IMPROVEMENTS IN FURNACES AND IN APPARATUS CONNECTED THEREWITH
Year: 1869

page_text: LETTERS PATENT to Samuel Chatwood, of Bolton-le-Moors, in the
County of Lancaster, Safe and Lock Engineer, and Robert Kenyon,
of Bolton-le-Moors, in the County of Lancaster, Millwright, for the
Invention of "IMPROVEMENTS IN FURNACES AND IN APPARATUS CONNECTED
THEREWITH"
Sealed the 7th January 1870, and dated the 12th November 1869.
PROVISIONAL SPECIFICATION left by the said Samuel Chatwood and
Robert Kenyon at the Office of the Commissioners of Patents,
with their Petition, on the 12th November 1869.
We, SAMUEL СHATWOOD, of Bolton-le-Moors, in the County of
Lancaster, Safe and Lock Engineer, and ROBERT KENYON, of Bolton-le-
Moors, in the County of Lancaster, Millwright, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN FORNACES AND IN
APPARATUS CONNECTED THEREWITH," to be as follows:-
Our Invention relates principally to boiler and other furnaces in which
fire-bars are used which are moveable, or part fixed and part moveable,
but part of our Invention is applicable to furnaces having fixed fire-
bars only.

page_text: Heretofore it has been usual when using moveable fire-bars to arrange
them in two sets, comprising the alternate bars which are moved to and
fro in opposite directions so as to break up the fire and prevent it from
caking on the bars, and sometimes one set of bars only has been made
moveable and the other fixed, the moveable bars having an up-and-down
motion, and also a to-and-fro motion partly above and partly level with
the fixed bars..
Our Invention consists in methods of giving the moving bars a
motion such that when one set of bars is moving forward they shall be
above the level of the other set whether the other set be fixed or move-
able bars, and when returning they shall be below the level of the others
whether fixed or moveable, our object being that the bars in coming
back shall be sufficiently clear of the fuel during the whole or part of
the return motion to avoid drawing the fuel back with them, so that
the effect may be not only to break up the fire, but also to carry the fuel
gradually forward at a rate proportioned to the progress of combustion,
and so keep the bars uniformly covered by the fire from front to back.
This may be effected as follows:-When the bars are alternately fixed
and moveable the bearer which carries the front end of the moving bars
is so attached to a rod or rods worked by one or more eccentrics or
cranks on a shaft carried in front of the furnace that the bearer is caused
to partake of all the motions of the eccentric or crank, that is, the bearer
rises as the eccentric rises, and moves forward, lowers, and moves back
as the eccentric moves forward, lowers, and moves back, and con-
sequently the fire-bars resting on the bearer are carried through the same
path, the eccentrics being so arranged that while the moving bars are in
their backward movement they are then in their lowest position and
below the level of the fixed bars, and in their forward movement above
the level of the fixed bars. When all the bars are made moveable in
separate sets, as above described, the same arrangement may be applied
to each set, the cranks or eccentrics which actuate each set being
placed at opposite points so as to cause the bars that are moving
towards the bridge to be always in their highest position, or nearly so,
when the bars that are moving from the bridge are at their lowest
position. A slow revolving motion is applied to the eccentric or crank
shaft, which imparts the necessary action to the fire-bars, by means of
which the fire is stirred up, spread evenly over the bars, and gradually
carried forward in the manner above described.

page_text: It may sometimes be found necessary to impart a more sudden and
jerking action to the fire-bars than is obtainable by the slow and gradual
movement above described in order to break up the fire more effectually,
as certain kinds of fuel aro more liable to cake on the bars than others.
This may be effected in a variety of ways; for instance, the eccentrics
above described may be carried loose on the shaft and carried round
by means of a driver which is fast on the shaft, and takes against a pin
or stop on the eccentric. The driver acting against the pin or stop
pushes the eccentric round until its centre of gravity is carried past the
centre of the shaft, when it naturally overbalances itself, and drops
suddenly away from the driver. The continued motion of the shaft again
brings the driver against the pin or stop, and carries the eccentric round
as before. The sudden dropping of the eccentric brings- the front bearer
down suddenly together with the bars carried thereon, and by this means
more effectually breaks up the fire. The same effect may also be pro-
duced by carrying the front bearer in such a way as to allow it a
certain amount of vertical play, which allows it to be lifted up and
dropped in passing over a short projecting piece fixed at each side of the
furnace in such a position that the ends of the bearer are carried over
the projections as it travels forward and backward.
Another convenient arrangement for effecting the same object may
be described as follows:-The ends of the front bearer are carried by
knee-jointed levers provided with stops or jaws after the manner of a
rule joint, one of which levers is placed at each side of the furnace, and
a to-and-fro motion imparted to them at their centre joints by suitable
mechanism.
The knee-jointed levers, as stated, are provided with double stops
or jaws, and act as follows:-The motion being applied to the middle
joint causes the moving bars to rise above the fixed bars (or the
alternate moving bars) until the jaws close, and thus cause the levers
to become rigid, and prevent them rising any more. The motion then
becomes a forward motion moving the bars forward to the desired extent.
The further motion of the driving gear then causes the arms of the
knee-joint lever to collapse, and so lower the moving bars suddenly
until they are brought a little below the level of the fixed bars, 'when
the jaws closing on the opposite side the lever again becomes rigid and
draws back the fire-bars to their original position, thus giving them the
desired motion, namely, to raise them to move them forward, to lower

