IMPROVE- MENTS IN THE FURNACES AND FURNACE DOORS OF LOCOMOTIVE AND OTHER STEAM BOILERS
Year: 1871

page_text: LETTERS PATENT to Francis Joseph Chatfield, Engineer, of Thorp
Hamlet, Norwich, County of Norfolk, for the Invention of “IMPROVE-
MENTS IN THE FURNACES AND FURNACE DOORS OF LOCOMOTIVE AND OTHER
STEAM BOILERS."
Sealed the 19th December 1871, and dated the 15th August 1871.
PROVISIONAL SPECIFICATION left by the said Francis Joseph
Chatfield at the Office of the Commissioners of Patents, with his
Petition, on the 15th August 1871.
I, FRANCIS JOSEPH CHATFIELD, Engineer, of Thorp Hamlet, Norwich,
County of Norfolk, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE FURNACES AND FURNACE DOORS OF LOCOMOTIVE AND
OTHER STEAM BOILERS," to be as follows:-
My improvements in the furnaces and furnace doors of locomotive
and other steam boilers consist in, 1st, certain improvements in the
furnaces of steam boilers, which consist in an improved method of
forming the frames or supports for the fire-bars, and the sides of the
fire-grates, by means of which a more perfect combustion of the fuel

page_text: is obtained, and less injury to the sides of the fire-box and stays is
caused by the action of the fire than by the plans in present use, from
which there results a considerable economy of fuel and a saving in
repairs.
The means by which I effect this I will now describe:-In the
present mode of supporting the fire-bars a space is left round the walls
of the fire-box and the ends and sides of the fire-bars forming the
grate greater in area than is allowed betwixt each separate bar,
through which space air is rapidly drawn by the combustion in the
furnace or fire-box; a part of the fuel is carried away unconsumed
by the draught so caused, and the sides of the fire-box and the stays
are burned. To obviate these evils I form the iron frame which supports
the fire-bars at their ends, and which I carry also round the sides of
the bars, hollow at the top and sides next the fire-box, for the purpose
of carrying fire-clay or other suitable material, by which means a close 1
joint can be made between the said frame and the sides and ends of the
fire-box, or the frame can be used without the fire-clay or other suitable
material to make a close joint between the frame and fire-box, but I
much prefer to use the fire-clay, and by these means the air drawn
into the furnace from the bottom then passes only through the spaces 2
between the fire-bars and through channels formed in the ends of the
fire-bars, and no air can pass through the space between the fire-bars,
framing, and the walls or sides of the furnace or fire-box.
2nd. In an improved construction of the furnace doors of steam
boilers, which may be used with or without the top scoop now in use. 2
The bottom part or plate of the door, which is hinged to the bottom of
the fire-door hole, is placed at an angle downwards and into the fire-
box so as to direct the air admitted for combustion into the fire-box
directly upon the fire; this bottom plate may be furnished with two
side wings to spread the air into the sides and corners of the fire-box, 3
and it is hinged outside so as to facilitate its removal from the holo
of fire-door. At the top of the fire-hole I place a hinged Venetian
flap, which shuts down on the top of the projecting part of the
bottom plate of the door; by this means the air can be freely admitted
to the fire-box, and the heat is prevented from radiating on to the foot 3
plate as on the present plans, and so protects the men from the heat
of the fire. A cover is provided for use with the Venetian flap, which
may be used or not as circumstances may require.

page_text: The top scoop when used in combination with the bottom door may
be made of cast iron or other suitable material, with channels on cach
side for conducting the air into the top corners of fire-box, which
channels will greatly improve the action of the top scoops now used.
My Invention may be applied with advantage to the fire-grates of
any steam boilers with internal flues, whether locomotive, portable,
marine, ors tationary.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Francis Joseph Chatfield in the Great Seal
Patent Office on the 12th February 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
JOSEPH CHATFIELD, Engineer, of Thorp Hamlet, Norwich, County of
Norfolk, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of August, in the year of
our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Francis Joseph Chatfield,, Her special
licence that I, the said Francis Joseph Chatfield, my executors,
administrators, and assigns, or such others as I, the said Francis
Joseph Chatfield, 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 " IMPROVEMENTS IN THE FURNACES AND FURNACE
DOORS OF LOCOMOTIVE AND OTHER STEAM BOILERS," upon the condition (amongst
others) that I, the said Francis Joseph Chatfield, 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
Offico within six calendar months next and immediately after the date
of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Francis Joseph Chatfield, 'do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
My improvements in the furnaces and furnace doors of locomotive 5
and other steam boilers consist in, 1st, certain improvements in tho
furnaces of steam boilers, which are as follows:-.
"
My Invention of improvements in the fire-grates of steam boiler
furnaces consist in an improved method of-forming the frames. or
supports for the fire-bars and the sides of fire-grates, by means of 1
which a more perfect combustion of the fuel is obtained, and less injury
to the sides of the fire-box and stays is caused by the action of the
fire than by the plans in present use, from which there results a con-
siderable economy of fuel, and a saving in repairs.
The means by which I effect this I will now describe:-In the 1
present mode of supporting the fire-bars a space is left round the walls
of the fire-box and the ends and sides of the fire-bars forming the grate,
through which space air is rapidly drawn by the combustion, in the
furnace or fire-box, a part of the fuel is carried away unconsumed by
the draught so caused, and the sides of the fire-box and the stays are 2
burned. To obviate these 'evils I form the iron frame which supports
the fire-bars at their ends, and which I carry also round the sides of
the bars, hollow at the top and sides. next the fire-box for the purpose
of carrying fire-clay or other suitable material, by which means a close
joint can be made between tho said frame and the sides and end of 2
the fire-box, or the frame can be used without the fire-clay or other
suitable materiál to make a close joint between the frame and fire-
box, but I much prefer to use the fire-clay, and by these means the
air drawn into the furnace from the bottom then passes only through
the spaces between the fire-bars and through channels formed in the 3
ends of the fire-bars, and no, air can pass through the space between
the fire-bars framing and the walls or sides of the furnace or fire-
box.
'
My Invention may be applied. with advantage to the fire-grates of
any steam boilers with internal flues, whether locomotive,' portable, 3
marine, or stationary.

