Improvements in Rock-drilling Machines.
Year: 1892

page_text: Date of Application, 4th June, 1892
Complete Specification Left, 14th Feb., 1893-Accepted, 18th Mar., 1893
PROVISIONAL SPECIFICATION.
Improvements in Rock-drilling Machines.
I, JOSEPH MURLEY of 115 Albert Road Morice Town, Devonport, in the County
of Devon, Engineer, do hereby declare the nature of this invention to be as
follows:-
My improvements are applicable to rock-drilling machines driven by stean or
compressed air, and consists of two parts, namely a metallic packing for the piston
rod, and the construction of the steam or air ways separate from the body of the
cylinder.
Referring firstly to the metallic packing; in place of the Tuck's or other packing
now employed around the piston rod, I insert in recesses formed for the purpose in
the brass bushing of the rod-chamber, three metal rings of conical section, the
centre ring being solid and accurately fitted to the rod, and the outer rings being
split, and made adjustable, so that when the stuffing box gland is screwed inwards
it forces a wedge shaped bush of metal against the outer split ring, and simul-
taneously forces the inner split-ring against a similar wedge shaped bush, whereby
both the rings are tightened on the piston-rod, and are made steam and air tight.
In this way grit is prevented from working up the rod as at present, and causing
leakage.
The second part of my improvements consists in making the steam or compressed
air ways to the cylinder separate to the actual body of the cylinder, and attaching
them thereto in some well known way.
The advantage of this alteration is that if as sometimes happens they become
broken or injured they can be repaired at small cost, whereas now the entire
machine becomes useless. Moreover should the pipes which convey the steam or
air be damaged, and no metal pipe be available I provide nipples for insertion into
the valve box and socket pieces of the cylinder, the outer ends of which nipples are
adapted for connecting to flexible tubing such as is supplied with the machine.
In this way a temporary feed pipe can be rigged up and the machine can be used
until a proper metal pipe can be procured.
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S. S. BROMHEAD,
97, Newgate Street, E.C., Agent for Applicant.
COMPLETE SPECIFICATION.
Improvements in Rock-drilling Machines.
1, JOSEPH MURLEY, of 115 Albert Road, Morice Town, Devonport, in the
County of Devon, Engineer, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This invention relates to machines for drilling rocks of the percussive type so
extensively used for mining and tunnelling purposes.
My improvements apply equally to rock-drilling machines, whether driven by
steam or compressed air, and consist of two parts, namely an improved metallic
packing for the piston rod, and an improved construction of the valve and arrange-
ment of the steam or air-ways, by which I make them separate from the body of
the cylinder, and enable the valve to work to and fro by steam or other fluid
pressure, and exhaust without the intervention of cams, tappers or other mechanical
contrivances.

page_text: I will now describe my improved rock-drill in detail, with reference
accompanying drawings; in which
to the
Fig. 1 shews a section taken length-ways of the cylinder and working parts of a
steam drill, with my improvements attached.
Fig. 2 shows a plan of the bottom of the valve-box as fixed on cylinder with the
top removed to shew ports.
Fig. 3 shows a side elevation of the wedge-shaped gland and packing rings on
piston rod.
Fig. 4 shows a nipple which may be applied with a flexible tube, in case either
of the feed pipes g, g¹, to cylinder become broken.
a is the main cylinder. b is the piston rod to which the boring bit is fixed, and
having a necks in the middle of its head. c is the piston valve. d is the piston of
the valve c, which moves to and fro therein. d', d, d³ are three recesses formed
on piston d, d', d³ being the annular inlet ports to the cylinder a through the
tubes, z, ¹, d² being the exhaust port to the atmosphere through the tube y.
e, e, are inlet tubes by which the steam or other fluid coming from fis admitted
into the valve c. g, g', are tubes by which the steam passes from valve c to
cylinder a. h, h, are four projecting ridges on the piston d which form the
boundaries of the recesses d', d³, d³, and have in their peripheries other recesses h¹
the object of which is to admit steam or compressed air and thus keep the valve
swimming in its chamber. i, is an exhaust passage, connecting with the atmosphere
and with the pipes i, . jj are two pipes leading from the chamber 1, 1, at the end
of the valve c, into the cylinder a, and exhausting into the atmosphere by means of
pipes, are two small restricted orifices of j; opening alternately by the
valve piston. and y are ports communicating respectively by passages, ¹, with
the two ends of the main cylinder. y is a port communicating with the atmosphere.
m is a coned split ring formed on piston rod b. n is a solid ring on same. o is
" is the
another coned split ring. p is a stuffing-box gland. 7 is the brass bushing.
nipple to be used in case of breakage. s is a neck on the piston b.
to
It will be seen that the valve c is constructed in the form of a piston, it has
three annular recesses d¹, d², d³, with four circular ridges that are recessed for a
passage of steam or other fluid to keep it swimming and the valve d is reciprocating
in the valve box c to which the steam or other fluid is admitted through the two
end recesses d', ds, and exhausts through the middle recess d. The valve box c
has two ports e, e, on top, and three other ports x, y, z, on the opposite side, two of
which and
X,
2, lead to the respective ends of main cylinder a, and the other Y,
the atmosphere. These ports are alternately opened and closed by the movement
of the valve piston d, and the steam or other fluid passes into and exhausts from
the two ends of the cylinder a, alternately, thereby imparting the required recipro-
cating movement to the main piston b, and to the boring bit fixed to the outer end
The valve motion is produced by allowing steam or other fluid to pass
into the recesses or chambers 7 at the end of the piston valve d. These two
recesses are in communication with the atmosphere by means of two small holes
or ports which are alternately opened or closed by the intervention of the moving
piston in the main cylinder a. The active pressure accumulates at one end of
the valve piston d and exhausts freely at the other end so that the valve d shoots
over into its proper position and effects continuously the movement of the main
piston rod b, to which the boring bit is fixed.
of same.
As the valve piston d reciprocates in the box c it puts the two ports e, e,
alternately by means of the grooves d, and d³, in the valve c, in communication
with the corresponding ports x, and 2, and thereby admits the air or fluid alter-
nately to the two ends of the main cylinder a, and it also puts these ports, a,
alternately in communication with the exhaust port y through the annular groove d
of piston valve so that the ends of the main cylinder a are alternately exhausted.
The reciprocating motion of the valve piston d is obtained by the steam or other
fluid leaking alternately through the two restricted passages j¹¹, into the chambers
or recesses 1, 1, at the respective ends of the valve. These two chambers.l, l, are

