IMPROVEMENTS IN APPARATUS FOR DRILLING ROCKS AND OTHER HARD SUBSTANCES, WHICH IMPROVEMENTS ARE PARTLY APPLICABLE TO OTHER PURPOSES
Year: 1878

page_text: LETTERS PATENT to William Wallace Dunn, of San Francisco, California, United
States of America, now of 8, Southampton Buildings, London, Engineer, for
the Invention of " IMPROVEMENTS IN APPARATUS FOR DRILLING ROCKS AND
OTHER HARD SUBSTANCES, WHICH IMPROVEMENTS ARE PARTLY APPLICABLE TO
OTHER PURPOSES.”
Sealed the 20th August 1878, and dated the 23rd February 1878.
PROVISIONAL SPECIFICATION left by the said William Wallace Dunn at
the Office of the Commissioners of Patents on the 23rd February 1878.
WILLIAM WALLACE DUNN, of San Francisco, California, United States of America,
now of 8, Southampton Buildings, London, Engineer. "IMPROVEMENTS IN AP-
PARATUS FOR DRILLING ROCKS AND OTHER HARD SUBSTANCES, WHICH IMPROVEMENTS
ARE PARTLY APPLICABLE TO OTHER PURPOSES."
This Invention relates to improvements in apparatus for drilling rocks and
other hard substances, which improvements are partly applicable to other
purposes.
The said Invention is designed to provide a drilling machine and apparatus
connected therewith which shall possess a combination of advantages not possessed
by any machine or apparatus heretofore in use for effecting the same objects,
and the said improvements comprise various details of construction herein-after
described.
In order to impart to the drill great power and consequent effectiveness, I provide
novel means by which the whole force of the steam is continued upon the piston up
to the moment at which the drill point strikes the rock, thus avoiding the loss of
force occasioned by the cutting off of the steam before the blow is struck, as is the
case when rods, tappets, or like devices are used for controlling the slide valve. By
this means I obtain the full effective power of the steam, and the result is that the
blow given by the drill point upon the rock or other substance to be operated upon
is much more powerful than would be the case with the same pressure of steam
when using levers, rods, or other mechanism for operating the slide valve as hereto,-
fore employed.

page_text: It is to be understood that I may use compressed air or other suitable power
instead of steam if found desirable.
In carrying this part of my said Invention into practice I provide a cylinder
of ordinary construction; but instead of employing the ordinary form of slide valve
for controlling the admission and exhaust of the steam I provide one of peculiar
construction, the said valve forming an important feature of my said Invention.
I construct the said valve and its case as follows, that is to say:-I provide a case
constructed of a solid piece of metal of any suitable shape, and through which I bore
a circular aperture in a longitudinal direction. Within this aperture I fit a cy-
lindrical sliding valve, which is arranged to slide to and fro for the purpose of opening
and closing the respective ports provided in the said case, and I plug or otherwise
cover up the two ends of the said case. The said cylindrical slide valve is entirely
enclosed within the said case, having no rod or other connection attached thereto.
The said valve is made in two parts, that is to say, a piece is cut out of the centre,
which piece is half round, or nearly so, in cross section, and of the desired length to
assume a proper position with regard to the ports in the reciprocating sliding
motion of the valve. The said piece retains its position in the valve, the object of
cutting it out being to provide means for self-adjustment, in order to compensate
for the wear caused by friction. This object is effected as follows, that is to say :-
The steam surrounding this part of the valve will force its way between the two
surfaces and keep the said piece, which works over the port faces, constantly
pressed tightly thereon, and therefore there will be no leakage through the wearing
away of the surfaces of this part. The said piece is cut out above the port faces,
so as to leave communication between one of the steam ports and the exhaust port
as usual
An annular channel is provided in the cylindrical slide valve at each side of
the said detached piece, which channels communicate with the respective steam
ports in the to-and-fro motion of the said slide valve, the steam passing through
the said ports to the opposite ends of the cylinder in the usual manner. I provide at
one or both ends of the said slide valve case a thumb-piece, which is carried outside
the said case for the purpose of enabling the attendant to push the valve over when-
ever this may happen to be required.
