CERTAIN IMPROVEMENTS ON AND ADDITIONS TO FIRE GRATES, WHICH I INTEND TO DENOMINATE ECONOMICAL FIRE GRATES
Year: 1820

page_text: TO ALL TO WHOM THESE PRESENTS' SHALL COME, I. WILLIAM
BRUNTON, of Birmingham, Engineer, send greeting.
WHEREAS His most Excellent Majesty King George the Fourth, did, by
Ilis Letters Patent under the Great Seal of that part of the United Kingdom
of Great Britain and Ireland called England, bearing date at Westminster, the
Nineteenth day of April, in the first year of His reign, give and grant unto
me, the said William Brunton, my exors, adñiors, and assigns, His especial
licence, full power, sole privilege and authority, that I, the said William
Brunton, my exors, adiñiors, and assigns, during the term of years therein
mentioned, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick upon Tweed, my Invention of
"CERTAIN IMPROVEMENTS ON AND ADDITIONS TO FIRE GRATES, WHICH I INTEND TO
DENOMINATE ECONOMICAL FIRE GRATES;" in which said Letters Patent there is
contained a proviso, that if I, the said Willian Brunton, shall not particularly
describe and ascertain the nature of my said Invention, and in what manner
the same is to be performed; by an instrument in writing under my hand and
seal, and cause the same to be inrolled in His Majesty's High Court, of
Chancery within six calendar months next and immediately after the date
of the sail Letters Patent, that then the said Letters Patent, and all liberties
and advantages whatsoever thereby granted, shall utterly cease, determine, and
become void, as in and by the same, relation being thereunto had, will more
fully and at large appear.
!

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
William Brunton, do hereby declare that the nature of my said improvements
on and additions to fire grates, and the manner in which the same are per-
formed, are particularly described and ascertained in the following description
thereof (that is to say):-
My said improvement consists in, 1st, the introducing the coal and distri-
buting the same in an equal and uniform manner over the surface of the fire,
without opening what is usually called the fire door; 2nd, in maintaining the
heat of the fire at nearly an uniform temperature; 3d, in obtaining a more
perfect combustion of the coal than is procured by fire grates of the common
construction; 4th, in producing a sudden and temporary diminution of the
effect of the fire where the nature of the process to which it is applied may
require it. My said improved fire grates are applicable to the coppers for
brewering stills, reverbiratory furnaces, for melting or refining iron, copper,
and lead, and also to furnaces for heating retorts, and to the furnaces of
stoves or ovens for annealing glass or cast iron, and are effected by means and
combinations herein described. The fire grate I make of a circular form, and
it is ultimately supported by a vertical shaft (which I call the grate shaft)
moveable round its axis, the lower end of which shaft stands in the ash pit,
and the upper end whereof is supported by a strong bar built into the brick-
work of the ash pit. (This shaft is similar to that described in the Patent
granted to me on Twenty-ninth day of June, One thousand eight hundred and
nineteen, for (certain improvements in steam engines and the furnaces of steam
engines, by which a saving in the consumption of fuel is effected, and the
combustion of the smoke is more completely attained; and so far it and its
accompaniments are not considered as new in the Invention which I am now
describing; but the support of its lower end and the means employed for
lowering the shaft vertically, which is the mechanical means employed when I
wish suddenly to diminish the effect of the fire on the boiler or still, are new to
fire grates of this construction; and the way of feeding the fire by means of a
shovel in the manner to be hereafter described is also new.) The said shaft is
kept in its vertical position by one or more bearers of cast iron, built into the
brickwork of the ash pit, through which bearer or bearers the said grate shaft may
be moved perpendicularly, and the lower end of the said shaft is supported on
a bearer, which is moveable perpendicularly between guides or side supporters.
To this.last-mentioned bearer I attach a rack and pinion, or sometimes a beam
or lever, by which the said grate shaft may be elevated or depressed at
pleasure; from the upper end of the said grate shaft, above the upper sup-
porting bar, are extended two or more arms, carrying a strong cast iron ring

