IMPROVED MACHINERY FOR BORING ROCKS AND HARD SUBSTANCES
Year: 1865

page_text: LETTERS PATENT to George Low, of Dublin, in the Kingdom of Ireland,
Engineer, for the Invention of "IMPROVED MACHINERY FOR BORING ROCKS
AND HARD SUBSTANCES."
Sealed the 24th November 1865, and dated the 5th July 1865.
PROVISIONAL SPECIFICATION left by the said George Low at the Office
of the Commissioners of Patents, with his Petition, on the 5th July
1865.
I, GEORGE LOW, of Dublin, in the Kingdom of Ireland, Engineer, do hereby
declare the nature of the said Invention for "IMPROVED MACHINERY FOR BORING
ROCKS AND HARD SUBSTANCES," to be as follows:-
This Invention of improved machinery for boring rocks and hard substances
relates, firstly, to various improvements upon my Patent of April 1868,
No. 903.
The first improvement under this head relates to the general arrangement
of the cylinder and boring motion, by which the tool as it bores into the rock
is advanced or moved forward. This is effected by means of the same agent
which works the tool by pressure. By this means the ordinary gearing is
dispensed with, and the durability of the machine is therefore greatly
increased

page_text: The second improvement consists in providing a cushion of compressed air,
steam, or other elastic gas behind the working cylinder and elsewhere, by
which the crystallization of the parts exposed to the direct line of percussion
blows is effectually prevented, and also the whole machine is rendered more
steady against such shocks.
The third improvement relates to the turning motion, which is imparted to.
the tool in the stationary cylinder, instead of to any of the reciprocating or
moveable parts. The durability of the machine is thus increased, as it has
been found that when the turning motion is adapted to the reciprocating part
the blows of the tool knock to pieces or otherwise derange the working
parts.
The fourth improvement relates to the advancement of the tool as it bores.
This is effected exactly in the same ratio as the tool cuts the hole, whether
the rock be hard or soft.
The boring machine is 4 ft. 9 in. long, and the working cylinder (con-
structed of brass) is placed inside another cylinder of wrought iron, in which
it-is free to move to and fro, and also to rotate on its longitudinal axis. The
back end of the working cylinder is provided with elastic packing so as to be
air or steam tight. The front end fits into a wrought-iron cross head (in
which it is free to revolve). This cross head is slotted on each side to fit into
two slide bars, or it may be made to work on two screw guide bars. The
cross head slides along the slide bars or screw guide bars as the working
cylinder is moved along inside the iron cylinder in the process of boring.
The sides of the cross head, where it fits into the slide bars, project in front on
each side of the slide bars, between which are placed two cam bars, partly
forked on each edge of the slide bars. The other ends of the cam bars rest
in notches on the inner edge of the slide bars, and are constantly kept pressed
against the bottom of the notches by two spiral springs. The other end of
the cam bars, which work on centres, are curved towards each other, so that
the end of the piston rod may strike them at the proper time.
The operation of the parts may thus be explained:-The air, steam, or
other motive gas is admitted by a.pipe which leads from one of the trunnions
into the wrought-iron cylinder behind the back end of the working cylinder,
and thus keeps it pressed outwards against the cross head, which is kept in its
place or from going forward by the two cam bars, each of which rests against
one of the notches in the slide bars. It will thus be understood that when'
the tool has advanced into the hole, the end of the piston rod (the end of
which is allowed to go beyond its limit) comes into contact with the cams or
curved end of the cam bars, and thus causes them to slip over one notch into

page_text: the next, and this is repeated till the end notch is reached. This will allow
the tool to advance at whatever rate it is cutting, that is to say, when the
tool cuts rapidly, the cams will slip from one to another rapidly, but when the
tool cuts slowly the cams will be so much the longer in slipping from one
notch to another. On the two cam bars are two diagonal wedges; which are
pressed forward by spiral springs between the teeth of the slide bars and cam
bars, to steady the cam bars and keep them in the positions to which they are
raised by the end of the piston rod at each blow. The spiral springs are thus
prevented from pulling the cams to the bottom of the notches. The cross
head is provided with two copper breaks pressed upon the side of the slide
bars by powerful spiral springs regulated by a screw fitted with double
handles, for the purpose of. enabling the break to be regulated by hand to
prevent the cylinder and the cross head and cam bars from slipping too
violently from one notch to another. The double handles serve also to pull
back the whole by hand.when it is necessary to change the tool. The
chamber into which the air is admitted in the iron cylinder and behind the
working cylinder serves to contain a portion of air which will act as a cushion
to prevent the crystallization of the parts which are exposed to the direct
concussion of the blows, and also to relieve; such shocks upon the carriage
generally. At the back end of the working cylinder is a circular valve, with
six or more inlet ports and six or more exhaust ports. This valve is turned
by a double spiral cam which is carried in the end of the piston and rod, in
which are four rollers which bear on both sides of the spiral wings of the cam.
These spiral wings are.so sloped that upon the reciprocation of the piston the
latter will be gently turned or twisted, and with it the valve to which it is
connected. The slopes on: the spiral wings of .the cam are so placed as to
cause the valve to open, the inlet ports to admit the air to act upon the large
area of piston, and to allow it to exhaust again after the piston has struck a
blow, when it will return by a constant pressure upon the small area maiu-
tained through two separate passages, and vice versa. The piston is prevented
from turning in the cylinder, except when desired, by means of two flats
planed on each side, which fit into corresponding flats on. the bush and
stuffing glands of the cylinder, which are prevented by two steel rings from
turning in the cylinder. The rotary motion of the working cylinder with the.
piston and tool is effected by a square bar working. inside the cam or spiral
bar, which receives the same turn at each stroke of the piston as the valve.
On the end of the square bar, outside the end of the iron cylinder through
which it. is carried, is a double lever, at each end of which are. two pawls
working into a ratchet wheel. on the end of a shaft parallel to the cylinder.