page_text: them quickly below the others, and to bring them back to their first
position.
say, the
Besides the methods above described we may feed the fuel along the
bars by what we may term a differential feed motion, that is to
fire-bars in their backward course may be so arranged as to carry back
the fuel a part of the distance through which it was advanced in the
forward stroke, the difference between the space carried in the forward
stroke and that carried back in the return stroke being the actual
amount of feed imparted to the fuel: The zig-zag" motion thus
imparted to the fuel will tend more effectually to prevent it from
caking on the bars.
"
Another part of our Invention consists in using in conjunction with
the moving fire-bars a cross bearer fixed under the grate bars in such a
position as to cause the bridge cnd of the bars to be tilted up when
the moving bearer at the front end is at the lowering part of its
motion.
When the moving bars are not in action, as, for instance, when the
furnace is left for the night, the grate bars should always be left on the
same level, otherwise the edges of those which may happen to be higher
than the rest are liable to be burnt away. In order to ensure the bars
being all on the same level when left standing we apply a catch, stop, or
other suitable contrivance, so placed as to hold the driving shaft fast at
that point in its revolution at which it brings the whole of the bars on
the same level.
The same arrangement may also be applied to moving bars which are
worked by hand, the bars being locked when left standing in such a
position that they are all on the same level, and unlocked by throwing
out the catch stop or other contrivance whenever it is desired to work
the bars.
Moving fire-bars, as hitherto constructed, have generally simply rested
by their own weight upon the bearer or rocking shaft from which they
derived their motion, and which fitted into semicircular recesses formed
in projecting pieces on the under side of the grate bars. One fault of
this arrangement is that it does not necessitate the grate bars following
the motion of the rocker downwards as well as upwards, for should
the bar become wedged with clinkers the rocker may return, leaving
the bar elevated.

page_text: One part of our Invention consists in giving these recesses such a
form that they may grip or lay hold of the bearer, so that they may not
merely rest upon it, but must necessarily follow the bearer in all its
movements up or down or to or fro; and when the grate bars are thus
arranged, in order that they may be the more readily taken out and put
into their places on the bearer we form notches in the bearer, these
notches being placed alternately between the bars, and being so formed
as to admit of the bar being first placed on the bearer and then slipped
sideways into its proper position, where it clips or is clipped by the
bearer.
The action of the fire-bars above described would naturally cause the
clinkers to collect in a heap against the bridge. In order to obviate
this we leave an opening through the bridge immediately above the fire-
bars, and in this opening we place a valve, so that when the valve is
opened the clinkers may be driven through by the action of the bars,
and at the same time air is admitted in sufficient quantity to effect the
more complete combustion of the fuel, and thereby tend to the pre-
vention of smoke. This valve may be actuated by self-acting mechanism
deriving its motion from the gearing which works the grate bars, or
direct from one or more of the grate bars, and its action should be so
timed that air is admitted at the moment when by the action of the bars
gas is being emitted from the fuel in greater quantity. The valve may
also be applied with advantage when moving fire-bars are not used,
being in that case worked by hand.
In the next place our improvements consist in applying a scraper,
which is moved by means of self-acting mechanism, to clear away the
clinkers as they fall.
One mode of applying this part of our improvements is to make the
valve above described of the form of a flap hanging from a centre in
the front part of the bridge, through which an opening is formed as
described immediately above the fire-bars, and to make it of sufficient
length to reach to the bottom of the flue, which is shaped to suit the
radius of the flap so as to prevent any clinkers from getting behind, and.
by a to-and-fro motion imparted to the flap the clinkers are all scraped
out towards the front. This to-and-fro motion of the valve and
scraper may be taken from the main driving gear, or direct from one or
more of the fire-bars; or the scraper might be made separate from the
valve and driven independently.

