IMPROVEMENTS IN MACHINERY FOR CUTTING COAL
Year: 1866

page_text: LETTERS PATENT to George Edmund Donisthorpe, of Leeds, in the
County of York, for the Invention of "IMPROVEMENTS IN MACHINERY FOR
CUTTING COAL."
Sealed the 4th September 1866, and dated the 8th March 1866.
PROVISIONAL SPECIFICATION left by the said George Edmund Donis-
thorpe at the Office of the Commissioners of Patents, with his Petition,
on the 8th March 1866.
I, GEORGE EDMUND DONISTHORPE, of Leeds, in the County of York, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
MACHINERY FOR CUTTING COAL," to be as follows:-
This Invention has for its object improvements in machinery for cutting
coal. In coal cutting by machinery it is now usual to employ a carriage with
the cutter and apparatus mounted upon it, and this carriage travels along
rails laid along the face of the coal, hence it results that the cut is made in a
line parallel to the rails except in so far as the line of cut may be varied by
hand adjustment. Now in place of following the line of the rails, which, as
the rails are rigid, is approximately a straight line, it is usually required that
the cut should follow accurately the line of the roof or floor of the working.
This being so I according to my Invention employ the roof or floor as a guide

page_text: for the cutter; this I prefer to do by mounting on the carriage as I have
heretofore practised an air cylinder with a piston or plunger in it, which when
air is admitted to the cylinder presses a roller or rollers firmly against the
roof so as to steady the carriage between the rails and roof; but in place of
as heretofore mounting the cutting apparatus on the carriage, which runs on
and is guided by the rails, I fix it to or connect it with the rising and falling
piston or plunger, which is pressed constantly up towards the roof as already
explained. The cutting apparatus which I prefer to employ is an air cylinder
and piston giving a rectilinear motion to a cutter or cutters fixed to the piston
rod. The same carriage may have two or more sets of cutting apparatus
mounted upon it. It is evident that in a similar manner the cutting
apparatus may be guided from the floor; but not; I think, so conveniently.
Similar arrangements are applicable where water under pressure is used as
the motive power.
-
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Edmund Donisthorpe in the Great Seal Patent Office
on the 8th September 1866.
;
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,- GEORGE
EDMUND DONISTHORPE, of Leeds, in the County of York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of March, in the year of our
Lord One thousand eight hundred and sixty-six, in the twenty-ninth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said George Edmund Donisthorpe, Her special licence that I, the
said George Edmund Donisthorpe, my executors, administrators, and assigns,
or such others as I, the said George Edmund Donisthorpe, 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. "IMPROVEMENTS IN MACHINERY FOR CUTTING.
COAL," upon the condition (amongst others) that I, the said George Edmund
Donisthorpe, 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

page_text: 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 George Edmund Donisthorpe, 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 machinery for cutting
coal. In coal cutting by machinery it is now usual to employ a carriage with
the cutter and apparatus mounted upon it, and this carriage travels along
rails laid along the face of the coal, hence it results that the cut is made in a
line parallel to the rails except in so far as the line of cut may be varied by
hand adjustment. Now in place of following the line of the rails, which, as.
the rails are rigid, is approximately a straight line, it is usually required that.
the cut should follow accurately the line of the roof or floor of the working.
This being so I according to my Invention employ the roof or floor as a guide
for the cutter; this I prefer to do by mounting on the carriage as I have.
heretofore practiced an air cylinder with a piston or plunger in it, which when
air is admitted to the cylinder presses a roller or rollers firmly against the
roof so as to steady the carriage between the rails and roof; but in place
of as heretofore mounting the cutting apparatus on the carriage, which runs!
on and is guided by the rails, I fix it to or connect it with the rising and
falling piston or plunger, which is pressed constantly up towards the roof as
already explained. The cutting apparatus which I prefer to employ is an
air cylinder and piston giving a rectilinear motion to a cutter or cutters fixed.
to the piston rod. The same carriage may have two or more sets of cutting.
apparatus mounted upon it. It is evident that in a similar manner the cutting
apparatus may be guided from the: floor, but not, I think, so conveniently.
Similar arrangements are applicable where water under pressure is used' as.
the motive
power.
In the Drawings hereunto annexed--I have shewn two perspective views of
a machine in which the cutting apparatus is carried by the piston or plunger.
of an air cylinder as above described. In each of these views the machine.
is shown to be supported on rails attached to iron sleepers or bearers such.
as are described in the Specification of a Patent granted to me on the 21st.
day of October 1864 (No. 2612).
The machine is composed of a frame a supported on wheels 6 which run on.
the rails c, c'; the frame a has brackets & projecting out from it which carry:
a worm e; this worm gears with the rack formed in the face of the rail c, and
is for the purpose of moving forward the machine as described in the Specifi-.