I effect the working of the said slide valve in a novel and very advantageous
manner, that is to say, by the direct action of the steam from the cylinder without
the aid of rods or other devices. To effect this object I provide communications
leading from the interior of the cylinder to the interior of the slide valve casing.
One of these communications leads from a point in the cylinder, which is just
cleared by the upper end of the piston when the latter has finished its stroke in
one direction, and the other communication leads from a corresponding point in the
cylinder, which will be just cleared by the lower end of the piston when the latter
has finished its stroke in the opposite direction.
These two communications lead to opposite ends of the slide valve casing. The
operation will therefore be as follows:-The steain enters one end of the cylinder,
and drives the piston to the end of its stroke; then this steam escapes through the
said aperture, communicating with one end of the slide valve casing, and forces the
slide valve to the other end of its path, thereby shutting off the steam port, which
was previously open, and opening the other steam port. The exhaust steam then
escapes through the steam port which was first open, and out through the exhaust
pipe. When the piston reaches the opposite end of its stroke the said aperture
leading to the opposite end of the slide valve casing is uncovered, and the same
movement of the slide valve takes place in the contrary direction. The said slide
valve casing may be attached to the cylinder in any suitable position, as may be
found most convenient for effecting the desired object.
I provide a movable cover upon the said slide valve case to facilitate inspection of
the interior of the same, In order to prevent the said cylindrical slide valve from
rotating in its case I may flatten a portion of the top of the former and provide a
corresponding flat surface at the top of the casing, leaving a sufficient space between

page_text: the two flattened surfaces to prevent friction; or instead of providing the said flat
surfaces I may cut away a portion of the said valve above the said detached piece
on each side, and provide extensions or ears on each side of the said detached piece,
which extensions will extend up towards the top of the casing, and meet the lower
ends of bolts projecting through from the outside, thus effectually preventing any
tendency to rotate.
The herein described improved slide valve, though chiefly designed for a rock-
drilling machine, may also be applied to engines used for other purposes if found
desirable.
"
In order that notice may be given to the attendant immediately the feed of the
drill requires adjustment, I provide a 'pulse" piston, or sounder working in a
cylinder attached to and in communication with the main cylinder of the machine.
There are two apertures connecting the said two cylinders, through which steam
can pass from one to the other, and these apertures are arranged in such a position
that so long as the feed is properly adjusted there will be a pressure upon the pulse
piston, keeping it in its normal position, but as soon as the feed requires to be
adjusted forward, the aperture leading to the other end of this piston will be
uncovered by reason of the main piston of the machine being driven further
forward, and steam will be admitted which will drive the said "pulse" piston
forward, so that it will strike a bell or operate some equivalent device for giving
notice to the attendant. To provide for the escape of the steam from the opposite
end of the "pulse" piston cylinder when the piston is thus driven from its normal
position, I turn off a part of the circumference of the main piston, so that there
is an annular space between the said piston and the walls of the cylinder along
a suitable length of the said piston. The said steam therefore passes into this space,
and thence into the exhaust pipe through an aperture provided for it.
In some cases I dispense with the above-described alarm apparatus, and provide
an automatic feed adjustment. In carrying this part of my said Invention into
practise I attach to the main cylinder of the machine a case, within which is a
cylindrical valve arranged to have a reciprocating motion in the said case; the
latter is cut out in the centre to admit a lever attached to a rod, the lever and rod
being at right angles to each other. The said lever fits loosely into an aperture
provided for it in the said valve, so that when the latter moves in the direction
caused by the forward position of the main piston when re-adjustment is required,
a slight motion is given to the lever, and so communicated to the rod attached
thereto. At the other end of this rod there is a toothed wheel having a ratchet
wheel and pawl in connection therewith. This toothed wheel gears with another
toothed wheel upon the shaft carrying the screw, which adjusts the feed in any
well-known manner. When the feed has been thus automatically adjusted, the
said valve slides back to its normal position, and the said lever is also carried back
thereby, but the toothed wheel on the rod is not operated because of the said ratchet
wheel and pawl; the said lever is then in position to act when the feed requires
adjustment again, and I provide some well-known means for throwing the said
ratchet wheel out of gear, so that the feed motion may be stopped instantly when
desired without any danger of deranging the machine.
