IMPROVEMENTS IN ROCK DRILLING APPARATUS
Year: 1873

page_text: LETTERS PATENT to John Imray, of No. 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN ROCK DRILLING APPARATUS." A communication
from abroad by Robert Julius Gottheil, Engineer, of Chemnitz, in
the German Empire.
Sealed the 30th December 1873, and dated the 22nd July 1873.
PROVISIONAL SPECIFICATION left by the said John Imray at the
Office of the Commissioners of Patents, with his Petition, on the
22nd July 1873.
I, JOHN IMRAY, of No. 20, Southampton Buildings, Chancery Lanc,
in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN ROCK DRILLING APPARATUS," to be as
follows
This Invention relates to apparatus for drilling holes in rocks, such as
are usually made for blasting. The apparatus is more particularly
applicable for being worked by hand, although it may be worked by
other convenient power, and is. so contrived that the drill or boring tool

page_text: may be readily directed in any desired line, and that the simple turning
of the driving wheel whether by a winch handle, or by other means
gives to the drill at the same time a rotary movement and an advance
with percussive action. For this purpose the drilling tool is attached to
a spindle mounted in bearings in a framing, so that it is free to turn and
also to slide longitudinally. The framing is itself mounted by vertical
and horizontal joints to a standard, so that it can be turned on these
joints so as to direct the drill either vertically or horizontally in any
intermediate attitude, and these joints are provided with clamping nuts
so that when the drill is set it is prevented from shifting its attitude.
At the side of the drill spindle on an axis at right angles to it is mounted
a wheel which can be turned by winch or by other power, and on the
side of this wheel are teeth of ratchet form which when the wheel is
turned act on a pawl lever mounted on the drill frame. This pawl lever
bears against the one edge of a clamp ring which encircles the drill
spindle, and which is kept up against the pawl lever by a strong volute
helical spring pressing against its opposite edge. As the ratchet wheel
is made to revolve each tooth which is inclined and rounded on the back
so as to act like a cam causes the pawl lever to press the clamp ring
backwards, but as the spring on its opposite edge is at the same time
pressing it forwards the clamping ring is canted into an oblique position
so that it takes fast hold of the drill spindle, and as the cam tooth
continues to press the ring backwards the drill spindle is drawn back-
wards with it, the spring behind the ring being compressed. When the
pawl escapes the point of the tooth the spring being then left free
pushes the clamp ring, and with it the drill spindle forcibly forwards, so
as to effect the impact of the drill against the rock. The pawl lever is
made to act on the ring so as to give a certain amount of rotary motion
or twist to the drill spindle as it pushes it backwards, also the spindle
being free in the clamp ring when the latter is not canted advances a
certain distance by its own momentum even after the stroke of the
spring is stopped by a buffer, which may be of wood provided for that
purpose. Thus by the simple turning of the wheel bringing successive
cam shaped teeth to act on the pawl lever so as draw back the drill and
let it be driven forward by the spring; when the lever escapes the
successive teeth the drilling tool is caused to make a succession of
strokes rotating a little and advancing a little each time, and thus to
bore a hole in the rock such as the blast holes usually driven by hand.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said John Imray in the Great Seal Patent Office on
the 12th January 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
IMRAY, of No. 20, Southampton Buildings, Chancery Lane, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-second day of July, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Imray, Her special license, that
I, the said John Imray, my executors, administrators, and assigns;
or such others as I, the said John Imray, my executors, adminis-
trators, and assigns, should at any time agree with, and no others from
time to time and at all times thereafter during the term therein ex-
pressed, 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 "IMPROVEMENTS IN ROCK
DRILLING APPARATUS," a communication to me from abroad by Robert
Julius Gottheil, Engineer, of Chemnitz, in the German Empire,
upon the condition (amongst others) that I, the said John Imray, 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 Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Imray, 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 :—
This Invention relates to apparatus for drilling holes in rocks, such as