page_text: k
cation of a. Patent granted to me on the 21st day of January 1864 (No. 158)..
The gearing for transmitting motion to the worm e from the hand wheels fis
clearly shewn in the Drawings. At each of the four corners of the frame a
is a hollow upright 9; these uprights form guides on which a bed or plate h
that carries the cutting apparatus is capable of rising and falling. Where
the uprights 9 pass through the plate h bosses h¹ are formed on its under
side in order that the plate may rise and fall truly. Upon the centre of the
carriage a is fixed an air cylinder k fitted with a piston or plunger k²; upon,
the top of which the plate à rests. Compressed air can be admitted into the
cylinder below the piston or plunger through the flexible pipe 7, which by a
union joint is connected with a pipe passing from the bottom of the
cylinder. Air can be allowed to escape from the cylinder by a tap mon a
pipe leading from the bottom of the opposite side of the cylinder. By this
means the plate h can be raised or lowered. On the top of the plate h is the
cutting apparatus, which in the arrangement shown in the Drawing is
composed of an air cylinder n carried by a plate n³, which is capable of
turning on a circular boss formed on the top of the plate h, so that the
cylinder n may be set at any desired angle to the frame and fixed in position;
by binding screws n³ as shown. Compressed air can be admitted alternately
to opposite ends of the cylinder n by a slide valve actuated by the lever o..
The piston rod of the cylinder n is by a cross head p connected with a,
slider that works in guides formed on the top of the cylinder. The slide r
carries the cutters that are to form a groove in or above the coal. The
cutters are by preference fixed to the slide in the following manner :-On.
the under side of the stems of the cutters teeth are formed similar to
ratchet teeth, and on the top of the slide are corresponding teeth, into
which the teeth of the cutter stems enter; the stems of the cutters are then
held down by bolts and nuts. By fastening the cutters in this manner the
cutters can readily be removed to be sharpened, they can also be set to
project to any desired distance from the end of the slide r, as nearly the
whole of the length of the slide is furnished with. ratchet teeth, and the
teeth on the cutter bars can be inserted between any of these teeth. On
the top of the plate h are also two wheels s, s, carried by stems capable of
rising or falling in vertical guides formed on the top of the plate. One of
these wheels is pressed upwards by a spiral spring t, the other can be set at
any desired height by means of a set screw. When the machine is at work
air is admitted into the cylinder k to cause the table h to rise and press the
wheels s against the roof of the working, and the wheels are by preference
arranged to run in shallow grooves previously cut for them. The height to

page_text: which tho table h can be raised by the air cylinder, and consequently the
height at which the cutting apparatus shall work, is regulated by the height
that the fixed wheels is set above the frame; the other wheels is pressed
upwards by a spiral spring as above mentioned, in order that both wheels
may at all times bear against the roof of the working notwithstanding any
irregularities in its surface. After that air has been admitted to the cylinder
k, the cutters carried by the slide p are set to work by alternately raising and
lowering the valve lever o, and at the same time the machine is moved
forward by turning one or other of the hand wheels f. By this means the
cutters will be caused to form a groove parallel with the roof of the working ;
the groove may either be in the coal itself or, as I believe to be preferable,
it may be in the narrow soft layer of shale which is frequently found
immediately above the vein of coal. The cutters are adjusted to work in
this layer by adjusting the height of the wheels s from the top of the table
h as above described. When a groove of material is thus removed from
above the vein of coal the coal below may in many cases be readily separated
into blocks by wedges, commencing to use the wedges near the top of the
vein of coal, and gradually working downwards as the upper part of the vein
of coal is removed. Although I prefer to arrange the machine so that it
may cut a groove close to the roof of the working, yet machines constructed
in the manner above described may be arranged to cut grooves either below
the coal or into the coal itself at any desired height from the bottom of the
vein or seam.
In witness whereof, I, the said George Edmund Donisthorpe, have here-
unto set my hand and scal, this Fourth day of September, in the
year of our Lord One thousand eight hundred and sixty-six.