IMPROVEMENTS IN ROCK BORING, TUNNELLING, AND SHAFT SINKING, AND IN MACHINERY TO BE USED FOR THESE PURPOSES
Year: 1876

page_text: LETTERS PATENT to Herbert Newton Penrice, of Hatfield, in the County of
Herts, for the Invention of "IMPROVEMENTS IN ROCK BORING, TUNNELLING,
AND SHAFT SINKING, AND IN MACHINERY TO BE USED FOR THESE PURPOSES."
d the 15th August 1876, and dated the 25th February 18
PROVISIONAL SPECIFICATION left by the said Herbert Newton Penrice at
the Office of the Commissioners of Patents on the 25th February 1876.
"IMPROVE-
HERBERT NEWTON PENRICE, of Hatfield, in the County of Herts.
MENTS IN ROCK BORING, TUNNELLING, AND SHAFT SINKING, AND IN MACHINERY TO
BE USED FOR THESE PURPOSES."
This Invention has for its object the formation of tunnels and shafts in rock more
quickly than heretofore practicable. This I effect partly by the manner in which I
form a tunnel and partly by so constructing the boring machinery that a greater
amount of power may be employed to effect the boring relatively to the size of the
bore.
Heretofore it has been proposed to form tunnels by employing a ram armed with
chisels, and receiving a reciprocating motion to cut a large annular groove, and
afterwards removing the core, and this core requiring to be broken up by miners
before it could pass the machine.
The machinery which I employ operates in this manner to cut a much smaller
hole, which is subsequently enlarged before the core is removed. In order to
ensure the ample power requisite for rapid progress I construct the cylinder or
cylinders used for giving motion to the ram and cutting head of a diameter nearly
equal to that of the annular groove cut by the head, and I enlarge the upper part
and sides of the bore in advance of the cylinders as the work progresses. The
enlargement is effected by means of holes formed at the sides and top of the bore.
To produce these holes three or more arms are fixed to the ram behind the cutting
head, and each arm carries a long chisel or tool. I prefer to employ a chisel or tool
which does not require to be turned, and which consists of an open ring punch,
with cutting edges passing across the ring, and leaving open channels for the debris
to pass. These holes may also be drilled in some cases by independent machines.
The main groove and the holes at the sides and above it proceed simultaneously, and
when some feet have been cut the machine is withdrawn and the holes around the
main groove receive small charges of dynamite, gunpowder, gun-cotton, or other

page_text: explosive. The charged holes are closed with 3 long steel wedges made to fit them
and inclined in opposite directions. When the charges are fired the centre wedge
is forced between the other two, the rock yields, and is pressed out laterally from
the side holes and then vertically from the top hole into the groove of the main bore.
The direct explosion of the dynamite or other explosive used suffices in most cases
to shatter the small core. The lower part of the bore is always preserved as the
bottom, so that the machine can be moved to and fro along it in a straight line. When
the material has been removed the machine is again moved forward to continue its
work. It will be seen that by constructing a bore in the manner above described a
very small proportion only of the material to be removed has to be pulverized, and
that the bulk of the material can be removed in comparatively large pieces, by
which the amount of work required to win a large bore is greatly reduced.
The apparatus I employ for cutting the bore is constructed as follows:-The
cutters for cutting the annular groove act percussively, and travel slowly around the
groove. The cutters consist of a series of chisels set .close together in the circum-
ference of a cylinder, except that two spaces are left for the escape of debris, and
for the passage of tubes for conveying water to wash out the annular groove and
cool the tools. The chisels are held by wedges in a massive cutter head, and the
wedges are locked by right and left hand nuts, over which again a keep is slidden.
The edges of the chisels are placed circumferentially and alternately nearer to and
farther from the centre, so that they actually chase two separate grooves close
together, from between which the rock flakes away as the work progresses. Thus
the quantity of rock which has actually to be pulverized in forming the bore is
reduced to a minimum.
The cutter holder or head is rapidly driven to and fro at the same time that it is also
slowly rotated; the cutter head is carried by a strong piston rod or ram, which passes
back through two or more cylinders, and carries pistons to work in each cylinder.
