An Improvement in Rock Drills.
Year: 1896

page_text: An Improvement in Rock Drills.
We, SIEMENS BROTHERS & Co., LIMITED, of 12 Queen Anne's Gate,
Westminster in the County of London, Electrical Engineers, do hereby declare
the nature of this invention to be as follows:-
This invention relates to a construction of drill in such a manner that the
advance of the drill and also its withdrawal is effected by hydraulic pressure, a
portion of the water used for the advance serving also to clear debris from the
bore hole.
The drill is caused to revolve by bevil gear worked by a flexible shaft from an
electric or other motor conveniently situated, and the drill frame, which is
preferably in form of a tube is capable of turning in the eye of a crosshead mounted
on trunnions on a vertical column which may also be capable of rotation so that
the drill frame can be directed in any required line, and turned on its axis so as to
bring the lateral connection for the flexible driving shaft into a convenient attitude
for being connected to the motor.
Thus
The drill proper is fixed at the front end of a tube which has at its rear end a
tooth or feather fitted to slide along a lateral slot of an outer tube or carrier which
is attached to and revolves with the bevil wheel at the rear of the frame.
the drill and the tube to which it is fixed can slide to and fro while it is caused to
revolve by the engagement of its feather in the slot of the revolving carrier, this
slot being preferably helical so as to equalize wear.
Within the drill tube but fixed to the rear part of the frame are two inner tubes
with an annular space between them; the innermost terminates in front in a leather
packed piston which works within the drill tube.
The rear end of the drill tube is also interually packed with leather working as
an annular piston on the outside of the outer of these two tubes as on a plunger.
At the front end of this outer tube it has lateral openings by which the annular
space communicates with the interior of the drill tube.
At the rear end of the drill frame there are a union inlet for admission of high
pressure water, an outlet for discharge, and two sets of ports and passages with a
cock or slide by which either the inlet or the outlet can be made to communicate
with the innermost of the two tubes within the drill tube, or with the annular
passage between them and consequently with the interior of the drill tube. When it
is desired to advance the drill, water under pressure is directed into the innermost
tube, and this, acting between the piston in that tube and a diaphragm in front of
it closing the drill tube, presses the drill tube and drill forwards, the annular space
being at this time open to discharge. A portion of the water issues through a
small hole in the diaphragm to clear the bore hole of debris.
When it is desired to withdraw the drill, the water under pressure is directed
into the annular space, while the innermost tube is opened to discharge, and the
pressure water acting on the annular piston at the rear of the drill tube causes it
and the drill to retreat. Suitable packings are employed to prevent communi-
cation between the passages, and outlets are provided for such water as may leak

page_text: past these. Also the front and rear bearings of the revolving carrier tube are
preferably made as ball bearings to lessen friction.
Doted thin onth day of Tul 1900
ABEL & IMRAY,
Agents for the Applicants.
We, SIEMENS BROTHERS & Co., LIMITED, of 12 Queen Anne's Gate,
Westminster, in the County of London, Electrical Engineers, do hereby declare
the nature of this invention (which has been communicated to us from abroad by
Siemens & Halske of Berlin in the German Empire, Electrical Engineers), 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 a construction of rock drill in such a manner that the
advance of the drill and also its withdrawal is effected by hydraulic pressure, a
portion of the water used for the advance serving also to clear the débris from the
bore hole.
We will describe the invention with reference to the accompanying drawing in
which Figure 1 shews a longitudinal section and Figure 2 an underside plan.
The rotary motion of the drill is effected by means of a suitable motor engine
such as an electromotor, through a flexible shaft of known construction the core of
which is coupled to the clutch H while its casing is connected to the socket G. The
bevil wheel R' driven by this means imparts motion to the bevil wheel R² fixed on
a tube D carried in the tubular bearing E and constituting the water pressure
supply tube; to the wheel R2 is fixed a carrier tube T which at the front end runs
on a ball bearing Q2 and is provided with an end piece T as shewn.
The carrier tube can be of any desired cross section that will permit of its having
a longitudinal slot. Preferably it is of cylindrical form.
This carrier tube has for its sole object to impart the rotary motion it receives
from the wheel R² to the tubular drill rod B that carries the drill head Z, while
the longitudinal to and fro motion of the drill rod is effected entirely by means of
fluid pressure supplied through the tube D extending concentrically through the
tubular drill rod B, which is guided at the front end by the tubular extension T
of the carrier tube T and at the rear end by the stuffing box K' fitting on tube D
with suitable packing, such as L 1.
The pressure supply tube D has fixed to its front end a piston K³ working with
packing L2 fluid tight in the tubular drill rod.
For imparting the rotary motion of the carrier tube T to the drill rod, this, or
its stuffing box K has a lateral feather F engaging with the slot of the carrier
tube.
For insuring a uniform wear of the guide surfaces, the carrier slot can be made
of helical form instead of straight, in which case the drill rod will have both a
longitudinal motion and a rotary motion relatively to the carrier tube.
The drill rod B has a partition X between its rear part and the crown Z,
through a hole in which partition some of the pressure water is made to pass
to the crown for cooling this and for washing out the bore hole in the usual
manner.
If now water under pressure is supplied in any suitable manner into the front
end of the tubular drill rod, in front of the piston K³, the drill rod and crown will

