IMPROVEMENTS IN FOR PROAL
Year: 1874

page_text: LETTERS PATENT to Edmund Edwards, of 38, Southampton Buildings,
Chancery Lane, in the County of Middlesex, Engineer and Patent
APPARATUS
Agent, for the Invention of "IMPROVEMENTS IN
FOR
PROVISIONAL SPECIFICATION left by the said Edmund Edwards at the
Office of the Commissioners of Patents, with his Petition, on the
28th May 1874.
I, EDMUND EDWARDS, of 38, Southampton Buildings, Chancery Lane,
in the County of Middlesex, Engineer and Patent Agent, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN APPARATUS
FOR SEPARATING SUBSTANCES OF DIFFERENT SPECIFIC GRAVITIES," to be as
follows:-
This Invention relates to that form of apparatus in which coal,
0 mineral ores, or other substances are separated from impurities of
different specific gravity by placing them upon a screen or sieve in a
cistern of water, and causing the water to rise and fall through such

page_text: and the lower one is opened and the sand discharged through it. It is
then again closed and the conical valve opened and the working
resumed. The bottom of the tank may be directly over a waggon or
other receptacle, into which the sand is discharged. And sometimes I
make the conical tank curved round so that the moveable door is at the
side instead of at the bottom.
Another novel method which I sometimes employ for removing the
sand is to make a door at the side of the tank at the bottom sufficiently
large for a waggon to be run through it into the tank. This waggon
receives the falling sand, and when full the door is opened and the
waggon removed, an empty one being substituted for it. I arrange
ledges or shoots round the inside of the tank above the waggon to direct
the sand into the latter.
Another method which I adopt for the same purpose is to form a
separate chamber at one or more of the sides or ends of the tank, and to
fit into this chamber a bucket wheel made to revolve at a suitable speed
by the same power which drives the machine. I make one or more
openings into this chamber from the tank, through which the sand
passes and is removed by the buckets upon the wheel as the latter
revolves, falling from them into a suitable discharge spout when they
arrive at or near the top of the wheel. I make the sides of the wheel
and buckets fit sufficiently close in the chamber to prevent the passage
of water to an injurious extent.
In the different arrangements described agitators may be used in the
tank worked by hand or other power.
In order to remove more readily the heavier fragments which settle
upon the screen or sieve I make the frame which carries vibrating
scrapers by which the upper part of the material operated upon is
removed moveable vertically, so that when necessary it can be lowered
down until the lower edges of the scrapers touch or nearly touch the
upper side of the screen or sieve, the front or discharge opening of the
apparatus (over which the lighter fragments are discharged) being at the
same time lowered until level with or below the top of the screen. For
this purpose I either make the rails or guides upon which the wheels
run which support the scraper frame moveable vertically by means of
racks and pinions or levers, or I suspend the scraper frame by links
from levers, which can be raised or lowered as required. I arrange the

page_text: screen or sieve so that when the discharge opening in front of it is lowered
as described it can be drawn out of its place or replaced without
lifting it.
In order to communicate the pulsations or vibrations to the water I
make the cams which strike down a flexible diaphragm below which the
water presses of such a shape that each cam not only strikes a sharp
blow upon the diaphragm but holds it down for a considerable time
instead of allowing it instantly to rise again. By this arrangement
considerable advantage is gained as the fragments which are thrown up
by the water upon the sieve or screen are allowed more time to settle in
the positions due to their respective gravities instead of being imme-
diately drawn down again by the returning water.
In order to form the screen or sieve upon which the material to be
washed is placed instead of making it of perforated plate or woven wire
my improved method consists of making it of bars of iron or other
suitable material crossing each other, but without being woven or inter-
laced. These bars may be of any suitable section, and may be held
together by separate bars or frames arranged above and below them and
screwed or fixed together. Or the bars forming the screen may them-
selves be rivetted or screwed together where they cross each other, at
which points they may also be recessed or notched so as to prevent them
from changing their position.
Sometimes instead of the method just described I make the screen or
sieve of bars having notches cut or formed in their sides, so that when
placed side by side and bolted or otherwise fixed together the notches
form the openings through which the water passes.
Another novel arrangement which I sometimes adopt is as follows:-
I make the sieve or screen circular in plan, preferably deeper at its
centre than at its edge, and I feed the coal or other material which is to
be washed through a central hopper. The vessel or receptacle into
which the screen is fitted is also circular in plan, and it has another
annular vessel arranged outside its outer edge, which is lower than that
of the outer vessel. I arrange a circular frame supported upon three or
more wheels which run upon the edge of the outer vessel, the centre of
the frame being guided either by a pin arranged in the centre of the
hopper or by the outside of the hopper itself. Upon this frame I fix
one or more scrapers arranged spirally or diagonally, and I cause the

