CERTAIN NEW AND Serul ImproveMENTS IN BOILERS FOR STEAM CARRIAGES
Year: 1855

page_text: LETTERS PATENT to Charles Frederic Thomas, of the State of Massa-
chusetts, of the United States of America, for the Invention of "CERTAIN
NEW AND Serul ImproveMENTS IN BOILERS FOR STEAM CARRIAGES
COMPLETE SPECIFICATION filed by the said Charles Frederic Thomas at
the Office of the Commissioners of Patents, with his Petition and Decla-
ration, on the 8th August 1855, pursuant to the 9th Section of the
Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME,
BE IT KNOWN that I, CHARLES FREDERIC THOMAS, of the State of Massa-
chusetts, of the United States of America, have made an Invention of "CERTAIN
NEW AND USEFUL IMPROVEMENTS IN BOILERS FOR STEAM CARRIAGES," and I do
hereby declare that the said Invention is fully described and represented in the
following Specification, and the accompanying Drawings, letters, figures, and
references thereof :-
Of the said Drawings, Figure 1 denotes a central, vertical, and longitudinal
section of the rear half or portion of a locomotive steam engine boiler con-
structed in accordance with the principles of my Invention; Figure 2 is a
vertical and transverse section of it, such section being taken through the fire-
place or furnace, and on the line C, D, of Figure 1. Figure 3 is anothe

page_text: Figure 4 is a
Figure 5 is an
transverse and vertical section thereof, it being taken through the furnace, the
stack of smoke tubes, and through the line E, F, of Figure 1.
horizontal section, taken on line G, H, of Figures 1, 2, and 3.
under side view of the bottom of the ash-pit..
In the Drawings, I exhibits the furnace or fire-place of a locomotive steam
boiler, the same being provided not only with a grate, as seen at K, but with
an ash-pit under the same, as shown at L. The furnace is disposed within a
boiler M, and so that there shall be a water space extending around it, as seen
in the Drawings at N, N, N.
Instead of arranging the tube sheet O at the extreme back of the furnace
in the usual way, I bring it, or the boiler and the stack of smoke tubes P, P, P,
forwards into the furnace or fire-place I, as seen in Figures 1 and 3, and more
particularly in the former, the boiler or enclosing sheet of said tubes being
made to extend over the grate in such manner that the flame and gases from
the fire may not only pass against the said tubes sheet O, O, and the said
enclosing sheet R, R, but through the extended part of the tubes. By this
improvement a very great and highly important increase, of the extent of the
heating surface exposed to the fire is attained.
For the purpose of supporting the crown sheet T as well as the sides of the
furnace under the great pressure of steam to which such are exposed, I
employ the said extension R, R, of the boiler in the furnace, sustaining said
crown sheet thereon by means of suitable posts or standards; or by hollow
tubes U, U, as seen in Figures 1 and 3, through which communication may
be opened between the water space N, N, above the crown sheet, and that
within the extended part R, R, of the boiler. These hollow, tubes, having
their external surfaces subjected to the action of the smoke and volatile, pro-
ducts of combustion proceeding from the fuel of the furnace, serve to aid in
facilitating the introduction of heat into the water.
The above-described mode of sustaining the crown sheet T and portions of
the sides of the furnace (viz.) by means of the extension R, R, is a very
advantageous means of accomplishing such a result. Between the top of the
extension R, R, and the crown sheet 1 there is a flue space W, through which
the smoke and the gases from the fire are enabled to circulate, and not only
heat the crown sheet T, but at the same time impart heat to the extension
R, R.
In order to discharge the surplus heat and gases from the flue space
W, I carry a series of pipes X, X, X, out of the same, and through the water
space of the boiler, as seen in Figures 1 and 4.
For the purpose of readily discharging the ash-pit, I provide its bottom
with an opening, to which I apply a large door C', and so that said door may