page_text: (which I call the grate ring), concentric with the said grate shaft, and having
its plane at right angles thereto; upon this grate ring I lay the grate bars,
which are similar to those in common use, but of different lengths, suited to
the places which they respectively occupy in the plane of the said ring when
placed parallel to its diameter and each other. To the exterior edge of the
said grate ring, and about three inches below its upper surface, is attached
another cast iron ring (which I call the brick ring): the plane of this ring,
which is also at right angles to the said grate shaft, and about six inches
broad, terminates at its exterior diameter in a vertical rim, rising from eight
to fourteen inches, according to the required thickness of the fire, thus
forming with the said plane and the above three inches of the grate ring a
circular case for a circle of fire bricks all round the grate, which fire bricks
should be of such a height as to stand from six to fourteen inches above the
grate (as the case may require) for the latteral support of the fire. To the
under side of the said grate ring is fixed a rim or cylinder (which I call the
air ring, made of strong sheet iron, projecting downwards about four inches into
a circular trough of suitable diameter, made of cast iron, which trough is built
into the brickwork of the ash pit, and concentric with the said grate shaft ;
the said air ring is not suffered to touch the bottom of the said trough, but
moves in sand with which the trough is filled; the use of the said air ring is to
prevent the passage e of air between the said grate ring and the said trough. The
inside of the furnace, or brickwork surrounding the said grate is made circular
and concentric with the fire grate, and about three inches more in diameter
than the outside of the brick ring; the wall rises off this diameter from the
level of the bottom of the said trough to serve as a receptacle for any dust or
ashes which may accidentally fall over the edge of the grate through the
insterstice of one inch and half left all round the said brick ring by the
greater diameter of the furnace. Into the said cavity I make two or more
openings at convenient places through the brickwork, with doors upon the
same, to be kept open or shint at pleasure, for the double purpose of cleaning
out the ashes and of permitting a current of atmospheric air to have access
through the said insterstice of one inch and half to the top of the fire
to ignite the smoke if necessary. In cases where the grate is to be moved
vertically, I attach a sand trough to the under side of the grate ring by
a cylindar of cast or wrought iron, the length of which cylindar I make
about six inches more than the intended range of the vertical motion of
the grate, and I fix the air ring by a flanch, to which it is joined into
the brickwork of the ash pit concentric with the grate shaft and said trough,
in such a position that when the said trough is filled with sand and elevated to

page_text: its greatest height, the air ring projecting downwards will enter the sand
sufficiently to prevent the admission of air between the air ring and the said sand
trough; when the grate is lowered the sand trough leaves the air ring, and the
grate descends into a circular chamber. of 'fire brick formed by a wall which
is built perpendicularly from the level of the air ring upwards, having an
insterstice round the brick ring of one inch and half. I at the same time
retard the combustion of the coal upon the grate by closing the opening of the
ash pit by doors attached thereto, and thus prevent the free admission of atmo-
spheric air. In that part of the furnace which is above the level of the brick
ring, I fix a fire door of the usual construction, for the purpose of cleaning and
lighting the fire, and also at a convenient place near to the said door, and in
the direction of a tangent of a radius of nine inches from the centre of the
grate, an opening is formed through the brickwork of the side of the furnace,
of suitable dimensions for the introduction of the coal, as hereafter described.
Connected with the said opening and extending in the same direction beyond
the brick work of the furnace, I fix an oblong close box or case of wrought or
cast iron (which I call the shovel box), of sufficient dimensions to receive the
shovel with its wheels (as hereafter described), and having suitable openings with
doors thereon in its sides for the purpose of examining or oiling the wheels of
the shovel. In the top of the said shovel box and in the direction of its
length, I make a hole or opening, the length of which is equal to half the
diameter of the grate, and its width about five inches (this I call the feeding
hole); over the said feeding hole is placed a box, which I call the fire feeder, or
for brevity, the feeder, which is made large enough to contain a supply of coal
sufficient for one or more hours; this fire feeder is in shape similar to the
hopper of a corn mill, excepting that the bottom is made oblong, its length
being equal to half the diameter of the grate, and its width about nine inches;
the aperture through which the coal passes from the fire feeder is on one of its
sides and close to the bottom, and this aperture is adjusted to the size of the
pieces of coal used by means of a sliding shutter, raised or lowered as occasion
may require, say, varying from two to five inches. The bottom of the fire fender
is an iron plate, about twelve inches wider than the lower orifice thereof, and
inclines downward about one in six towards the side on which is the aperture
for discharging the coal and in the same direction; it has a reciprocating motion
upon a pivot fixed at that end of the bottom of the fire feeder which is next.
the grate (that is, the pivot is nearly or directly over the end of the feeding
hole next the grate), by which reciprocating motion the coal resting upon the
bottom of the fire feeder, that (is, on the said iron plate which has the said
reciprocating motion) is passed through the aforesaid opening in the side of the

