AN IMPROVED SCREENING APPARATUS
Year: 1871

page_text: LETTERS PATENT to William Edward Gedge, of No. 11, Wellington
Street, Strand, in the County of Middlesex, Patent Agent, for the
Invention of "AN IMPROVED SCREENING APPARATUS "-- Communication
from abroad by Mathieu Maric Felix Devillaine, Engineer, Manager
of the Mines of Montrambert and de la Béraudière, La Ricamarie,
near St. Etienne, Loire, France.
PROVISIONAL SPECIFICATION left by the said William Edward Gedge
at the Office of the Commissioners of Patents, with his Petition, on
the 29th September 1871.
I, WILLIAM EDWARD GEDGE, of No. 11, Wellington Street, Strand,
in the County of Middlesex, Patent Agent, do hereby declare the
nature of the said Invention for "AN IMPROVED SCREENING APPARATUS,"
a communication to me from abroad by Mathieu Marie Felix Devillaine,
Engineer, Manager of the Mines of Montrambert and de la Béraudière,
La Ricamarie, near St. Etienne, Loire, France, to be as follows:-
-
This Invention relates to a shifting screen with variable inclination.

page_text: The screening is intermittent in so far that coal is slid on to the fixed
screen until the moveable screen is suitably furnished with large coals,
which are stopped at its fore end by the barrier o, o¹. The sorting then
takes place with every possible facility, after which the moveable screen
is lowered to b, c, and the large coals perfectly freed from small or slack
slide over the barrier o, o', into the waggon as gently as desired, passing
over the shifting shoot e, f. Not only are the screening and sorting
perfect, but they are accomplished so easily that this apparatus renders
quite practicable the idea of the momentary separation of the slack
("menus-fins") to facilitate the sorting of the coals sold in the state of
small coal ("menu-sortant) (as they come), which idea the Inventor
believes has never hitherto been applied, at any rate upon any large
scale, although it has been put forth in several works.
The sorting of the stones from the small coal is much hindered by the
proportion of at least 50% of slack mixed with picces big enough to be
sorted by hand. It is therefore desirable to eliminate this slack by a
screening preliminary to the sorting, provided the mixing is easily
re-effected; and this is obtained with the greatest facility by placing
beneath the screens a, b, and b, c, a sheet-iron plate, which first leads
the slack into the waggon, where the large coal rejoins it directly after
the sorting.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Edward Gedge in the Great Scal Patent
Office on the 27th March 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD GEDGE, of No. 11, Wellington Street, Strand, in the County of
Middlesex, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of September, in the
year of our Lord One thousand eight hundred and seventy-one, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Edward Gedge, Her special
licence that I, the said William Edward Gedge, my executors,
administrators, and assigns, or such others as I, the said William

page_text: Edward Gedge, 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 "AN IMPROVED SCREENING APPARATUS," a communication
to me from abroad by Mathieu Maric Felix Devillaine, Engineer,
Manager of the Mines of Montrambert and de la Béraudière, La
Ricamaric, near St. Etienne, 'Loire, France, upon the condition
(amongst others) that I, the said William Edward Gedge, my exe-
cutors 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 William Edward Gedge, 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:-
This Invention relates to a shifting screen with variable inclination.
When recourse is not had to mechanical sifting or screening for
sorting and classifying coals, fixed screens are used, the inclination of
which often diminishes towards the lower part in order to check the
speed of the pieces sliding thereon, which speed generally increases
with the separation of the smaller parts and the length of the screen.
Advantage is often taken of the passage of the "grélassons" (pieces of coal
of from 5 to 8 centimeters, herein termed the large coal) on the screen
to sort by hand the impure parts mixed therewith. With ordinary
screens it generally happens either that the coal slides too rapidly and
heaps up towards the bottom of the screen, 1°, in breaking a little,
2°, in too thick a layer to be sorted with all the facility desirable; or
that if it is endeavoured to avoid these two defects the coal does not
slide enough, and it becomes necessary to make it slide along with the
shovel, and there is in every case an increase of small coal or slack and
of labour.

page_text: To obtain a good sifting or screening, succeeded by a good sorting, the
coal must first pass over a screen sufficiently inclined to prevent any
stoppage of the large coal, and then pass on to another screen having
such an inclination that the speed acquired on the first screen is
gradually deadened, and on which the large coal spreads out in a rather
thin layer to facilitate the sorting, after which the coal must slide of
itself into the waggon.
itself into the waggon.
Such are the results obtained by the screen with variable inclination.
the subject of this Invention, which is made to follow the fixed screen.
Description of the Apparatus, reference being had to the accompanying
Sheet of Drawing, Fig. 1 being a side view of apparatus embodying
this Invention, Fig. 2 a front view, and Fig. 3 a plan view of same.-At
the outlet of a hopper placed above the screen, and holding say ten tons
of coal, are two traps regulating the arrival of the coal upon the fixed
screen a, b, upon which the sifting or screening is effected, and which is
followed by a moveable screen b, c, of from 1". 50% to 2. 00 in length,
upon which the sorting takes place. This moveable screen pivoting
upon an axle q is exactly counterbalanced by a counterweight P, and
accordingly as the condition of the coal renders it more or less slippery
the inclination b, c, is varied by means of the holes pierced at various
heights in the lower part of the rod m, m³, by means of which the
moveable screen is worked, and which is fixed by hooking it to a stud
placed against the plate which forms the side of the fixed screen.
The screening is intermittent in so far that coal is slid on to the fixed
screen until the moveable screen is suitably furnished with large coals,
which are stopped at its fore end by the barrier o, o'. The sorting then
takes place with every possible facility, after which the moveable screen
is lowered to b, c, and the large coals perfectly freed from small or slack
slide over the barrier o, o', into the waggon as gently as desired, passing
over the shifting shoot e, f. Not only are the screening and sorting
perfect, but they are accomplished so easily that this apparatus renders
quite practicable the idea of the momentary separation of the slack
("menus-fins") to facilitate the sorting of the coals sold in the state of
small coal ("menu-sortant") as they come, which idea the Inventor
believes has never hitherto been applied, at any rate upon any large
scale, although it has been put forth in several works.