page_text: frame to revolve at a sufficient speed by means of toothed wheels or
bolts connected with the apparatus, which causes the vibrations or
pulsations in the water beneath the sieve or screen in the methods
already described. The frame in its revolutions thus continually
removes the upper (or lighter) layer of the material which is being
washed, and forces it over the edge of the vessel into the outer annular
vessel, whence it is discharged through one or more openings in the
latter, either by its own weight or by one or more scrapers attached to
the revolving frame and carried round in the annular vessel.
At the centre of the screen or sieve I make a circular opening fitting
round the upper end of a circular pipe or vessel, the lower end of which
passes down through the tank or cistern of water in which the screen or
sieve is fitted, and is provided with a moveable door. The upper end of
this pipe or vessel is closed by a sliding plug or stopper, which can be
raised or lowered by means of a rod passing through the centre of the
hopper, and it has a sufficient number of openings round its side for the
escape into the pipe of the heavy fragments which settle upon the screen
or sieve, as already described. The plug or stopper can be raised or
lowered as desired by means of the rod, and the discharge of the heavy
fragments can thus be regulated; and to aid in their discharge one or
more scrapers arranged spirally or diagonally (but preferably at opposite
angles to those of the scrapers already described) are fixed to the
revolving frame and arranged so as to scrape the surface of the screen or
sieve and force the heavy fragments upon it towards the central pipe,
into which they are thus discharged. The sand and fine particles
passing through the screen or sieve into the tank or cistern may be
removed in any of the methods already described.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDMUND
EDWARDS, of 38, Southampton Buildings, Chancery Lane, in the
County of Middlesex, Engineer and Patent Agent, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of May, in the year of our
Lord One thousand eight hundred and seventy-four, in the thirty-seventhi
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Edmund Edwards, Her special licence, that I,
the said Edmund Edwards my executors, administrators, and assigns, or
such others as I, the said Edmund Edwards, 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 "IMPROVEMENTS IN APPARATUS FOR
SEPARATING SUBSTANCES OF DIFFERENT SPECIFIC GRAVITIES," upon the condition
(amongst others) that I, the said Edmund Edwards, my executors or
administrators, by an instrument in writing under my, or their, or one
of their hands and seals, 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 Edmund Edwards, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement and accompanying Drawings (that is to say) :-
My Invention has reference to that form of apparatus for separating
coal, mineral ore, or other substances from impurities of different
specific gravity, in which they are placed upon a screen or sieve in a
cistern of water, which water is caused to rise and fall through such
screen or sieve in pulsations or vibrations, whereby the heavier pieces of
the material which is being washed accumulate upon the screen or sieve,
whilst the lighter parts remain above them and are removed from time
time; and it relates especially to further improvements in the machinery
or apparatus for the said purpose, for which I obtained Royal Letters
Patent bearing date August 14th, A.D. 1861, and Numbered 2024; and
bearing date May 15th, A.D. 1867, and Numbered 1443.
My present Invention has for its objects, first, improved methods of
constructing and arranging apparatus and appliances for readily

page_text: removing the finer particles of the substances which are being washed
from the tank or cistern into which they fall through the interstices of
the screen or sieve.
Also of improved methods of and arrangements of apparatus for
removing when necessary the heavier fragments which accumulate upon
the sieve or screen.
Also of improved methods of constructing and shaping the apparatus
by which the pulsations are communicated to the water.
Also of improved methods of constructing and arranging the sieve or
screen upon which the coal, mineral ore, or other material is to be
washed.
In such washing apparatus as heretofore constructed the sand or fine
particles which pass through the screen and accumulate in the tank
below it are removed from time to time through a door at or near the
bottom of the tank by means of hand rakes or scrapers.
One part of my present Invention consists in making the lower part
of the tank underneath the screen circular or rectangular (in plan), and
preferably conical with its wider part below. The lower end of this
conical tank is open and is fitted with a moveable door, which can be
readily opened or closed, and when closed forms a water-tight joint
against the tank by means of india-rubber or other soft substance. At
the upper part of the conical tank I form a ring or seat for a large
conical valve, which can be pressed up against it by means of levers or
screws worked from the outside of the tank, the joint being made water-
tight by means of india-rubber or other soft substance. By this
arrangement when the lower part of the tank is sufficiently filled with
sand the conical valve is shut upwards and the lower door is opened and
the sand discharged through it. It is then again closed and the conical
valve reopened. The bottom of the tank may be arranged directly
over a waggon or other receptacle, into which the sand is discharged.
I sometimes make the tank curved or bent round so that the moveable
door is at its side.
In the accompanying Drawings Figure 1, Sheet I. is a sectional
clevation in illustration of this arrangement. a is the tank in which
the screen bis fitted. The lower part of the tank at c is made circular
(or rectangular) in plan, and is of greatest diameter at the bottom,