page_text: turn downward on hinges; as seen at 'D': In order to close the opening, the
said door may be fastened by means of lever latches E', E', connected with a
hand lever by a lever G and joining rod H', as seen in Figure 5, each of
said latches being made to operate in combination with a suitable hook or
staple I' affixed to the ash-pit. I would take occasion to remark, that in con-
nection with the extension of the boiler and its tube stack into the furnace or
fire-place in the manner herein-before described, such boiler may be provided
with a series of hollow tubes, as seen at L' in Figures 1, 2, and 3, they being
made to project into the furnace to open into the water space surrounding it,
and to have their ends which are within the furnace closed. These tubes serve
as so many additional means of heating the water' or contents of the boiler.
Their application and use are not, however, to be understood as making any
part of my Invention.
;
The rear end of the ash-pit L, I provide with an opening or air blast passage
A¹ (see Figure 1), which I furnish with a revolving gate or damper B', and I
form and dispose each of the grate bars a, a, a, with respect to such passage as
seen in Figure 1, each grate bar being curved near its rear end, and in such a
manner that the blast of air made to enter the opening A¹ may be made to
pass into the side of the mass of fuel resting on the grate, as well as upward
through the bottom of the grate: In this way the blast or a portion thereof
is made to rush horizontally through the fuel as well as vertically into the
same, and it also passes in the same manner through the interstices between"
the grate bars, and in so doing serves not only to produce a better circulation
of the air through the fuel (and particularly when the grate is more or less
choked by coals or clinkers), but also to keep the grates cooler than would
be the case were such air blast only permitted to pass in vertical directions
between the grate bars.
Of the remaining portions of the Drawings, Figure 6 denotes a vertical
central and transverse section of the front half or portion of the boiler and
chimney of the said locomotive steam carriage having the remainder of my
improvements applied to it, the said section being taken in the plane of
the line C, D, of Figures 10, 14, 15, and 16, to be herein-after described.
Figure 7 is a front end elevation of the said front half or portion as it appears
without its air deflector or trumpet mouth. Figure 8 is a vertical and trans-
verse section, taken through the steam blast pipes, or on the line A, B, of
Figures 6, 10, 14, 15, and 16, such section being made to exhibit the parts on
the right of such line. Figure 9 is a similar section, but constructed so as to
represent the parts on the left of such line A, B. Figure 10 is a horizontal
section, taken on the line G, H, of Figures 6, 7, 8, 9 and 11, such section

page_text: exhibiting the partition between the air passage and the smoke box, as well
as the central valves as open, and the outer valves as closed. Figure 11 is a
rear view of the deflector and its system of valves and air openings. Figure 12
is a horizontal section of the same, taken on the line G, H, of Figure 11, the
middle or central valves being represented as closed, while the outer valves are
shown as open. Figure 13 is a top view of the air passage, damper, or valve.
Figure 14 is a plan or top view of the box or contrivance for receiving the
exhaust steam from the cylinder and carrying it either to the chimney or to
or through the water tank of the engine, as occasion may require. Figure 15
is a horizontal section of such, the said section being taken on the line I, K²,
of Figures 6, 7, and 9, and made to show the valves of the tank pipes as open.
Figure 16 is a similar horizontal section, with the exception that the valves
of the tank pipes are exhibited as closed.
In most locomotive engines or steam carriages the draft is accelerated by
permitting the waste steam to escape into the chimney through blast pipes,
their upper ends or mouths being generally contracted, in order to compress
the steam and prolong the time of its emission; the production of steam by
the boiler is consequently increased, but the pressure of that arrested for the
purpose of creating draft acts, as it were, contrary to the movement of the
piston, and tends to diminish the motive power. This loss of power becomes
very considerable at high velocities. Under ordinary circumstances the con-
traction of the mouths of the blast pipe creates a loss of power from 35 to 40
per cent. of the actual power of the steam. I have therefore sought to apply
to locomotive engines some contrivance which, while it would enable me to
dispense with the contracted mouths of the blast pipes, would improve the
draft sufficiently for all practical purposes.
In carrying out my Invention, I provide the chimney I with a secondary
chimney K, which is arranged therein as seen in Figures 6, 7, 8, and 9,
and I surround the same by au air passage M, M, which is made to com-
municate with an opening or passage L, formed through the front end of
the engine. The air passage or chamber M, M, lies between the main
chimney and the said secondary chimney, but not only has no communication
with the main chimney excepting at the top of the secondary chimney, but
when in use has none with the smoke box O.
The blast pipes are shown at N, N, in the Drawings as leading into the
smoke box O, which communicates with the fire-place by pipes P, P, extend-
ing through the boiler in the ordinary way. The opening or passage I, before
named, I provide with butterfly valves, as seen at S, S, in Figures 6, 10, 11,
and 12, and I also furnish said passage with a trumpet mouth or deflector T,

page_text: so formed as to cause the air against which its front surface impinges while
the engine is running on the railway to pass towards and into the opening L,
provided the valves thereof be not closed. The diameter of this deflector T is
made somewhat greater than that of the smoke box O, the deflector near its
periphery being carried backward, as seen at a, a, the rearward curve of it
constituting what may be termed a reverse deflector, its purpose when the
engine is run backwards being to deflect air into other openings U, U, arranged
around the opening L, as seen in Figures 6, 11, and 12; the said openings U; U,
being made through the front head of the engine, and so as to lead the deflected
air into the passage M, M, of the said openings U; U; an annular valve plate
V is applied, it being so formed as to enable us either to close them or uncover
them, as occasion may require. The said annular valve plate is so connected
with the butterfly valves S, S, by means of rods or links W, W, jointed both
to it and the valves, that when it is turned in one direction, or so as to close
its valves, it shall open the butterfly valves, and when turned so as to open its
valves, it shall close the butterfly valves. For convenience of obtaining access
to the smoke box, the front of the part K may be provided with an opening
and closing port or man-hole, as seen at X, in Figures 6 and 7, and the whole
front head Y of the engine may be applied to the body of it by means of a
hinge, as seen at Z, such enabling such end together with the deflector I to be
turned around, so as to have the whole front of the passage M entirely open.
The upper part of said passage M, I provide with annular valve, as seen at
c, in Figures 6, 8, 9, and 13. This valve when depressed contracts the dis-
charging mouth of the passage M, and the current of air which rushes out of
the same and over the top of the secondary chimney K. By so contracting
the said tubular column of air passing out of the passage M, the draft up the
chimney K will be materially promoted. The conical passage through the
valve serves to produce such contraction of the air. The stem of the valve
carries a toothed rack d, which works in a pinion e fixed upon a shaft f. By
rotating the said shaft the valve may be either raised or lowered at pleasure.
By means of my Invention I am enabled to employ steam blast tubes N, N,
without contracted mouths of discharge, the steam carriage while going either
forward or backward being made to operate its air draft apparatus so as
to produce sufficient draft to keep up the necessary supply of steam.
I am
also enabled to accomplish this with a great saving of fuel in comparison with
what is consumed when the blast tubes are constructed with contracted mouths
of discharge.
The box or chamber X' (see Figures 6, 7, 8, 9, 14, 15, and 16,) is provided
with, one or more openings a', a', for the reception of the exhaust steam from