The said case containing the valve which operates the said lever is connected
with the main cylinder, and the valve is operated in the same manner as herein-
before described for operating the "pulse" piston.
For the purpose of conveniently adjusting the drill for tunnelling or similar
operations, and for fixing it firmly and securely in order to obtain the best results,
I form the lower end of the pillar or column upon which the coupling apparatus
carrying the machine slides of taper form and tapering downwards, and a corres-
ponding aperture being provided in the frame of the carriage carrying the said
pillar; the latter may be fitted securely therein without screws or other fastening
devices. The said lower end of the pillar may be of any suitable shape in cross
section other than round. This arrangement provides means for fitting the said
pillar in place expeditiously and with great security.

page_text: To provide for the expeditious raising and lowering of the drilling machine
vertically along the said pillar, a chain is attached to the said machine, which chain
passes over a sheave or pulley fixed at the upper end of the said pillar. The said
pulley is attached to a ring, which is placed loosely upon the said pillar, and capable
of revolving thereon far enough to bring the said pulley into such a position on
opposite sides of the pillar, as desired, so as to be vertically above the drilling machine,
whichever side of the piliar the said machine may be. The said ring may be
provided with a projection or shoulder to prevent its dropping down the pillar,
and the pillar will be provided with studs or projections to prevent the ring from
turning too far round.
I provide an improved double coupling, which slides vertically upon the said
pillar to allow of easy adjustment of the drilling machine. The said coupling device
is so arranged that it may be turned round the said pillar (the latter forming its
axis), so as to adjust the drill to either side as required. Two arms project from
the centre or hub of this coupling device, one on each side, one being placed a little
higher than the other. These arms extend in a horizontal direction, and upon each
one is a box coupling with two apertures drilled or bored in the face thereof. These
apertures are to receive a corresponding projection on the bottom of the drilling
machine, and one of the said coupling boxes thus supports the said machine, according
to which side of the column the machine is to be placed. The said machine is so
fitted upon the said coupling box that the former is capable of being rotated in a
horizontal direction.
The said coupling device being arranged to rotate around the said vertical column,
the machine being upon one of the said boxes; if it is desired to turn the machine
round to the other side of the column, this may be done instantaneously by rotating
the said coupling device accordingly. The said machine being then in the other
side of the pillar, the drill point will be in the wrong direction for work, but by
reason of the aforesaid provision for rotating it upon the coupling box, it may be
readily turned round without removal, so as to bring the point into the desired
position. The said coupling boxes are made to slide horizontally upon the aforesaid
projecting arms, and they may be turned vertically around the latter, so as to
provide for the adjustment of the drill point to any desired angle.
When the machine has been turned round from one side of the pillar to the other
side, the ring carrying the pulley or sheave is rotated far enough to bring the latter
vertically over the machine in its altered position, so that the lifting chain will be
directly over the machine to raise and depress the latter, as required.
Before shifting the ring, the chain should be removed from the pulley, and
replaced when the ring has been shifted.
I also provide improved means for effecting the rotation of the piston rod and
drill or perforator; and for this purpose I employ devices similar to those described
in the Specification of former Letters Patent granted to me the Twenty-fifth day of
May, A.D. 1876, No. 2208, but the said devices are rendered more efficient in the
following manner, that is to say:-Instead of providing a ratchet wheel at the end
of the spiral rod, I form teeth around the interior circumference of the recess in the
cylinder head, and a pawl is attached to a hub or disc provided on the end of the
said spiral rod, the spring which keeps the pawl in position being let into a slot
in the said hub or disc. By this arrangement the teeth remain stationary and the
pawl travels around as the piston rotates. I am also enabled to use only one pawl
instead to two as heretofore.
By the above-described improvements I provide a drilling machine which is
powerful in its action, and which can be readily and quickly adjusted to the
varying positions which such a machine has to occupy in the course of its operations.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Wallace Dunn in the Great Seal Patent Office on the 23rd
August 1878.
WILLIAM WALLACE DUNN, of San Francisco, California, United States of America,
"IMPROVEMENTS IN AP-
now of 8, Southampton Buildings, Loudon, Engineer.
PARATUS FOR DRILLING ROCKS AND OTHER HARD SUBSTANCES, WHICH IMPROVEMENTS
ARE PARTLY APPLICABLE TO OTHER PURPOSES."