page_text: Another convenient arrangement of scraper consists of a shaft carry-
ing a number of blades of a form suited to the shape of the flue. This
shaft carries a ratchet wheel, to which a slow revolving motion is
imparted by means of a catch on one or more of the fire-bars.
The next part of our Invention has for its object the more perfect
combustion of the smoke generated in a furnace by means of the
admission of air at the front of the furnace in quantities regulated by
valves, which act in such a manner as to effect the admission of air in
greater quantities when most gas or smoke is being evolved from the
fuel, that is, immediately after the fireman has added more fucl, and to
shut off the air gradually in proportion as the amount of smoke or gas
evolved diminishes. This has been before effected by means of clock.
work set in action by the opening or closing of the fire-door, but wo
propose to effect the same object by means of self-acting mechanism
actuated by the same gearing which works the fire-bars above described,
or by any convenient shaft driven from an engine.
Valves are
that upon
One mode of carrying this part of our Invention into practice may
be described as follows:-A shaft is fixed in a convenient position and a
revolving motion imparted to it. Where moving fire-bars are used the
same shaft that drives the bars will servo the purpose.
formed in the door, and the mechanism is so arranged
shutting the door these valves will always be found open.
door is shut the teeth of a rack are brought into gear with the teeth of
a wheel fixed on the shaft, which working into the teeth of the rack
cause the valves to close slowly. Instead of the rack and pinion a bevil
wheel gearing into a sector might be used.
When the
Our improvements consist in the next place in an improved arrange-
ment of hopper for supplying the furnaces with fuel. This hopper we
carry by an arm or jib working on a centre, so that when out of use it
may be swung away from the boiler. Hitherto these hoppers have
usually been supplied with feed rollers, which feed in the coal and at
the same time crush it. Instead of these feed rollers we apply an
arrangement similar to that known as "Blake's stone crusher"
"Archer's stone crusher," which are so well known as not to require
further description.
or
We may also effect the breaking and feeding of the coal by a single
toothed roller working against an inclined or curved surface applied to

page_text: the lower part of the hopper. The rate at which the fuel is supplied
from the hopper may be regulated by varying the speed of the feeder
by means of cone pulleys or by change wheels. We sometimes provide
this hopper with a damper, which is of a hollow form, só as to allow a
stream of water or other fluid to flow through it. When this hopper is
applied we make the air valves above described in the front plate of the
furnace, and when moving bars are also used we may open and close
the valves by mechanism actuated by that which gives motion to the
bars, so applied as to admit more air to the furnace when the bars aro
breaking the fire and thereby producing more smoke.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Samuel Chatwood and Robert Kenyon in the Great
Seal Patent Office on the 12th May 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, SAMUEL
CHATWOOD, of. Bolton-le-Moors, in the County of Lancaster, Safe and
Lock Engineer, and ROBERT KENYON, of Bolton-le-Moors, in the County
of Lancaster, Millwright, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of November, in the
year of our Lord One thousand eight hundred and sixty-nine, in the
thirty-third year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Samuel Chatwood and Robert Kenyon,
Her special licence that we, the said Samuel Chatwood and Robert
Kenyon, our executors, administrators, and assigns, or such others as
we, the said Samuel Chatwood and Robert Kenyon, our 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 mako, 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 FURNACES
AND IN APPARATUS CONNECTED THEREWITH," upon the condition (amongst
others) that we, the said Samuel Chatwood and Robert Kenyon, our
executors or administrators, by an instrument in writing under our or
their hands and seals, or under the hand and seal of one of us or
them, should particularly describe and ascertain the nature of the said

