IMPROVEMENTS IN ROCK BORING MACHINERY
Year: 1874

page_text: LETTERS PATENT to David Thomson, of No. 3, Old Street, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN ROCK
BORING MACHINERY."
Scaled the 1st December 1874, and dated the 5th October 1874.
PROVISIONAL SPECIFICATION left by the said David Thomson at
the Office of the Commissioners of Patents, with his Petition, on
the 5th October 1874.
I, DAVID THOMSON, of No. 3, Old Street, in the County of Middlesex,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN ROCK BORING MACHINERY," to be as follows:-
:-
My Invention relates to means of driving the drills employed in rock
boring by the direct application to the revolving drill spindle of an
engine worked by steam, compressed air, or water under pressure, so as
to avoid the complexity of the intermediate gearing usually employed

page_text: for communicating movement to such drills. For this purpose I connect
the drill spindle directly to the shaft of the engine, and I mount the
engine and spindle on a framing capable of being adjusted to any desired
position and angle, so that the hole can be bored in any required
direction, the pipe for supplying the fluid under pressure being cither 5
made in part flexible or with sliding or turning joints to admit of
variations in the position and attitude of the engine.
"
For supplying water to the interior of a hollow drill spindle driven as
above described I either introduce it through a hollow shaft of the
engine, or I enclose part of the drill spindle within a sleeve provided 1
with packing at both ends, and I form a hole or holes through the side
of the spindle where it is so enclosed, so that water supplied to the
sleeve enters the spindle while it revolves within the sleeve.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said David Thomson in the Great Seal Patent Office 1
on the 31st March 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
THOMSON, of No. 3, Old Street, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her 2
Letters Patent, bearing date the Fifth day of October, in the
year of our Lord One thousand eight hundred and seventy-four, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said David Thomson, Her special
license that I, the said David Thomson, my executors, administrators, a
and assigns, or such others as I, tho said David Thomson, 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 "IMPROVE-
MENTS IN ROCK BORING MACHINERY," upon the condition (amongst

page_text: others) that I, the said David Thomson, my executors or admini-
strators, by an instrument in writing under my, or their, or one
of their hands and seals, should particularly 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 immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said David Thomson, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the accompanying
Sheet of Drawings, and to the figures and letters marked thereon, that
is to say:-
My Invention relates to means of driving the drills employed in rock
boring by the direct application to the revolving drill spindle of an
engine worked by steam, compressed air, or water under pressure, so as
to avoid the complexity of the intermediate gearing usually employed
for communicating movement to such drills. For this purpose I connect
the drill spindle directly to the shaft of the engine, and I mount the
engine and spindle on a framing capable of being adjusted to any desired
position and angle, so that the hole can be bored in any required
direction, the pipe for supplying the fluid under pressure being either
made in part flexible or with sliding or turning joints to admit of
variations in the position and attitude of the engine.
For supplying water to the interior of a hollow drill spindle driven as
above described I either introduce it through a hollow shaft of the
engine or I enclose part of the drill spindle within a sleeve provided
with packing at both ends, and I form a hole or holes through the side
of the spindle where it is so enclosed, so that water supplied to the.
sleeve enters the spindle while it revolves within the sleeve.

page_text: The framing consists of a part A made to encircle a cylindrical
bearer or pipe A', so that it can be slid thereon or turned round it and
clamped in the desired attitude. A dovetail guide B is secured to A by
a central bolt, and by two bolts passing through circularly slotted holes,
so that the inclination of B can be varied. On the dovetail guido B is
fitted a sliding frame C forming part of the framing of the three cylinder
engine D. The drill spindle F is coupled directly to the crank shaft E.
The engine D represented in the Figures is of the triple cylinder kind
described in the Specifications of Patents granted to P. Brotherhood, on
the 24th January 1873, No. 287, and the 5th June 1873, No. 2003. It
is obvious however that any other suitable compact form of motor
engine driven by steam, water, or air under pressure might be applied.
The drill spindle F is usually made tubular, and supplied with a stream
of water. The water might be introduced at the top of the engine shaft,
which with its crank would in that case be made with channels for the
passage of the water through it. When the shaft and crank has no such
channels I enclose the upper part of the tubular drill spindle within a
sleeve H, chambered round the spindle as shewn in section in Fig. 1;
and I provide a hole or holes in the spindle facing the chamber of the
sleeve, so that water under pressure supplied by a flexible pipe or
otherwise to the chamber of the sleeve passes through the holes in the
spindle and down its interior to the drill. The weight of the engine
spindle and sliding frame gives the pressure on the drill, and as the drill
penetrates the rock the engine follows it up by sliding down the dovetail
guide B. The amount of pressure on the drill may be diminished or
increased by applying counterweights or adding weight to the engine or
drill spindle. The steam, compressed air, or other fluid that works the
engine is supplied to the inlet of the said engine by a flexible pipe in
such a way as to admit of the motor engine following up the drill as
above described, and the fluid can be conveyed away by the same means
after use if desired.
Having thus described the nature of my Invention, and in what
manner the same may be applied, I desire it to be understood that this
Invention is not applicable to rock drills acting by percussion, and also
that the manner of applying it may as to details be varied according to
circumstances; but what I claim is, the driving of rotary rock boring
drills by steam or other motor engines applied to work them without

page_text: the intervention of toothed gearing, and in such a way that the motor
engines follow up the drills as they penetrate the rock.
In witness whereof, I, the said David Thomson, have hereunto
set my hand and scal, this Twentieth day of March, in the
year of our Lord One thousand eight hundred and seventy-
five.