The forward end of one of these cylinders is kept constantly in communication with
the supply of compressed air or steam by which the engine is worked. The forward ends
of the other cylinders are open, and the back ends of all the cylinders are alternately
opened to the compressed air or steam supply and to the exhaust by valves worked
by a separate engine at the rear end of the machine. By this means the cutter
head is moved to and fro with short quick strokes, and any desired amount of
power can be applied to it, according to the number of cylinders employed. In rear
of the last cylinder the ram passes through an internal toothed wheel, by means of
which a slow revolving motion is given to it. In rear of this wheel is a small
engine worked by compressed air or steam. The crank shaft of this engine is at
right angles to the ram, and has upon it a worm gearing into a worm wheel upon a
strong shaft, which at its rear end can be clutched to the end of a long screw which
passes backwards from the rear end of the machine, and working in a long nut
very firmly fixed to the rock; by this means the machine is moved forwards or
backwards. The shaft at its forward end carries a pinion to drive an intermediate
shaft, from which motion is transmitted to the internal toothed wheel before men-
tioned, which is to give the slow revolving motion to the ram.
The small engine at the rear end of the machine also gives a to-and-fro motion to
slide valves, by which compressed air or steam is alternately admitted to and
allowed to escape from the back ends of all the cylinders used for giving the to-and-
fro motion to the ram. This slide valve is constructed in such a manner that the
cutter head is caused to make two strokes for each revolution of the small engine.
Inclined shafts may be sunk by the same apparatus, and for vertical shafts a
suspended machine may be employed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Herbert Newton Penrice in the Great Seal Patent Office on the 25th
August 1876.
"
IMPROVE-
HERBERT NEWTON PENRICE, of Hatfield, in the County of Herts.
MENTS IN ROCK BORING, TUNNELLING, AND SHAFT SINKING, AND IN MACHINERY TO
BE USED FOR THESE PURPOSES."
This Invention has for its object the formation of tunnels and shafts in rock more
quickly than heretofore practicable. This I effect partly by the manner in which I
form a tunnel and partly by so constructing 'the boring machinery that a greater
amount of power may be employed to effect the boring relatively to the size of the
bore.
Heretofore it has been proposed to form tunnels by employing a ram armed with
chisels and receiving a reciprocating motion to cut a large annular groove, and after-
wards removing the core, and this core requiring to be broken up by miners before
it could pass the machine.
The machinery which I employ operates in this manner to cut a much smaller
hole, which is subsequently enlarged before the core is removed. In order to ensure
the ample power requisite for rapid progress I construct the cylinder or cylinders
used for giving motion to the ram and cutting head of a diameter nearly equal to
that of the annular groove cut by the head, and I enlarge the upper part and sides
of the bore in advance of the cylinders as the work progresses. The enlargement is
effected by means of holes formed at the sides and top of the bore. To produce.
these holes three or more arms are fixed to the ram behind the cutting head, and
each arm carries a long chisel or tool. I prefer to employ a chisel or tool which does
not require to be turned, and which consists of an open ring punch with cutting
edges passing across the ring, and leaving open channels for the debris to pass.
These holes may also be drilled in some cases by independent machines. The main
groove and the holes at the sides and above it proceed simultaneously, and when
some feet have been cut the machine is withdrawn and the holes around the main
groove receive small charges of dynamite, gunpowder, gun-cotton, or other explosive..
The charged holes are closed with three long steel wedges made to fit them, and
inclined in opposite directions. When the charges are fired the centre wedge is
forced between the other two, and is pressed out laterally from the side holes, and
then vertically from the top hole into the groove of the main bore. The direct
explosion of the dynamite or other explosive used suffices in most cases to shatter
the small core. The lower part of the bore is always preserved as the bottom, so
that the machine can be moved to and fro along it in a straight line. When the
material has been removed the machine is again moved forward to continue its
work. It will be seen that by constructing a bore in the manner above described a
very small proportion only of the material to be removed has to be pulverized, and
that the bulk of the material can be removed in comparatively large pieces, by
which the amount of work required to win a large bore is greatly reduced.