page_text: This shaft is provided with a square part on which is a .brass pinion wheel
which works into a toothed wheel on the end of the working cylinder, and by
the ratchet causes it to rotate with the piston and tool. The brass pinion
slides along the square part of the shaft as the working cylinder is advanced
by the cams slipping over the notches.. It is, however, preferred to turn the
shaft. by hand; at the end of the two slide bars are two screws with steel
points for the purpose of steadying the end of the machine against the rock:
The end of the tool is steadied in a bearing across the end of the two slide
bars in order to compel the tool to bore straight, and it is so arranged
that upon turning a lever the top bearing or step can be easily lifted out when
the tool requires changing.
..
"
. In another arrangement two round two-threaded screw bars are used in
lieu of the slide bars with notches. On the two screw bars are two brass
bushes chased to fit the thread on the bars; the cross head on the end of the
working cylinder presses against the two bushes, which latter are prevented
from turning by four projecting pieces on each bush nut, one of which presses
against two cam bars, which upon being raised by the end of the piston rod
at the proper time will cause the projecting pieces then against the cam bars
to slip past. The pressure of the cylinder and cross head against the two
bush nuts will then cause the latter to turn round on the screw, when the
next projecting piece will come against the cams. The bush nuts will then
make one-quarter of a revolution, and allow the cylinder to advance of an
inch. The two bush nuts are provided with worm gear to wind the cylinder
back when necessary, and to act as breaks to prevent the nuts from turning
too violently from one projecting piece to another.
In the first arrangement of the slide bars with notches two screws having a
two-threaded pitch can be used in lieu of the breaks, and are used to wind
the cylinder back in the same manner as described above, but the slide bars
and notches 'are retained.
.
The machine can be arranged for coal cutting on either system, and so
modified that in driving adits or headings, or working coals, stoop and
room,"
," where the roof is dangerous, it will cut and trench 3 feet deep all
round the sides by a traversing motion in addition to the percussive blows,
while at the same time a central hole can be bored and widened at the
bottom in the usual way, which on being blasted will dislocate the whole mass;
and if it be objectionable to blast, as. in some coal mines, the mass may be
dislocated by driving wedges in the trench. In the long-wall, system of
holeing or kirving coal the machine can be adapted to, cut a continuous trench
along the bottom of the seam, by which two successive displacements of coal

page_text: can be effected, each three feet long before the rails need be shifted nearer
to the face of the working. In addition to the above vertical and angular
cutting may also be effected by machine, and all the movements made self-
acting if desired.
The machine when adapted for tunnelling purposes consists of a pillar or
column mounted on a low traversing carriage frame. The machine is
clamped securely betwixt the top and bottom of the tunnel in the following
manner: The column is bored out and fitted with solid pistons at top and
bottom. Air, steam, or other gases are admitted between the two pistons and
cause them to strike outwards against the roof and bottom of the tunnel;
when they are secured by means of catches dropped into teeth cast on the
pistons. By another method racks are cast on the two pistons, into which
pinions work, and on each side of the pistons are two ratchet wheels, into
which a catch drops at whatever position the pistons may be shot out, thus
securing them in their position. On each end of the shafts which carry the
pinions and ratchet wheels is a square, upon which a ratchet lever may be
placed if desired, so as to put an extra pressure by hand outward, assisted by
the compressed air, steam, or other gases, and by reversing the catch on the
ratchet lever the pistons will be brought back when necessary to change the
carriage frame. The column has a central boss in which a hollow spindle
passes; this spindle has a circular motion given to it by a worm and worm
wheel, so as to adjust the frame which carries the jib and pivot with a ball-
and-socket joint for supporting the working cylinder, and bringing it round to
any part of the face of the tunnel. It can also be moved longitudinally by a
screw and hand wheel without removing the carriage frame. The object of
this arrangement is to permit the heading to be driven beyond the portion the
rails may be laid, so as to obviate the necessity of laying down short rails.
The frame consists of two columns, each of which is fitted with piston clamps,
the same as those described for the other column, to secure them between
any part of the sides, or top and bottom of the tunnel, but in this case extra
pipes are brought to the other sides of the pistons to bring them back, so
that if necessary a few blows can be given to the piston clamps, in order
that they might make themselves recesses in the rock to fit into, so as to
prevent them from slipping hold. The pinions working into the two racks of
these pistons are in this case placed side by side, one being in 'a solid shaft,
and the other on a hollow one working round the same solid shaft. One
pinion is geared into one rack on one side, and the other into the other rack
on the other side, so that each motion is separate, although on one shaft, so
that one piston clamp may go out further or less than the other, according to