page_text: Figure 2, Sheet I. is a side view, and Figure 3, Sheet I. a front view
partly in section shewing the arrangement of a bucket wheel, as and for
the purpose described. a is the tank supporting a screen upon which
the materials are washed and the lighter parts removed, in the same
way as has been already described; 6 is a vessel containing the bucket
wheel and communicating with the lower part of the tank a by the
passage c. The bucket wheel is preferably formed conically, as shewn,
and is fitted with bucket plates d, d, d, d, &c., which lift the sand and
discharge it over the sides of the vessel bat e. The bucket wheel is
shewn driven by a chain and chain wheels at f, but may be driven in
any convenient way. Figure 4, Sheet I. is a front view of the bucket
wheel in the vessel b.
I claim the methods of removing the sand from the tanks of apparatus
for washing coal, mineral ores, or other substances of different specific
gravities, substantially as described and shewn in the Drawings.
In order to remove more readily the heavier fragments which settle
during the process of washing upon the screen or sieve I make the
vibrating frame which carries the suspended scrapers which remove the
upper part of the material moveable vertically, so that when necessary
it can be lowered down until the lower edges of the scrapers touch or
nearly touch the upper surface of the screen or sieve, the front or
discharge opening of the apparatus (over which the lighter fragments
are discharged) being at the same time lowered until level with or below
the top of the screen. For this purpose I either make the rails or
guides upon which the wheels run which support the scraper frame
moveable vertically by means of racks and pinions or levers, or I
suspend the scraper frame by links jointed to them and to the ends of
levers, which can be raised or lowered as required. I prefer to arrange.
the screen or sieve so that when the discharge opening is lowered, as
described, it can be drawn out of its place or replaced without
lifting it.
I claim the methods of raising and lowering the scrapers, substantially
as and for the purpose described.
In order to prevent the too rapid return of the water after it has been
forced up through the screen or sieve I make the cams which strike
down the flexible diaphragm upon the water of such a shape that each
cam not only strikes a sharp blow upon the block which depresses the

page_text: diaphragm but holds it down for a considerable time instead of allowing
it instantly to rise again. By this arrangement of the shape of the
cams, which is shewn in Figure 1, Sheet I. at o, o¹, o", considerable
advantage is gained as the fragments which are thrown up by the water
upon the screen are allowed more time to settle in the position due to
their respective specific gravities, instead of being immediately drawn
down again by the returning water. I sometimes for the same purpose
make the shape of the cam such that after its first blow it continues to
depress the diaphragm slightly for some time before releasing it, as
shewn at Figure 7 in Sheet I.
I claim the use of cams constructed of the shape substantially as and
for the purpose described and shewn in the Drawings.
In order to form the screen or sieve upon which the material to be
washed is placed instead of making it of perforated plate or woven wire
my improved method consists of making it of bars of iron or other
suitable material crossing each other, but without being woven or
interlaced. These bars may be square or of other suitable section, and
may be held together by separate bars or frames arranged above and
below them and screwed or otherwise attached together, or the bars
forming the screen may themselves be rivetted or screwed together at
some of the points where they cross each other, at which points they
may also be recessed or notched into cach other.
Sometimes I make the screen of bars having notches cut or formed
in their sides so that when placed side by side and bolted or otherwise
fixed together the notches form the openings through which the water
passes.
I claim the methods of constructing the screens or sieves in apparatus
for washing coal, mineral ores, or other substances of different specific
gravity, substantially as and for the purpose described.
Another part of my Invention consists in making the screen or sieve
circular in plan, either flat or preferably somewhat depressed at its
centre, and in feeding the coal or other material to be washed through a
central hopper. The vessel or receptacle into which the screen is fitted
is also circular in plan, and it has another annular vessel or channel
arranged round its outer edge, which edge is lower than that of the
outer vessel. I arrange a frame supported horizontally upon three or
more wheels, which travel upon the edge of the outer vessel or upon a