The apparatus I employ for cutting the bore is constructed as follows:-The
cutters for cutting the annular groove act percussively and travel slowly around the
groove. The cutters consist of a series of chisels set close together in the circum-
ference of a cylinder, except that two spaces are left for the escape of debris and for
the passage of tubes for conveying water to wash out the annular groove and cool
the tools. The chisels are held by wedges in a massive cutter head, and the wedges
are locked by right and left hand nuts, over which again a keep is slidden.
The edges of the chisels are placed circumferentially and alternately nearer to and
farther from the centre, so that they actually chase two separate grooves close
together, from between which the rock flakes away as the work progresses. Thus
the quantity of rock which has actually to be pulverized in forming the bore is.
reduced to a minimum.
The cutter holder or head is rapidly driven to and fro at the same time that it is
'

page_text: also slowly rotated; the cutter head, is carried by a strong piston rod or-ram, which
passes back through two or more cylinders, and carries pistons to work in cach
cylinder. The forward end of one of these cylinders is kept constantly in com-
munication with the supply of compressed air or steam, by which the engine is
worked. The forward ends of the other cylinders are open and the back ends of all
the cylinders are alternately opened to the compressed air or steam supply and to
the exhaust by valves worked by a separate engine at the rear end of the machine.
By this means the cutter head is moved to and fro with short quick strokes, and
any desired amount of power can be applied to it, according to the number of
cylinders employed. In rear of the last cylinder the ram passes through an internal
toothed wheel, by means of which a slow revolving motion is given to it. In rear
of this wheel is a small engine worked by compressed air or steam. The crank
shaft of this engine is at right angles to the ram, and has upon it a worm gearing
into a worm wheel upon a strong shaft which at its rear end can be clutched to the
end of a long screw which passes backwards from the rear end of the machine, and
works in a long nut very firmly fixed to the rock; by this means the machine is
moved forwards or backwards. The shaft at its forward end carries a pinion to
'drive an intermediate shaft, from which motion is transmitted to the internal
toothed wheel before mentioned, which is to give the slow revolving motion to the
ram.
The small engine at the rear end of the machine also gives a to-and-fro motion to
slide valves by which compressed air or steam is alternately admitted to and
allowed to escape from the back ends of all the cylinders used for giving the to-and-
fro motion to the ram. This slide valve is constructed in such a manner that the
cutter head is caused to make two strokes for each revolution of the small engine.
Inclined shafts may be sunk by the same 'apparatus, and for vertical shafts a
suspended machine may be employed.
In order that my said Invention may be most fully understood and readily carried
into effect I. will proceed to describe the Drawings hereunto annexed.
Figure 1 is a plan of a machine constructed according to my Invention. It is
adapted for tunnelling and shaft sinking in hard rock. Figure 2 is a longitudinal
section of the same.
Figures 3, 4, and 5 are transverse sections taken on the lines A, B, C, D, and E, F,
in Figure 1 respectively. Figure 6 is an end elevation.
a, a, is the main frame or bed of the machine; its form on the under side is semi-
cylindrical, and its curvature is the same as that of the groove left at the bottom of
the hole by the cutting head, so that the machine when at work rests with perfect
steadiness in this groove, and when moved forward maintains a true line with but
little care on the part of the workmen. a¹, a², a³, are three cylinders; they are
made in two parts, and the lower portions are cast with the frame. In each of the
cylinders there is a piston, and these pistons are formed on the ram b, which, when
actuated by compressed air or steam admitted to the cylinders, traverses to and fro
for a short distance in the bearings in which it is carried. On the end of the ram
is the head b¹, in which the chisels c are fixed. An annular groove is formed in the
head to receive the rear ends of the chisels which are shaped to a dovetail form, and
when inserted into the groove they butt solidly one against the other. The chisels
are held in their places by two curved wedge pieces, which are drawn home and
locked each by two nuts, one right-handed and one left-handed, screwed on to their
stems; these nuts are prevented from shaking loose by a metal keep outside both
the nuts, which is retained in its place by a rim on the outer nut, and an india-
rubber ring or spring over the inner nut. Gaps are left in the ring of chisels, one
on each side, say, for one-sixth of the circumference or rather less, so that the chisels
may be put in with facility and a free escape afforded to the debris. Along these
spaces also water pipes, not shown in the Drawings, are led, and jets of water under

page_text: heavy pressure are thrown into the groove cut in the rock to wash away the debris.