page_text: the varying surface of the rock. There are two combined capstans! and
ratchet wheels with catches, one being 'keyed on a solid shaft and the other
on the hollow shaft, for the purpose of assisting the compressed air or other
gases to press the clamps against the rock by a lever when they are secured by
the catches' locking the ratchet wheels. A jib is fitted: on the double:column
and rest, and can be adjusted radially by two screws and. a 'hand wheel.:.-In
this jib is a conical pivot carrying a ball-and-socket joint for carrying the
boring cylinder. The conical pivot can be turned-round by a worm and worm
wheel actuated by a hand wheel, the same hand wheel, by being put into gear
with another mitre wheel, works a worm and worm nut to tighten the conical
pivot (in any desired position) by drawing it into the conical bearing. All
these movements will enable the working cylinder with: its jumper to bore
holes in the exact line the miner may wish; and all-the movements are central
and within easy reach of the attendant, in whatever direction or position the
boring cylinder may be, or at any possible angle in either direction.
"
By this arrangement greater space is gained around the machine, so that
all parts may be more readily reached. The debris may also be removed whilst
the machine is at work, and all the various movements are within easy
reach, and at all times central. Also greater: expedition in clamping and
making the machine fast is gained by the piston clamps acted upon by the
compressed air or other gases, and so soon. as the catches lock the piston
clamps the air is shut off.
When the machine is adapted to the "long-wall" system of getting coal it
is provided with two columns placed ten feet apart. It is supported on wheels,
and connected by two screw bars of double thread, as well as by two plain
bar stays at top. Each of the columns are fitted with piston clamps acted
upon by compressed air or other gases, for the purpose of keeping the clamps
against the roof and bottom of the cutting; they are also provided with a lever
and capstan with ratchet wheel and catches to secure the same. :On two screw
.bars is mounted a pivot table by two bush nuts chased to fit the screw bars.
These bush nuts are secured on each side of the pivot table by collars, but they
are free to revolve. On one end of each bush nut are ratchet wheels actuated
by a pawle; which gets its motion from the piston rod by means of a connecting
rod. This arrangement causes the pivot table to move with the working
cylinder along the two screw bars in the progress of cutting the trench. The
working cylinder has a conical pivot or trunnion, which fits into the female
pivot in the pivot table; the cylinder is also fitted with a worm, which
gears into a quadrant worm wheel cast on the pivot table. This arrangement
allows the cylinder with the tool to commence cutting the trench at an angle,

page_text: when it is gradually turned in till it is at right angles to the screw bars, when
the pawle working the ratchet wheels on the bush nuts is put into gear by the
connecting rod attached to the piston rod; this will move the cylinder and
tool with, the pivot table about inch per stroke, and 18 inches. deep along
the trench at the bottom of the coal seam till the end of the screw bars are
reached, when the pawle is disconnected, and the cylinder will bore a hole 18
inches deeper. The two cylinders and valve motion are the same as in the
former machine, but without, the, turning motion. The screw guide bar of
double. thread in this case is placed along the outside of the cylinders, and
fits into a female screw cast upon the working cylinder. The male screw.
guide bar is caused to turn and go forward by the pressure of the working
cylinder against it, upon being released by a catch coming in contact with the
bottom of the slot in the piston rod. Upon the completion of the hole 18
inches deep, or with the 18 inches previously opened, 3 feet altogether, the
5 pawle is again put into gear and the catch reversed, when the cylinder with
the tool will travel back, cutting the second course 18 inches deep, and com
pleting the trench to 3 feet deep till the other end is reached, when the whole
machine is shifted forward 10 feet and re-clamped, so as to continue the
cutting of the trench. The tool always finishes at the front end, and is ready.
to commence the next division of the trench (after the machine is shifted), the
cylinder being drawn back by a hand wheel on the male screw guide bar. It
will be understood that the tool is serrated and stepped in four divisions, one
projecting inch beyond the other as they become nearer to the cylinder end,
or, in other words, each step recedes inch till the end is reached. This
5 allows the whole depth of 18 inches to be cut in four ledges at once.
.
This arrangement is also adapted for cutting rectangular trenches in
headings, and "stoop and room" workings, by adapting the carriage frame
differently, so as to allow one or more cylinders to cut up the sides as well as
the horizontal cut at bottom.
.
0 The objects gained by the above coal-getting machine are that rails are not
necessary, thereby saving the time occupied in laying them. The machine is
perfectly steady at work by means of the powerful clamps and the air cushion
behind the working cylinder, therefore the tool will not jam in the trench, as
it so often does in others. The cutting of the trench being self-acting will
5 be more equal and the blows will be equalized..