This Invention relates to improvements in apparatus for drilling rocks and other
hard substances, which improvements are partly applicable to other purposes.
The said Invention is designed to provide a drilling apparatus or machine which
shall possess advantages not possessed by any apparatus or machine heretofore in use
for the same purposes; and the said improvements comprise various details of con-
struction herein-after described, and illustrated in the accompanying Drawing, in
which,
my Invention
Figure 1 is a side elevation of a machine constructed according to
Figure 2 is a horizontal section on the line x, x, Figure 1; Figure 3 is a transverse
section on the line y, y, Figure 1.
Figure 4 shews a portion of the said machine detached and herein-after
described.
i
Figure 5 is a transverse section illustrating a modification of the said Invention.
Figure 6 is a side view; and Figure 7, a top view; and Figure 8 is a front edge
view of an improved tool or implement for use in a rock-drilling apparatus or
machine.
Figure 9 is a side elevation; and Figure 10 is an end elevation of a frame or
stand for supporting or carrying a rock drill drawn to a reduced scale; Figure 11
is a horizontal section on the line z, z, Figure 9.
Like letters indicate the same parts throughout the Drawing.
A is the main frame which supports the drilling mechanism; a is the cylinder
which may be of the usual construction; b is the piston; b¹ is the piston rod; c is
the drill or implement; d is the valve chest or casing. The remaining parts are
herein-after indicated.
According to one part of my said Invention I render a rock-drilling apparatus or
machine capable of exerting great power and useful effect by providing means
whereby the whole force of the steam is continued upon the piston in its forward
stroke up to the moment when the drill point strikes the rock, thus avoiding the
loss of force occasioned by cutting off the steam before the blow is struck.
In carrying this part of my said Invention into practice, instead of employing
the ordinary form of slide valve for controlling the admission and exhaust of the
steam, I provide a valve of peculiar construction, the said valve forming an
important feature of my Invention. The valve e consists of two parts, namely, the
valve proper, e¹, and the carrier e², fitted within the case d, which may be arranged
and fixed upon the cylinder a transversely to the axis of the same, as shewn in
Figure 3, or may be otherwise arranged if desired.
The casing d is preferably cast in one piece with the cylinder a, and requires no
fitting or fixing thereon. It simply requires boring to make it truly cylindrical for
the reception of the valve. The ends of the said casing are closed by screw caps
or plugs d'. The said valve is arranged to slide to and fro in this cylindrical casing
for the purpose of opening and closing the steam admission ports f, g, and is entirely
enclosed within the said case, having no rod or other connection attached thereto,
the reciprocating motion of the valve being obtained by steam pressure on the ends
es of the carrier e³, which ends are properly fitted to work as pistons in the cylinder

page_text: casing. The central or intermediate portion e* of the carrier is of smaller diameter
than these ends or pistons.
The part e¹, which forms the valve proper, is half round, or nearly so, in cross
section, and of the desired length to open and close the ports in its reciprocating
motion. The said valve is fitted in a recess in the carrier e², which keeps it in
position, and ensures its moving with the carrier, while permitting the self-adjust-
ment of the said valve to compensate for wear, that is to say, the steam surrounding
this part of the valve will enter between the surface of the back of the valve e¹,
and the under side of the carrier e², and will keep the said valve constantly pressed
down upon the port face; therefore there will be no leakage or loss of steam through
the wearing away of the surfaces of this valve or the port face. It will be seen
that the valve is chambered centrally so as to permit communication in the usual
manner between each steam and exhaust port h.
By reason of the reduced diameter of the intermediate part of the carrier e³, an
annular space is provided between the carrier and the valve casing, and a space is
left at each end of the said valve, as shewn in Figure 3, by which the steam in this
annular space has access to each of the steam ports, as the same is uncovered in the
to-and-fro motion of the said slide valve, the steam passing through the said ports
to the opposite ends of the cylinder through longitudinal passages extending from
the said ports to the cylinder ends.
I provide at one or both ends of the said slide valve casing d a thumb-piece or
pusher i, which is provided inside the casing with a head ², and is extended through
the screw caps for the purpose of allowing the attendant to push the valve from
one side to the other of the casing, if required, in starting the machine.
