by resting upon the
surface of the cylinder J', aided by the pressure of the steam in the
boiler, and is capable of accommodating itself, as will be seen, to the
varying position of the parts.'

page_text: Thus, the valve L is connected to and forms the axis of the lever M,
one end of which supports the float N, for resting upon the surface of the
water in the boiler, whilst the other end has affixed to it the counter-
balance weight o. Supposing the water in the boiler to descend below
a given level, by the float descending the valve L will be turned in its
cylinder J', so as to uncover the openings K, and admit of the steam
passing to the chamber. J', and thence away by the tube J; but supposing
the pressure of the steam to increase beyond that of the weights I', with-
out any diminution of the quantity of water in the boiler, the valve I
will be raised, raising with it the axis L and lever M, until the upper
end of the stem N' of the float N, by coming against the upper surface
of the boiler, by preventing the upper end of the lever M rising further,
will cause the valve L to turn so as to uncover the openings K, and
admit of the steam also escaping by the passage J, as before explained,
.until by such escape the pressure within the boiler is reduced, when the
parts will fall into their original position. The valve L with the hollow
tube J may also be applied to the boiler separately of the valve I.
Having thus described the nature of our said Invention, and the means
we adopt in carrying the same into effect, we would have it understood
that we do not confine ourselves to the precise arrangements shewn, so
long as the peculiar character of any part thereof be retained; but what
we do claim is,―
First, the forming steam boilers with means for combining the flame
and heating products from fires placed internally and externally thereof,
as explained. Also the forming the internal flues in separate cells or
chambers, separated by water spaces, and connected by smaller passages,
as explained.
Secondly, we claim the application of rotating shafts with blades or
fans within the boiler, for obtaining circulation to the water therein, as
explained.
Thirdly, we claim the supply pumps to boilers with a hollow ram,
acting in manner and for the purpose explained.
Fourthly, we claim the application of a tubular slide to the float in
the boiler, as explained.
Fifthly, we claim the forming adjustable parts to glass water guages,
as explained in respect of Figures 11 & 12.
Sixthly, we claim the mode of combining the feed and overflow valves
of boilers, as explained in respect of Figure 13.
Seventhly, we claim the forming stop valves of steam boilers with
spherical surfaces, having the pressure thereto applied at a point below
the seating, as explained in respect of Figure 14.

page_text: Eighthly, we claim the mode of forming valves for the discharge of
mud from boilers, as explained in respect of Figure 15.
Ninthly, we claim the mode of forming fusible plugs to boilers, as
explained in respect of Figures 16 & 17.
And, lastly, we claim the arrangement and combination of parts
forming a safety valve, as explained in respect of Figure 18.
In witness whereof, we, the said Thomas Cowburn and George
Walker Muir, have hereunto set our hands and seals, this Twenty-
first day of June, in the year of our Lord One thousand eight
hundred and fifty-six.
THOMAS COWBURN.
(L.S.)
Witness,
THOMAS BROWN.
5 Witness,
GEORCE FALKNER.
GEORGE WALKER MUIR. (L.S.)