page_text: Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Scal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Samuel Chatwood, on behalf of
myself and the said Robert Kenyon, 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 thereof, that is to say:-.
Our Invention relates principally to boiler and other furnaces in which
fire-bars are used which are moveablo or part fixed and part moveable,
but part of our Invention is applicable to furnaces having fixed fire-bars
only.
Heretofore it has been usual when using moveable fire-bars to arrange
them in two sets, comprising the alternate bars which are moved to and
fro in opposite directions, so as to break up the fire and prevent it from
caking on the bars, and sometimes one set of bars only has been made
moveable and the other fixed, the moveable bars having an up-and-
down motion and also a to-and-fro motion partly above and partly level
with the fixed bars.
Our Invention consists in methods of giving the moving bars a motion
such that when one set of bars is moving forward they shall be above
the level of the other set, whether the other set be fixed or moveable
bars, and when returning they shall be below the level of the others
whether fixed or moveable, our object being that the bars in coming
back shall be sufficiently clear of the fuel during the whole or part of
the return motion to avoid drawing the fuel back with them, so that
the effect may be not only to break up the fire, but also to carry the
fuel gradually forward at a rate proportioned to the progress of com-
bustion, and so keep the bars uniformly covered by the fire from front
to back.
The methods in which our Invention consists are as follows:-When
the bars are alternately fixed- and moveable the bearer which carries the
front end of the moving bars is so attached to a rod or rods worked by
one or more eccentrics or cranks on a shaft carried in front of the
furnace that the bearer is caused to partake of all the motions of the
eccentric or crank, that is, the bearer rises as the eccentric rises, and
moves forward, lowers, and moves back as the eccentric moves forward,

page_text: lowers, and moves back, and consequently the fire-bars resting on the
bearer are carried through the same path, the eccentrics being so
arranged that while the moving bars are in their backward movement
they are then in their lowest position and below the level of the fixed
bars, and in their forward movement above the level of the fixed bars..
This arrangement is shown in Figure 1 of the accompanying Drawings.
A is the driving shaft; B, one of the eccentrics; C, the bearer which
carries the moving bars; D is one of the moving bars shewn in its
highest position; E is one of the fixed bars; F is the plate upon which
the bars rest at the bridge end of the furnace. In this plate are formed
holes G through which the rods attached to the eccentrics work. Tho
shaft A revolves in the direction indicated by the arrow. The action of
the fire-bars above described would naturally cause the clinkers to
collect in a heap against the bridge. In order to obviate this we leave
an opening H through the bridge immediately above the fire-bars.
When all the bars are made moveable in separate sets as above described
the same arrangement may be applied to each set, the cranks or eccentrics
which actuate each set being placed at opposite points so as to cause the
bars that are moving towards the bridge to be always in their highest
position or nearly so when the bars that are moving from the bridge arc
at their lowest position. A slow revolving motion is applied to the
eccentric or crank shaft which imparts the necessary action to the fire-
bars by means of which the fire is stirred up, spread evenly over the
bars, and gradually carried forward in the manner above described.
It may sometimes be found necessary to impart a more sudden and
jerking action to the fire-bars than is obtainable by the slow and gradual
movement above described, in order to break up the fire more effectually,
as certain kinds of fuel are more liable to cake on the bars than others.
This may be effected by carrying the front bearer in such a way as to
allow it a certain amount of vertical play, which allows it to be lifted
up and dropped in passing over a short projecting piece fixed at each
side of the furnace in such a position that the ends of the bearer are
carried over the projections as it travels forward and backward. Where
fixed and moveable bars are used they may be so set as to feed the fuel
along the bars by what we may term a differential feed motion, that is
to say, the fire-bars in their backward course may be so arranged as to
carry back the fuel a part of the distance through which it was advanced.

page_text: in the forward stroke, the difference between the space carried in the
forward stroke and that carried back in the return stroke being the
actual amount of feed imparted to the fuel. The "zig-zag" motion
thus imparted to the fuel will tend more effectually to prevent it from
caking on the bars.
Another part of our Invention consists in using in conjunction with
the moving fire-bars a cross bearer fixed under the grate bars in
such a position as to cause the bridge end of the bars to be tilted up
when the moving bearer at the front end is at the lowering part of its
motion.
This arrangement is shown in Figure 2. A is the driving shaft;
B, the excentric; C, the bearer carrying the moving bars; D is one of
these bars shown. tilted up at bridge end, the eccentric being at its
lowest position; E is a fixed bar; Fis the cross bar which accomplishes
the tilting action. The arrow shows the direction in which the shaft
revolves.
When the moving bars are not in action, as, for instance, when
the furnace is left for the night, the grate bars should always be left on
the same level, otherwise the edges of those which may happen to be
higher than the rest are liable to be burnt away. In order to ensure
the bars being all on the same level when left standing we apply a catch,
stop, or other suitable contrivance so placed as to hold the driving shaft
fast at that point in its revolution at which it brings the whole of the
bars on the same level.
This arrangement is shown in Figure 3. A is the driving shaft; 2
B, the excentric in the position it occupies when all bars are on
same level; D, a plate with notch in it at E; F, a catch which is
dropped into the notch E, and so holds the gear in position; G,
dotted lines showing the position of the catch when the gear is working.
The same arrangement may also be applied to moving bars which are 3
worked by hand, the bars being locked when left standing in such a
position that they are all on the same level, and unlocked by throwing
out the catch, stop, or other contrivance whenever it is desired to work
the bars.
Moving fire-bars, as hitherto constructed, have generally simply rested 3