I form a recess in each of the screw caps or plugs d, and insert therein a small
coiled spring, as shewn in Figure 3, to serve as a cushion, and prevent noise in the
working of the valve.
I provide a moveable cover upon the said slide valve case to facilitate inspection
of the interior of the same.
To prevent the rotation of the cylindrical slide valve in its case d, I fit inside the
said casing the plates d*, whose lower edges rest on the projecting edges of the part
el of the said valve, as shewn in Figure 38, which is a longitudinal section on the line
x*x*, Figure 3. Or I may flatten a portion of the top of the valve carrier and
provide a corresponding flat surface in the top of the casing, leaving a sufficient space
between the two flattened surfaces to prevent friction; or I may cut away a portion
of the said carrier above the said valve or part e¹ on each side, and provide on each
side of the said valve extensions which extend up towards the top of the casing, and
meet the lower ends of bolts projecting through from the outside, thus effectually
preventing any tendency to rotate.
The herein-described improved slide valve, though chiefly designed for a rock- drilling.
machine may also be applied to engines used for other purposes, and I may use
compressed air or other fluid instead of steam for working my improved drilling
machine.
I provide passages leading from the interior of the cylinder to the opposite ends
of the slide valve casing d. One of these passages leads from a point k in the 4
cylinder which is just cleared by the upper end of the piston when the latter has
finished its stroke in one direction, and the other passage leads from the point
the cylinder which will be just cleared by the lower end of the piston when the
latter has finished its stroke in the opposite direction.
in
The passage k admits steam from the cylinder a to the end d² of the casing d, and 5
the passage admits steam from the said cylinder to the opposite end d³ of the
said casing. The operation will therefore be as follows:-Steam being admitted to
the casing d, passes through the uncovered steam port to one end of the cylinder a,
driving the piston b to the end of its stroke; then this steam passes from the cylin-
der a through the aperture and passage communicating with one end of the slide 5
valve casing, and forces the slide valve to the other end of its stroke, thereby closing

page_text: the said steam port and opening the other steam port. The exhaust steam then
escapes through the steam port which was first open, and out through the exhaust
port and pipe. When the piston b reaches the opposite end of its stoke, the aper-
ture leading from the cylinder a to the opposite end of the slide valve casing d is
uncovered, and the same movement of the slide valve takes place in the contrary
direction.
By this novel and advantageous manner of operating the slide valve of a rock
drilling machine, that is to say, by the direct action of the steam on the ends of the
valve carrier, I not only am able to dispense with rods, levers, and other mechanism
which add to the cost and increase the number of parts of the machine, but I also
obtain the full effective power of all the steam admitted into the cylinder, and the
blow of the drill point upon the rock or other substance being drilled or perforated
is much more powerful than would be practicable with the same pressure of steam
when using levers, rods, or other mechanism for operating the slide valve, as hereto-
fore employed.
According to another part of my Invention, I provide means for warning or
giving notice to the attendant immediately the feed of the drill requires adjustment.
For this purpose I employ a device which I terin a "pulse" piston or sounder. The
said device consists of the small cylinder m fixed at the side of the main cylinder a,
and in which is fitted a piston n whose rod n' is arranged to strike the bell or
piece o when the drill requires feeding. The said cylinder m is in communication
with the main cylinder by means of two apertures m', m², through which steam can
pass from one to the other cylinder. The action of the small piston n is entirely
dependent upon the position of the piston b in the main cylinder, as will be apparent
from the following description.
"
The apertures m¹, m², as shewn in Figure 2, are arranged in such a position that
while the drill is working without requiring to be fed or moved forward the
aperture m² will not be opened to the exhaust and the pressure upon the "pulse
piston n will keep the same in the position shewn, but as soon as the feed requires
to be adjusted, the aperture m³ will be uncovered by reason of the main piston of
the machine being driven farther forward and bringing the groove m³ therein
opposite the aperture m², and steam will be admitted alternately at both ends of the
pulse" piston n, thereby giving the same a to-and-fro movement, so that it will
strike the bell or piece o or operate some equivalent sounding device for giving
notice to the attendant. Steam is admitted from the space in front of the piston b
by the passage m* to the groove m³. To provide for the escape of the steam from the
opposite end of the "pulse" piston cylinder, when the piston is thus driven from its
normal position, I turn down the central part 62 of the main piston b so that there is
an annular space between this part of the said piston and the interior surface of the
cylinder a between the two heads or ends of the said piston. When this inter-
mediate part of the piston passes over either of the apertures m², m², the steam
passes from the cylinder m into this annular space, and thence into the exhaust
pipe through the aperture m², Figure 3. Instead of using a cylinder placed parallel
with the main cylinder, as shewn in the Drawing, for the purpose of giving an
alarm, I may place a cylinder at right angles to the said main cylinder, and provide
a lever connected with the piston to sound the bell or other device.
