IMPROVEMENTS IN APPARATUS FOR SUPPLYING FUEL TO FURNACES be ass
Year: 1884

page_text: :I, THOMAS HENDERSON, of Castle Street Liverpool, in the county of Lancaster,
Mechanical Engineer do hereby declare the nature of my said invention for
"IMPROVEMENTS IN APPARATUS FOR SUPPLYING FUEL TO FURNACES
to be as
follows:
:-
""
This invention has for its object a mechanical stoker that shall take up little
room, shall be very cheap in construction and repair, and that shall distribute the
coal well over the furnace bars.
Beneath the usual single or double hopper for coals I place an archimedean
screw with hollow shaft in a cylindrical box-the screw feeds onto the casing in
which revolves a rotary shovel or beater-a wheel revolving on a horizontal axis
and having two or more horizontal beaters on its arms instead of having a rim, the
benters being curved or otherwise so as to spread the coal evenly over the fire and
to best advantage as they revolve, and the arms being cut away for half of the
width of the rotary shovel so as to admit of the archimedean screw delivering the
coal at the centre of the shovel box. The rotary shovel is in a casing immediately
above the ordinary fire door. The shaft of the rotary shovel can pass freely
through the hollow archimedean screw shaft and by worm gearing, vertical shaft,
eccentric countershaft and ratchet movement drives the screw. It is itself driven
in any ordinary manner preferably by fast and loose pulley and belt. The
eccentric on the vertical shaft drives the countershaft by means of an arm on the
latter to which it is linked. In two-furnaced boilers there are of course two
screws on the same axial line and each is preferably driven by independent wheel
and axis. The gearing in such case is preferably arranged at one end and the
driving mechanisin at the other, the rotary shovels being next these and the two
screws (one right handed and the other left-or both right handed but fed in
opposite directions) in the centre under the hopper. The two screw boxes or
casings are preferably united by the strong casting that carries the bearings of the
ratchet shaft.
The mode of action is as follows: The slack being fed into the hopper sinks
down onto the screw and is slowly crushed along the two turns of the screw till it
falls onto the casing in which revolves the rotary shovel. The latter goes at a very
rapid speed relatively to the screw and throws the coal forward and slightly
upward into the fire. The main shaft passing through the hollow screw without
having bearings in it little turned work is required.
Dated thi 10th
1004

page_text: I, THOMAS HENDERSON, of Castle Street, Liverpool, in the county of Lancaster,
Mechanical Engineer, do hereby declare the nature of my said invention for
"IMPROVEMENTS IN APPARATUS FOR SUPPLYING FUEL TO FURNACES," and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
This invention has for its object a mechanical stoker that shall take up little
room, shall be very cheap in construction and repair, and that shall distribute the
coal well over the furnace bars.
The invention is best described by aid of the acompanying drawings, in which:
Figure 1 is a front elevation of a boiler fitted with the apparatus.
Figure 2 section through line 1. 2. of Figuro 1.
Figure 3 section through line 3. 4 and
Figure 4 end elevation.
In these A is the usual hopper for coals. B is an archimedean screw with hollow
shaft (both shewn in dots) encased in a cylindrical box C, the screw feeds or
conveys the fuel on to the casing D, in which revolves a rotary shovel or beater,
shown in dots at E. The beater in construction resembles a wheel revolving on a
borizontal axis H, and having two or more horizontal beaters F on its arms,
instead of having a rim, the beaters being curved or otherwise, so as to spread the
coal evenly over the fire, and to best advantage as they revolve, and the arms
being cut away for half of the width of the rotary shovel so as to admit of the
archimedean screw delivering the coal at the centre of the shovel box. G is the
ordinary fire door. The shaft H Fig 4 of the rotary shovel can pass freely through
the hollow archimedean screw shaft, and by worm gearing I I, vertical shaft J,
eccentric K, joint P, arm O keyed on to the countershaft L, and the ratchet
movements M, m, m' drive the two screws. These screws can each be driven
independently of each other, and at different speeds by throwing one or other
ratchet pawl out of gear, or giving one ratchet pawl a longer feed than the other.
Shaft is itself driven in any ordinary manner, preferably by fast and loose
pulley W and belt. The eccentric K on the vertical shaft drives the counter-
shaft L, by means of an arm O on the latter, to which it is linked by link P and
pin p. The two screw boxes or casings are preferably united by the strong
casting R, that carries the bearings of the ratchet shaft L. SS are brackets for
carrying shafts. The ratchet movement is in duplicate and consists of arm M,
link m, and ratchets U, U', kept in position by link m² on the worm shafts, and
ratchet wheels TT. If in place of the joint m³, the link M were pierced by
numerous holes into any of which link m could be linked, then any required feed
of ratchet could be obtained by ratchets. V is a bracket bolted to the interior of
cylinder C, and carrying end of hollow shaft of worm B. W driving pulleys.
The archimedean screw for each furnace is mounted on a separate shaft, the
screw which conveys the fuel to one furnace being a right hand screw, and to the
other a left hand screw. The ratchet wheels are placed on the inner end of their
two respective screw shafts, and are actuated by separate ratchets U, U, so that
the feed to one furnace may be stopped at any time without interfering with the
other.
The mode of action is as follows:-
The coal, slack, or other fuel being fed into the hopper sinks down onto the
screw, and is slowly carried along the two turns of the screw till it falls onto
the casing in which revolves the rotary shovel. The latter goes at a very rapid

page_text: speed relatively to the screw, and throws the coal forward and slightly upward
into the fire. The main shaft passing through the hollow screw, without having
bearings in it, little turned work is required.
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:-
1st The manufacture and use of mechanical stoking machines, in which the coal
is delivered by an archimedean screw into a casing from which it is thrown onto
the fire by a vertically revolving shovel or beater, substantially as described.
2nd The combination of the screw having hollow shaft and going at slow speed,
with the vertically revolving beater, running at high speed on a shaft concentric
with the worm, or nearly so, and cut away in the centre to near the middle, so as
to allow the worm to project into it, by which means the archimedean worm can
deliver its coal onto the casing, immediately in front of the central portion of the
revolving beater.
3rd The mechanism for driving the slowly revolving screws from the rapidly
revolving main shaft independently of each other, combined and arranged
substantially as and for the purposes described
Сиси од any or ivovember lo
WP. THOMPSON & Co.,
Of 6, Lord Street, Liverpool,
and 323, High Holborn, London,
Patent Agents for the Applicant.