IMPROVE- MENTS IN APPARATUS FOR CUTTING COAL
Year: 1876

page_text: LETTERS PATENT to Edward Alfred Cowper, of No. 6, Great George Street,
Westminster, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN APPARATUS FOR CUTTING COAL."
PROVISIONAL SPECIFICATION left by the said Edward Alfred Cowper at the
Office of the Commissioners of Patents on the 9th August 1876.
EDWARD ALFRED COWPER, of No. 6, Great George Street, Westminster, in the
County of Middlesex. "IMPROVEMENTS IN APPARATUS FOR CUTTING COAL."
Percussive rock drills of various kinds, worked by compressed air or other fluid
under pressure, have been applied in coal pits for the purpose of cutting chases in
the face of a mass of coal, so that the coal might be easily detached in pieces³
therefrom.
-
My Invention relates to modes of mounting drills for this purpose and to the
construction of framing or stands for such drills, so as to render them conveniently
portable and to give facilities for rapidly and securely fixing them in any required'
position.
For detaching coal from the face of the seam it is found convenient to cut a
chase horizontally, or nearly so, at or near the bottom of the working, and chases
vertical, or nearly so, to separate the portion to be detached from the run of the
seam. I will first describe the arrangement of stand or framing which I employ
for the horizontal chase or under cut. I forn a tripod or stand of three legs which
may be either tubes or solid bars connecting then near the base by ties. To the
hind leg I joint the cradle which carries the cylinder of the rock drill in such a
manner that the said cradle can be swept from side to side radially resting on a
bar which joins the two front legs of the tripod. The cylinder of the rock drill
with its piston valves and feed or advancing gear may be of any known con-
struction.
For sweeping the drill cradle from side to side I employ a screw mounted by a
swivel on the front of the tripod, the said screw working in a nut swivelled to the
cradle. The tripod may be held down in position by a screw bearing against the
roof of the working when the roof is conveniently within reach, or it may be held
down by a lever one end of which is inserted into a hole in the face of the coal
[Price 10d.]

page_text: and the other is loaded by sand bags, lumps of coal, or other convenient weights,
the lever being placed so as to bear near its front end on the top of the tripod or
of a screw mounted therein; the weights placed on its back end act with considerable
leverage to keep the apparatus firmly in position.
Instead of one lever bearing on the top of the tripod two levers may be employed,
one acting on a stud or projection from each side of the tripod near its base.
The stand or framing which I employ in cutting the vertical chase is also of
tripod form, the cradle of the drill being pivotted at the apex of the tripod so that
the drill can sweep up and down in a vertical plane, being by preference counter-
balanced. For this purpose I employ means of fixing similar to those already
described, but I prefer also to provide a strut extending from the apex some distance
backwards to a point where it is fixed into the floor of the working by driving a
pin through its end and loading with weights. The tripod frames themselves are
either made with pointed feet or with eyes or sockets at their feet, through which
sharp pins can be driven into the floor of the working.
In constructing the chisels or drills for cutting the chases in the coal, as above
described, I prefer to provide on them besides their front cutting faces spurs or
cutting edges projecting from their shanks at various distances behind the front
cutting face, so that as the drill advances the chase is cut wider at the front by
means of these projecting spurs.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Alfred Cowper in the Great Seal Patent Office on the 8th
February 1877.
EDWARD ALFRED COWPER, of No. 6, Great George Street, Westminster, in the
County of Middlesex, "IMPROVEMENTS IN APPARATUS FOR CUTTING COAL,"
Percussive rock drills of various kinds, worked by compressed air or other fluid
under pressure, have been applied in coal pits for the purpose of cutting chases in
the face of a mass of coal, so that the coal might be easily detached in pieces
therefrom.
My Invention relates to modes of mounting drills for this purpose and to the
construction of framing or stands for such drills, so as to render them conveniently
portable and to give facilities for rapidly and securely fixing them in any required
position.
For detaching coal from the face of the seam it is found convenient to cut a
chase horizontally, or nearly so, at or near the bottom of the working, and chases
vertical, or nearly so, to separate the portion to be detached from the run of the
seam. I will first describe the arrangement of stand or framing which I employ
for the horizontal chase or under cut. I form a tripod or stand of three legs, which
may be either tubes or solid bars connecting them near the base by ties. To the
hind leg I joint the cradle which carries the cylinder of the rock drill in such a
manner that the said cradle can be swept from side to side radially resting on a bar
which joins the two front legs of the tripod. The cylinder of the rock drill.with
its piston valves and feed or advancing gear may be of any known construction.
For sweeping the drill cradle from side to side I employ a scrow mounted by a
swivel on the front of the tripod, the said screw working in a nut swivelled to the
cradle. The tripod may be held down in position by a screw bearing against the
roof of the working when the roof is conveniently within reach, or it may be held
down by a lever, one end of which is inserted into a hole in the face of the coal
and the other is loaded by sand bags, lumps of coal, or other convenient weights.
The lever being placed so as to bear near its front end on the top of the tripod or
of a screw mounted therein, the weights placed on its back end act with considerable
leverage to keep the apparatus firmly in position,

