AN IMPROVEMENT IN THE CONSTRUCTION OF FURNACES."
Year: 1855

page_text: LETTERS PATENT to Edward Jeffreys, of Shrewsbury, Engineer, for the
Invention of "AN IMPROVEMENT IN THE CONSTRUCTION OF FURNACES."
PROVISIONAL SPECIFICATION left by the said Edward Jeffreys at the
Office of the Commissioners of Patents, with his Petition, on the 6th
November 1855.
I, EDWARD JEFFREYS, of Shrewsbury, Engineer, do hereby declare the nature
5 of the said Invention for "AN IMPROVEMENT, IN THE CONSTRUCTION OF FURNACES"
to be as follows:-
The object of this Invention is to provide a larger area for the passage of
air up through the burning fuel than is at present obtained in a given capacity
of fire-place, and otherwise to facilitate the combustion of smoke in furnaces.
To this end, instead of placing the fire bars in a line with each other, I
arrange them at angles, and 1 mount them in a rocking frame, which is
capable of being rocked on the trunnions which support it. By this means
I am enabled to adjust the level of the fuel on the fire bars as required to
effect the most economic consumption of the fuel.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edward Jeffreys, in the Great Seal Patent Office on the
6th May 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
JEFFREYS-of-Shrewsbury, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters.
Patent, bearing date the Sixth day of November, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Edward Jeffreys, Her special license that I, the said Edward
Jeffreys, my executors, administrators, and assigns, or such others as I, the
said Edward Jeffreys, 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 "AN IMPROVEMENT
IN THE CONSTRUCTION OF FURNACES," upon the condition (amongst others) that I,
the said Edward Jeffreys, by an instrument in writing under my hand and
seal, should particularly describe and ascertain the nature of the said Inven-
tion, 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 Edward Jeffreys, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawings hereunto annexed, and to
the letters and figures marked thereon (that is to say):
:-
This Invention relates to a novel mode of mounting the fire bars of steam
boiler and other furnaces, the object being to effect a more economical con-
sumption of fuel than is commonly obtained.
In the accompanying Drawings I have shewn my Invention under some-
what varying forms, but in each case the same principle of construction is
embodied, with the view of providing, first, a larger area between the fire bars
for the passage of air up through the burning fuel than is at present obtained'
in a given capacity of fire-place; and, secondly, means for facilitating the
charging of the furnace with fuel, so that dense volumes of smoke shall not"
be emitted therefrom. The second feature of the Invention may, however, be

page_text: used with advantage where the ordinary construction and arrangement of fire
bars is employed.
In order to obtain the above-mentioned advantages, instead of setting all
the fire bars in the same horizontal plane, I arrange them at different levels,
rising from the central group to the sides or from the sides to the central
group. These fire bars I mount in a rocking frame, which is capable of being
rocked by the stoker on the trunnions which support it, and thus of changing
the level of the fuel on the fire bars, as required to effect the most economic
consumption of the fuel.
of the same.
The Figures in Sheet I. represent my Invention as applied to the furnace
of a locomotive engine, Fig. 1 being a longitudinal section of so much of the
engine as will suffice to explain the Invention, and Fig. 2 a transverse section
a, a, a, are the fire bars, arranged in three different planes, and
mounted in a rectangular frame b; forming together a rocking grate. This
frame is provided at its sides with trunnions c, c, which are supported by
bracket bearings d, d, connected in any convenient way to the boiler or the
main framing of the engine. The trunnions c are set somewhat nearer to
the inner than the outer end of the frame, for the purpose of giving greater
elevation to the outer end of the frame than the inner end when adjusting the
surface level of the fire. A rocking motion is communicated to the frame b
by means of two pairs of links e, e, which connect the frame with a pair of
rock levers f, f, mounted on a horizontal shaft g. This shaft g is situate below
the furnace, and is supported in bearings in the bracket pieces d, d. To one
end of this shaft a worm wheel h is keyed, and into it gears a worm i
koyed to a rod k, which is provided at top with a hand wheel for giving it
an axial motion.
It will now be understood, that by turning the hand wheel to the right or
left, either end of the fire bars may be raised or depressed to any required
angle. Now, the advantage of this arrangement is, that I can throw the fuel
forwards towards the tubular flues or back towards the fire door at pleasure;
thus, when I wish to put on a fresh supply of coals, I lower the forward end
of the rocking frame and thereby shift the coal forward, causing it to accu-
mulate at the depressed end of the grate, and having closed the door I depress
the raised end, and thus throw back the red-hot coal on to the fresh charge.
By this means the smoke and other gaseous products given out by the fresh
fuel will be compelled to pass through the overlying bed of hot coal, and in
their passage the smoke will become consumed. The large area provided
in the bed of the furnace for the indraft of air will, by permitting of a copious

