IMPROVEMENTS IN CONTROLLING THE DRAFT AND IN DISPOSING OF THE SPARKS IN LOCOMOTIVE BOILERS
Year: 1873

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of
" IMPROVEMENTS IN CONTROLLING THE DRAFT AND IN DISPOSING OF THE
SPARKS IN LOCOMOTIVE BOILERS." -A communication from abroad by
Jackson Richards, George Washington Wait, Ezekial Cooper
Shapley, and Charles F. Jones, all of Philadelphia, Pennsylvania,
United States of America
Sealed the 21st April 1874, and dated the 18th November 1873.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition,
on the 18th November 1873.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN CONTROLLING THE DRAFT AND IN DISPOSING
OF THE SPARKS IN LOCOMOTIVE BOILERS,' a communication to me from
abroad by Jackson Richards, George Washington Wait, Ezekial Cooper
""

page_text: Shapley, and Charles F. Jones, all of Philadelphia, Pennsylvania, United
States of America, to be as follows:
This Invention relates to that class of steam boilers in which the
exhaust steam of the engine is discharged into the chimney for the
purpose of increasing the draft, and the object of the Invention is the
general equilization of the draft, the attainment of economy in the con-
sumption of fuel, the prevention of the abstraction of large masses of
ignited fuel from the fire-place, and the effectual disposal of the sparks
which find their way into the chimney.
According to one mode of carrying out this Invention it is proposed
to place within the chimney and above the blast pipe a check, which is
the prominent feature of this Invention, as it neutralizes the violent
pulsation of the exhaust steam. This check may be constructed in
many different ways. In the present instance it consists of an inverted
corrugated cone, the corrugations where the check has the largest
diameter extending to the chimney, to which the cone is secured in any
suitable manner.
While the inverted cone checks the violent pulsations
of steam sufficient space is presented for the passage of the steam and
sparks between the corrugations.
To the top of the cone, which it is preferred to make inclined for the
purpose explained hereafter, is attached the lower end of a tubular
screen of wire gauge, perforated plates, or wire netting, and this screen
is by preference corrugated round its sides longitudinally.
The shape of the screen will in a great measure be determined by
that of the chimney. In the present instance the lower portion is
cylindrical, or it may have a slight taper, and larger in diameter above
than below, the upper portion being of a tapering form conforming or
nearly so with the exterior shape of that portion of the chimney, within
which it is situated.
The upper edge of the screen is so united to the upper edge of the
chimney that the space between the two is closed at the top, and to the
top of the chimney above the open top of the screen may be secured a
casing with bevelled sides.

page_text: roughened or serrated annularly, and the pipe being so connected to the
chimney that it can be adjusted vertically to and from the check.
The blasts of steam as they escape from the exhaust pipe are arrested
and their force in a measure neutralized by the check, hence there is
not within the tubes of the boiler those violent and intermittent
pulsations which disturb the fuel in the fire-places of ordinary locomotive
boilers, and which tend to force masses of ignited fuel through the tubes
and through the smoke box into the chimney; while large particles of
ignited fuel however are thus prevented from gaining access to the
chimney small particles or sparks must necessarily be induced by the
escaping steam to pass through the tubes and enter the lower flaring
end of the short pipe, with the interior of which many of the sparks
must be brought into violent contact and disintegrated by the roughened
inner surface of the said pipe. These disintegrated sparks together with
many which are not brought into contact with the said roughened
surface are projected upward through the corrugations of the check and
impinge against the screen, through the meshes of which and through
the chimney they will pass in particles too minute to be a source of
injury as regards ignition of property adjacent to the track which the
locomotive traverses. Particles which are too large to pass through
the meshes of the screen fall downward into the inclined top of the
check, by which they are directed through the corrugations of the said
check and through the space between the short pipe and the interior of
the chimney, where they are again brought under the influence of the
blasts of exhaust steam and projected upward to be disintegrated by
contact with the interior of the pipe or by impact against the screen.
It is important that the pipe should be adjustable so that the annular
space between it and the check may be expanded or contracted and the
draft thereby regulated.