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Low in the Great Seal Patent Office on the 5th
January 1866.
.i
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
Low, of Dublin, in the Kingdom of Ireland, Engineer, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of July, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said George Low, Her special licence that I, the said. George. Low,. iny
executors, administrators, and assigns, or such others as I, the said George.
Low, 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 "IMPROVED MACHINERY FOR BORING
ROCKS AND HARD SUBSTANCES," upon the condition (amongst others) that I, the
said George Low, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-
ticularly 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 imme
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Low, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawings hereunto annexed, and to the
letters and figures marked thereon (that is to say):
This Invention of "Improved Machinery for Boring Rocks and Hard
Substances "relates, firstly, to various improvements upon my Patent-of April,
One thousand eight hundred and sixty-three, No. 903.
"
The first improvement under this head relates to the general arrangement
of the cylinder and boring motion, by which the tool as it bores into the rock
is advanced or moved forward. This is effected by means of the same agent
which works the tool by pressure. By this means the ordinary gearing is.
dispensed with, and the durability of the machine is therefore greatly
increased.
The second improvement consists in providing a cushion of compressed air,

page_text: steam, or other elastic gas behind the working cylinder and elsewhere, by
which the crystallization of the parts exposed to the direct line of percussive
blows is effectually prevented, and also the whole machine is rendered moro
steady against such shocks.
The third improvement relates to the turning motion, which is imparted to
the tool in the stationary cylinder, instead of to any of the reciprocating or
moveable parts. The durability of the machine is thus increased, as it has
been found that when the turning motion is adapted to the reciprocating part.
the rapidity of the blows of the tool knock this part of the machine to pieces,
or otherwise derange the working parts.
'
. The fourth improvement relates to the advancement of the tool as it bores..
This is effected exactly in the same ratio as the tool cuts the hole, whether
the rock be hard or soft.
.
In the accompanying Drawing, Fig. 1, Sheet I., is a plan view, and Fig. 2.-
a sectional elevation, of a boring machine constructed according to my present...
improvements.
The boring machine is four feet nine inches long, and the working cylinder a
(constructed of brass) is placed inside another cylinder 6 of wrought iron, in
which it is free to move to and fro, and also to rotate on its longitudinal axis.
The back end of the working cylinder a is provided with elastic packing a', a',
so as to be air or steam tight. The front end of the cylinder fits into a
wrought-iron cross head d (in which it is free to revolve on its longitudinal
axis). This cross head is slotted on each side to fit into two slide bars e, e,
or it may be made to work on two screw guide bars, as shewn in Sheet II.,
which will be presently described. The cross head d slides along the slide
bars or screw guide bars e, e, as the working cylinder a is moved along
inside the iron cylinder 6 in the process of boring. The sides of the
cross head d, where it fits, into slide bars e, projects in front on each
side of the slide bars, between which are placed two cam bars f, f, partly
forked on each edge of the slide bars, as seen in the detached sectional view
Fig. 5. The other, ends of the cam bars f, f, rest in notches 9, 9, on the
inner edge of the slide bars e, e, as seen best in Fig. 1, one of the bars being
shewn in section.. The cam bars are constantly kept pressed against the
bottom of the notches 9,.9, by two spiral springs h, h. The other end of
the cam bars f,.f, which work on centres i, i, are curved towards each other,
so that the end of the piston rod c may strike them at the proper time.
The operation of the parts may thus be explained: - The air, steam, or,
other motive gas is admitted by a pipe k, which leads from one of the
trunnions into the wrought-iron cylinder 6 behind the back end of the working

