IMPROVEMENTS IN STEAM BOILER AND OTHER FUrnaces.
Year: 1875

page_text: LETTERS PATENT to Joseph Sawyer, of Alma Street, New North
Road, in the County of Middlesex, Engineer, for the Invention of
** IMPROVEMENTS IN STEAM BOILER AND OTHER FUrnaces.
"
"IMPROVEMENTS IN STEAM BOILER AND OTHER FURNACES,
PROVISIONAL SPECIFICATION left by the said Joseph Sawyer at
the Office of the Commissioners of Patents, with his Petition, on
the 17th August 1875.
I, JOSEPH SAWYER, of Alma Street, New North Road, in the County
of Middlesex, Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN STEAM BOILER AND OTHER FURNACES," to be
as follows, that is to say :-
My improvements in steam boiler and other furnaces consist in the
application and employment of longitudinally sliding furnace bars, and
of an air conducting box or chamber, whereby a more perfect com-
bustion of the fuel is effected, and less smoke is produced than hitherto,
thus effecting an economy in the quanitity of fuel consumed.

page_text: another plate or bearing at a
These two plates may be cast
plate, the space between them
the introduction of atmospheric
In carrying out my improvements I employ furnace bars of any suitable
known construction. The back ends of the bars are placed and slide
in the bearing bar at the bridge end of the furnace, such bearing bar
being made hollow for that purpose instead of solid as hitherto. The
inner ends of the furnace bars are placed and slide in a space between
the under side of the dead plate and
short distance below the dead plate.
in one piece and form a hollow dead
also forming an opening or passage for
air to the furnace. In any suitable position on the outside of the
furnace I place two lever handles working spindles, provided with arms
or quadrants, connected to the furnace bars in such a manner that by
moving the said handles in opposite directions half the numbers of bars,
that is to say, cach alternate bar, will be moved longitudinally in onc
direction, and the other bars will be moved longitudinally in the opposite
direction. By this sliding motion of the bars the clinkers and scoria will
be moved, and the air passages between the bars will be kept free; thus
effecting a more perfect combustion of the fuel than hitherto.
The sliding motion of the bars may also be effected by other suitable
arrangements of mechanism. On the top of the dead plate I fix a
flanged plate or box, the inner side of the box being perforated. The
object of this perforated box is to serve for the introduction of atmo-
spheric air above the furnace bars and through the fuel to assist the
consumption of smoke.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 2
filed by the said Joseph Sawyer in the Great Scal Patent Office
on the 17th February 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
SAWYER, of Alma Street, New North Road, in the County of Middlesex,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of August, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
3

page_text: furnace I place a lever handle working toothed segments which drive
spindles provided with arms or cams, operating the furnace bars in such
a manner that by moving the said handle backwards and forwards half
the number of bars, that is to say, each alternate bar will be moved
longitudinally in one direction, and the other bars will be moved longi-
tudinally in the opposite direction; a slightly rising movement being
also communicated to the bars. By this motion of the bars the clinkers
and scoria will be cleared, and the air passages between the bars will be
kept free, thus effecting a more perfect combustion of the fuel than
hitherto. On the top of the dead plate I fix a flange plate or box, the
inner side of the box being perforated. The object of this perforated
box is to serve for the introduction of atmospheric air above the furnace
bars, and through the fuel to assist the combustion, and also to facilitate
the consumption of smoke.
To make my Invention better understood I will now proceed to
describe the same by reference to the accompanying Drawing, in which
Figure 1 is a longitudinal section, shewing my improvements in
furnaces applied to an ordinary Cornish boiler; Figure 2, side elevation ;
and Figure 4, front elevation of the same; Figure 3 plan of the fire-
grate.
Similar letters in all the Figures represent similar parts.
a, a, a¹, a¹, are the furnace bars which in the Drawing are shewn hollow,
but it will be understood that the bars may be of any other suitable
known construction. The back ends of the bars a, a, a¹, a¹, move between
the plate band the bearing bars c, d; or the plate band the bars c, d, may
be cast in one piece so as to form a hollow bearing bar; e is the plate,
taking the place of the usual dead plate; the inner or front ends of the
bars a, a, a, a, being placed and moving between the under side of this
plate e and the bearing bar or plate f. The two plates e and f may be cast
in one piece so as to form a hollow dead plate. g, h, are two spindles
working in brackets i, k, bolted to or cast on the front of the dead plates;
I and m are toothed segments gearing with one another and carried
respectively by the spindles g and h. These spindles and are also
provided with similar toothed segments 1, m³, at their other ends; n is
a lever handle fixed to the spindle g. The spindle y carries a number of
projecting pieces or cams o, taking into recesses in the front ends of the
fire bars a, a; and the spindle is provided with a similar cams s, 8,

page_text: taking into similar recesses in the front ends of the fire-bars a¹, a¹.
Thin side bars (not shewn in the Drawing) may be fixed in the spaces
x, x. By this arrangement it will be understood that if the lever
handle n be pulled forward the spindle g will be partly rotated, and by
means of the segments I, and m, l, m³, the spindle & will also be partly
rotated, but in the opposite direction to that of the spindle g; as the
cams o and s will move with their respective spindles, it follows that the
fire-bars a, a, will be moved forward by the cams o, o, and the fire-bars
a', a', will be moved backwards by the cams s, s, and a slightly rising
motion will also be communicated to the fire-bars as the cams are set so
as to come against the bottom of the recesses in the fire-bars before
reaching their vertical position. If the lever handle n be moved
back to its normal position the fire-bars will be moved in the opposite
direction to that herein-before described. By the motion thus com-
municated to the bars the formation of clinkers and scoria will be
avoided, thus keeping free the air passages between the bars. p, q, are
rollers placed underneath the back ends of the fire-bars a, a¹, to facilitate
the motion of the bars.
For large furnaces the spindles 9 and 1 may be operated in any
suitable manner from the steam engine. On the top of the dead plate e
I fix a flange plate t, the inner side being perforated at u, u. This plate t
thus forms, with the plate e, a perforated box open at the front, and
serves for the introduction of atmospheric air above the furnace bars
and through the fuel. That part of the open front of the perforated
box may be closed by a suitable slide, either fixed to the door or hinged
to the front of the perforated box so as to regulate the quantity of air
to the furnace. Although only one length of bars is shewn in the
Drawing two lengths may be employed. This perforated flanged plate
may be applied to existing furnaces with fixed bars.
Having thus described my Invention and the best means with which
I am acquainted for carrying the same into effect, I wish it to be under-
stood that I do not confine myself to the precise details herein laid
down, but what I do claim is,―
Firstly. The peculiar arrangement of mechanism for communicating
motion to the fire-bars of steam boiler and other furnaces, substan-
tially as herein-before described and represented in the accompanying
Drawing.

page_text: Secondly. The application to steam boiler and other furnaces of a
flanged perforated plate forming, in combination with a dead plate, a
hollow box for the admission of atmospheric air above the fire-bars and
through the fuel, endwise of the fire.
In witness whereof, I, the said Joseph Sawyer, have hereto set
my hand and seal, this Seventeenth day of February, Onc
thousand cight hundred and seventy-six.
Witness,
G. F. REDFERN,
4, South Street, Finsbury,
London.
JOSEPH SAWYER. (L.S.)