page_text: in communication with the atmosphere by means of two small ports jj leading to
the main cylinder by two holes or passages i¹, P, in the top of cylinder. The
ports and the openings ",, are alternately opened and closed by the main
piston b, that is to say each of the ports j is opened and put into communication
with the atmosphere by means of the passages i, 2, through the neck 8 of main
piston rod b, up through 1,, into main exhaust y and to the atmosphere as piston
comes opposite such ports and openings. The steam accumulates in one or
other of the recesses 1, 1, and exhausts freely from the other; the action being
alternate so that the piston valve dis shot over and effects the necessary changes
of movement of the main piston b. In the position of the parts as shewn in the
drawings the port e is in communication with the port and passage g and the
main piston has just completed its stroke to the left. The left hand end of
the main piston has just exhausted through the passage g and port x, groove d² in
the piston valve d and through port into the atmosphere. The steam is leaking
through the passage in the chamber and the other chamber 7 has already
exhausted through the port into necks of main piston through the opening,
into main exhaust y to atmosphere as shewn on plan of the bottom of valve box.
The steam entering the chamber will now cause the valved to shoot over so as
to admit steam through the port a and passage g to the left hand end of the main
cylinder a and put the right hand end in communication with the atmosphere
through the passage g', port, grooved in the valve through port y. During the
stroke of the main piston b which will now take place the tube will exhaust into
necks of main piston through the opening into the main exhaust y and thence
to the atmosphere; so by exhausting from the valve d to the main exhaust y the
advantage would be that the rock drill would work under water by applying a
rubber hose to the main exhaust y and the other end would be taken to the water's
surface and exhaust to the atmosphere.
In the second part of my improvements by applying my improved metallic
rings m, n, o, for packing two or three times longer life will be given to the piston
rod than if it is packed by Tuck's or any substance of packing, for the Tuck's
packing allows a lot of grit to enter so that it roughens the rod and makes an
escape of air which is required to do its work behind the piston b whereas the
metallic rings m, n, o, will clear all grit from the piston and keep it air tight and
smooth and keep the piston rod b from straining or bending when boring in a hole
in ground that lies at an angle as one often gets a half of the hole hard and the
other soft. My improved packing will cause an important saving in the con-
sumption of air. There are two coned split rings mo, with one coned washer or
collar and the rings are closed air tight by screwing the stuffing box gland p
towards the coned bushing g in the cylinder cover, whereby it closes the rings m, n, o,
on to the piston rod band at the same time closes the rings in the coned parts tight,
they being made male and female from gland p to the bushing q. The passages g
and 9' are short portable copper pipes and in case of their being broken can be
replaced in a very short time. If there are not any spare pipes, nipples r can be
placed in the ends of ports of valve box d and to the passages g and g¹ in top of
cylinder a and connected by two short pieces of flexible tube, such as are used to
the passage on valve box c from the main steam pipes. For in case of a passage
being broken that is cast in one with the cylinder the rock drill becomes useless
and by my invention all ports and passages are machined or made by hand so that
there is always clean air, steam or other fluid going into the cylinder a and valve
box c, but in case of passages being cast on the cylinder a, a lot of sand is burnt
into the pores of the iron that cannot be cleaned out by hand, but when the pressure
of steam is admitted to the cylinder expansion takes place and with the jump and
jar of the drill it will loosen the grit and sand in the casting and elsewhere and
pass it to the cylinder and valve box and this causes a great wear and tear of both.
By my invention I have overcome this danger from dirt and grit that would injure
the internal parts of the drill.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a rock drill an improved valve, with piston action and with portable air
or steam passages and improved metallic packing, substantially as herein described
and set forth.
2. In a rock drill the construction of the valve box and feed pipes external
to and separate from the main cylinder, as herein described and set forth.
Dated this 14th day of February 1893.
S. S. BROMHEAD,
97, Newgate Street, E.C., Agent for the Applicant.
S. S. BROMHEAD,
97, Newgate Street, E.C., Agent for the Applicant.