IMPROVEMENTS IN REVOLVING SADERNS FOR SCREENING COAL AND OTHER MATERIALS.” SOREANG PAD SCREENING COAL AND OTHER MATERIALS
Year: 1867

page_text: LETTERS PATENT to Charles Dutton, of West Bromwich, in the County
of Stafford, Engineer, for the Invention of "IMPROVEMENTS IN REVOLVING
SADERNS FOR SCREENING COAL AND OTHER MATERIALS.”
SOREANG PAD SCREENING COAL AND OTHER MATERIALS."
POR
Sealed the 22nd October 1867, and dated the 2nd May 1867.
PROVISIONAL SPECIFICATION left by the said Charles Dutton at the
Office of the Commissioners of Patents, with his Petition, on the
2nd May 1867.
I, CHARLES DUTTON, of West Bromwich, in the County of Stafford, Engineer,
do hereby declare, the nature of the said Invention for "IMPROVEMENTS IN
REVOLVING SCREENS FOR SCREENING COAL AND OTHER MATERIALS," to be as
follows:-
My Invention consists in constructing in the manner herein-after described
compound revolving screens for screening coal and other materials whereby
the coal or other material may be screened into different sizes by the same
screen.
I construct the revolving screens of two or more concentric cylinders made
of bars, wire gauze, or perforated metal, and revolving within one another.
The mesh or pitch of the screen cylinders is largest in the inner cylinder and
smallest in the outer cylinder; by this means the coal of largest size is
screened in the inner cylinder, and coal of smallest size is screened in the
outer cylinder; the screen cylinders may be made to revolve at the same

page_text: speed or at different speeds, and in the same direction as or in opposite
directions to each other as may be required. The said screen cylinders may
be driven by friction pulleys working outside the said cylinders or in any
other convenient manner. The screen cylinders are inclined and the screened
coal passes out of the mouths of the respective cylinders and is received by
suitable receptacles; the dust or smallest particles fall through the outer screen
cylinder.
When I make the cylinders of bars I prefer to make the said bars oval
in cross section and capable of turning on their axes, so that by changing
the position of the said bars the spaces between them may be made greater
or less.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Dutton in the Great Seal Patent Office on the
28th October 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
DUTTON, of West Bromwich, in the County of Stafford, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of May, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Charles Dutton, Her special licence that I, the said Charles Dutton,
my executors, administrators, and assigns, or such others as I, the said
Charles Dutton, my executors, administrators, and assigns, should at any
tine agree with, and no others, from time to time and at all times there-
after 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 "Im-
PROVEMENTS IN REVOLVING SREENS FOR SCREENING COAL AND OTHER MATERIALS," upon
the condition (amongst others) that I, the said Charles Dutton, 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.

page_text: NOW KNOW YE, that I, the said Charles Dutton, do hereby declare
the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :―
My Invention consists in constructing in the manner herein-after described.
compound revolving screens for screening coal and other materials whereby
the coal or other material may be screened into different sizes by the same
screen.
I construct the revolving screens of two or more concentric cylinders made
of bars, wire gauze, or perforated metal, and revolving within one another.
The mesh or pitch of the screen cylinders is largest in the inner cylinder and
smallest in the outer cylinder; by this means the coal of largest size is
screened in the inner cylinder, and coal of smallest size is screened in the
outer cylinder. The screen cylinders may be made to revolve at the same
speed or at different speeds, and in the same direction as or in opposite
directions to each other as may be required. The said screen cylinders may be
driven by friction pulleys working outside the said cylinders, or in any other
convenient manner. The screen cylinders are inclined, and the screened
coal passes out of the mouths of the respective cylinders, and is received by
suitable receptacles. The dust or smallest particles fall through the outer
screen cylinder.
When I make the cylinders of bars I prefer to make the said bars oval in
cross section and capable of turning on their axes, so that by changing the
position of the said bars the spaces between them may be made greater
or less.
Having explained the nature of my Invention I will proceed to describe,
with reference to the accompanying Drawing, the manner in which the same
is to be performed.
Figure 1 represents partly in end elevation and partly in cross section a
compound revolving screen for screening coal and other materials constructed
according to my Invention; Figure 2 is a plan of the same (a portion being
broken off); and Figure 3 is a side elevation of the same; Figure 4
represents one of the bars of the screen cylinders separately. The same
letters of reference are employed to indicate the same parts in each Figure of
the Drawing.
The said compound screen consists of three concentric screen cylinders
marked respectively a, b, c, the mesh or space between the bars of the screen
cylinders being largest in the inner screen cylinder a, less in the middle
screen cylinder b, and smallest in the outer screen cylinder c. The base

