IMPROVEMENTS IN DRESSING CANNEL COAL AND OTHER MINERALS, AND IN APPARATUS EMPLOYED FOR THAT PURPOSE
Year: 1870

page_text: LETTERS PATENT to William Firth, of Leeds, in the County of
York, for the Invention of "IMPROVEMENTS IN DRESSING CANNEL COAL
AND OTHER MINERALS, AND IN APPARATUS EMPLOYED FOR THAT PURPOSE."
Sealed the 7th March 1871, and dated the 21st December 1870.
PROVISIONAL SPECIFICATION left by the said William Firth at the
Office of the Commissioners of Patents, with his Petition, on the
21st December 1870.
I, WILLIAM FIRTH, of Leeds, in the County of York, do hereby
5 declare the nature of the said Invention for "IMPROVEMENTS IN DRESSING
CANNEL COAL AND OTHER MINERALS, AND IN APPARATUS EMPLOYED FOR THAT
PURPOSE," to be as follows:-
This Invention has for its object improvements in dressing cannel
coal and other minerals.

page_text: It has hitherto been the practice in dressing cannel coal to detach the
"hub," or 66
shale," or other objectionable matter from the pure coal by
hand labor, the dresser using a small pick or tool suitable for the
purpose; but that process is very uncertain in its results, and much
deleterious matter is often left adhering to the pure coal, which is
injurious to the gas and coke produced therefrom; besides this, the waste
of good coal is often very serious and the cost of dressing is expensive.
My improvements have in view the substitution of mechanical
arrangements instead of manual labor.
The block of cannel coal as it is hewn is placed on a table, over which
a separating tool (or it might be tools) is mounted. The joint between
the strata which it is desired to separate is brought beneath the tool,
which is then forced down by steam, air, or water acting in a cylinder,
or by other sufficiently powerful means, and so the separation is effected
at the line of cleavage. The tool or tools may, if preferred be arranged
to work horizontally.
In some cases a moving table may be used with endless chains or
other suitable contrivance to carry the separated matter from the
dressing table to the wagons used for its removal.
I also propose to apply my Invention to the dressing of iron ore and
athan minowels which require cleansing before being used.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Firth in the Great Seal Patent Office
on the 20th June 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
FIRTH, of Leeds, in the County of York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of December, in the
year of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Firth, Her special license that I,
the said William Firth, my executors, administrators, and assigns, or
such others as I, the said William Firth, my executors, administrators,

page_text: 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 "IMPROVEMENTS IN DRESSING CANNEL
COAL AND OTHER MINERALS, AND IN APPARATUS EMPLOYED FOR THAT PURPOSE,"
upon the condition (amongst others) that I, the said William Firth, 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.
NOW KNOW YE, that I, the said William Firth, 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 :—
This Invention has for its object improvements in dressing cannel
coal and other minerals, and in apparatus employed for that purpose.
It has hitherto been the practice in dressing cannel coal to detach
the "hub" or "shale" or other objectionable matter from the pure
coal by hand labor, the dresser using a small pick or tool suitable for
the purpose; but that process is very uncertain in its results, and
much deleterious matter is often left adhering to the pure coal, which
is injurious to the gas and coke produced therefrom, besides this, the
waste of good coal is often very serious, and the cost of dressing is
heavy.
My improvements have in view the substitution of mechanical
arrangements instead of manual labor.
The block of cannel coal as it is hewn is placed on a table, over which
a separating tool (or it might be tools) is mounted. The joint between
the strata which it is desired to separate is brought beneath the tool
which is then forced down by steam, air, or water acting in a cylinder,
or by other sufficiently powerful means, and so the separation is effected
at the line of cleavage. The tool or tools may if preferred be arranged
to work horizontally.

page_text: In some cases a moving table may be used with endless chains or
other suitable contrivance to carry the separated matter from the dressing
table to the wagons used for its removal.
I also propose to apply my Invention to the dressing of iron ore
and other minerals which require cleansing before being used.
In order that my said Invention may be most fully understood and
readily carried into effect I will proceed to describe the Drawings
Figure 1 is a plan of a double machine for dressing cannel coal and
other minerals. Some of the parts are removed and others are partly
in section; Figure 2 is a side view partly in section of a part of the
machine; and Figure 3 is a vertical section.
a is a table on which the blocks to be dressed are placed, each block
is then in succession so arranged that the joint between the shale and
coal or between the strata which it is desired to separate is over the
steel edge a¹ of the table, and so that the parting tool 6 when it is
caused to descend will enter the joint as nearly as may be. The
dresser then places his foot on the treddle c, and the separation is
effected by the forcible descent of the parting tool. In the machine
represented in the Drawing the treddle c when depressed partially
rotates a valve d which admits steam to the top of a cylinder e whilst
it allows it to escape from the lower part. A piston works in the
cylinder e, and the parting tool 6 is fixed to a cross head ƒ which is
attached to the piston rod and provided with guides on either side;
thus the depression of the treddle causes the rapid descent of the
parting tool. When the dresser takes his foot off the treddle ca
spring 9 brings back the valve to the point from which it started,
and in so doing it allows the escape of the steam from the upper
part of the cylinder and admits it to the lower, in consequence of
which the parting tool is raised ready for the next operation.
What I claim is the process of dressing coal and other minerals by
means of a reciprocating parting tool which is guided in its motion and
actuated by suitable apparatus, so as to be forced into the block at the
line of cleavage, substantially as described.

page_text: I also claim the construction of apparatus for dressing coal and other
minerals substantially as described.
In witness whereof, I, the said William Firth, have hereunto
set my hand and seal, this Seventeenth day of June, in the
year of our Lord One thousand eight hundred and seventy-
one.