page_text: said feeder, and precipitated over the lower edge of the said plate through the
said feeding hole. . In order, to prevent any air from entering the furnace
through the said feeding hole, I connect the said feeder to the top of the shovel
box by a case, which incloses the lower part of the said feeder with its moveable
bottom plate, making a hole through the side 'of the said case of sufficient, size
to allow a rod to pass through to communicate the said reciprocating, motion
(obtained by connecting the same with an engine or other convenient power),
and upon the upper edge or mouth of the fire feeder I form a horizontal
channel or gutter to hold water or sand, into which a rim,projecting down-
wards, from the under, side of the cover of the said feeder is received, and
thereby I prevent all passage of air downwards through the interstices among
the pieces of coal. The said cover is suspended so as to be easily removed.or
lifted upwards when the feeder is to be supplied with coal: For the purpose
of conveying the coal to the grate and distributing the same thereon in an
equal and uniform manner, I construct a plate of wrought iron (which I call the
shovel), and I cause it to move horizontally between the grate and the feeding
hole, alternately through the said opening in the brickwork and within the said
shovel box, by, power obtained from an engine or other convenient source,
connected to the said shovel by a rod or chain passing through a small hole in
the end of the said shovel box. The said shovel I make, as long as the half
diameter of the grate and about twelve inches wide; having a margin about
two inches high at each end and along the back or side edge over which it does
not discharge, and when the said shovel is at the extremity of its range from
the grate it is perpendicularly under the said feeding hole, so as to receive the
charge of coal from the fire feeder, and when it is at the opposite extremity
of its range, one end of it is over or against the centre of the grate, the other
end is over its periphprey; the longitudinal motion of, the shovel, that is, its
motion between the said feeding hole and the grate, is in the same direction
with the aforesaid opening left in the brickwork, and in the line of a tangent
of radius of nine inches, as already noticed; in order that the shovel in
discharging the coal from from the side nearest the centre of the grate, may
fall upon its radii, or nearly so. To the end of the shovel I attach a bar,
extending in the same plane and in a direction parallel to its side edges; the
bar, with the shovel thus attached, I support upon four wheels, the axles of
which are placed upright angles to the said bar, and the said wheels run upon
two rails, parrallel to each other, and so fixed within the said opening and
shovel box as to conduct or guide the shovel between the feed hole, from
which it receives the charge of coal, and the grate where it is to be discharged
upon the fire;. to the end of the bar opposite to that to which the shovel is