page_text: be forced forward. If on the other hand pressure water be admitted behind
piston K in the annular space between pressure supply tube D and drill rod B,
then the latter will be forced backward.
In both cases the reacting pressure is taken by the pressure supply tube D, or
by the piston K' fixed thereto, and is in the one case transmitted to the ball
bearing Q by the wheel R and in the other case is transmitted by wheel R
and carrier tube T to the ball bearing Q.
By a suitable well known arrangement of the ball bearing at Q' this might be
arranged to take both pressures.
The supply of pressure water to the above described parts can be readily
effected in a simple manner, and with little loss by friction, as shewn on the
drawing. The necessary water channels and stuffing boxes for the purpose are
arranged in a rear extension V of the casing. The pressure supply tube D, has a
second supply pipe w concentrically within it, which is fixed to D at both ends, so
as to leave a small annular space between them. This annular space communicates
at the front end by holes b, with the annular space between pressure tube D and
drill rod B, and at the rear end by holes 62 with an chamber r2 and channel k 2 in
casing V. The interior of supply pipe to communicates at the front end with the
space in the drill rod in front of the piston K, and at the rear end with a
chamber r1 and channel k 1. By means of a four-way cock /, or other suitable
known device, the channels k1 & 2 can be alternately made to communicate with
the supply branch for the water pressure and with the discharge branch a for
the waste water, so that the alternate forward and backward motion of the drill is
effected by the corresponding motion of the cock. The chambers 1 and 2 are
rendered water-tight by means of stuffing boxes 1 and 2.
If any water should leak through 2 it can flow off through the enlargement A
of the casing V, which is formed with openings for this purpose, as also for
facilitating the introduction of a spanner for screwing up the gland of the stuffing
box s 2.
In order also to prevent any water that may leak through the packing L 1 of
the stuffing box K1 from penetrating to the outer parts of the drill, the carrier
tube T can be enclosed by a thin tubular covering as indicated by the black line
at U. The leak water will then flow within this tubular covering into the ball
bearing Q2 and past the drill rod B to the outside, where it is thrown off from the
drill by the revolving shield W.
The clamping ring S in which the drill is held, serves to secure it to a suitable
column (preferably telescopic) such clip being mounted on the latter with flanged
trunnions shewn in Figure 2, so as to be held in any desired angular position. In
order to adjust the casing M of the drill into the position most convenient for the
flexible driving shaft, it is arranged rotatable in the ring S S, and when adjusted it
is secured by the setting screw P.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. A rock drill with revolving drill receiving its to and fro motion by hydraulic
pressure, wherein a tubular drill rod B is mounted concentrically between a
pressure water supply tube D and a revolving carrier tube T which carries the
drill rod round with it as it reciprocates longitudinally, the drill rod being made
to work water-tight upon the pressure supply tube D by means of stuffing
boxes K, K, at each end, substantially as described.
2. In the construction of rock drill referred to in the first claim, constructing the
pressure supply tube D with an inner concentric tube w so as to form a central
fluid pressure channel which communicates with the space in the tubular drill rod
in front of a fixed piston therein, and an outer annular water supply channel which
communicates with the annular space between the pressure supply tube and the
inner surface of the drill rod, the rear ends of the said two water supply channels

page_text: being made to communicate with chambers r 1, r 2, that can be alternately put in
communication with the water pressure supply, substantially as described.
Dated this 20th day of Anril 1807
ABEL & IMRAY,
Agents for the Applicants.