page_text: flange connected to the latter, the centre of the frame being guided by a
vertical pin or bar arranged in the centre of the hopper or by the outside
of the hopper itself. Upon this frame I fix one or more adjustable
scrapers arranged spirally or diagonally, and I cause the frame to revolve
at a sufficient speed by means of toothed wheels or belts connected with
the driving shaft, which causes the vibrations or pulsations of the water
through the sieve or screen in the method already described. During
the revolution of the frame the lower edges of the scrapers (which are
adjusted to a proper height for the purpose) continuously remove the
upper (or lighter) layer of the material being washed, and force it over
the edge of the vessel into the outer annular vessel or channel, whence
it is discharged through one or more openings in the side or bottom of
the latter, either by its own weight or by one or more scrapers attached
to the revolving frame and carried round by it in the annular
channel.
In the centre of the screen or sieve I make a circular opening fitting
round or upon the upper end of a circular pipe, the lower end of which
passes down through the tank or cistern of water upon which the screen
or sieve is fitted, and is provided with a moveable door. Or it may be
made to lead into a separate tank or cistern provided with one or more
moveable doors. The upper end of this pipe is provided with a sliding
plug, which can be raised or lowered by means of a rod passing through
the centre of the hopper, and it has a sufficient number of openings
round its sides for the escape into the pipe of the heavy fragments which
settle upon the screen or sieve, as already described.
Instead of the plug or stopper I sometimes use a conical valve, which
when raised closes the upper end of the circular pipe, but which can be
adjusted to any required extent of opening by a central regulating rod
which passes up through the hopper, and may also serve as a guide for
the revolving frame.
In order to aid the discharge of the heavy fragments upon the screen
into the pipe one or more shallow scrapers arranged spirally or diagonally,
but at opposite angles to those already described are fixed to the
revolving frame so as to scrape the upper surface of the screen and to
collect and discharge the heavy fragments upon it through the valve
and into the central pipe. I arrange a flat or conical distributing plate
upon the revolving frame, which prevents the material from falling

page_text: directly into the pipe, but distributes it upon the screen at a proper
distance from the centre. The sand and fine particles passing through
the screen or sieve into the tank or cistern may be removed by any of
the means already described.
Figures 5 and 6, Sheet II., are in illustration of this part of my In-
vention, Figure 5 being a sectional elevation, and Figure 6 a plan of
the apparatus. a is the screen, circular in plan, and 6 is a hopper,
through which the material is supplied; c is the circular vessel, in
which the screen a is fitted; and d is an annular chamber round c; e is
a frame supported by wheels f.f.f, which run upon the flange g;
and h, h, h, (shewn in dotted lines) are spirally arranged scrapers fixed
to the frame e, which is made to revolve by the toothed bevil wheels i, k,
driven by the driving shaft 7. The scrapers h, h, h, remove the upper
part of the washed material and discharge it over the edge of the
vessel c into the annular chamber d, whence it is discharged through
the opening and spout m by means of the scrapers n, n³, also carried by
the frame e. o is a circular opening in the centre of the screen a and
fitting the upper end of the pipe p, the lower end of which commu-
nicates with the chamber or tank r, which is provided with one or more
moveable doors. The opening o is fitted with a valve s guided and
regulated by the bar t, round which the frame e revolves. A spiral
scraper v is carried by the frame e and revolves close to the screen a
collecting the heavy fragments upon the screen and discharging them
through the valve 8 into the pipe p. The distributing plate w distributes
the material to be washed, together with a sufficient supply of water
from the hopper b, and prevents them from falling directly into the
opening o.
A is a rectangular tank upon which the vessel c is fixed, and which
is fitted with a flexible disc B, concave plate C, and block D for causing
the rise and fall of the water through the screen a, in the same way as
in the arrangement shewn in Figures 1 and 2, Sheet I. The block D is
struck by cams E carried by the driving shaft l, which also actuates
gear driving the bucket wheel x similar to that. already described for
raising and discharging the sand from the tank. y shews (in dotted
lines) an agitator which may be used to facilitate the passage of the sand
into the bucket wheel.
Instead of the one shewn I sometimes use a helical agitator revolving

page_text: in a longitudinal channel at the bottom of the tank and conveying the
sand endways to the bucket wheel x.
I claim the general arrangement of apparatus for washing coal,
mineral ores, or other substances, substantially as described and shewn
in Figures 5 and 6, Sheet II.
Also the arrangement of revolving frame carrying scrapers for the
purpose of discharging into their proper receptacles the light and heavy
parts of the material being washed.
In witness whereof, I, the said Edmund Edwards, have hereunto
set my hand and scal, this Twenty-eighth day of November,
in the year of our Lord One thousand eight hundred and seventy-
four.