page_text: cylinder a, and thus keeps it pressed outwards against the cross head d, which
is kept in.its'place or from going forward by the two cam bars f, f, each of
which rest against one of the notches 9, 9, in the slide bars e, e. It will thus
be understood that when the tool c' has advanced into the hole, the end of
the piston rods (the end of which is allowed to go beyond its limit) comes
into contact with the cams or curved end of the cam bars f, f, and thus cause's
them to slip over one of the notches ginto the next notch, and this is repeated
till the end notch of the bars e, e, is reached. This will allow the tool s' to
advance at whatever rate-it is cutting, that is to say, when the tool cuts
rapidly the camsf will slip from one notch. 9. to another rapidly, but when
the tool cuts slowly the cams will be so much the longer in slipping from one
notch to another. On the two cam bars ƒ are two diagonal wedges m,. m,'"
which are pressed forward by spirál or other springs placed between the teeth
of the slide bars e and the cam bars f, so as to steady the cam bars and keep
them in the positions to which they are raised by the end of the piston rod at.
each blow. The springs behind the wedges m are thus prevented from pulling
the cams f to the bottom of the notches g until the cams slip over the notch,
when the ends of the diagonal wedges m, m, come against the notch, and will
thus be pushed back into their normal position again. The cross head d is pro-
vided with two copper breaks n, see sectional view, Fig. 6, which are. pressed
upon the side of the slide bars e by powerful spiral springs n', regulated by a
screw fitted with handles, for the purpose of enabling the break to be
regulated by hand, so as to prevent the cylinder and the cross head and. cam
bars from slipping too violently from one notch to another. The handles on
the screw o serve also to pull back the cylinder and its appendages by.hand
when it is necessary to change the tool. The chamber or space a², into which
the air is admitted in the iron cylinder b, and behind the working cylinder a,
serves to contain a portion of air which will act as a cushion to prevent the
crystallisation of the parts which are exposed to the direct concussion of the
blows, and also to relieve such shocks upon the carriage generally. At the
back end of the working cylinder is a circular valve p, p, with six or more
inlet ports and six or more exhaust ports, as shewn in the detached sectional
view; Fig. 4. This valve p is turned by a double spiral cam q, which is
carried through the end of the working cylinder a...The piston rod c carries
four rollers o, o, which bear on both sides of the spiral webs or wings of the
cam q. These spiral webs or wings are so sloped that. upon the reciprocation
of the piston the cam 9 will be gently turned or twisted, and with it the
valve p, to which it is connected, and also the boring tool c' at the other. end
of the piston rod. The slopes on the spiral wings of the cam 2 are so placed

page_text: as to cause the valve p to open the inlet ports to admit the air to act upon
the large area of the piston, and to allow it to exhaust again after the piston
has struck a blow, when it will return by a constant pressure upon the
small area maintained through two separate passages, and vice versa. The
piston is prevented from turning in the cylinder a by means of two flat
places c, c, Fig. 6, which are planed on each side of the piston. These flat
sides fit into or against corresponding flat places made on the bush and
stuffing glands of the cylinder. These glands are prevented by two steel pins
from turning in the cylinder. The rotary motion of the working cylinder a
with the piston c and tool is effected by means of a square bar s, Figures 2 and 4,
working inside the cam or spiral bar q, which receives the same turn as the
valve p at each stroke of the piston. On the end of the square bar s, outside
the end of the irou cylinder 6 through which it is carried; is a double. lever t,
at each 'end of which are two pawls t¹, t, working into a ratchet wheel u on
the end of a shaft v parallel to the cylinder. This shaft vis provided with a
square part,' on which is a brass pinion wheel w, which works into a toothed
wheel a' on the end of the working cylinder, and; by the ratchet wheel u,
worked by the pawls t¹, t¹; causes it to rotate with the piston c and the
boring tool. The brass pinion w slides along the square part of the shaft v
as the working cylinder a is advanced by the cams f slipping over the notches
g of the side pieces e, e; it is, however, preferred to turn the shaft v by hand.
At the end of the two slide bars e are two screws with steel points, for the
purpose of steadying the end of the machine against the rock. The end of
the boring tool c¹ is steadied in a bearing j across the end of the two slide
bars e, in order to compel the tool to bore straight, and it is so arranged that
upon turning a lever y the top bearing or step j¹ can be easily lifted out when
the boring tool requires changing.
•
In the arrangement shewn in Sheet II. of the Drawings, two round two-
threaded screw bars e are used in lieu of the slide bars 'e, with notches'g, in the
arrangement already described; Fig: 1 is a plan view; and Fig. 2 is a sectional
elevation, Figures 3 and 4 are cross sections of this modification. On the two
screw bars e are two brass bushes f, chased to fit the threads on the screw
bars e, and therefore act as substitutes for the cam bars and notch arrange-
ment shewn in Fig. 1. The cross head d on the end of the working cylinder a
presses against the two bushes f, which are prevented from turning by four
projecting pieces f¹, f¹, on each bush nut, one of which presses against two
catches on the bar'h, which upon being raised by the end of the piston rod c
at the proper time will cause the projecting pieces f³, f, then against the
catches on the bar h, to slip past. The pressure of the cylinder a and cross