page_text: Instead of one lever bearing on the top of the tripod two levers may be employed,
one acting on a stud or projection from each side of the tripod near its base.
The stand or framing which 1 employ in cutting the vertical chase is also of
tripod form, the cradle of the drill being pivotted at the apex of the tripod so that
the drill can sweep up and down in a vertical plane, being by preference counter-
balanced. For this purpose I employ means of fixing similar to those already
described, but I prefer also to provide a strut extending from the apex some
distance backwards to a point where it is fixed into the floor of the working by
driving a pin through its end and loading with weights. The tripod frames them-
selves are either made with pointed feet or with eyes or sockets at their feet
through which sharp pins can be driven into the floor of the working.
In constructing the chisels or drills for cutting the chases in the coal, as above
described, I prefer to provide on them besides their front cutting faces spurs or
cutting edges projecting from their shanks at various distances behind the front
cutting face, so that as the drill advances the chase is cut wider at the front by,
angang of these mucinatin
Fig. 1, Sheet I., is a side elevation of a machine, constructed according to my
Invention, for the horizontal chase or under cut; Fig. 2, Sheet II., is a front
elevation; and Fig. 3, Sheet III., a plan of the same machine.
a, b, c, are the legs forining the tripod frame or stand connected together near
the base by the tie bars d, e, f. The legs are in this case formed of wrought iron
tubes, with solid ends attached by welding, screwing, or other means.
This con-
struction combines the advantages of stiffness and lightness; but the legs may be
made of solid bars throughout; g is the cradle jointed to the hind leg c, and
carrying the cylinder h which is capable of sliding along in it from end to end, two
projecting ribs on the cylinder being fitted into two V grooves in the cradle. The front
end of the cylinder is continued forwards under the piston rod n some distance so
as to guide and support it, by which means the piston rod may glide fairly back-
wards and forwards without any undue strain, the weight of its piston balancing
the weight of the tool. The cradle pivotting upon the hind leg c is capable of
sweeping from side to side, being supported by the bar d, upon which it slides and
to which it is confined by the staple y below the said bar; i is a screw turning in
a swivelled bearing, and giving motion to the cradle by means of the nut which
is attached by a swivel to the cradle. One end of the screw i is fitted with a
handle by which it is rotated, and the other end is supported in a slot in a
bracket m attached to the framing, which affords the necessary freedom for the
vibration of the screw caused by the motion of the nut following the arc of a
circle. The piston rod n is bored to receive the shank of the tool o, which may
have the spurs or cutting edges projecting from it as shewn (in addition to the front
cutting face) to cut the chase wider at the front. A flexible pipe is employed to
convey the air or steam to the cylinder, and another as an exhaust pipe. The
cylinder is moved along the cradle by the screw p, which is turned by a handle and
works in the bearings q, q, on the cradle and the nut on the cylinder. By this
means the cylinder is gradually advanced as the cutting of the chase proceeds, and
is drawn back before commencing work in a new place. At the corners of the base
of the tripod stand are three pointed screws a, b, c, with capstan heads for
screwing down into the floor, and at the apex is a long screw passing vertically
through the metal of the frame, to be forced up against the roof to firmly fix the
machine in any position. A hand wheel is provided by which this screw is
turned.
In cases where the roof is too high to be conveniently reached by a screw a
lever 21 is to be used to press down on the top of the tripod frame, the front end
of the lever being inserted a short distance into the face of the coal, and the back
end being weighted by sand bags, coal, or other convenient weight. Or two,

