IMPROVEMENTS IN MACHINERY OR APPARATUS FOR SEPARATING SUBSTANCES OF DIFFERENT SPECIFIC GRAVITIES
Year: 1878

page_text: LETTERS PATENT to Edmund Edwards, of 40, Southampton Buildings,
Chancery Lane, in the County of Middlesex, Engineer and Patent Agent, for
the Invention of "IMPROVEMENTS IN MACHINERY OR APPARATUS FOR
SEPARATING SUBSTANCES OF DIFFERENT SPECIFIC GRAVITIES."
Sealed the 9th May 1879, and dated the 12th November 1878.
PROVISIONAL SPECIFICATION left by the said Edmund Edwards at the
Office of the Commissioners of Patents on the 12th November 1878.
EDMUND EDWARDS, of 40, Southampton Buildings, Chancery Lane, in the County
of Middlesex, Engineer and Patent Agent. "IMPROVEMENTS IN MACHINERY OR
APPARATUS FOR SEPARATING SUBSTANCES OF DIFFERENT SPECIFIC GRAVITIES."
This Invention relates to machinery or apparatus used for washing or cleaning
coal, mineral ores, or other substances, and separating them from impurities of
different specific gravity by placing them in water upon a perforated screen through
which the water is made to rise and fall in a series of vibrations and pulsations,
whereby the heavier pieces of the material which is being washed accumulate upon
the screen,
whilst the lighter parts become arranged above them in order corre-
sponding to their several relative specific gravities.
My present Invention relates especially to that form of such washing apparatus
in which the perforated screen is made circular in plan, and it has for its objects
improvements in such machinery, by which the several portions into which the
material is separated are more readily and continuously removed, the heavy parts
which settle upon the perforated screen being continuously delivered (or nearly so)
at one point, the lighter parts which become arranged above them being delivered
at another point, and the fine particles which pass through the perforated screen
being delivered at a third point. If coal is being washed the upper or lighter parts
consist of clean coal. If mineral ores are being washed the corresponding lighter
parts are waste.

page_text: I make the perforated screen or sieve circular in plan, and preferably flat,
and I feed the coal or other material which is to be washed upon it through
a central hopper through which water is also supplied as necessary.
The
screen is arranged in a cylindrical vessel and rests upon supports at a suitable
distance from the upper edge of the vessel. At the centre of the perforated screen
I fix a vertical cylinder, the upper edge of which is somewhat higher than the edge
of the outer vessel, its lower end being closed or resting upon a plate which
occupies the centre of the screen. Outside this cylinder I arrange a second cylinder
of greater diameter, and having its upper edge level with that of the inner one.
Its lower edge however does not reach to the screen (or to the central plate already
described) but leaves an annular space between them all round.
Outside the outer vessel in which the screen is fitted I make an annular trough
or vessel, the bottom of which is some distance below the outer edge of the vessel,
whilst the upper edge of its outer vertical side is at the same (or higher) level as
that of the inner cylinder. Outside the annular trough I make a continuous angle
iron or flat flange, upon which run friction wheels fitted to the ends of three or
more radial arms, which unite at the centre of the machine and fit upon the end of
a central vertical shaft or axis which passes down through a bearing or opening
in the central plate already described (which may be supported by a collar upon
the shaft). The vessel containing the screen is made preferably conical below the
latter, tapering down to a chamber into which the fine particles of material passing
through the screen descend. The lower end of the vertical shaft or axis revolves
in a step or bearing at the bottom of this chamber.
The vessel arranged and fitted as described communicates at any convenient part
(below the screen) with a vertical cylinder containing a piston, which can be niade
to work rapidly up and down in it by steam or other suitable power, so that if
the vessel be filled with water and the piston set in motion the water is forced up
and down through the perforated screen in a series of pulsations. I prefer to make
the length of the stroke of the piston variable, as desired.
The bars and wheels running upon the flange already described are made to
revolve slowly by the use of bevilled toothed wheels or other convenient means,
driven by the same power which actuates the piston or by other suitable power,
and to the arms are fixed adjustable scrapers arranged spirally, and having their
lower edges adjusted so as to dip sufficiently into the material upon the screen.
