IMPROVEMENTS IN MINERAL AND ROCK DRILLING APPARATUS
Year: 1869

page_text: LETTERS PATENT to John Darlington, of Moorgate Street Chambers,
Moorgate Street, in the City of London, Mining Engineer, for
the Invention of "IMPROVEMENTS IN MINERAL AND ROCK DRILLING
APPARATUS."
Sealed the 6th August 1869, and dated the 18th February 1869.
PROVISIONAL SPECIFICATION left by the said John Darlington at
the Office of the Commissioners of Patents, with his Petition, on..
the 18th February 1869.
I, JOHN DARLINGTON, of Moorgate Street Chambers, Moorgate Street,
in the City of London, Mining Engineer, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN MINERAL AND ROCK DRILLING
APPARATUS," to be as follows:-
This Invention consists in a peculiar combination and application of
certain known mechanical forms and movements towards simplifying
and rendering more effective the action and consequent force applied to
the drill used for boring rocks or mineral substances.

page_text: The drilling bar used in my apparatus may vary in length, and may
either be enclosed in great part in a cylinder, so as to be conveniently
acted upon by hydraulic or other pressure, a piston being fixed to the
end which is enclosed in the cylinder, or it may be supported and guided
in a frame, and the necessary pressure imparted to it by means of a
spring or springs. To the lower end of the drilling bar, the end which
projects from the cylinder, is fastened a drill piece fitted with diamonds
or other material adapted for boring or cuttting stone or mineral sub-
stances. Now the pressure and action applied to the drill as aforesaid
merely impel it directly forward, but that it may effect the required
object there must be combined with this direct forward motion a rotary
movement acting more or less rapidly in alternate opposite directions.
In the means I employ to give the latter movement to the drill consists
the chief novelty of my Invention.
I propose to place beside and generally parallel to the aforesaid
cylinder or frame which carries the drilling bar a rod having either a
feather or feathers or a slot or slots, made to surround it in a very
oblique spiral direction. To the lower end of this rod or screw, and to
the lower part of the drilling bar, a cogged wheel is to be respectively
fixed. These wheels are so adjusted as to work into each other in order
that a quickly alternating rotary action may be maintained between
the boring tool and the rod with its spiral feather or feathers, slot or slots.
The desired rotary movement may be given to this rod by means of a nut
through which the said rod may pass, but which it should accurately
fit, the nut being provided at its inner surface with a spiral slot or slots,
if the rod have a feather or feathers, or vice versa. The power necessary
to give the nut a direct rigid upward and downward movement on the
spiral rod, so as to impart a reciprocating rotary action to the cogged
wheel at the lower end of the said rod, and thereby communicate a
similar action to its companion wheel, and through that to the tool or
cutter, may be variously supplied; as, for example, if the nut aforesaid
be attached to the end of a ram or piston rod, to which a reciprocating
motion may be given by hydraulic pressure arrangement or otherwise.
Thus, then I supply (1) a directly impelling power and progressive
movement to the drilling tool, and (2) a method by which the necessary
rotary action may be given to the said drilling tool, a method which
forms the immediate subject of my present Invention.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Darlington in the Great Seal Patent Office
on the 16th August 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
DARLINGTON, of Moorgate Street Chambers, Moorgate Street, in. the City
of London, Mining Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of February, in the
year of our Lord One thousand eight hundred and sixty-nine, in the
thirty-second year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said John Darlington, Her special
licence that I, the said John Darlington, my. executors, administrators,
and assigns, or such others as I, the said John Darlington, 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 MINERAL AND ROCK DRILLING APPARATUS," upon the condition
(amongst others) that I, the said John Darlington, my executors: or
administrators, 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 Scal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Darlington, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to
say:
This Invention consists in a peculiar combination and application of
certain known mechanical forms and movements towards simplifying
and rendering more effective the action and consequent force applied
to the drill used for boring rocks or mineral substances. The improve-

page_text: ments consist in the use of a screw or of a rod having spiral slots in
connection with certain wheel gearing, the whole being so arranged and
combined that if rotary motion be given to the screw a simultaneous
and similar motion is communicated to the drilling bar.
In order that this peculiar combination of mechanical appliances, the
exact movement of their several parts, and the power by which that
movement is obtained may be fully and accurately comprehended, I will
proceed, with the assistance of the annexed Sheet of Drawings, to point
out the details and to describe minutely the action of my apparatus.
Fig. 1 represents an elevation of an example of the proposed screw,
an elevation of the lower end of the drilling bar or head of the crown
picce, and an elevation of the wheels which communicate motion from
the screw to the drilling bar; it presents also a part section of the
drilling bar, a part section of the cylinder in which the drilling bar is
guided, and also a section of the cylinder in which works the piston
that gives motion to the screw, which in its turn conveys a rotary action
to the drilling bar. Fig. 2 is a view of the fore end, and Fig. 3 a view
of the back end of my apparatus. Fig. 4 is a cross section of the ap-
paratus through the line Y, Z. The same letters of reference indicate
identical parts throughout all the Figures.
A is a cylinder enclosing the drilling bar B, the centre line of which
coincides with that of the cylinder; C is a piston connected with the
top of the drilling bar; D is the drill piece or boring tool either affixed
to the lower end of the drilling bar or forming an integral part of it, and
is fitted with diamonds or other suitably arranged cutting material;
E are set screws serving to fix the apparatus in any convenient position;
F is a piston working in the cylinder H, and G the piston rod. To
the outer end of the piston rod is fixed a travelling nut I through
which passes the screw J. K is a bar which serves to guide and steady
the nut I. The dotted circles L and M represent apertures through which
a column or bar of water passes with a certain velocity and force. The
dotted line O represents a pipe or tube which affords communication
between the under side of the piston F and the top of the piston C. N is
an aperture for the introduction of water under calculated pressure.
Having thus pointed out and described the chief parts of which my
apparatus is composed I will now proceed to explain the action and
operation of the said apparatus. When, by means of the set screws E,

