IMPROVEMENTS IN APPARATUS FOR SCREENING COALS OR SIMILAR MATERIALS
Year: 1878

page_text: LETTERS PATENT to Jaines Stedman Dixou, of Glasgow, in the County of
Lanark, North Britain, Mining Engineer, for the Invention of "IMPROVEMENTS
IN APPARATUS FOR SCREENING COALS OR SIMILAR MATERIALS."
Sealed the 29th October 1878, and dated the 7th May 1878.
PROVISIONAL SPECIFICATION left by the said James Stedman Dixon at tho
Office of the Commissioners of Patents on the 7th May 1878.
JAMES STEDMAN DIXON, of Glasgow, in the County of Lanark, North Britain,
Mining Engineer. “IMPROVEMENTS IN APPARATUS FOR SCREENING COALS OR
SIMILAR MATERIALS."
This Invention has for its object the screening of coals or similar materials in an
improved manner, and by apparatus which is more uniform and perfect in its.action
and more convenient in use than that ordinarily employed.
In the improved apparatus the screen which is slightly inclined or horizontal is
made to travel so as to move the coals or other materials gently and gradually from
the end at which they are put upon the screen to the other end, and at the same
time a transverse reciprocating motion is imparted to the screen to cause the dross,
slack, or smaller particles to pass through.
The regular travelling motion admits of the operation of picking out refuse or
objectionable materials too large to pass through, being performed very conveniently
and satisfactorily.
For these purposes the screen is, according to one modification, made to consist of
endless wire ropes stretched round drums, one or more of which is or are driven so
as to impart the travelling motion to the screen, whilst another is mounted in
movable bearings, to which weights are connected so as to apply the requisite ten-
sion to the wire ropes.
The transverse reciprocation is imparted to the screen by giving the necessary
movement to the driving drum by means of a small rapidly rotating crank or
eccentric worked by the driving gearing, or in any other convenient way.

page_text: The drums may be grooved so as to keep the wire ropes at suitable spaces apart,
and the grooves on the drum at the discharge end of the screen may be formed
wider apart, or alternately wider and closer, or otherwise, so as to make the spaces
between the wire ropes or some of those spaces gradually wider towards the dis-
charge end of the screen. Beneath the screen shutes or partitions are arranged so
as to collect the materials passing through in separate sections of different
qualities.
The wire ropes may be prevented from separating from each other, or opening
too widely, by grooved guide pulleys placed at intervals along the screen, or the
series of wire ropes or separate wires may be connected by a wire or wires intor-
laced with them transversely like a weft, the screen being in that case an endless
web of coarse and open wire cloth or netting.
The transverse reciprocating motion herein-before described may in practice be
found unnecessary, at least in some cases.
.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Stedman Dixon in the Great Seal Patent Office on the 6th
November 1878.
JAMES STEDMAN DIXON, of Glasgow, in the County of Lanark, North Britain,
Mining Engincer. "IMPROVEMENTS IN APPARATUS FOR SCREENING COALS OR
SIMILAR MATERIALS."
My said Invention has for its object the screening of coals or similar materials in
an improved manner, and by apparatus which is more uniform and perfect in its
action and more convenient in use than that ordinarily employed.
In my improved apparatus the screen which is inclined or horizontal is made to
travel so as to move the coals or other materials gently and gradually from the end
at which they are put upon the screen to the other end, and at the same time a
transverse reciprocating motion is imparted to the screen to cause the dross, slack, or
smaller particles to pass through.
The regular travelling motion admits of the operation of picking out refuse or
objectionable materials too large to pass through, being performed very conveniently
and satisfactorily.
For these purposes the screen is, according to one modification, made to consist of
endless wire ropes stretched round drums, one or more of which is or are driven so
as to impart the travelling motion to the screen.
The transverse reciprocation is imparted to the screen by giving the necessary
movement to the driving drum by means of a small rapidly rotating crank or
eccentric worked by the driving gearing or in any other convenient way.
The drums may be grooved so as to keep the wire ropes at suitable spaces
apart, and the grooves on the drum at the discharge end of the screen may
be formed wider apart, or alternately wider and closer, or otherwise, so as to make
-