The action of the apparatus so far is as follows:-The coal or other material which
is to be washed being fed into the apparatus through the central hopper (below
which is a distributing plate which prevents it from falling. into the central
cylinders), and the piston being set in motion the heavy parts settle upon the screen
whilst the lighter parts become arranged in the order of their relative specific
gravities. When the space above the perforated screen is full of material thus
washed, the spirally arranged scrapers attached to the revolving arms scrape and
force the upper part of it over the edge of the vessel into the annular trough.
At one point of the bottom of this trough an opening is inade, and a scraper is
fixed to one or more of the revolving arms which scrapes round the material
delivered into the trough and discharges it through the opening. My improved
apparatus for delivering or discharging the heavier parts of the material which
settle upon the screen is constructed and arranged as follows:-I take a spirally
shaped scraper or bar attached by bars to one or more of the revolving arms
already described, and adjusted so that its lower edge passes round at a short
distance above the perforated plate or screen. This scraper has very little depth
and its spiral shape is such that as it revolves it collects the parts of the material
lying upon the screen and draws them towards the centre of the apparatus where
they collect, passing under the lower edge of the outer central cylinder and filling
to a certain height the angular space between it and the inner central cylinder.
I arrange and connect to one of the revolving arms a hinged scraper which is
drawn round in this annular space, its lower edge (the height of which is adjustable)
collecting and scraping up the heavy material which accumulates there, and in one'

page_text: part of its revolution I arrange an inclined plane up which it is forced to travel,
drawing with it the material which it discharges through an opening at the top
of the inclined plane above the level of the water in the machine. Another
inclined plane then descends, down which the scraper passes and collects a fresh
supply of the material.
The stuff discharged as described passes down a passage or tube leading from the
opening at the top of the inclined planes laterally into the central inner cylinder,
down which it passes parallel with the central shaft already described, through the
central plate, and thence diagonally down until it passes out through an opening
in the side of the lower part of the machine. The heavy parts of the material are
thus continually collected and discharged through this opening without stoppage
or loss of water. Instead of the arrangement just described I sometimes arrange
the spirally shaped scraper so as to operate in the opposite direction, and distribute
the heavy material upon the perforated screen towards the circumference of the
latter instead of collecting it towards the centre. I make a second annular trough
outside the one already described, and under the bottom of the latter I make a
passage communicating with it, so that the heavy material upon the perforated
screen is forced through it by the spiral bar into the outer annular trough, from
which it is removed by a scraper and conveyed up an inclined plane through an
opening, at the top of which it is discharged in a way similar to that already
described. The lighter parts delivered into the inner annular trough in the way
already described are in this form of arrangement delivered through an opening or
spout, passing down laterally through the outer annular trough at the part where
the inclined planes described are situated and it passes out under them.
In order to deliver and discharge the sand or fine particles which pass through
the perforated screen into the lower or conical part of the vessel and thence into a
chamber, as already described, I use an endless chain of buckets or scrapers actuated
by the power which drives the machine, and drawing the fine particles or sand up
a passage or tube of corresponding section, which is continued to a sufficient height,
and discharging them into a shoot or discharge pipe. The buckets or scrapers thus
emptied pass down through another corresponding passage or tube in which they
fit as closely as possible.
I prefer to use endless metallic chains for the purpose of driving the buckets or
scrapers, cach chain being composed of parallel metallic links jointed together, and
I prefer to make the scrapers of metallic plates fitting the tube, and having their
ends rivetted or bolted to the links. Upon the inner sides of the tubes or passages
I make longitudinal grooves or guides, in or between which the links travel, so
that the plates are kept in their position at right angles to the line of the chains.
The vertical shaft or axis already described passes down the centre of the
chamber in which the sand collects, from an opening in the side of which it is
collected by the buckets or plates. At its lower part, opposite this opening, I fix
upon it an agitator having spiral blades, which as it revolves forces the sand into
the opening and so insures its being carried away by the buckets. I prefer to
connect the vertical shaft or axis to the horizontal revolving bars already described,
and which drive it by means of an adjustable clutch, so that the vertical shaft and
agitator need only be made to revolve when desired.
By the novel arrangements described the action of the apparatus is made
continuous, and the coal or other material is washed or cleaned with very little
attention, so long as the rough material with the small quantity of water required
are supplied without any necessity for stopping the machine at intervals in order
to clean it.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edmund Edwards in the Great Seal Patent Office on the 12th
May 1879.