page_text: .
other convenient power, and is so contrived that the drill or boring tool
may be readily directed in any desired line, and that the simple turning
of the driving wheel. whether by a winch handle, or by other means
gives to the drill at the same time a rotary movement and an advance
with percussive action. For this purpose the drilling tool is attached to
a spindle mounted in bearings in a framing, so that it is free to turn and
also to slide longitudinally. The framing is itself mounted by vertical
and horizontal joints to a standard so that it can be turned on these
joints, so as to direct the drill either vertically or horizontally or in any
intermediate attitude, and these joints are provided with clamping nuts
so that when the drill is set it is prevented from shifting its attitude.
At the side of the drill spindle on an axis at right angles to it is mounted
a wheel which can be turned by winch or by other power, and on the
side of this wheel are teeth of ratchet form which when the wheel is
turned act on a pawl lever mounted on the drill frame. This pawl lever
bears against the one end of a clamp ring which encircles the drill
spindle, and which is kept up against the pawl lever by a strong volute
helical spring pressing against its opposite edge. As the ratchet wheel
is made to revolve cach tooth which is inclined and rounded on the
back so as to act like a cam causes the pawl lever to press the clamp
ring backwards, but as the spring on its opposite edge is at the same
time pressing it forwards the clamping ring is canted into an oblique
position so that it takes fast hold of the drill spindle, and as the cam
tooth continues to press the ring backwards the drill spindle is drawn
backwards with it, the spring behind the ring being compressed. When
the pawl escapes the point of the tooth the spring being then left
free pushes the clamp ring, and with it the drill spindle forcibly
forwards so as to effect the impact of the drill against the rock. The
pawl lever is made to act on the ring so as to give a certain amount of
rotary motion or twist to the drill spindle as it pushes it backwards, also
the spindle being free in the clamp ring when the latter is not canted
advances a certain distance by its own momentum even after the stroke
of the spring is stopped by a buffer, which may be of wood provided
for that purpose. Thus by the simple turning of the wheel bringing
successive cam shaped teeth to act on the pawl lever so as to draw back
the drill and let it be driven forward by the spring; when the lever
escapes the successive teeth the drilling tool is caused to make a sucession
of strokes rotating a little and advancing a little each time, and thus to
bore a hole in the rock such as the blast holes usually driven by hand.
"a
1

page_text: Fig. 1. represents a side view; Fig. 2, a vertical, and Fig. 3, a horizontal
section of that portion of rock drilling apparatus to which the improve-
ments which form the subject of this Invention are applied.
A is part of a standard, the upper portion of which forms a pivot on
which the boss B of the drilling apparatus can be turned horizontally in
any required direction, being secured in the desired attitude by screwing
down the nut a. In a hole in the boss B is fitted a pivot C to which,
the drill frame is fixed, and on which it can be turned vertically in any
required direction, being sccured in the desired attitude by screwing
down the nut c. D is part of the stem of the drill which may be of any
known form, and which is held in a split socket at the end of a spindle.E
by driving a ring e on the taper exterior of the socket. The spindle E
passes through bushes at each end of the drill frame so that it can freely
slide and revolve therein, and having no collar or projection on it
behind the socket it can be drawn out of the drill frame when required
for cleaning, oiling, or other purpose. Within the drill frame F which
is tubular is a volute spring G; which at one end bears against the cap ƒ
and at the other against an annular piece 9 having a projection on its
face. His a buffer of wood or other somewhat yielding material, and
I is a ring surrounding the spindle E, but nearly fitting it only in its.
middle so that it can be canted as will hereafter be described into an
oblique attitude on the spindle.
.
"
Instead of the solid ring I shewn in Fig. 3 the construction shewn in
section and front view at Fig. 4 may be employed where an outer
ring I has within it a number of separate segmental pieces i. K is a
wheel which may be worked by a winch by hand, or may be driven
by other power in the direction of the arrow, Fig. 1. This wheel
is mounted on a spindle at the side of the drill frame, which spindle may
be the extension of the central bolt of the pivot C, as shewn. On the
face of the wheel K there are teeth L of ratchet form, which as the
wheel revolves cause a lever M mounted on the drill frame to oscillate by
successively acting on a projection m on the outer side of the lever M.
On the inner side of the lever M is a projection ” which bears against
one edge of the ring I, while the projection on the annular piece ġ is
caused by the spring G to press against the opposite edge of the ring I.
On turning the wheel K each of its teeth L in pushing aside the lever M

page_text: causes the ring I to cant to an oblique attitude so as to clamp itself on
the spindle E, and by its continued movement backwards to draw back
that spindle and the drill D attached to it compressing the spring G.
When the lever M escapes the tooth L, the pressure of the spring G
drives forward the ring I and with it the spindle E until the ring I
meeting the buffer H is righted and releases the spindle E from its grasp,
whereupon the spindle and drill continue to advance with the momentum
imparted by the spring, the drill making its stroke in the rock. As
another tooth L engages with the lever M. the drill is again retracted
and the operation is repeated. The lever M is so pivotted in relation to
the axis of the spindle E that its projection n in making its back stroke
moves in a circular arc, and having hold by friction on the ring I causes
it to turn through a small portion of a revolution, turning with it the
spindle E and drill D. Thus at every back stroke of the drill it is
turned a little round before making its succeeding stroke forwards.
Having thus described the nature of the said Invention and in what
manner the same is to be performed, as communicated to me by my
foreign correspondent, I claim,-
First. The use of apparatus substantially as herein described for
working a rock drill so as to cause it to make longitudinal strokes, and
to turn partly round its axis, in which apparatus a clamp ring on the
drill spindle is acted on by a spring on the one side, and on the other
side by a lever moved by the ratchet teeth of a continuously revolving
wheel so as alternately to seize and to let go the drill spindle.
Second. The arrangement of horizontal and vertical joints, whereby 2
the apparatus above referred to is mounted on a frame so that the
drill can be directed in any desired attitude, substantially as herein
described.
In witness whereof, I, the said John Imray, have hereunto
set my hand and seal, this Seventh day of January, in the 3
year of our Lord One thousand eight hundred and seventy-