page_text: head d against the two bush nuts f, f, will then cause the latter to turn a
quarter round on the screw bars e, when the next projecting piece f¹ will
come against the catches on the bar h. The bush nuts f will then make one-
quarter of a revolution, and allow the cylinder to advance three-quarters of
an inch. The two bush nuts f, f, are provided with worm gear 9, g, to wind
the cylinder back when necessary, and to act as breaks to prevent the nuts
from turning too violently from one projecting piece f¹ to another.
In the arrangement of the slide bars e with notches, as shewn in Sheet I.,
two screws having a two-threaded pitch, such as the arrangement shewn at g
in Sheet II., can be used in lieu of the breaks n, o, Figures 2 and 6, Sheet I.,
and are used to wind the cylinder back in the same manner as just described
in reference to the arrangement shewn in Sheet II., but the slide bars e and
notches g of Sheet I. are retained.
In Sheet III. I have shewn another modification in which some of the
parts are simplified by dispensing with the arrangement for causing the
rotation of the piston rod and boring tool. Fig. 1 is a sectional elevation of
this arrangement, Figs. 2 and 3 are sections of the same, which consists of
a wrought-iron cylinder a, which forms both the working cylinder at one end
and also carries the tool holder at the other end. There are four longitudinal
openings 6, 6, extending from the tool end to the front end of the cylinder;
this allows the packing gland c with four wings fitting into the four openings b,
to enter the front of the cylinder and advance up to the bush o, o, which is
fastened inside the cylinder. The ends of the longitudinal openings b, b, are
turned out in order to bolt the wings of the packing gland to the piston; the
valve and its motion are the same as in the arrangements already described,
but the air cushion, instead of being placed at the back end of the working
cylinder, is situated at the front end or near the cross head of the piston rod
and behind the hammer head d; the space for this air cushion is marked e,
and is made purposely of smaller diameter than the piston rod in order to
allow the hammer block d to spring in a little upon striking, so as to relieve
the back force of the blows off the hands of the operator, as this arrangement
is intended to be used as a portable hand-boring machine. The hammer
block d is constantly kept pressed out by the compressed air (which enters
the holes formed in the piston rod); the hammer block d is also prevented
from springing too far back by the plug g, which enters the air hole f¹, and so
confines the air in the cushion chamber e. The cross head p of the piston
fits into the four longitudinal openings 6, 6, so as to prevent it from turning,
and there are attached to it bars h, h, with spiral wings j, j, which fit into
and slide through two rings i, i, on each side of the ratchet wheel k, between

page_text: which is fitted a ratchet catch working into the teeth of the ratchet wheel k
and holding the tool. The reciprocation of the piston as it strikes the tool
causes the spiral wings j, j, to draw through the ratchet catch rings i, i, and
so turn them slightly, or to as great an extent the spiral wings will allow, thus
turning the ratchet catch rings i, i, and with them the ratchet wheel K, a
thirteenth part of a revolution at the back stroke; this will allow the ratchet
catch to slip into a fresh tooth at every forward stroke, and thus turn the tool
before every stroke. Although in this arrangement the piston rod strikes the
tool holder, in other arrangements the tool will reciprocate with the piston.
The cylinder is fitted with handles to hold the same by hand in any position
it is desired; to bore holes, one of the handles, which is cast on the cylinder
cover and is screwed into the back end of the cylinder, forms the pipe, to which
a flexible pipe is attached admitting the compressed air into the cylinder, and
is fitted with a circular stop valve n having eight ports; this valve is actuated
by the forefinger pressing on the trigger lever r, so as to admit air at pleasure
to work the machine; a spring keeps the valve shut. Upon the tool being
taken out and a die inserted the machine can be used for rivetting and shaping
purposes.
The machine can be arranged for coal cutting on either of the systems
shewn in Sheet I. or II., and may be so modified that in driving adits or
headings or working coals ("stoop and room"), where the roof is dangerous it
will cut and trench three feet deep all round the sides of a traversing motion
in addition to the percussive blows, while at the same time a central hole can
be bored and widened at the bottom in the usual way, which on being blasted'
will dislocate the whole mass, and if it be objectionable to blast (as in some
coal mines) the mass may be dislocated by driving wedges in the trench. In
the long wall system of holeing or kerving coal, the machine can be adapted
to cut a continuous trench along the bottom of the seam, by which two suc-
cessive displacements of coal can be effected, each three feet long, before the.
rails need be shifted nearer to the face of the working. In addition to the
above, vertical and angular cutting may also be effected by machine, and all
the movements made self-acting if desired.
The machine when adapted for tunnelling purposes consists of a pillar or.
column mounted on a low traversing carriage frame. The machine is clamped.
securely betwixt the top and bottom of the tunnel in the following manner:'
-The column is bored out and fitted with solid pistons at top and
bottom; air, steam, or other gases are admitted between the two pistons and.
causes them to strike outwards against the roof and bottom of the tunnel.
This arrangement of carriage frame is shewn in elevation at Figure 1,