EDMUND EDWARDS, of 40, Southampton Buildings, Chancery Lane, in the County
of Middlesex, Engineer and Patent Agent. "IMPROVEMENTS IN MACHINERY OR
APPARATUS FOR SEPARATING SUBSTANCES OF DIFFERENT SPECIFIC GRAVITIES."
My Invention relates to machinery or apparatus used for washing or cleaning
coal, mineral ores, or other substances, and separating them from impurities of
different specific gravity, by placing them in water upon a perforated screen,
through which the water is made to rise and fall in a series of pulsations or
vibrations, whereby the heavier pieces of the material which is being washed accu-
mulate upon the screen whilst the lighter parts become arranged above them in
order corresponding to their several relative specific gravities.
My present Invention relates more especially to that form of such washing appa-
ratus for which I obtained her Majesty's Royal Letters Patent, dated May 28th,
1874, and numbered 1861, in which the perforated screen is made circular in plan,
and it has for its objects improvements in such machinery by which the several
portions into which the material is separated are more readily and continuously
removed, the heavier parts which settle upon the perforated screen being delivered
continuously (or nearly so) at one point, the lighter parts which become arranged
above them being delivered continuously at another point, and the fine particles
which pass through the perforations or openings in the screen being delivered con-
tinuously at a third point.
If coal is being washed the upper or lighter parts consist of clean coal; if
mineral ores are being washed the upper or lighter parts are waste or poor.
In order to put my Invention in operation I take a screen or sieve, circular in
plan and preferably flat, and arranged horizontally in a circular vessel containing
water, and I feed the coal or other material which is to be washed upon it through
a central hopper, through which water may also be supplied when necessary. The
screen rests upon supports at a suitable distance below the upper edge of the vessel,
and at the centre of the screen I fix a vertical cylinder, the upper edge of which is
somewhat higher than the edge of the outer vessel, its lower end being closed or
resting upon a plate which occupies the centre of the screen.
Outside this inner cylinder I arrange a second cylinder of greater diameter, and
having its upper edge level with that of the inner one.
Its lower edge however does not reach down to the screen (or to the central plate
already described), but leaves an annular space between them all round, the depth
of which space may in some cases be made variable and adjustable.
Outside the outer vessel, in which the screen is fitted as described, I make an
annular trough or vessel the bottom of which is some distance below the outer edge
of the vessel, whilst its outer vertical side rises as high as or higher than the edge
of the vessel, and outside the annular trough I make a continuous circular flat flange
or angle iron, upon which run friction wheels fitted to the outer ends of three or
more radial bars, which unite at the centre of the machine and fit upon the end of
a central vertical shaft or axis, which passes down through the central plate already
described, which plate may itself rest upon a collar upon the shaft. The vessel is
made preferably conical below the screen, tapering downward until it ends in a
chamber, into which the fine particles passing through the screen fall. The lower
end of the vertical shaft or axis revolves in a step or bearing at the bottom of this
chamber.
The vessel arranged and fitted as described communicates at any convenient part
below the screen with a vertical cylinder containing a piston or plunger, which can
be made to work rapidly up and down in it by means of an excentric or cam set in
motion by steam or any other convenient power, so that if the vessel be filled with

page_text: water and the plunger so set in motion the water is forced up and down through
the perforated screen in a series of pulsations. Or one or more flexible diaphragms
may be used as an equivalent for the plunger.
The bars or arms carrying the wheels running upon the outer flange already
described are made to revolve slowly by means of bevilled toothed wheels or other
convenient means driven by the same power which actuates the plunger, or by
other suitable power, and to the radial arms are attached adjustable scrapers arranged
spirally, and having the positions of their lower edges adjusted so that they dip
sufficiently into the coal or other material upon the screen. The action of the
apparatus arranged as described is as follows:-The coal or other material which is
to be washed being fed into the apparatus through the central hopper (below which
is arranged a distributing plate, which prevents the coal from falling into the central
cylinders), and the plunger being set in motion, the heavy parts settle upon the.
screen, whilst the lighter parts become arranged in position corresponding with their
several relative specific gravities.
At
When the space above the screen is full of material thus washed, the spirally
arranged scrapers attached to the revolving arms scrape and force the upper part of
it toward the outer edge of the vessel, and over it into the annular trough.
one part of the bottom of this annular trough an opening is made, and a scraper is
fixed to one or more of the revolving arms, which scrapes round the material
delivered into the trough, and discharges it through the opening, which may be
connected by a spout or shoot with a waggon or other receptacle.