page_text: the spaces between the wire ropes or some of those spaces gradually wider towards
the discharge end of the screen. Beneath the screen shutes or partitions are arranged
so as to collect the materials passing through in separate sections of different
qualities.
The wire ropes may be prevented from separating from each other or opening
too widely by grooved guide pulleys placed at intervals along the, screen, or trans-
verse rods forming part of and travelling with the screen, may have strung on them
washers or thickness pieces to keep the wire ropes at the proper distances apart.
Separate wires or rods may be used instead of ropes, and the ropes or wires may be
connected by a wire or wires interlaced with them transversely like a weft, or
otherwise, the screen being in that case an endless web of coarse and open wire cloth
or netting.
The transverse reciprocating motion herein-before described may in practice bo
found unnecessary, at least in some cases.
And in order that my said Invention and the manner of performing the same
inay be properly understood, I hereunto append two Sheets of explanatory Drawings
to be herein-after referred to, and representing a modification of my improved
screening apparatus. In these Drawings the same reference numerals are used to
mark the same or like parts wherever they are repeated.
Figure 1, on Sheet 1 of the accompanying Drawings, is a sectional side elevation;
and Figure 2 is a sectional plan of the apparatus.
Figure 3 is an enlarged transverse vertical section showing the acting part of
the screen with the lateral gangways for pickers.
Figures 4 and 5 on Sheet 2 are onlarged views showing the driving and shaking
gear in sectional plan and in elevation; and Figure 6 is an enlarged section of the
screen at a part where the distance pieces or washers are attached to it.
My improved screen is of an endless form, 1, indicated by dotted lines in Figure 1,
and is stretched upon or distended by drums 2, 3, 4, 5, which are carried in
bearings on a framing 6.
The acting part of the scroen is in a slightly inclined position between the upper
drums 2, 3, and it travels in the direction of the arrow.
From the drum 3, at the lower end of the incline, the screen proceeds down-
wards to a lower drum 4, and then returns horizontally in a trough or passage
below the ground level 7 to a drum 5, from which it re-ascends to the highest
drum 2.
In this modification the screen is formed by a series of wire ropes or stout wires 8,
the series having at each side a strong. plate link chain 9.
The chains are con-
nected by transverse rods 10 placed at intervals, and on each rod 10 there are
strung a series of washers, or distance pieces 11 (Figure 6), which abut against
each other, but are formed with semicircular grooves to enclose the ropes or
wires 8.
The combination of parts, namely, the chains 9, ropes or wires 8, transverse
rods 10, and washers 11, thus forms a kind of open metal web or netting, which is
well adapted for screening purposes, and for the desired continuous travelling
motion.
The drums 2, 3, 4, 5, are formed with polygonal facets at the parts receiving the
chains 0, and with grooves parallel to their axes at the parts where the transverse
rods 10 will engage with them.
The travelling or progressive motion is given to the screen by means of the
highest drum 2, which is driven through suitable gearing from a steam engine
indicated at 12, in Figure 2, the second motion shaft 13 of this engine being
geared by bevil wheels 14 to a vertical shaft 15, having at its upper end a bevil
pinion 16, which gears with a bevil wheel 17, on the shaft 18, of the drum 2.
The drum 2 is not fixed on the shaft 18, but is driven by means of a groove and
key so that it can move along the shaft, and it is provided with a grooved neck 19
at one end, by means of which it receives a reciprocating motion from a lever 20,

page_text: this lever being acted on by the rod 21 of an eccentric or cam 22 on the vertical
shaft 15.
Gangways 23 are provided alongside the screen, and as the coal is carried along
from the higher end where it is tipped upon the screen from a truck or wagon,
refuse and inferior pieces too large to pass through are removed by pickers standing
on the gangway. At the delivery end of the screen there is placed a hinged plate
or shute 24, which guides the screened coals gently down to a truck or cart.
Hoppers or shutes 25 may also be fitted under the screen to receive or guide
the small coal or slack which passes through the screen.
More than one of the drums 2, 3, 4, 5, may be driven if found desirable, and one or
more of the drums may be carried in adjustable bearings to admit of the screen
being tightened or slackened if required.
When it is wished to separate the produce of a coal mine into several different
sizes, a number of the screens may be arranged in order so that the coals may
travel over one after the other in succession, each screen being made with wider
meshes or spaces between the ropes or wires than its predecessor. The screens of
such a series may each be comparatively short.
Having thus particularly described my said Invention, and the manner of per-
forming the same, I have to state that I do not restrict myself to the precise details
⚫herein described or delineated, but that what I believe to be novel and original,
and claim as the Invention secured to me by and in terms of the herein-before in
part recited Letters Patent, is,-
1. The arranging or combining together of the parts of apparatus for screening
coals or similar materials, substantially in the manner herein-before described.
2. The application of a combination of wire ropes, or of wires, or wire netting,
for screening coals or similar materials, such combination being arranged in an
. endless form and acting substantially as herein-before described.
In witness whereof, I, the said James Stedman Dixon, have hereunto set my
hand and seal, this Fifth day of November, in the year of our Lord
One thousand eight hundred and seventy-eight.
JAMES S DIXON. (L.S.)