IMPROVEMENTS IN LOCOMOTIVE, PORTABLE, . AND OTHER LIKE ENGINES
Year: 1877

page_text: LETTERS PATENT to James Pollock, of Porson Street, Battersea Park, and
William Wilkinson, of Wandsworth Road, both in the County of Surrey,
Engineers, for the Invention of "IMPROVEMENTS IN LOCOMOTIVE, PORTABLE,
. AND OTHER LIKE ENGINES."
Sealed the 9th November 1877, and dated the 17th August 1877.
PROVISIONAL SPECIFICATION left by the said James Pollock and William
Wilkinson at the Office of the Commissioners of Patents on the 17th August
1877.
JAMES POLLOCK, of Porson Street, Battersea Park, and William Wilkinson, of
Wandsworth Road, both in the County of Surrey, Engineers.
IMPROVEMENTS IN
LOCOMOTIVE, PORTABLE, AND OTHER LIKE ENGINES."
The object of this Invention is to form a distinct vacuum chamber in the smoke
box of a locomotive; portable, or other like engines for the purpose of receiving the
exhaust steam from the cylinders, and to ensure an equal distribution of heat and
flame through the upper as well as through the lower fire tubes leading from the
fire-box, whereby the usual sucking away of particles of fuel from the fire is obviated,
and the escape of sparks prevented from the chimney.
By this Invention the usual brick or other bridge in the fire-box can be dispensed
with, and a more uniform distribution of heat established; also an economy in the
consumption of fuel.
.
The Invention consists in fitting in the smoke box of a locomotive, portable, or
other like enginé, an inverted funnel or bell-shaped casing, open top and bottom,
with a clearance between the top portion of it and the entry to the chimney to
permit of flame and gases passing from the upper rows of tubes which are outside
the casing to the chimney by that clearance, a clearance being also formed between
the bottom of the casing and the bottom of the smoke box to allow the flame and
gases from the lower rows of tubes to enter the casing by that part.
The blast pipe from the cylinders terminates just inside the lower part of the
casing, and forms, so to speak; a suction from the lower rows of tubes, the flame

page_text: and gases from which are drawn downwards, and under to the inside of the casing,
while the flame and gases from the upper rows of tubes pass over the top edge of the
casing into the chimney, where they commingle with the residue of the flame and
gases from the lower rows of tubes, which pass up through the casing.
The casing is of smaller diameter at the upper part than at the lower, and forms
a vacuum chamber to ensure an alternate suction and exit of the flame and gases
from the tubes.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Pollock and William Wilkinson in the Great Seal Patent
Office on the 16th February 1878.
JAMES POLLOCK, of Porson Street, Battersea Park, and William Wilkinson, of
Wandsworth Road, both in the County of Surrey, Engineers. "IMPROVEMENTS IN
LOCOMOTIVE, PORTABLE, AND OTHER LIKE ENGINES."
The object of this Invention is to form a distinct vacuum chamber in the smoke
box of a locomotive, portable, or other like engine for the purpose of receiving the
exhaust steam from the cylinders, and to ensure an equal distribution of heat and
flame through the upper as well as through the lower fire-tubes leading from the
fire-box, whereby the usual sucking away of particles of fuel from the fire is obviated,
and the escape of sparks from the chimney prevented.
By this Invention the usual brick or other bridge in the fire-box can be dispensed
with, and a more uniform distribution of heat established; also an economy in the
consumption of fuel.
The Invention consists in fitting in the smoke box of a locomotive, portable, or
other like engine, an inverted funnel or bell-shaped casing, open top and bottom,
with a clearance between the top portion of it and the entry to the chimney to
permit of flame and gases passing from the upper rows of tubes, which are outside
the casing to the chimney by that clearance, a clearance being also formed between
the bottom of the casing and the bottom of the smoke box, or top of cylinders, to
allow the flame and gases from the lower rows of tubes to enter the casing by that
part.
The blast pipe from the cylinders terminates just inside the lower part of the
casing, and forms, so to speak, a suction from the lower rows of tubes, the flame and
gases from which are drawn downward and under to the inside of the casing, while
the flame and gases from the upper rows of tubes pass over the top edge of the
casing into the chimney, where they commingle with the residue of the flame and
gases from the lower rows of tubes, which pass up through the casing,
The casing is of smaller diameter at the upper part than at the lower, and forms
a vacuum chamber to ensure an alternate suction and exit of the flame and gases
from the tubes.
•
The Invention will be clearly understood by reference to the annexed Drawings,
in which Figure 1 is a sectional elevation of the smoke box end of a locomotive or
other similar engine, showing a portion of the boiler tubes; while Figure 2 is a
cross section through the line a, b, of Figure 1; and Figure 3, a horizontal section
on the line c, d, of Figure 2.
A is the inverted funnel or bell-shaped casing forming the exhaust chamber,

page_text: between which and the bottom of the smoke box B there is a space or clearance C,
by means of which the smoke or gases from the lower boiler tubes enter the
exhaust chamber, through which they pass to the chimney, as herein-after
explained.
Above the exhaust chamber A, and between it and the chimney D there is
another space or clearance E, by means of which the smoke and gases from the
upper rows of boiler tubes enter the chimney; F is the end of the exhaust or blast
pipe coming from the cylinders, which terminates as shown just inside the base of
the exhaust chamber. The spent steam issuing from the exhaust pipe creates a
vacuum in the lower part of the inverted funnel or bell-shaped casing, and the
result is that the hot air and gases from the lower rows of boiler tubes are drawn or
sucked in through the space or clearance C to the said casing, through which they
are drawn or caused to pass to the chimney D. The exhaust steam and gases in
their passage from the casing A to the chimney D create a draught at the
clearance E, through which the flame and gases from the upper rows of tubes are
drawn or sucked to commingle with the exhaust steam, and with the flame and
gases coming from the lower rows of boiler tubes. By this means a far more equal
distribution of heat in the upper rows of boiler tubes than has hitherto been effected
is obtained, the comparative uniformity of the distribution, both in the upper and
lower rows of tubes being in direct proportion to the rate at which the exhaust
steam issues from the cylinders, and consequently to the speed of the engine. The
result is that the whole of the boiler tubes are rendered effective for the generation
of steam instead of as hitherto, mainly the lower rows, by which means a great
economy of fuel is effected, the efficacy of the boiler increased, and all deposit of
ashes in the smoke box or boiler tubes obviated.
And having now described the nature of our said Invention, and in what manner
the same is to be performed, we declare that we claim as our Invention of improve-
ments in locomotive, portable, and other like engines, the employment of a distinct
vacuum chamber in the smoke box of a locomotive, portable, or other like engine to
receive the exhaust steam from the cylinders, as and for the purposes set forth, and
substantially as shown in the annexed Drawings.
In witness whereof, we, the said James Pollock and William Wilkinson, have
hereunto set our hands and seals, this Fourth day of January, One thousand
eight hundred and seventy-eight.
JAMES POLLOCK.
(L.S.)
WILLIAM WILKINSON. (L.S.)