page_text: The screen is of a continuous tapering form, the lower end being fitted
to the hub of the check, and the upper end united to the top of the
chimney. The function of this check will be precisely the same as that
of the first-mentioned check, and the disposal of the sparks will be the
same, with this exception, that the larger sparks which have not in the
first instance yielded to the disintegrating action of the screen will fall
through the annular space between the two casings of the screen.
According to another modification the screen, which need not be
corrugated, terminates below in a check of the shape of an inverted cone
with sides arranged in steps so as to present sharp edges to the sparks
impelled against them.
The check, as well as the screen connected therewith, admits, as will
be readily seen, of many other modifications, but in all cases the area of
the passage for the steam and sparks above the check should be con-
siderably larger than the area of the space between the check and casing
of the chimney, for it has been found that the steam should be per-
mitted to expand after passing the check in order that the Invention
may be properly carried into effect.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 9th May 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of November, in the year
of our Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Henry Johnson, Her special license
that I, the said John Henry Johnson, my executors, administrators, and
assigns, or such others as I, the said John Henry Johnson, my executors,
administrators, or assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein

page_text: 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 CONTROLLING
THE DRAFT AND IN DISPOSING OF THE SPARKS IN LOCOMOTIVE BOILERS," a com-
munication to me from abroad by Jackson Richards, George Wash-
ington Wait, Ezekial Cooper Shapley, and Charles F. Jones, all of
Philadelphia, Pennsylvania, United States America, upon the con-
dition (amongst others) that I, the said John Henry Johnson, my
executors or administrators, by an instrument in writing under my
hand and seal, should particularly describe and ascertain the nature
of the said Invention, and in what manner the same was to be per-
formed, 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 John Henry Johnson, 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, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to
say:
This Invention relates to that class of steam boilers in which the
exhaust steam of the engine is discharged into the chimney for the
purpose of increasing the draft, and the object of the Invention is the
general equalization of the draft, attainment of economy in the con-
sumption of fuel, the prevention of the abstraction of large masses of
ignited fuel from the fire-place, and the effectual disposal of the sparks
which find their way into the chimney.
The many devices heretofore employed for arresting sparks in loco-
motive engines have been more or less defective owing to the contraction
by screens of the space for the escape of the exhaust steam and sparks,
and to the clogging of the screens and passages by the masses of fuel
which are discharged from the fire-place through the tubes and into the
chimney, a difficulty which by this Invention is obviated by so checking
the violent action of the blasts of exhaust steam in the chimney that the
tendency of such blasts to withdraw from the fire masses of ignited fuel
is prevented, in other words the chimney is so contracted as to equalize
the violent pulsations of steam which are the main cause of the defects
in ordinary spark arresters.

page_text: And in order that the said Invention may be fully understood I shall
now proceed more particularly to describe the same, and for that
purpose shall refer to the several Figures on the annexed Sheet of
Drawings, the same letters of reference indicating corresponding parts in
all the Figures.
Figure 1 illustrates a sectional perspective view of one mode of
carrying the Invention into effect.
A represents the chimney, and C the pipe for the escape of the
exhaust steam.
Within the chimney is fitted the check B, which is the prominent
feature of this Invention as it neutralizes the violent pulsations of the
exhaust steam. This check may be constructed in many different ways.
In the present instance it consists of an inverted corrugated cone (seen
in plan on Figure 3), the corrugations where the check has the largest
diameter extending to the chimney, to which the conc is secured in any
suitable manner. While this inverted cone checks the violent pulsations
of steam sufficient space is presented for the passage of the steam and
sparks between the corrugations.
To the top of the cone, which it is preferred to make inclined as
shown for the purpose explained hereafter, is attached the lower end of
the screen c¹ of wire guage, perforated plates, or wire netting, and this
screen is by preference corrugated as shewn.
The shape of the screen will in a great measure be determined by
that of the chimney. In the present instance the lower portion is
cylindrical or it may have a slight taper, and larger in diameter above
than below, the upper portion being of a tapering form conforming or
nearly so with the exterior shape of that portion of the chimney within
which it is situated.
The upper edge of the screen is so united to the upper edge of the
chimney that the space between the two is closed at the top, and to the
top of the chimney above the open top of the screen may be secured a
casing a¹ with bevelled sides, as shewn in the Drawing.
In most cases it is preferred to secure to the interior of the chimney
below the check B a short pipe F of the shape shown, the interior of
this pipe being roughened or serrated, as shewn, and the pipe being so