page_text: supply of air to the burning fuel, greatly assist in the furtherance of this
object. (Fig. 1) is a stop piece, composed of fire brick or metal, for the
purpose of preventing the fuel from falling down and impeding the action
of the rocking frame.
!.
...
4.A
I would remark, that as my improved grate produces by its rocking action
an essentially different effect from the simple-vibratory-fire bars, which have
heretofore been proposed to be employed in steam boiler and other-fur-
naces, it must not be mistaken for such.contrivances, as their action is not
such as to permit of the fresh fuel being buried by the red-hot coals, as
explained.
A modification of the above-described arrangement is shewn at Figs. 3
and 4, Sheet II., as applied to a locomotive engine. In this example, instead
of rocking the frame 'b'of the grate from near the centre, I effect-the-depres-
sion of either end by the employment of two pairs of crank levers m, m;
connected respectively by links n to the opposite ends of the frame, and
forming the support for that frame. These pairs of levers m, m*, have their
fulcrums at o, and they are connected together by a rod-p, so as to ensure
their reciprocal movement. Keyed to the axle of the levers m is an arm'q,
the raising or lowering of which, by turning a threaded shaft r that passes
through a tapped nut carried by the arm-q (or by any (other suitable and
well-known mechanical contrivance), will cause the grate to take either of
the positions indicated in the Drawing, or any intermediate position, for the
purpose above set forth.
ic
.
Figs. 5 and 6 shew the application of my Invention to stationary boilers;
Fig. 5 being a longitudinal section, and Fig. 6 a cross section, of the furnace
so fitted. In this example (which is the simplest form of application), the
grate, composed as before of fire bars set at different levels in a rocking
frame, is fitted with trunnions so situated that the grate is balanced or nearly
so. A simple lever arrangement, therefore, at the side of the fire-place will
suffice to change the position of the grate as required. The brickwork, it
will be seen, on inspecting Fig. 5, is hollowed out slightly to receive the ends
of the grate and prevent the necessity for a stop piece; as at 4; Fig. 1.
...: When constructing new locomotive engines to receive my improved rocking
grate, I propose in lieu of using the stop piece,Fig. 1, to form the tube
plate and the back plate of the fire-box with concavities or hollows, 'as shewn
at ss, Fig. 7; Sheet III., into which hollows the ends of the grate will pro-
ject, and the ends being shaped to a corresponding figure, the ordinary rocking
of the grate to change the distribution of the fuel on the bars will not open a

page_text: passage for the admission or escape of the fuel. Fig. 8 shews, in cross section,
a modified arrangement of the fire bars a, a, which, however, admits of a
similar proportional increase of area for the indraft of air to the fire to that
shewn in the other Figures; in this instance the central group of fire bars is
the highest, and the other bars reach step by step a lower level. An incidental
advantage of both these plans over other arrangements of fire bars, having
varying or irregular levels, is, that the clearing of the bars from clinkers may
be effected with the greatest facility, which is not the case where the bars are
set transversely of the engine.
Having now set forth the nature of my Invention of "An Improvement in
the Construction of Furnaces," and explained the manner of carrying the
same into effect, I wish it to be understood that under the above in part
recited Letters Patent I claim, arranging the fire bars longitudinally and at
different levels, as described, and setting them in a rocking frame, which admits
of the elevation of either end, for the purpose of facilitating the proper
distribution of the fuel upon the fire bars.
And I further claim the use of the rocking frame, acting as above set forth,
irrespective of the special arrangements of fire bars described and shewn
in the Drawings.
In witness whereof, I, the said Edward Jeffreys, have hereunto set my
hand and seal, the Third day of May, in the year of our Lord One
thousand eight hundred and fifty-six.
Witness,
5
J. W. MOFFATT,
66, Chancery Lane.
(L.S.) EDWD JEFFREYS.