My improved apparatus for collecting, and delivering and discharging the heavier
parts of the coal or other material which settle upon the screens is constructed and
arranged as follows:-
I take a spirally shaped scraper or bar, which is attached by bars.to one or more
of the revolving arms already described, and is adjusted so that its lower edge passes
round at a short distance above the perforated plate or screen. This scraping bar
has but little depth, and its spiral shape is such that as it revolves it collects the
parts of the material which lie upon the screen and draws them toward the centre
of the apparatus, where they accumulate passing under the lower edge of the outer
central cylinder and filling to a certain height the annular space between it and the
inner central cylinder.
I arrange and connect to one of the revolving arms a hinged scraper, which is
drawn round in this annular space, its lower edge (the height of which may be
made adjustable) collecting and scraping up the heavy material accumulating there
as just described. In one part of its revolution I form an inclined plane in the
space between the two cylinders, up which it is forced to travel, drawing with it
the material, which it discharges through an opening at the top of the inclined
plane above the level of the water in the machine. Another inclined plane then
descends, down which the scraper travels, and then collects a fresh supply of the
material.
The stuff discharged through this opening in this way passes down a pipe or
passage leading from the opening at the top of the inclined planes and thence
laterally into the central inner cylinder, whence it passes through the central plate
and diagonally downward until it passes out through an opening in the side of the
lower part of the machine. The heavy parts of the material are thus continuously
collected and discharged through this opening without stoppage of the machine or
loss of water.
In order to deliver and discharge the sand or other fine particles which pass
through the perforated screen into the lower or conical part of the vessel, and thence
into the chamber, as already described, I use an endless chain of buckets or scrapers
actuated by the power which drives the machine, and drawing the fine particles or
sand up a passage or pipe of corresponding section which is continued to a sufficient
height, and thence discharging them into a shoot or discharge pipe.
The buckets or scrapers thus emptied then return through another corresponding
passage or pipe, within which they fit as closely as possible.

page_text: I prefer to use endless metallic chains for the purpose of driving the buckets or
scrapers, each chain being composed of parallel metallic links jointed together; and
I prefer to make the scrapers of metallic plates fitting the passages or pipes through
which they pass, and having their ends rivetted or bolted to the links.
Upon the inner sides of the passages I make longitudinal grooves or guides in or
between which the links travel, so that the plates are kept in their position at right
angles to the line of the chains.
The vertical shaft or axis already described passes down the centre of the chamber
in which the sand collects, and from an opening in the side of the chamber the sand
is collected by the moving buckets or plates described. At the lower part of the
shaft or axis opposite this opening I fix upon it an agitator having radial or spiral
blades, which as it revolves forces the sand into the opening and so ensures its
being carried away by the buckets or plates.
The accompanying Drawings are in illustration of my Invention.
Figure 1 is a longitudinal section, Figure 2 an end view, and Figure 3 a plan
(partly broken off) of a machine. a is the circular screen or sieve, supported in the
circular vessel b by the flange c and the cross beams d, d, the circular plate e being
at the centre of the screen. f is a hopper carried by the frame work of the plat-
form from which the material is supplied; and g is a distributing plate under the
hopper f. Upon the plate e is fixed the inner vertical cylinder h, to which the outer
vertical cylinder in is connected by the inclined planes k, kl, in the annular space
between them. Outside the vessel b is an annular trough l, round which is formed
the flange m, upon which run the friction wheels n, m, n, upon the ends of the
radial bars o, o¹, o², which unite at their centre, which fits upon the upper end of
the vertical shaft p, revolving in the bearing in the plate e and the footstep rat
the bottom of the chamber s below the conical part 61 of the vessel b. The vessel b
is connected with the vertical cylinder t and piston t¹ driven by an excentric u
upon the shaft v, which is itself driven at the desired speed by pullies and belts, as
shewn, or in any other convenient way. The shaft v also causes the radial bars
o, o', o², to rotate slowly by means of the bevilled toothed wheels w, and these bars
carry adjustable spirally arranged scrapers x, x, x, by which the upper surface of the
material washed is forced outward and into the annular trough 1, whence it is
collected and discharged through the opening y by the scraper z upon the radial
bar o..