The stems of the chisels are so formed that they fit closely the one to the other, and
it is better that their sides should be shaped so as to lock together in such a way as
to prevent the stems bending independently of the chisels on either side. The
chisels are hooped together near their cutting edges. Filling pieces are inserted into
the gaps in the ring of chisels both where they enter the head of the ram and
within the hoop, care being taken in the latter case so to arrange them that they
may not interfere with the flow of water and debris. The edges of the chisels, it
will be observed, are set circumferentially and alternately on the inner and outer
side to the annular groove which they cut, so that the actual cuts are very narrow
and the rock flakes away between them, or, if necessary, a shorter cutter may be
introduced to clear away any ridge which may form. d, d, are arms firmly
connected with the head, but in such a way that the head can rotate independently
of them; they carry at their ends tool holders d', which pass through guides to
steady them as they slide to and fro. In these tool holders the borers e, e, are fixed;
they are chisels with cutting edges of peculiar form, a cross with a ring around it,
and there are openings for the passage away of the debris in the spaces between the
cross cutting edges. These tools penetrate the rock simultaneously with the cutting
head. They may be made to rotate if necessary. A strong jet of water is thrown
into the holes which they produce to wash away the debris. The tool may con-
veniently be made hollow for the passage of the water. The compressed air or
steam to actuate the ram is admitted to the cylinders a¹, a², a³, by means of three
valves. A longitudinal section of one of them is shown full size at Figure 7, and a
transverse section at Figure 8. These valves are connected directly to the piston
rod of a donkey engine; the crank shaft of which is seen at f. Each traverse of the
valves admits and exhausts the air or steam to and from the cylinders, so that the
strokes of the ram occur twice as frequently as those of the donkey engine. The
return of the ram each time the exhaust is opened results from the cylinder a¹ being
closed at the front and a constant back pressure of air or steam being maintained on
the front of the piston. In practice the ram may thus conveniently in some cases
be worked at a speed as high as 600 strokes a minute, or even more.
The ports leading to the cylinders are double, and the valves are made to corre-
spond, as it is essential to rapid working that the air or steam passages should be as
free as possible. fl is the cylinder of the donkey engine; its piston drives the crank
shaft fin the usual way by a connecting rod. An eccentric on the crank shaft works the
valve. is a worm on the crank shaft; it drives a worm wheel g, on the shaft of
which is a pinion g¹ driving a wheel h, which, when held in gear by a clutch, drives
a pinion on its shaft, and this in turn gives motion to a wheel with internal
teeth i on a hollow axis carried in a bearing on the frame, and through which the
ram b passes.
The ram and the hollow axis engage together by means of grooves
and feathers, so that as the wheel i slowly rotates it carries the ram with it.
On the rear end of the shaft of the worm wheel g there is a clutch by which it
can be made to engage with a screw k, the fore end of which is held in a bearing on
the frame and the rear end works through a massive nut which is made fast in rear
of the machine. The nut is mounted on a block shaped to the curve of the groove
left in the rock by the cutting head. This block is jammed down in its place by a
screw-jack from above, and is strutted so as to prevent longitudinal movement by
screw struts both before and behind.
By the rotation of the screw k, obtained in the manner already described, the
whole machine can be moved at a comparatively rapid rate to and from the face of the
rock. When the machine is at work, however, a slower forward or feed motion is
required to move the frame forward at the rate at which the cutters are able to
penetrate the rock. The workman tending the machine makes it follow the progress
of the chisels by means of a hand wheel h², which, operating on a friction clutch,
serves to clutch and unclutch the toothed pinion ³ carried on the axis of the wheel h,
and the wheel h³ gears with a wheel of larger size on the axis of the screw k. A
little rod is connected with the hinder piston and leads back to the rear of the

page_text: machines; it serves as an indicator to inform the workman when to throw the feed
into and out of gear.
