Improvements in Self-feeding, Self-stoking, and Self-cleaning Furnace Fire Grates.
Year: 1886

page_text: Date of Application, 22nd Nov., 1886
Complete Left, 22nd Sept., 1887
Complete Accepted, 25th Oct., 1887
PROVISIONAL SPECIFICATION.
Improvements in Self-feeding, Self-stoking, and Self-cleaning
Furnace Fire Grates.
I, LEWIS HOPCRAFT of No. 10 Bethune Road Stamford Hill, N. Engineer
do hereby declare the nature of this invention to be as follows:-
This invention consists in constructing furnace fire grates of a circular flat form of
cast iron or other suitable material having the necessary spaces for air to pass through
to the fuel placed thereon; the centre of the grate is formed with a tube of suitable
material & size passing from the surface of the grate downwards to a hopper for
containing a supply of fuel, said tube contains a worm creeper or other device suitable
for conveying or elevating fuel placed in the hopper to the surface of the grate.
The combined arrangement of grate, tube, and elevating gear is so constructed that
it can be revolved also tilted when necessary to any desired angle. Teeth or projections
of suitable shape and material are so arranged and mounted as to pass up, at suitable
" Prickers."
intervals of time, through the air spaces in the grate so as to act as
Dated this 20th day of November 1886.
LEWIS HOPCRAFT.

page_text: Furnace Fire Grates.
I, LEWIS HOPCRAFT, of No. 10 Bethune Road, Stamford Hill, N., Engineer,
do hereby declare the nature of this invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the following
statement:
This invention consists in constructing furnace fire grates of a circular flat form of
cast iron or other suitable material, having the necessary spaces for the air to pass
through to the fuel placed thereon; the centre of the grate is formed with a tube of
suitable material and size passing from the surface of the grate downwards to a hopper
for containing a supply of fuel; the said tube contains a worm creeper for conveying
or elevating fuel placed in the hopper to the surface of the grate. The combined
arrangement of grate, tube, and elevating gear is so constructed that it can be
revolved, and also tilted when necessary to any desired angle.
The furnace bars are in preference concentric rings approximately V shaped.
To show more clearly how my invention is carried out, I furnish drawings in which
the same letters represent corresponding parts throughout.
Fig. 1 is a side elevation showing the arrangement adapted for an under fired boiler,
one side of the ashpit being removed.
Fig. 2 is a plan of grate.
Fig. 3 is a vertical section of a furnace bar resting on radial arm.
Fig. 4 is a front view of standards supporting the arrangement with the grate in a
horizontal position.
The furnace bars A rest upon radial arms D in a slot C, and are kept apart by lugs
or distance pieces B on the outer edge of every ring except the outermost. The
innermost ring has lugs on each side, or the tube E, which occupies the centre of the
grate has lugs on its outer circumference. The tube E reaches to, or nearly to, the
level of the top surface of the bars. The radial arms D are secured to or made in one
piece with the tube E, and rest upon or are fitted into a ring R, which encircles but is
not attached to the tube E. This top ring R rests upon friction wheels S, which
preferably taper inwards, and run in slots of another encircling ring S¹. These
friction wheels S run on a lower ring T which also encircles the tube E but is not
attached to it. On this lower ring Tare trunnions U supported on trunnion bearings V
of standards W fixed in the bed of the ashpit X. Within the tube E is an elevating
worm H with shaft J, the top end of which shaft works in a bracket K attached to the
tube E. The whole arrangement of grate, tube, and elevating worm can thus be tilted
together on the trunnion bearings V, and adjusted, and fixed to any desired angle by
wedges, screws, or other well known means. The tube E and grate can also be
revolved on the ring T, and the worm H with the shaft J is capable of being revolved
independently.

page_text: When in operation the worm H and shaft J are turned so as to elevate the fuel
placed on it, and the grate with the tube E is turned in the opposite direction.
By this action, the fuel which is fed into the bottom of the tube E is carried up by the
worm H and delivered on the furnace bars, and distributed over the said bars.
Any convenient method of driving the apparatus may be employed as well as any
convenient method of feeding the tube and worm with fuel.
A suitable method of doing this is as follows:
To the lower end of the shaft J is attached a wheel L driven by the worm M which
may be driven from any motive power by a band round a wheel attached to its shaft
or axle. To this axle is also attached a pinion N driving directly or by intermediate
gearing the toothed wheel O connected with the worm P driving the wheel Q, which
is attached to the base of the tube E. The shaft J, when the apparatus is tilted, rests
in a bearing C to steady it while in operation. At or near the base of the tube E are
orifices G to allow the entrance of fresh fuel into E and on to the worm H. B¹ is a
hopper surrounding the tube E but not revolving with it. The hopper works in
slots F on the standards W, so that when the arrangement is tilted the hopper is
tilted also.
Y is the boiler which in this case is underfired.
Z is the front of the furnace and ashpit.
A is the bridge at the back of the furnace.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed I declare that what I claim is.
The combination of a circular fire grate attached to a central tube containing a worm,
which grate and tube can be made to revolve in one direction, while the worm is made
to revolve in the opposite direction for the purpose of feeding fuel to the furnace and
distributing it over the grate, the whole combination being capable of being tilted and
worked at any desired angle.
Dated this 21st day of September 1887