IMPROVEMENTS IN SCREENS FOR SCREENING COALS. AND OTHER SUBSTANCES REQUIRING TO BE SCREENED
Year: 1852

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
YOUNG HALL, of the Town and County of Newcastle-upon-Tyne, Coal Owner
and Colliery Viewer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twenty-third day of
February, One thousand eight hundred and fifty-two, in the fifteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Thomas Young Hall, my exors, admiors, and assigns, Her
especial licence, full power, sole privilege and authority, that I, the said
Thomas Young Hall, my exors, adñors, and assigns, or such others as I,
the said Thomas Young Hall, my exors, admors, or assigns, should at any
time agree with, and no others, from time to time and at all times during
the term of years therein expressed, should and lawfully might make, use,
exercise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, my Invention of "IMPROVEMENTS IN SCREENS FOR SCREENING COALS.
AND OTHER SUBSTANCES REQUIRING TO BE SCREENED;" in which said Letters.
Patent is contained a proviso that J, the said Thomas Young Hall shall
cause a particular description of the nature of my said Invention, and in
what manner the same is to be performed, by an instrument in writing.
under my hand and seal, to be inrolled in Her said Majesty's High Court
of Chancery within six calendar months next and immediately after the

page_text: date of the said in part recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Young Hall, hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are fully described
and ascertained in and by the following statement thereof, reference being
had to the Drawings hereunto annexed, and to the figures and letters marked
thereon, that is to say:-
My improvements in screens for screening coals and other substances
consist in making the longitudinal or screening bars to rest on pins or pivots
fixed to moveable levers or cross bars, placed at such an angle with respect to
each other, and so connected, as to form a combination resembling the letter
V or W, so that by means of a screwed rod and handle their angular position
may be changed, and the spaces between the whole of the hars which are
attached to the levers or any portion of them thereby varied or adjusted,
according to the size desired to be given to the meshes or interspaces.
In the Drawings hereunto annexed is shewn a representation of what I
consider the best arrangement for carrying out my improvements. Figure 1
is a plan of the screen showing the bars in two positions. Figure 2 is a
longitudinal section of the same. Figure 3, a cross section, shewing the
position of the bars with 3/8-inch spaces between them; and Figure 4, a cross
section with the bars screwed out to the full extent. In this Drawing the
same letters have reference to the same parts in each Figure. a, a, &c. is a
frame of wood; b, b, &c. are iron cross stays, bolted at certain distances
apart to the side pieces of the framing; and c, c, &c. is a square bar or stay
with a screw and nut at each end, passing up through the centre of the frame,
and notched into the top side of the cross pieces, the whole being screwed
together, as represented by the Drawing. The centre joints of the levers
d, d, &c. are made to work upon pins fixed in the longitudinal stay c, c, &c.,
and the outer ends of the said levers are connected by a pin fixed in the
pieces of T iron e, e, &c., which with the iron plates f. f. form the sides of the
g, g, &c. are the screen bars, to the under side of which pins are
fixed at certain distances apart; and in the levers d, d, &c. are holes to
receive these pins at such a distance between centres as to correspond with the
pins fixed in the said bars, or the pins may be fixed in the levers and loose in
the bars. The levers being free to move upon the framework to or from the
centre joint fixed to the longitudinal bar, their angular position is changed by
means of a right and left handed screwed rod h, h, &c., which works in
On the under side of
bearings i, i, &c. fixed at each end to the framework.
screen.

page_text: each of the T pieces is fixed a nut k, k, &c., which as the handle 1, l, &c. is
turned in one direction will move from the centre, and when turned in the
opposite direction will move towards the centre; and these side pieces and the
screen bars being all placed parallel with each other upon the moveable levers,
the dimensions of the spaces between the bars can be thereby varied according
to the substance to be screened and the purpose for which it may be required.
The ends of the screen bars at the top work under the framework and at the
bottom end they work on the upper side of a plate on which the coals or other.
substance to be screened is delivered, the smaller particles having passed.
through between the bars; and in the arrangement represented by the Draw-
ing these smaller particles are again screened by a wire gauze (m, Figure 2),
which separates the dust or "duff" from what has passed through the regu-
lating screen, each division having a shoot to deliver the same into separate
wagons, as represented. A second regulating screen may be substituted in
the place of the wire gauze when two sizes of large coal are required, or the
top screen may be divided into two lengths, and each portion made and
worked independent of the other, so that each may screen different sizes, the
shoots on the under side being made to deliver the material from the
respective portions into wagons, as in the arrangement already described.
These screens can be screwed up, so that the bars will go close together and
form a dumb screen or shoot when the coals are not required to be screened.
I prefer the use of levers, as herein described, for the purpose of varying the
distance between the bars, to any other mechanical movement which might
answer a similar purpose, on account of their great simplicity and little
liability to get out of order. By the arrangement of screens here described,
coals can at any time with the same screens and without any delay be
screened into any number of sizes to meet the demand of different localities or
purposes for which they may be required, and the necessity of having a great
variety of the ordinary screens with fixed bars, and consequently much space
for their arrangement, will be avoided, which will be found a great advantage
in all situations where space is valuable. These improved screens can be
made either fixed or portable, and can be placed at such an angle as the
locality or purpose for which they are intended may require. The portable
screens, with independent framework, may be used in discharging coals from
ships into barges or other vessels in rivers or docks, or they may be used in
certain localities where it would not be convenient or practicable to have fixed
screens or where screens are only occasionally used, and they may be made to
hang in a vertical position when not in use, and the space they would other-
wise occupy be made available for other purposes. In situations where power

page_text: can be obtained from any prime mover, and where the necessary height
or inclination of the screen for the substance to be screened is limited, I
"shake," the
prefer to give them a lateral motion, technically termed a
screens being hung on links or placed on vibrating supports, by which means
the coals or other substances can be screened with the screens placed at a
very slight inclination. I prefer making these screens of wrought iron and
wood, as described, and as represented in the Drawing, but they may be made
altogether of wrought iron or cast iron, or of a combination of both, or of iron
and wood combined; and I do not confine myself to the particular construc-
tion here described, however the same may be modified or varied, so long as
the essential features of my Invention are adhered to. But I declare that
what I claim is the means employed for varying the position of the bars (with
or without independent framework), and for making the screen either fixed or
portable, and forming them into a dumb screen or shoot, as before described.
I claim also the application of the "shake" to the same in certain cases, as
described.
In witness whereof, I, the said Thomas Young Hall, have hereunto set
my hand and seal, this Twenty-first day of August, One thousand eight
hundred and fifty-two