IMPROVEMENTS IN CAR ROLLED AND OTHED FURNACES
Year: 1853

page_text: LETTERS PATENT to David Mushet, of Coleford, in the County of
Gloucester, Gentleman, for the Invention of "IMPROVEMENTS IN
CAR ROLLED AND OTHED FURNACES"
PROVISIONAL SPECIFICATION left by the said David Mushet at
the Office of the Commissioners of Patents, with his Petition,.
on the 16th September 1853.
I, DAVID MUSHET, of Coleford, in the City of Gloucester, Gentleman,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN STEAM-ENGINE BOILER AND OTHER FURNACES" to be as follows:-
My improvements relate, first, to peculiar constructions of furnace
grates; and, secondly, to a mode of charging the same with fuel.
And for the better understanding of my said Invention, I will now
proceed to describe the Drawing hereunto annexed, reference being.
made to the letters marked thereon.
Fig. 1, shows a common engine boiler with my improvements
attached. A, is the boiler; B, the furnace; C, the bridge; D, the
flame bed leading to the flues and chimney shaft; E, is my improved
grate made so as to rock or swing on the point E, as a centre. This

page_text: grate is formed by the fire bars being arranged in a suitable frame to
carry them firmly and steadily; and to the back end of this frame is
attached a perforated semi-circular plate of iron F, the full width of the
grate, and of the required depth to which it is intended to depress the
front portion of the bars, where the dead plate G has a similar plain or
perforated curved iron plate H, corresponding to the plate F. The
action of the grate so arranged is that, when the bars are depressed
to I in front, and consequently raised to J at the back, the curved
plate H prevents the improper admission of air in front, and the
plate F, rising with the bars against the clinker plate K, also acts to
prevent the too free admission of air from the back of the ash pit L;
and while in this position, the coals N, in the hopper M, regulated by
the slide plate at O, fall down over the inclined plate P, which is
provided at Q, with a receptacle for a portion of the coals, which, by
various simple contrivances, may be made to project the coal by
raising or springing forward a false bottom therein, while the level
portion of P, will charge the front of the grate bars, which are then
returned to their proper level G, K. To clean out the furnace, the
hopper M can be removed, and the plate P lowered on to the dead
plate G.
Having thus described one arrangement of my improvements, I
would observe that my Invention is capable of numerous modifications
to suit various kinds of furnaces according to their length, situation,
or other circumstances.
For the furnaces of Cornish boilers the action of the grate may be
from right to left, or the reverse, moving on a centre bearer running
from the front to the back of the furnace. Likewise, the curve required
at the back of the furnace may be made in the brick work, and in
some arrangements both the back and front curvatures may be formed
in the brick work. Also, the grate, instead of rocking on the centre,
causing the back to have a motion contrary to the front; may be set
to rise or fall either in halves or throughout its whole length, or
to slide backwards & forwards either wholly or in part. I do not
therefore restrict myself to any particular form of furnace, bars, or
hopper, or the dimensions, materials, or situation of the several parts,

page_text: so long as the principle of my Invention is adhered to. And I do
declare that what I claim as my Invention is, namely,-first; the pecu-
liar construction of a semi-rotatory, a rising & falling, or a sliding
furnace grate; and, second, the mode of supplying fuel, whether pro-
jected from a hopper, or falling therefrom, by depressing or sliding the
grate as described.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said David Mushet in the Great Seal Patent Office
on the 16th March 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
DAVID MUSHET, of Coleford, in the County of Gloucester, Gentleman,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of September, in the
year of our Lord One thousand eight hundred and fifty-three, in the
'seventeenth year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto me, the said David Mushet, Her special
licence that I, the said David Mushet, my executors, administrators,
and assigns, or such others as I, the said David Mushet, my exceu-
tors, 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,
ánd vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN STEAM-ENGINE BOILER AND OTHER FURNACES," upon the condition
(amongst others) that I, the said David Mushet, by an instrument in
writing under my hand and seal, 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 Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said David Mushet, do hereby de-
-clare the nature of iny said Invention, and in what manner the same

