IMPROVEMENTS IN FURNACES AND MACHINERY EMPLOYED IN THE MANUFACTURE OF COMPRESSED FUEL AND OTHER MATTERS
Year: 1862

page_text: PROVISIONAL SPECIFICATION left by John Doddridge Humphreys at
the Office of the Commissioners of Patents, with his Petition, on the
4th April 1862.
I, JOHN DODDRIDGE HUMPHREYS, of 11, Aldhous Terrace, Barnsbury, in
the County of Middlesex, Engineer, do hereby declare the nature of the
Invention for "IMPROVEMENTS IN FURNACES AND MACHINERY EMPLOYED IN THE
MANUFACTURE OF COMPRESSED FUEL AND OTHER MATTERS," to be as follows:-
The furnace employed is constructed on the reverberatory principle, so that
the heats beats down into the chamber (containing the substance to be heated),
in its passage from the fire to the chimney. The substance to be heated is
supplied into this chamber by a feed wheel working air-tight in the crown of
the furnace. In the chamber of the furnace is fitted an agitator to keep the
fuel constantly stirred while subjected to heat. At the bottom of the chamber,
is a worm which moves the heated fuel out as required by the moulding
machine. Inside the crown of the furnace is fixed a light metal box con-
taining lead or other substance that melts at about the degree of heat that it
is required to raise the furnace to; an ordinary governor is fixed above the
furnace, the spindle of which is connected with a disc or plate, that revolves
in this melted substance. The rise and fall lever of the governor is connected
to a large throttle valve damper placed under the fire-door, the governor is

page_text: driven by a friction coupling so as to allow it to stand still with the damper
open when the substance in the box is hard, and to cause them to revolve and
close the damper as soon as the substance melts, or a blowing fan may be
regulated by a governor on the same principle, and thus may the heat of
furnaces be regulated.
Another part of my Invention consists in certain improvements on a machine
patented by Andrew Spottiswoode on the 30th June 1857, No. 1829. In
my improved machine a revolving table is used, having a number of holes or
moulds pierced through it, which moves upon a fixed table, and under a top
plate, round these are fixed at different distances three plungers, all worked by
lever motions from one main shaft, the first of which, called the feeder,
works in a box upon the top plate, and presses the mould full with a regu-
lated pressure as the fulcrum is carried by a weighted lever; the second or
main press works through a guide in the lower table, rises partially into the
mould, and compresses the substance. To prevent breakage, the fulcrum of
the levers of this press is caused to rest upon an hydraulic ram, the cylinder
of which is fitted with a long small ram kept in by weights, and connected
with a fork attached to the driving band of the machine, so that when the
pressure is excessive, the hydraulic ram is driven down, and the small ram
forced outwards, the small ram then raising the weights until the water escapes,
and in so doing throws off the band, and stops the machine. The third press
is placed at the greatest possible distance from the previous one to allow the
substance time to cool; this press has a plunger guided from the top plate,
and working through the revolving table so as to push the blocks out, which
fall upon an inclined plane, down which they are pushed by a movement of a
crank, or they may be forced through a pipe surrounded by water so as to
thoroughly cool the blocks before they can expand or crack.
The revolving table is worked by a ratchet motion from a worm of the
same description as that used in a double platten printing machine, but it is
regulated to an exact position by a tapered plunger which is forced through
holes bored in it just before the plunger of the main prèss enters at each
stroke.
To make the blocks more solid, and to draw out any gases that may be in
the substance, I attach to the first for feed plunger four or more points about
the size of a finger, which are bored throughout the upper part, forming a
barrel which works by the stroke of the plunger upon a stationary piston, and
so exhausts any gases as the point is entering the mass, at its return stroke
a small rod suspended from the piston pushes right through, clearing the
passage of any
bits that may have entered..

page_text: To allow the escape of gas during the compression, I also bore a number
of holes in the main plunger, which are cleared out by wires upon the same
principle. When the block is required less than the moulds in the table
I use division plates having slots across the discharge plunger to allow of
them.