page_text: connected to the chimney by lugs f that it can be adjusted vertically
to and from the check.
The blasts of steam as they escape from the exhaust pipe G are
arrested and their force in a measure neutralized by the check F, hence
there is not within the tubes of the boiler those violent and intermittend
pulsations which disturb the fuel in the fire-places of ordinary loco-
motive boilers, and which tend to force masses of ignited fuel through
the tubes and through the smoke box into the chimney, while largé
particles of ignited fuel however are thus prevented from gaining access
to the chimney, small particles or sparks must necessarily be induced by
the escaping steam to pass through the tubes and enter the lower flaring
end of the short pipe F, with the interior of which many of the sparks
must be brought into violent contact and disintegrated by the roughend
inner surface of the said pipe. These disintegrated sparks together with
many which are not brought into contact with the said roughened
surface are projected upward through the corrugations of the check B
and impinge against the screen c¹, through the meshes of which and
through the chimney they will pass in particles too minute to be a
source of injury as regards ignition of property adjacent to the track
which the locomotive traverses. Particles which are too large to pass
through the meshes of the screen fall downward into the inclined top of
the check, by which they are directed through the corrugations of the
said check and through the space between the short pipe F and the
interior of the chimney, where they are again brought under the
influence of the blasts of exhaust steam and projected upward to be
disintegrated by contact with the interior of the pipe F or by impact
against the screen. It is important that the pipe F should be adjustable
so that the annular space between it and the check may be expanded or
contracted and the draft thereby regulated.
The corrugations of the check may if desired be roughened or cor-
rugated so as to insure the more thorough trituration or disintegration of
the sparks.
In Figure 2 the chimney differs in shape from that last described, and
consists of a cylindrical casing A with an enlarged top a and an inner
casing A¹, to which is fitted the check B, the latter consisting in the
present instance of a series of wings or rams e projecting from a central
hub d. as best observed in Figure 4.

page_text: The screen c¹ is of the continuous tapering form represented, the
lower end being fitted to the hub d of the check, and the upper end
united to the top of the chimney. The function of this check will be
precisely the same as that described in reference to the check illustrated
in Figure 1, and the disposal of the sparks will be the same, with this
exception, that the larger sparks which have not in the first instance
yielded to the disintegrating action of the screen will fall through the
annular space between the two casings of the screen.
In Figure 5 the screen which is not corrugated terminates below in a
check B of the shape of an inverted cone with sides arranged in steps so
as to present sharp edges to the sparks impelled against them.
The check, as well as the screen connected therewith, admits, as will
be readily seen, of many other modifications, but in all cases the area of
the passage for the steam and sparks above the check should be con-
siderably larger than the area of the space between the check and casing
of the chimney, for it has been found that the steam should be per-
mitted to expand after passing the check in order that the Invention
may be properly carried into effect.
In the modification shown in Figure 6 the short pipe F is permanently
fixed to the casing A, while the check B is rendered vertically adjustable.
This permits the annular space between the said check and pipe F to be
expanded or contracted for the purpose of regulating the draught as
readily as the reverse arrangement shown in Figure 1, while it also
permits an adjustment of the said check in respect to the exhaust pipe
which is often desirable.
Having now described and particularly ascertained the nature of the
said Invention and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider
to be novel and original and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is,―
First. The mode of controlling and equalizing the draft in the fires of
locomotive boilers by placing in the chimney a check for neutralizing or
partly neutralizing the forcible pulsations of exhaust steam, substantially
as herein-before described.
Second. The application to the chimney of a locomotive boiler of a
screen terminating below in a check, substantially as and for the purpose
set forth.

page_text: Third. The combination with the check of an adjustable pipe F or
its equivalent, substantially as and for the purpose herein-before
described.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, the Fifth day of May,
One thousand eight hundred and seventy-four.]
described.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, the Fifth day of May,
One thousand cight hundred and seventy-four.]