page_text: Sheet IV., Fig. 2 being a sectional end elevation; Figures 3, 4, and 5 are cross
sections of the same. The pistons c, c, in the supporting column a are secured
by means of catches
dropped into teeth cast on them. By another method
racks e are cast on to the two pistons c, c, as shewn at the lower piston of the
column a in Fig. 1. Pinions f, f, work into these racks e, and on each side
of the pinions are two ratchet wheels g, into which a catch drops at what-
ever position the pistons may be shot out, thus securing them in their position.
On each end of the shafts f¹, which carry the pinions f and ratchet wheels g,
is a square, upon which a ratchet lever may be placed if desired, so as to put
an extra pressure by hand outward, assisted by the compressed air, steam, or
other gases within the column a. By reversing the catch on the ratchet lever
the pistons c will be brought back when necessary, to change the carriage,
frame. The column a has a central. boss, in which a hollow spindle h passes..
This spindle h has a circular motion given to it by means of a worm i¹ and
worm wheel i, so as to adjust the frame j, which carries the jib and pivot, with
a ball-and-socket joint u for supporting the working cylinder k, and bringing
it round to any part of the face of the tunnel. The frame; can also be moved
longitudinally by a screw and hand wheel without removing the carriage
frame b. The object of this arrangement is to permit, the heading to be
driven beyond the place where the rails may be laid, so as to obviate
the necessity of laying down short rails. The frame ; consists of two
columns m, m, each of which is fitted with piston clamps, the same as those
described for the other column a, to secure them between any part of the sides
or top and bottom of the tunnel; but in this case extra pipes are brought to
the other sides of the pistons to bring them back, so that if necessary a few.
blows can be given to the piston clamps, in order that they might make,
themselves recesses in the rock to fit into, so as to prevent them from slipping
their hold. The pinions n,. n, working into the two racks o, o, of these
pistons m³, m³, are in this case placed side by side, one being in a solid shaft,,
and the other on a hollow one working round the same solid shaft; one
pinion n is geared into one rack o on one side, and the other into the other.
rack o on the other side, so that each motion is separate although on one
shaft, so that one piston clamp. may go out further or less than the other,
according to the varying surface. of the rock. There are two combined,
capstans p, p, and ratchet wheels with catches, one being keyed on a solid
shaft and the other on the hollow shaft for the purpose of assisting the com-
pressed air or other gases to press the clamps against the rock by a lever
when they are secured by the catches, which lock the ratchet wheels. A jib g
is fitted and rests on the double column, and can be adjusted radially by two

page_text: screws,, actuated by worm wheels and worm worked by a hand wheel s.
In this jib q is a conical pivot t, carrying a ball-and-socket joint u for carrying
the boring cylinder k. The conical pivot can be turned round by a worm
and worm wheel v, actuated by a hand wheel w, which when put into gear
with a mitre wheel w¹ works its shaft, and through it the worm and worm
nut v.
In order to tighten the conical pivot t (in any desired position) the
bevil pinion on the hand wheel shaft w is thrown into gear with another bevil
pinion on the end of the shaft y, which will actuate a screw nut on the end
of the conical bearing t, and will draw it up tight. All these movements will
enable the working cylinder k, with its jumper, to bore holes in the exact line
the miner may wish, and all the movements are central and within easy reach
of the attendant, in whatever direction or position the boring cylinder may be.
By this arrangement greater space is gained around the machine, so that
all parts may be more readily reached. The debris may also be removed
whilst the machine is at work, and all the various movements are within easy
reach and at all times central. Also greater expedition in clamping and
making the machine fast is gained by the piston clamps, which are acted upon
by the compressed air or other gases, and so soon as the catches lock the
piston clamps the air, &c. is shut off.
When the machine is adapted to the "long-wall" system of getting coal,
it is provided with two columns placed ten feet apart. This arrangement is
shewn at Sheet V., in which Fig. 1 is a plan view, and Fig. 2 a sectional
elevation. The machine is composed of two columns a, a, supported on
wheels b, b, and connected by two screw bars c, c, of double thread, as well
as by two plain bar stays at top. Each of the columns a, a, are fitted with
piston clamps d, d, acted upon by compressed air or other gases for the
purpose of keeping the clamps against the roof and bottom of the cutting.
They are also provided with a lever and capstan with ratchet wheel e, and
catches to secure the same. On the two screw bars c, c, is mounted a pivot
table f, by two bush nuts 9, 9, chased to fit the screw bars c, c. These bush
nuts are secured on each side of the pivot table f by collars, but they are free
to revolve. On one end of each bush nut 9, 9, are ratchet wheels h, h, actuated
by a pawle i, which gets its motion from the piston rod by means of a con-
necting rod j. This arrangement causes the pivot table f to move with the
working cylinder k along the two screw bars c, c, in the progress of cutting
the trench. The working cylinder k has a conical pivot or trunnions 7, which
fits into the female pivot in the pivot table f; the cylinder & is also fitted with
a worm m, which gears into a quadrant worm wheel n cast on the pivot
table f. This arrangement allows the cylinder k with the boring tool to com-