In some cases I dispense with the above-described alarm apparatus, and provide
automatic feed mechanism, as shewn in Figure 5. In carrying this part of my
said Invention into practice, I attach to the main cylinder a of the machine a case p*,
within which is a cylindrical valve p fitted to move to and fro in the said case, the
latter has in its centre an aperture to admit a lever q¹ attached to a rod or spindle q,
the said lever and rod being at right angles to each other. The lever q' fits loosely
into the aperture provided for it in the valve p, so that the latter as it moves
actuates the said lever, and so communicates motion to the spindle q. At the other
end of this spindle there is a toothed wheel q², having a ratchet wheel and pawl in
connection therewith. This toothed wheel gears either directly or through an

page_text: intermediate wheel with another toothed wheel q³ upon the feed screw shaft r.
When the feed has been thus automatically adjusted the valve p returns to its
normal position, and the lever q is also moved back, but the toothed wheels are
not turned backward because of the said ratchet wheel and pawl; the lever q¹ is
then in position to act when the feed again requires adjustment, and I provide some
well-known means for throwing the said ratchet wheel out of gear, so that the
feed motion may be stopped instantly when desired without any danger of deranging
the machine.
The case p* containing the valve p is connected with the main cylinder a by
Buitable apertures or passages whereby steam is admitted to and exhausted from the
said case to operate the said valve as above described.
My improved drill, shewn in Figures 6, 7, and 8, is provided with two cutting
edges c¹ which are not parallel with each other, but converging as will be seen by
reference to Figure 8. This drill provided with the converging cutting edges as
shown is very effectual in cutting grooves or channels in the rock or other hard
substances.
Drills as heretofore constructed for the above purposes have a perpendicular
cutting edge, and have left a series of ridges upon the surface of the rock in cutting
a channel in the same, but by the use of my improved drill a perfectly clean cut is
made, as any ridges left by the one inclined edge of the drill will be removed
during the progress of the same by the other edge which inclines in the opposite
direction.
The converging cutting edges of the drill may be of circular or other shape instead,
of the form shown in the above-named Figures.
For the purpose of conveniently adjusting the said machine for tunnelling or
similar operations, and for fixing it firmly and securely in order to obtain the best
results, I form the lower end 8 of the pillar or column 8 upon which the coupling
apparatus carrying the machine slides, as shewn in Figure 10, that is to say, I make
the same taper, and a corresponding aperture is provided in the frames of the
carriage whereon the said pillar is mounted, so that the latter inay be fitted securely
therein without screws or other fastening devices. The said lower end 8 of the
pillars may be of any suitable shape in cross section other than round. This
arrangement provides means for fitting the said pillar in place expeditiously and
with great security.
To provide for the expeditious raising and lowering of the drilling machine
vertically upon the said pillar, a chain t is attached to the said machine, which chain
passes over a sheave or pulley t' fixed at the upper end of the pillar 8. The said
pulley is attached to a ring to which is placed loosely upon the said pillar, and is
capable of revolving thereon far enough to bring the said pulley into such a position
on opposite sides of the pillars as may be desired, so that it will be vertically above
the drilling machine on whichever side of the pillar the said machine may be. The
ring t may be provided with a projection or shoulder to prevent its dropping down
the pillar, and the said pillar is provided with studs or projections to prevent the
ring from turning too far round.