page_text: is to be performed, to be particularly described and ascertained in and
by the following statement:
My said improvements relate, firstly, to peculiar constructions of
furnace grates; and, secondly, to modes of charging the same with
fuel.
And for the better understanding of my said Invention, I will now
proceed to describe the Drawing hereunto annexed, reference being
had to the letters marked thereon.
DESCRIPTION OF THE DRAWING.
Figure 1, is a vertical longitudinal section of the front end of a
common engine boiler, with my improvements applied to the furnace
thereof. A, is the boiler; B, the furnace; C, the bridge; D, the
flame-bed leading to the flues and chimney shaft; E, is my improved
grate made as to rock on central or nearly central pivots at E',
when either end of the grate is raised or lowered by racks, levers, or
other suitable mechanical appliances. This grate is formed by the fire
bars being arranged in a frame to carry them firmly and steadily while
being moved on the bearing E¹; and to the back end of the frame is
attached a perforated semi-circular iron plate F, being the full width of
the grate, and of the required depth to which it is intended to depress
the front portion of the bars, this perforated plate being thereby
elevated within, at the back of the furnace, so as then to face the fire-
bridge C; a similar plate H, about the same width, and either plain or
perforated, is attached to the dead plate G. The action of the grate
so arranged is, that when the bars are depressed to I in front, and
consequently raised to J at the back, as shown by the dotted lines I, J,
the curved plate H prevents the improper admission of air in front,
while a plain or perforated plate F, rising with the bars against the
clinker plate K, also acts to prevent an undue admission of air from
the back of the ash-pit L; and in this position, the coal M, in the
hopper N, regulated by the slide plate at O, falls down over the
inclined plate P, which is provided at Q, with a receptacle for a portion
.of the coal, and which, by various simple contrivances, may be made to
project the fuel into the furnace, by raising or springing forward a false

page_text: bottom therein; or a plate suspended against the inside face of the
hopper may be actuated by a suitable handle or lever; while the
level portion of P, will charge the front of the grate bars, which may
then be returned to their ordinary situation G, K. To clean out the
furnace, the hopper N, may be removed, and the plate P, lowered on
the dead plate G. The plates F, and H, may be plain or perforated;
and the plate H, if desired, may be placed above, on the grate framing,
before the hopper; or a plate corresponding to H, may be attached to
the under side of the end a, of the grate framing, and one corresponding
to F, attached at b, to the under edge of K.
For some forms of boilers, and some descriptions of fuel, I prefer to
omit the receptacle Q, and continue the front of the hopper downwards,
united with the inclined plate P. A spindle, carrying vanes or notched
projections, may then be inserted through the hopper from side to side,
to revolve on proper bearings at each end, and when rotated with due
velocity, will intercept and project small portions of the coal falling
from the hopper, and impel them rapidly over the grate, and towards
the back of the furnace.
Having thus described several arrangements of my Invention, I
would here observe that the same is capable of numerous other modi-
fications to suit various kinds of furnaces according to their length,
situation, uses, and other circumstances. Thus, for the furnaces of
Cornish boilers the action of the grate may be from side to side, on a
centre bearer, parallel with the flue. Likewise, the curve required at
the front or the back end of the furnace may sometimes be con-
veniently made in the brickwork. Also, the grate may be set so as to
slide backwards and forwards, and I then prefer to attach the clinker
plate K, to the grate framing, the plate being plain or perforated, and
sliding through a slot in the back brickwork of the furnace. I do not,
therefore, restrict myself to any particular form of furnace, or of bars,
or hopper, or the dimensions, material, or the precise situation of the
several parts, so long as the principle of my said Invention is main-
tained. And I do declare, that what I claim as my improvements are,
namely, first, the peculiar construction of a semi-rotatory, or rising

page_text: and falling, or a sliding furnace grate; and, second, the mode of sup-
plying fuel, whether projected from a hopper, or falling therefrom, on
sliding or depressing the grate, as described.
In witness whereof, I, the said David Mushet, have hereunto set
my hand and seal, this Fifteenth day of March, in the year
of our Lord One thousand eight hundred and fifty-four.
DAVID MUSHET. (L.S.)