page_text: plated and the screen cylinders a, b, c, are inclined, as represented in Figure 3,
for the purpose of facilitating the removal of the screened coal from the said
screen cylinders. The said screen cylinders a, b, c, are driven by friction
pulleys on the parallel shafts e, f; the said shafts e, f, are supported by the
bearings 9, and rotatory motion in opposite directions is communicated to the
said shafts e, f, by the end shaft h and bevil gearing i, k. The end shaft h is
supported by the bearings I, and is driven by a pulley m on the said shaft, or
in any other convenient way. The screen cylinders a, b, c, are provided with
flanges marked a, b, c, respectively, and rotary motion is communicated to
the said screen cylinders by the said flanges engaging with the friction pulleys
on the shafts e, f. The inner screen cylinder a is 'driven by the friction
pulleys n, n, and o, o, the pulleys n, n, being fixed on the shaft e, and the other
pulleys o, o, being loose on the other shaft f. The middle screen cylinder b is
driven by the friction pulleys p, p, and q, q, the pulleys p, p, being fixed on the
shaft f, and the other other pulleys q, q, being loose on the other shaft 'e. The
outer screen cylinder c is driven by the pulleys r, r, and's, s, the pulleys'r, r, being
fixed on the shaft f, and the other pulleys s, s, being loose on the other shaft e;
the loose pulleys o, q, s, constitute moveable bearings only for one side of the
screen cylinders a, b, c. On giving rotation to the end shaft h the screen
cylinders a, b, c, are made to rotate, the inner screen cylinder a rotating in
one direction and the middle and outer screen cylinders b, c, rotating in the
contrary direction, the speed of the inner screen cylinder a being greater than
that of the middle and outer screen cylinders b, c; the whole of the screen
cylinders may however be made to revolve at the same speed and in the same
direction. At the end marked A, Figure 3, of the compound screen a hopper
is situated, from which hopper the coal to be screened passes into the inner
screen cylinder a. On the rotation of the compound screen the coal of the
largest size is screened in the said inner cylinder a, and the coal of less size
passing through the said inner cylinder a is screened by the middle cylinder b,
while coal of still less size passes through the middle cylinder 6 and is screened
by the outer cylinder c, the said screened coal passing out at the lower ends of
the respective cylinders, and is received by trucks or by other suitable
receptacles. The smallest particles or dust falls through the outer screen
cylinder c and passes through an opening in the base plate d, and is received
in a suitable receptacle. By the arrangement described the coal is screened
into different sizes by the same screen. In the accompanying Drawing the
screen cylinders are made of bars of an oval figure in cross section; one of
these bars is represented separately in Figure 4. These bars are capable of
turning in the ends or flanges a², 62, c², of the screen cylinders a, b, c; by

page_text: changing the positions of the said bars the spaces between them may be made
greater or less, as will be understood by an examination of the sectional part
of Figure 1. The bars of which the screen cylinders are made are fixed by
the screw nuts, represented bearing against the flanges of the screen cylinders.
Instead of employing oval shaped bars for forming the screen cylinders fixed
bars of a circular or other figure in cross section may be employed; or the said
screen cylinders may be made of wire gauze, or of perforated metal.
Although in the accompanying Drawing I have represented a compound
screen composed of three concentric screen cylinders, yet two screen cylinders
or more than three screen cylinders may be employed; and although I have
described and represented the best arrangement with which I am acquainted
of driving or giving rotation to the screen cylinders, yet other equivalent
arrangements may be employed for driving the said screen cylinders with the
same or nearly the same effect.
Having now described the nature of my Invention, and the manner in
which the same is to be performed, I wish it to be understood that I do not
limit myself to the precise details herein described and represented, as the same
may be varied without departing from the nature of my Invention; but I
claim as my Invention the improvements in revolving screens for screening
coal and other materials herein-before described and illustrated in the accom-
panying Drawing, that is to say, constructing the said revolving screens of
two or more concentric or nearly concentric screen cylinders substantially
as described and illustrated, whereby the coal or other material may be
screened into different sizes by the same screen.
. In witness whereof, I, the said Charles Dutton, have hereunto set my
hand and seal, this Twenty-fifth day of October, in the year of our
Lord One thousand eight hundred and sixty-seven.
Witness,
0
RICHARD SKERRETT,
Clerk to George Shaw,
Birmingham.
CHARLES DUTTON. (L.S.)