page_text: attached, I fix a weight sufficient to counterpoise the shovel and to equalize
the pressure upon the four wheels; the bar of the shovel, while it is supported
by the axles longitudinally, is moveable on its own axis, and the coal is
discharged from the shovel by its cross section turning by the said bar to
about sixty degrees from level, which position I induce it to take by making
the said shovel heavier on that side from which I intend it shall discharge;
and to restore the said shovel to a level position preparatory to its receiving a
supply of coal, I fix upon and at right angles to the said shovel bar a lever,
about fourteen or sixteen inches long, the end of which I cause to bear upon a
curved guide, fixed so as to be equidistant through through its whole length from
the centre of the shovel bar, and forming an angle of thirty degrees with the rails
on which the shovel moves longitudinally; as the shovel retires from the grate
it is restored to a level position by the said lever sliding upon the said curved
guide, which terminates against another guide which is fixed parallel to the
said rails (which I call the parallel guide), against which the said lever con-
tinues to slide, and thereby supports the shovel in a level position till it
reaches the feeding hole, through which receiving a supply of coal it is
returned toward the grate, the lever still bearing upon the said parallel guide;
but to prevent the lever in its progress towards the grate from following the
curved guide, I apply a tongue similar to that of a turnout waggon rail, which
forms a continuation of the parallel guide, moveable upon a round stud or pin
at its extremity, on which its other end being fitted to the curved guide and
held thereto by a weight or spring, presents a continuity of the parallel guide
upon which the said lever slides, and it supports the shovel loaded with coal
until it has reached the end of its range towards the grate, where the lever
passing off at the end of the tongue falls against the curved guide, and the
coal is thereby discharged; and the grate being made to revolve by power
obtained from an engine or other convenient scource, the fewel, as noticed
above, is distributed equally and uniformly over the whole surface or area of
the fire grate, whilst the coal introduced upon the fire at short intervals, say
of fifteen or twenty seconds, the heat of the fire is maintained at an uniform
temperature; and also by the revolving of the grate the pieces of coal thereon
are exposed successively on all their sides to the current of the fire passing
constantly in one direction towards the chimney or flew; the combustion of
the coal is thereby rendered more complete, and by lowering the grate into
the chamber, as before noticed, and shutting the said doors of the ash-pit, the
effect of the fire upon the boiler or still will be thereby greatly diminished and
the combustion of the coal retarded. No competent engineer will find any
difficulty in connecting the said grate shaft with a steam engine or other

page_text: convenient power, so as to make it revolve on its axis and give the required
motion to the fire grate (the velocity at which I prefer the grate to move in
one revolution in about six minutes for a grate of five fect diameter, and so in
proportion to any other diameter), nor will any engineer find difficulty in
borrowing from any convenient power what may be necessary to give the
reciprocating motion to the inclined moveable bottom of the fire feeder, or
the horizontal motion to the shovel, but I shall describe a method for doing
so which may be easily understood. Upon the grate shaft, at any convenient
height above its lower end, fix a spur wheel, nearly as large as the grate, to be
driven by a pinion upon another vertical shaft turned by an engine or other
convenient power, (introducing, if necessary, another wheel or wheels between
the said spur wheel and the said pinion, and proportioning the number of
their teeth to the velocity wanted); when the grate is intended to be moved
vertically, the wheel or pinion into which the spur wheel upon the grate shaft
works must be of sufficient depth to permit the said spur wheel to move the
whole distance of its vertical range, without getting out of the teeth of the said
wheel or pinion. Upon the above-mentioned vertical shaft, having the pinion
and being driven by the engine, fix a cam or excentric curve, including ninety
degrees, which being brought round by the revolutions of the said shaft, may
act against a lever connected with the sliding bottom plate of the fire feeder,
and moved in one direction, at the same time raising a weight connected with
and sufficiently heavy to move the said plate back again in the opposite
direction whenever the cam ceases its action upon the said lever. In order to
regulate the quantity of coal introduced by each movement of the said sliding
bottom plate, cause the said lever to act against or fall upon a wedge, which,
by moving longitudinally, will increase or diminish the space through which
the said sliding bottom plate moves. Upon the before-mentioned vertical
shaft and at a convenient height above the aforesaid cam, fix a bevil wheel,
which, turning another bevil wheel of equal dimensions fixed upon a horizontal
shaft, upon which fix another cam or excentric, which I call the shovel.cam),
including about one hundred and twenty degrees, and of such excentricity as
when turned round by the said horizontal shaft will move the end of a lever
suspended over and bearing (by a roller) upon the said cam, through a space
equal to that through which the shovel moves horizontally; to the said end of
this lever (the other being stationary) fix a chain, which passing under a
pulley fixed to the outside of the end of the shovel box and passing in
a horizontal direction through the said end and round another pulley fixed
so near to the grate and between the aforesaid rails as the chain when passed
round it and attached to the shovel is drawn out by the elevation of the said