page_text: bottom part or plate of the door which is fixed to the bottom of the
door hole is placed at an angle downwards, and into the fire-box, sq
as to direct the air admitted for combustion into the fire-box; this
bottom plate may be furnished with two side wings to spread the air
into the sides and corners of the fire-box, and it is hinged outside so
as to facilitate its removal from the hole of the door: At the top of
the fire-hole I place a hinged Venetian flap, which shuts down on the
top of the projecting part of the bottom plate of the door, by this means
the air can be freely admitted to the fire-box, and the heat is prevented
from radiating on to the foot plate as on the present plans, and so
protects the men from the heat of the fire. A cover is provided for
use with the Venetian flap, which may be used or not as circumstances
may require.
The top scoop when used in combination with the bottom door may
be made of cast iron or other suitable material, with channels in each
side for conducting the air into the top corners of fire-box.
Having thus described the nature of my Invention, I will now proceed
to show more particularly by means of the annexed Drawings the
construction and action of my Invention, as applied to a locomotive
engine boiler.
Fig. 1 is a section, Fig. 2 an elevation, Fig. 3 is a section through a
part of the fire-box showing how the fire-clay or other suitable material
is applied round the furnace. Fig. 4 is an elevation of a fire-door, and
Fig. 5 is a section of the same, showing a construction somewhat
different from that shown in Figs. 1 and 2. Figs. 5, 6, and 7, show
improved methods of securing the ring of the fire-door, so that it may
be easily replaced, and is so formed that it is less liable to injury from
the heat than the forms now in use. In all the Figures similar letters
indicate similar parts.
A, Figs. 1, 4, 5, 6, 7, is the ring forming the hole of the fire-door,
its construction is clear from the Drawings; B, Figs. 1 and 2, is the
frame forming the sides of the fire-door. C, Figs. 1 and 2, is the top
scoop, used for deflecting the air downwards on to the fuel. D, Figs. 1
and 2, is the bottom part of door hinged at D', and furnished with
two side wings E to spread the air into the sides and corners of the
fire-box. F, Figs. 1 and 2, is a bolt to secure the bottom part of door D
in position. G, Figs. 1 and 2, is a ventilator flap hinged at G', Figs. 1
and 2, so that it can be turned up and secured by the bolt H, Figs. 1

page_text: and 2. I, Figs. 1 and 2, is a covering flap used to regulate the admission
of air, it is hinged at I, and can be turned up out of the way. Tho
action of the door may be thus described :-The upper and lower parts
of the door being placed in the position shown in Figs. 1 and 2, and
the flap I being turned up and secured by the bolt H, the air rushes &
in through the Venetian flap and is directed on to the fuel, or the flap
I may be regulated by means of the hinge K so as to admit less
air.
I
The same effect is gained, but not so handily, by the modifications
shown in Figs. 4 and 5. O' is the top scoop; D' is the bottom door; 10
G' is the Venetian flap which can be moved upwards by its hinge, or
the whole door can be moved out of the way sideways by means of
the hinge E, Fig. 4.
Various modifications can of course be made in the arrangement and
form of the parts of my Invention; the upper scoop C¹ and C, Figs. 1 15
and 5, can be omitted, but I prefer the combination shown in Figs. 1
and 2.
Figs. 4, 5, 6, and 7 show at A novel methods of forming the rings
of fire-doors, so that such rings can be easily renewed.
Figs. 1 and 3, at L, show the method described above, by means of 20
which the destruction of the lower part of the inside flues of the fire-
box and the stay bolts is prevented. L is the fire-clay or other suitable
materials supported by the frame M, which passes round the furnace
bars, as described.
In witness whereof, I, the said Francis Joseph Chatfield, have here- 25
unto set my hand and scal, this
day of February, in
the year of our Lord One thousand eight hundred and seventy-
two.