page_text: derived their motion, and which fitted into semicircular recesses formed
in projecting pieces on the under side of the grate bars. One fault of
this arrangement is that it does not necessitate the grate bars following
the motion of the rocker downwards as well as upwards, for should the
bar become wedged with clinkers the rocker may return, leaving the bar
clevated.
One. part of our Invention consists in giving these recesses such.
a form that they may grip or lay hold of the bearer so that they
may not merely rest upon it but must necessarily follow the bearer in
all its movements up or down or to or fro, and when the grate bars are
thus arranged in order that they may be the more readily taken out and
put into their places on the bearer wo form notches in the bearer, these
notches being placed alternately between the bars and being so formed
as to admit of the bar being first placed on the bearer and then slipped
sideways into its proper position where it clips or is clipped by the
bearer.
Figures 4, 5, and 6 illustrate this arrangement. Figure 4 shows a
portion of a moving bar A. and a section of the notched bearer B;
Figure 5 is a plan of the notched bearer; Figure 6 is a side view of the
same.
The next part of our Invention has for its object the more perfect
combustion of the smoke generated in a furnace by means of the
admission of air at the front of the furnace in quantities regulated by
valves which act in such a manner as to effect the admission of air in
greater quantities when most gas or smoke is being evolved from the
fuel, that is, immediately after the fireman has added more fuel, and to
shut off the air gradually in proportion as the amount of smoke or gas
evolved diminishes. This has been before effected by means of clock-
work set in action by the opening or closing of the fire-door, but we
effect the same object by means of self-acting mechanism actuated by
the same gearing which works the fire-bars above described, or by any
convenient shaft driven from an engine.
One modo is as follows:-A shaft is fixed in a convenient position
and a revolving motion imparted to it. Where moving fire-bars are
used the same shaft that drives the bars will serve the purpose. Valves
are formed in the door, and the mechanism is so arranged that upon.

page_text: shutting the door these valves will always be found open. When the
door is shut the teeth of a rack are brought into gear with the teeth of a
wheel fixed on the shaft, which working into the teeth of the rack
cause the valves to close slowly..
This arrangement is shown in Figure 7. A is the driving shaft;
B, the furnace door with valves C, C, C. These valves are suitably
connected to the upright rod D. When the door is opened a projection
E'on rod D works against inclined plane F, which thus causes the rod to
rise, and consequently opens the valves C, O, at the same time throwing
the weighted lever G over the centre into the position of the red lino H.
This weighted lever keeps the valves open while the door is being shut,
and when the door is shut the rack I on end of rod D comes into gear
with pinion K on the slowly revolving shaft A. The valves are thus
caused to close slowly. Instead of the rack and pinion a bevel wheel
gearing into a sector might be used.
Our improvements consist in the next place in an improved arrange-
ment of hopper for supplying the furnaces with fucl. This hopper we
carry by an arm or jib working on a centre, so that when out of use it
may be swung away from the boiler. Hitherto these hoppers have
usually been supplied with feed rollers which feed in the coal, and at the
same time crush it. Instead of these feed rollers we apply an arrange-
ment similar to that known as "Blake's stone crusher" or "Archer's'
stone crusher," in which the fuel is broken between surfaces, one of
which alternately approaches and recedes from the other. This arrange-
ment is illustrated by Figure 8. A is the driving shaft; B, the
eccentric; C, the bearer; D, the fire-bars; E, the hopper. This
hopper. may be carried by a small jib crane so that it may be easily.
swung out of the way when not in use. When in use the train of
gearing F, F, F, is brought into gear with whcel G on the driving shaft,
and motion is thus imparted to the inclined ribbed side H by means of
the eccentric I, and also the corrugated roller K is slowly rotated, and so
the fuel is broken to a uniform size and fed on to the fire-bars.
We may also effect the breaking and feeding of the coal by a single
toothed roller working against an inclined or curved surface applied to
the lower part of the hopper, as shewn in Figure 9. The rate at
which the fuel is supplied from the hopper may be regulated by´

page_text: varying the speed of the feeders by means of cone pulleys or by change
wheels.
In witness whereof, I, tho said Samuel Chatwood, have hereunto
set my hand and seal, this Eleventh day of May, in the year
of our Lord One thousand eight hundred and seventy.
SAMUEL CHATWOOD. (L.S.)