page_text: the apparatus has been fixed in a convenient position for working the
drill, I propose to communicate (using any ordinary initial motive power)
an amount of velocity and force to a bar of water made to pass through
the opening L sufficient to compel the piston F, being in the position
represented on the Drawing, to perform its up stroke in the cylinder H.
The motive force of this bar of water is then intermitted, and the down
stroke of the piston is effected by the weight of another bar of water, or
of a bar of water to which pressure is applied, passing through the aper-
ture N and acting on the upper side of the piston. During the course of
the up stroke of the piston Fa bar of water branching from that which
enters through the aperture L passes through the tube O, and presses
upon the upper side of the piston C which acts directly upon the drilling
bar B.
The several results which the foregoing applications of force arc
calculated to produce may be easily perceived, and conjointly represent
the effective working of my boring apparatus. The motive power
exerted in this apparatus takes two courses which flow parallel to each
other. (1.) In the direction of the screw. When the fore end of the
impelled bar of water enters the orifice L it forces the piston F to make
its up stroke, the down stroke being effected by a counter pressure of
water, as before described. Now as the nut I is fixed to the end of the
piston rod G its movement must be coincident with that of the piston F,
and as the screw J placed parallel to the piston rod passes through and is
closely fitted to the nut and is allowed solely to turn on its own axis, it
follows that the nut will pass up and down the screw as the piston passes
up and down the cylinder, the immediate effect being a more or less rapid
alternating rotary action of the screw upon its axis. Whatever, therefore,
is fixed to the end of the screw will also have an alternating rotary
motion, and I propose that there be connected with it a cog wheel P,
which is made to work in a pinion Q fixed towards the end of the
drilling bar, which is thus constrained to turn with it. In this way I
maintain a simultaneous and similar alternating rotary action between
the screw J and the drilling bar B, and effect one of the two necessary
movements of the drill. (2.) In the direction of the drilling bar. The
aforesaid bar of water which represents the applied motive power not
only enters the cylinder H but finds its way through the tube O into the
upper part of the cylinder A above the piston B, which is attached to the
drilling bar and affords the necessary pressure for a sufficiently rapid
direct onward movement of the drill.

page_text: These are the means, shewn on the accompanying Drawing, which I
consider adapted to give to the drill the dualistic movement necessary to
ensure its effective working; but certain important modifications may
be mentioned, for example, instead of a pressure of water to effect the
onward motion of the drill a spring or springs may be employed. Then as
the pressure of water to propel the drill should vary to suit the hardness
of the rock it will be necessary occasionally to apply pressure to the
piston C from an independent source from, for instance, a weighted plunger
or pump or pressure of water, springs, &c., and it will be convenient at
times to cut off the communication between the two cylinders A
and H. Again, the drilling bar can have rotary motion imparted to
it by means of fixed or oscillating hydraulic cylinders, the pistons or
rams of which may be worked by faced trunnions or cock valves, or by
slide valves or balance bar valves, the whole arranged so as to form part
of the drilling apparatus. With regard to the form of the screw J, I by
no means confine myself to that shewn in the annexed Drawing;
indeed the screw may be replaced by a rod having cither a feather or
feathers or a slot or slots made to surround it in a very oblique spiral
direction, the hole in the nut which is made to receive the screw or rod
being formed to correspond fitly with such changes. Increased efficiency
may be given to the apparatus, and any tendency to a lateral pressure
that may possibly be exerted by the nut whilst acting upon the screw be
counteracted, if the various movements of the apparatus were accurately
balanced by distributing the power and the gearing for turning the drill
tool equally on opposite sides of the drilling bar and cylinder, that is to
say, by placing the screw J and its accessories on the right as well as on
the left of the drill cylinder. Rams may be substituted for the pistons
shewn on the Drawing, and steam, or other liquid than water, may be
used to propel the pistons. If the alternating action imparted to the
drill, as herein described, be found inconvenient rotary motion in one
direction only may be given to the said drill by the ordinary application
and working of ratchet wheels and pawls or by depriving the upward or
downward action of the nut I upon the screw J of any effect upon the
drilling bar.
Having thus described the nature of my said Invention, and the manner
in which the same may be carried into effect. I now observe in conclusion

page_text: therefrom without deviating from the main features of my Invention ;
but what I consider to be novel and original, and therefore claim is, the
application and use of a screw or screw-formed shaft or rod, or of a rod
surrounded by spiral slots or feathers, as a means of communicating
either an alternating or a regular rotary motion to the drill used for
boring rocks or mineral substances, substantially as herein-before
described.
In witness whereof, I, the said John Darlington, have hereunto
set my hand and seal, this Fourteenth day of August Onc
thousand eight hundred and sixty-nine.
(L.S.) JOHN DARLINGTON.