page_text: lever; the shovel will be thereby moved to the extremity of its range toward
the grate, whilst another chain, attached also to the shovel, and passing directly
through the said end of the shovel box, and over a pulley fixed on the outside
thereof, raises 'a weight sufficiently heavy to draw the shovel back again from
grate to the feed hole, whenever the cam. has ceased to act upon the said
lever. That the respective movements of the sliding bottom plate (by which
the coal is discharged from the feeder), and of the shovel (by which the coal is
conveyed towards the grate horizontally, may correspond with each other
in feeding the fire, it is necessary that the cam operating upon the sliding
bottom plate shall cease to act on its lever, and the coal be discharged thereby
before the action of the shovel cam commences; and as the first-mentioned
cam includes ninety degrees and the shovel cam one hundred and twenty
degrees, the action of both may be accomplished in about two thirds of the
revolutions of the said vertical and horizontal shafts upon which the said cams
are respectively fixed, leaving a period of time equal to one third of the said
revolution for the operation of withdrawing the shovel from the grate to the
feeding hole, preparatory to receiving the next charge. Upon the said grate
shaft above and resting upon the said spur wheel I fix a circular plate of iron
somewhat larger than the fire grate; upon this plate the ashes fall, and are
by the motion of the plate urging them against an excentric bar of iron,
which bar is fixed to the side of the ash-pit, swept from the surface of the
plate into the lower part of the ash-pit. With my said improved grate and its
appendages the smallest coal may be used, but pieces larger than would pass
through in every direction a ring four inches diameter, must be broken
previously to their being put into the fire feeder. I have already intimated,
and I wish it to be clearly understood, that the said improvements which form
the subject of the present Specification, do not consist in the invention or
construction of the said revolving-grate and fire feeder, these having been
already described in my Specification of the Invention for which I obtained
His Majesty's Royal Letters Patent, dated the Twenty-ninth day of June, in
the year One thousand eight hundred and nineteen, for certain improvements
in steam engines and the furnaces of steam engines, by which a saving in the
consumption of fuel is effected, and the combustion of the smoke is more
completely attained, though I have thought it adviseable for the sake of
perspecuity to repeat here many part of the description given in the Specifica-
tion just alluded to. The said improvements which form the subject of the
present Specification consist in the means which I now employ and have
before described), to apply the said circular grate and fire feeder to coppers for
brewing, to stills, to reverberatory furnaces for melting or refining-metals, to

page_text: furnace for heating retorts, to the furnaces of stoves for annealing glass
or cast iron, or to any other furnaces to which the said circular grate and fire
feeder may be applicable, namely, the moveable support and side guides of the
lower end of the upright shaft and the power of vertical movement now given
to the said shaft, and the shovel now combined with the said fire feeder, as
above described, it being by these means that the said revolving circular grate
and fire feeder are rendered applicable to furnaces on which it would be
either inconvenient or impracticable to introduce coal through the roof of the
furnace.
In witness whereof, I, the said William Brunton, have hereunto set my
hand and seal, this Seventeenth day of October, in the year of our
Lord One thousand eight hundred and twenty.
WILLIAM (L.S.) BRUNTON.
AND BE IT REMEMBERED, that on the Seventeenth day of October,
5 in the year of our Lord 1820, the aforesaid William Brunton came before our
said Lord the King in His Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stampt according to the
tenor of the Statute made for that purpose.
Inrolled the Eighteenth day of October, in the year of our Lord One