page_text: levers, may be used to press down on hooks or lugs a, b, attached to the
front of the frame, the front ends of these levers are inserted a short distance into
the face of the coal whilst the back ends is weighted; the back corner of the
frame is, in this case, to be kept down by weights laid on bars hooked on the
frame and on the levers.
The method of working this machine is as follows:-The machine being fixed in
the manner described, with the cylinder drawn back to the hinder end of the cradle,
the piston carrying the tool is set in motion by opening the cock in the supply pipe,
thus causing the tool to commence striking the face of the coal. The handle on
the screw being turned alternately in opposite directions, the cradle with the
cylinder and tool is made to sweep from side to side. A horizontal chase is thus
commenced by the front cutting face of the tool, which is increased in depth by the
advance motion given to the cylinder by means of the feed screw p. When a
certain depth of chase has been attained the first pair of spurs or projecting cutting
edges come into contact with the face of the coal and commence their work of
widening the chase. In the same manner the other spurs (if any) at intervals
along the shank, having edges projecting still farther, comne seriatim into use and
increase the width of the chase from the face inwards.
The
Fig. 4, Sheet IV., is a side elevation of a machine arranged for cutting a vertical
chase; Fig. 5, Sheet V., is a back elevation; and Fig. 6, Sheet VI., a plan of the
same machine. The stand or frame is of a tripod form very similar to that
employed for the horizontal chase machine, having also similar screws at the corners
of the base. At the top of the frame or stand is provided a socket v to receive the
lower end of a moveable hollow post or strut w, into the upper end of which passes
a screw x, having a pointed end to be forced against the roof, so as to firmly fix
the machine. Another method of fixing is as follows:-At the apex of the tripod
are formed two lugs w¹, w¹, either of which receives a moveable strut extending
backwards and provided with a pin capable of being driven down into the floor of
the working; a lever a¹ (Fig. 5) is to be used to press down the frame inserted, as
shown, just below the trunnion, and taking a bearing in the face of the coal and
being loaded behind, the same as the other levers before mentioned; or two levers
may be used to press down on the side of the bottom of the frame, being weighted
at their back ends the same as the levers for the horizontal chase machine.
cradle g¹ is in this case pivotted at the apex of the tripod by means of the
trunnion 8 cast upon its side at or near the centre of its length, which passes
through the head of the frame and has upon its outer end a worm wheel t. The
worm wheel is actuated by the worm u, which is provided with suitable
handles u¹, u¹, by which it is rotated. The cylinder ¹ slides in the cradle in the
same manner as in the horizontal machine, being moved by the screw p¹ which is
turned by a winch handle 21 or by means of ratchet and pawl 21, and works
in the bearings q, q, on the cradle and in the nut on the cylinder. The shank
of the tool o¹ is fitted into the end of the piston rod n¹ as in the horizontal machine.
The method of working the vertical chase machine is similar to that of the hori-
zontal machine, with the exception that the tool sweeps up and down in a vertical
plane, and that this motion is given to it by the oscillation of the cradle on its
trunnion by means of the worm and worm wheel above described. The action of
the front cutting face of the tool is the same as in the horizontal machine, but it
necd not in this case bo provided with the spurs. This machine is adapted to
cutting a vertical chase, either on the right hand side or the left hand side of the
working, by simply turning over the cradle with its cylinder end for end, as the
flexiblo pipes for supply and exhaust will then be at the top, a rounded hook is
provided on the strut near the roof for conveniently supporting them.
Having thus described the nature of my Invention and in what manner the same
is to be performed, I claim in respect of apparatus for cutting chases in the face of a
coal working,
First. The use of a tripod or three legged stand for supporting the drill and
cradle, substantially as herein described.

page_text: Second. Mounting the drill cradle so as to work on a joint at the hinder part
of the tripod frame while its front slides to and fro upon a horizontal support on
the front part of the frame, substantially as and for the purpose herein described
with reference to Figs. 1 to 3 of the Drawings.
Third. In apparatus of the kind referred to in the foregoing claim the use of a
swivelling screw and nut for effecting the horizontal to and fro motion of the drill
cradle, substantially as herein described.
Fourth. For the purpose of cutting a vertical chase mounting the drill cradle by
a trunnion on a tripod stand, the drill being caused to sweep up and down in a
vertical plane by means of worm gearing, substantially as herein described with
reference to Figs. 4 to 6.
Fifth. The method herein described of securing tripod stands, such as are above
referred to by means of bars or levers, inserted by one end into the face of the
working, and loaded or otherwise held down at the other end while they bear upon
the tripod at an intermediate point of their length.
Sixth. Providing the chasing tool with one or more lateral spurs or cutting edges
at intermediate points of its length for the purpose of widening the chase as it is
deepened, substantially as herein described.
In witness whereof, I, the said Edward Alfred Cowper, have hereunto set my
hand and seal, this Fifth day of February, in the year of our Lord One
thousand eight hundred and seventy-seven.
EDWARD ALFRED COWPER, (L.S.)