By the moans described the cuts are made to penetrate to a depth of four, five, or
more feet into the rock, according to the nature of the material, and then the
machine is drawn back a sufficient distance to be out of the way. Small charges of
dynamite or other explosive are then placed in the holes produced by the borers c,
and the holes are closed by clay or wedges, three steel wedges together forming a
cylinder being inserted into each hole with the base of the centre wedge towards
the charge. The two lateral charges are first fired, and immediately afterwards the
charge in the upper hole. The pieces of rock are brought back by a trolly working
on a temporary tramway laid down in one piece on the left-hand side of the
machine, and this having been done the machine is run back again to its work,
advantage having been taken of the delay to change the chisels and borers if it
should be found necessary. In this way very rapid progress can be made.
Figure 9 is a side elevation, and Figure 10 is a longitudinal section of a machine
adapted for sinking shafts; Figure 11 is an end elevation of the same. The machine
is so similar to that already described, and it is so clearly represented in the
Drawings, that it is unnecessary to describe the Drawings in detail, and it will
suffice to direct attention to those points in which differences of importance between
the two machines occur. The frame of this machine is not adapted to run in the
groove produced by the cutting head, but it is guided as the work progresses by
guide wheels fixed to it at either end.
The detail of one of these guide wheels is shown at Figure 12; it is furnished
with a strong spring, as is shown, enabling the wheel to yield to slight inequalities
in the surface over which it runs. These guide wheels are arranged to run in the
grooves left by the borers e, of which in this machine there are four in place of three.
One pair of borers, opposite the one to the other, are shorter than the others, and
the charges in the holes which they produce are fired first; they clear the way
for the more distant holes to operate efficiently. The machine is furnished with
but one air or steam cylinder, the circumstances admitting of this cylinder being
made of any size deemed requisite. The whole machine is suspended from the
screw, which at its upper end is held in a nut contained in a frame, which, by rigid
struts set up with screws, is firmly fixed in the centre of the shaft at a short dis-
tance above the machine. A portion of the weight of the machine may con-
veniently be borne by a wire rope passing over a pulley and having counter weights
attached.
Having thus described the nature of my said Invention, and the manner of per-
forming the same, I would have it understood that I do not confine myself to the
exact details described, but I claim,――
First. The construction of machinery for rock boring, tunnelling, and shaft
sinking, substantially as herein described.
Second. In a machine consisting of a ram with cutting head producing an annular
groove and a cylinder or cylinders for actuating such ram, the construction of the
frame of the machine of such a form as to fit within the said groove and be able to
traverse along it in a straight line, substantially as described.
Third. The combination with the ram and cutting head of borers boring holes at
suitable distances from the annular groove produced by the cutting head for the
purpose of forcing in the rock towards the main hole, substantially as described.
Fourth. The combination with the ram and cutting head and the bed frame of two
or more cylinders for actuating the said ram, substantially as described.
Fifth. The construction of the cutting head with cutters having their edges set
circumferentially to the annular groove they are required to cut, substantially as
described.
Sixth. The construction of the valve and the means of actuating it by the donkey
engine so that two strokes of the ram may be obtained for each stroke of the
donkey engine, substantially as described.

page_text: Seventh. The peculiar method of locking the nuts by which the chisels are
retained in the cutting head.
Eighth. The peculiar drill or borer e, giving a large wearing surface on the circum-
ference, ensuring a circular hole, cutting without the necessity of rotating, and
allowing the debris to pass through it.
In witness whereof, I, the said Herbert Newton Penrice, have hereunto set
my hand and seal, this Fourteenth day of August, One thousand eight
hundred and seventy-six.
HERBERT NEWTON PENRICE. (L.S.)