I provide an improved double coupling as shewn at u, which slides vertically
upon the pillars to permit the easy adjustment of the drilling machine. The said
coupling device is so arranged that it may be turned round the pillar 8, as its axis, to
adjust the machine for drilling on either side as required. Two arms u' project
from the centre or hub of this coupling device one on each side, one being placed a
little higher than the other. These arms u' extend in a horizontal direction, and
upon each one is a box coupling u³ with two apertures drilled or bored in the face
thereof. These apertures are for the reception of a projection or trunnion v on the
bottom of the drilling machine, as shewn in Figure 3, and one or other of the
coupling boxes u² will afford support for the said machine, according to the side of
the column, whereon the machine is to be placed. The said machine is so fitted

page_text: upon the said coupling box that the former is capable of being rotated in a horizontal
direction.
The said coupling device being arranged to rotate around the vertical column 8,
and the machine being upon one of the said boxes on one side of the column, if it
is desired to turn the said machine round to the other side of the column, the
adjustment may be effected instantaneously by rotating the coupling device u. The
drill point will then be in the wrong direction for work, but by reason of the
aforesaid provision for rotating it upon the coupling box, it may be readily turned
round without removal, so as to bring the drill point into the desired position. The
said coupling boxes are made to slide horizontally upon the aforesaid projecting
arms, and they may be turned vertically around the latter to provide for the adjust-
ment of the drill point to any desired angle.
When the machine has been turned round from one side to the other side of the
pillar the ring t carrying the pulley or sheave is rotated far enough to bring the
latter vertically over the machine in its altered position, so that the lifting chain t
will be directly over the machine to raise and depress the latter as required.
Before shifting the ring the chain should be removed from the pulley and
replaced when the ring has been shifted.
I also provide improved means for effecting the rotation of the piston rod and
drill or perforator, and for this purpose I employ devices similar to those described
in the Specification of former Letters Patent granted to me the 25th of May,
A.D. 1876, No. 2208, but the said devices are rendered more efficient in the following
manner, that is to say-Instead of providing a ratchet wheel at the end of a spiral
rod, I form teeth around the interior circumference of the recess in the cylinder head
as shewn in Figure 4, and a pawl w is attached to a hub or disc w' provided on the
end of the spiral rod, the spring w² which keeps the pawl in position being inserted
in a slot in the said hub or disc. By this arrangement the teeth remain stationary
and the pawl w travels around as the piston b rotates. I may use one pawl or two
pawls, as may be most convenient.
By the above-described improvements I construct a drilling machine, which is
powerful in its action, and which can be readily and quickly adjusted to the varying
positions which such a machine has to occupy in the course of its operations.
Having thus fully described my said Invention, and the manner of performing the
same, I wish it understood that I claim,―
First. A drilling or perforating apparatus or machine wherein the valve that
regulates the admission and exhaust of the steam or other fluid is operated without
the intervention of cranks, rods, levers, or similar devices, and whereby the full
force of the steam or other fluid is maintained upon the piston in its forward stroke
until the blow of the drill is delivered upon the rock or other material.
Second. The peculiar construction of the valve and carrier, and the arrangement
thereof in the casing in combination with the admission and exhaust ports of the
cylinder as above set forth.
Third. The apparatus, herein termed the "pulse" piston or "sounder," arranged in
combination with the main cylinder and piston by means of suitable apertures and
passages therein, and operating as and for the purpose specified.
Fourth. The automatic feed apparatus consisting of the small piston in its case or
cylinder, and connected by means of the lever and the ratchet and other gearing
with the feed screw, and operating as above set forth.
Fifth. The ratchet mechanism for rotating the piston and drill constructed and
operating as above specified.
Sixth. A rock drilling apparatus or machine embodying the above-described novel
construction of the slide valve, and the "pulse" piston (or the automatic feed
mechanism) and the ratchet mechanism arranged and operating in combination with
the other parts of the said drilling machine, as and for the purposes set forth.
Seventh. The improved construction of the frame or stand, as shown in Figures 9,
10, 11, and comprising the taper end of column fitted in the taper hole in the base,

page_text: the ring at the top of the said column, and the double coupling for the reception and
support of the machine frame as above set forth and for the purposes specified.
In witness whereof, I, the said William Wallace Dunn, have hereunto set my
hand and seal, this Fifth day of August, in the year of our Lord One
thousand eight hundred and seventy-eight.
W. W. DUNN. (L.S.)