page_text: the cylinders. It also has one or more eduction pipes 61, 61, leading from it,
they being carried into or through the valve of the tank of the "tender" of
the engine. These eduction pipes are furnished with valves c', c¹.
From the above
The blast pipes N, N; are made to lead out of the chamber X' and into the
chimney K, and they may be so applied to the box X' as to slide vertically in
tubes d¹, d', and respectively down upon conical seats e¹, e¹:
it will readily be seen, that when the valves of the tank tubes b', b', are opened
and the blast tubes down on their conical' seats, the steam from the box X¹
will flow through the tank tubes to or through the water of the tank, and be
made to heat the same; but when the valves of the tank tubes are closed,
and the blast tubes raised above their seats, the exhaust steam will rush up
the blast tubes into the chimney."
I claim the improvement of extending the tube sheet '(0), smoke tubes
(P, P), and boiler (M), or its enclosing sheet R, and into the fire-place (I),
and over the fire grate (K), in manner described and shown in Figures 1, 2,
3, and 4, in order not only that the part so extended may serve as a beam or
strut to support the crown sheet against the superincumbent' pressure of the
steam, but that the flame and gases from the fire may not only pass against
the tube sheet and enclosing sheet R of the extended part of the boiler, but
also through the extended parts of the tubes within such projected part of the
boiler as specified, the same serving to greatly increase the extent of heating
surface exposed to the fire.
I also claim the above-described arrangement of the grate bars a, a, , and the
air-blast passage 'A', with respect to each other, so that the entering blast of
air may pass into the side of the mass of fuel as well as up through its bottom,
the same serving not only to produce better circulation of the air and draft,
but to keep the grates cooler, than is the case when the air passes only
upwards through them, and they are more or less clogged with clinkers
or fuel.
I do not claim combining with a chimney a 'tube for receiving a current
of air and injecting it into the chimney in order to improve its draft; nor
do I claim a steam eduction pipe with the chimney of a locomotive steam
carriage, that the steam 'proceeding from the pipe may be caused to flow or
rush up the chimney so as to improve its draft; nor do I claim combining
with the furnace of a locomotive steam engine an air blast apparatus; nor
do I claim merely arranging on the front of a chimney or flue of a locomotive
steam carriage a funnel or mouth for introducing air into the flue or
chimney, and increasing its draft when the carriage is in motion so as to carry
the funnel or mouth against it; but what I do claim is, combining with an

page_text: air-receiving mouth L (arranged on the front end of the locomotive steam
carriage) the chimney I and the smoke box O, a secondary chimney K, and a
concentric or surrounding air passage M, (see Figures 6, 8, 9, 10, and 12,)
whereby when the steam carriage is in movement on the railway a current of
air may be caused to rush into the chimney, and around and about the mouth
of the secondary chimney, and so as to aid in increasing the draft through the
smoke tube, as specified.
And in combination with the air deflector T, the air passage L, and one or
more closing valves to the former, I claim the curved deflector a, one or more
other mouths or openings U, U, and a closing contrivance or annular valve V,
(see Figures 6, 8, 9, 10, and 11,) the same being so applied as to enable the
engine either in moving forwards or backwards to cause a current of air to
enter its chimney, in manner and for the purpose as specified.
I also claim the manner in which the valve e is made and applied to the
passage M and the secondary chimney K, (see Figures 6, 8, 9, and 13,) in
order that it may not only serve to diminish the discharging mouth of said
passage, but deflect or contract the tubular current of air passing out of it, and
so as to improve the draft, as stated.
I also claim combining the blast pipes and eduction or tank pipes with a
chamber X', and in manner substantially described, that the exhausted' steam
in such chamber may be led either into or through the tank or into the
chimney, as specified.
In testimony whereof, I have hereunto set my signature and seal, this
Twentieth day of July, in the year of our Lord One thousand eight
hundred and fifty-five.
CHARLES FREDERIC THOMAS. (L.S.)
CHARLES FREDERIC THOMAS. (L.S.)