page_text: mence cutting the trench at an angle, when it is gradually turned in by means
of the worm wheel m and crank handle till it is at right angles to the screw
bars c, c, when the pawle i, which works the ratchet wheels h, h, on the bush
nuts g is put into gear by the connecting rod ; attached to the piston rod.
This will move the cylinder k and boring or cutting tool with the pivot table f
about half an inch per stroke and eighteen inches deep along the trench at
the bottom of the coal seam till the end of the screw bars care reached, when
the pawlo i is disconnected, and the cylinder k will bore a hole eighteen inches
deeper. The two cylinders and valve motion are the same as in the former
machine, but without the turning motion. In order to cut the hole eighteen
inches deeper, as above mentioned, the screw guide bar o, which is double-
threaded in this case, is placed along the outside of the cylinders k, and fits
into a female screw 2 cast upon the working cylinder. The male screw guido
bar o is caused to turn and go forward by the pressure of the working cylinder
against it, upon being released by a catch a coming in contact with the end
of the slot in the piston rod r. Upon the completion of the hole eighteen
inches deep, or with the eighteen inches previously opened (three feet alto-
gether), the pawle i is again put into gear and the catch is reversed, when the
cylinder with the cutting tool will travel back cutting the second course
eighteen inches deep, and completing the trench to three feet deep till the
other end is reached, when the whole machine is shifted forward ten feet and
re-clamped, so as to continue the cutting of the trench. The cutting tool
always finishes at the front end, and is ready to commence the next division
of the trench (after the machine is shifted), the cylinder being drawn back
by a hand wheel on the male screw guide bar. It will be understood that the
cutting tool is serrated and stepped in four divisions, as shewn in the Drawing
at Fig. 1, one division projecting half an inch beyond the other as they become
nearer to the cylinder end, or, in other words, each step recedes half an inch
till the upper end is reached. This allows the whole depth of eighteen inches
to be cut in four ledges at once.
This arrangement is also adapted for cutting rectangular trenches in
headings and "stoop and room" workings by adapting the carriage frame
differently, so as to allow one or more cylinders to cut up the sides as well as
the horizontal cut at bottom.
The objects gained by the above coal-getting machine are that rails are not
necessary, thereby saving the time occupied in laying them. The machine is
kept perfectly steady at work by means of the powerful clamps. The air
cushion behind the working cylinder will prevent the cutting tool from jam-
ming in the trench, as it so often does in other machines. The cutting of the

page_text: trench being self-acting will be more equal than heretofore, and the blows
will be equalized.
Having now described my Invention of improved machinery for boring
rocks and hard substances, and having explained the manner of carrying
the same into effect, I claim as the Invention secured to me by Letters Patent
as aforesaid, the general arrangement and construction of parts herein shewn
and described, or any mere modification thereof, for boring or cutting rocks or
other hard substances.
I claim particularly the mode or modes herein set forth of advancing the
tool in proportion to the speed at which it cuts its way into the rock, and of
advancing the tool by pressure instead of any kind of gearing.
I also claim the use of a cushion of air behind the boring or cutting tool
for the purpose of lessening the effects of the blows of the boring tool, and
preventing the shocks occasioned thereby from injuriously affecting the
working parts of the machine.
I further claim the mode or modes herein set forth for causing the rotation
of the boring or cutting tool during the boring operation.
I also claim the construction or arrangement of parts for mounting or
supporting the working mechanism as herein set forth, so that all the parts
thereof may be reached with facility, and space may be afforded for removing
the debris produced by the operations of the boring machinery.
In reference to the coal-cutting machine I claim, lastly, mounting and
arranging the mechanism, as herein set forth, for the purpose of enabling the
tool to cut forward a considerable distance without the necessity of too frequent
removals of the whole machine, or requiring the use of rails or tramways.
In witness whereof, I, the said George Low, have hereunto set my
band and seal, the Third day of January, in the year of our Lord
One thousand eight hundred and sixty-six.
Witness,
J. M. MURRAY,
35, College Green, Dublin,
Not. Pub.
GEORGE LOW. (L.S.)