To one of the bars o is also attached the spiral collecting bar 1, which revolves
just above the screen a, from the surface of which it collects the heavy parts of the
material in the space between the two inner cylinders h and i. To one of the arms o
is connected the hinged scraper 2, which draws the accumulated stuff up the inclined
plane and discharges it through the opening .3 and down the passage 4 out
through the side of the machine at 5, the scraper then descending the second
inclined plane k¹.
The sand in the chamber s is driven by the agitator 6 upon the vertical shaft p
through the opening 7, whence it is raised by endless chains carrying transverse
plates working through passages, as already described and as shewn at 8, the sand
being discharged through the shoot 9. Sometimes the heavy material may pass
under the edge of the cylinder i (Figure 1), the top of which may be closed in, and
over the upper edge of the cylinder h, the height of which may be made adjustable,
the stuff being discharged into the vessel b through openings in the plate e.
The said elevating and discharging apparatus is shewn driven by pullies, belts,
shafts, and toothed wheels at 10.
I sometimes connect the radial bars o, o, o, to the top of the vertical shaft or
axis p by a moveable clutch or coupling so that the shaft, and with it the agitator 6,
are only set in motion when necessary.
Instead of the arrangement of apparatus described and shewn for collecting and
discharging the heavy parts of the material which settles upon the screen I some-
times use the following modified method of arrangement: I arrange the spirally
shaped revolving collecting bar so as to operate in the opposite direction and

page_text: distribute the heavy material towards the circumference of the vessel instead of
collecting it toward the centre. I make a second annular trough outside the one
already described, and under the bottom of the latter I make a passage all round
communicating with the outer one, so that the heavy material upon the screen is
forced by the spiral har under the first aunular trough and into the second one, in
which it rises, and is removed by a hinged scraper and conveyed up an inclined
plane, through an opening in the top of which it is discharged in a way similar to
that already described. In this method of arrangement the lighter parts delivered
into the first annular trough are discharged through an opening or spout which
passes down laterally through the outer annular trough at the part where the
inclined planes are situated, and it passes out under them.
Figures 4 and 5 represent this method of arrangement. a is the screen, and b is
the annular trough into which the light material is delivered by the scraping plates
x, x, x.
The outer annular trough c is arranged outside the inner one b, and com-
municates with the screen a by the circular passage d under the trough b. The
spiral scraping bar 1 distributes the heavy material upon the screen a through the
passage d into the trough c, where it is removed by the hinged scraper 2, which
after drawing it up the inclined plane discharges it through the opening 3 and
then descends the inclined plane k¹. The lighter stuff in the trough 6 is collected
by the scraper and delivered through the opening y which passes out under the
inclined planes and by the side of the discharge opening 3. The two last described
arrangements may be used in combination, one of the spiral bars being arranged at
a higher level than the other.
The operation of my improved machinery or apparatus is continuous in every
part, and the coal or other material is washed or cleaned with very little attention
so long as the rough material together with the small quantity of water required is
supplied without any necessity for stopping the machine at intervals for the purpose
of cleaning it.
Having now described my Invention and the manner in which it is to be per-
formed, I claim, the revolving hinged scraper, the inclined planes between two
concentric cylinders, and the discharge opening and passage at the top of the
inclined planes for the purpose of removing and discharging the heavier parts from the
screens of washing machines, substantially as described and shewn in the Drawings.
Also the combination with such revolving hinged scraper, inclined planes, and dis-
charge opening and passage of a spirally shaped revolving collecting bar, arranged and
operating substantially as and for the purpose described and shewn in the Drawings.
Also the combination with the revolving hinged scraper, inclined planes, and
discharge opening and passage of the annular trough, the revolving bases and
friction rollers, the spirally arranged adjustable scraping plates, and the scraper
revolving in the annular trough, substantially as described and shewn in the
Drawings. Also the combination with the revolving hinged scraper, inclined
planes, and discharge opening and passage of the lifting apparatus, consisting of
endless chains of metallic links, transverse plates, fitting in passages having grooves
or guides for the endless chains, and driving wheels and pulleys, arranged and
operating substantially as and for the purpose described and shewn in the
Drawings.
In witness whereof, I, the said Edmund Edwards, have hereunto set my