Improvements in Rock-drilling Machines.
Year: 1890

page_text: Date of Application, 18th Nov., 1890-Accepted, 16th May, 1891
Improvements in Rock-drilling Machines.
I, THEODORE WELD STERLING, Gentleman, of Union League Club, Fifth
Avenue, in the City, County and State of New York, United States of America,
do hereby declare the nature of this invention 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 rock-drilling machines, and particularly to that class in
which the blows are struck upon the drill-tool or a part holding it, and in which the
drill-tool is rotated between the blows.
The object is to produce a rock-drilling machine which shall be compact, com-
paratively light, and simple and inexpensive of construction, capable of operation
with expenditure of a minimum amount of power, and capable of being rapidly and
conveniently manipulated to bring it into any desired position for use; furthermore,
to accomplish the rotation of the tool or part holding the tool, in a simple and
efficient manner;
furthermore, to accomplish forward-feed of the machine
automatically; and, finally, to accomplish the forward-feed of the machine
automatically, but cause the forward movement to be checked automatically should
the advance be proportionately too rapid.
With these objects in view, the invention consists in the combination with a drill
and the operating mechanism of a striking device therefor, of means connected with
the operating mechanism which will cause a partial rotation of the drill tool between
the blows; furthermore in the combination with a drill and the operating mechanism
of the striking device therefor, of means connected with the operating mechanisin,
acting automatically to accomplish forward-feed of the machine; and, finally, in
the combination with a drill and the operating mechanism of a striking-device
therefor, of means connected with the operating mechanism for accomplishing the
forward-feed of the machine automatically, and for checking the advance auto-
matically, when this becomes too rapid.
The striking device consisting of two hammers, adapted to reciprocate in the
direction of impact and to be reciprocated to and from the line thereof, is not part
of the present application but forms the subject matter of another. The present
invention is capable of use with various striking mechanism.
In the accompanying drawings,
Figure 1) is a view in perspective, representing a drilling machine, the drill-
shaft being in a tube supported on a standard by collar and sleeve, which permits
the drill to be tilted up and down and turned or shifted ground, and also to be
moved longitudinally, or to slide, the striking mechanism to which this rock-drilling-
mechanism is here, for mere illustration of a mode of use shown attached, being in a
housing (the cover of which is removed) projecting backward from the tube of
the drill.
Figure 2) is a top plan view representing the operation of the means of rotating
the drill-shaft and part of the means for accomplishing automatically, feed forward
of the drill and automatic arrest thereof, the cover of the striking-mechanism being
off the stems of the upper hammer and the actuating spring removed, and the end
of the drilling-tube broken off.
Figure 3) is a view in elevation, looking at and into the housing of the striking-
mechanism, between the end of, the forward projecting portion of the movable
frame and the upper end of the drill-shaft, with the housing, for containing
a feed screw and an interiorly-screw-threaded tube (as shown in Figure 6), in
section.

page_text: Figure 4)- -is a view, partly in section, and partly in elevation being a vertical,
central, longitudinal section, taken on the line of Figure 4, showing the drill-
shaft having the surface grooves into which the spline or feathers of the ratchet
wheel are set for a short distance, to hold the wheel on the shaft against turning
independently thereof, but leaving the shaft free to slide or be pushed.
Figure 6)—is a view in vertical, longitudinal section, taken through the rock-
drilling mechanism and through the housing of the striking-mechanism attached
thereto. the end of the rock-drilling mechanism being broken away, leaving
in elevation, part of the drill-shaft, the segmental gear wheel with depending plate
to hold it against displacement inward, the feed-screw for the drill, a rod in the
casing of the drill-tool, attached at its outer or lower end to the drill-shaft by
means of a projection therefrom, to be moved longitudinally thereby, (as shown in
Figure 9) a part of the front pin from the longitudinally-movable connecting-frame,
part of this connecting-frame and a cam shaft with can to enable the shaft to be
pulled back by hand; furthermore, leaving, in elevation, of the striking-mechanism,
the hammers to display their shape, their springs, the stem, appearing, of the lower
one, and its tube (more fully seen in Figure 13)-the view representing the means
for producing forward-feed of the machine and parts of the means for automatically
arresting the feed in conformity with the work to be performed.
Figure 7) is a view, in elevation, the end of the housing being removed to
display the parts, representing the rear of the striking-mechanism with means, from
the operating-mechanism thereof, of actuating the feed of the machine and rotating
the drill.
Figure 8) is a view in perspective, representing the main driving-shaft with
means for actuating the feed of the machine and the rotation of the drill.
Figure 9) is a view in perspective, with a portion of the drill-tube removed to
display parts therein, and the drill-shaft and tube being cut off outside of or beyond
the situation of the shells, representing, in detail, the means for automatically causing
and for automatically arresting the feed of the machine on its standard.
Figure 10) is a view, partly in elevation and partly in section.
Figure 11) is a view, in side-elevation, the housing being removed, representing
the manner of drawing back the hammers against their springs.
Figure 12) is a view in perspective, representing, in detail, the means of moving
the arm up and down to reciprocate the movable frame.
Figure 13) is a view, in vertical, longitudinal section, taken through the fore-
part of the stationary frame and the rear portion of the movable frame in the line
of a stem, each, for the upper and lower hammers, leaving the stems (broken away
toward the hammers) in elevation, as well as locking-levers or roller-pawls, pawl-
springs, and a guide-bar, the casing being removed to display the parts.
Figure 14) is a view in perspective, representing the greater portion of the
stationary frame on the block, in a front recess or jaw of which the inovable frame,
carrying the hammers, slides; and
Figure 15) is a view in perspective, representing the greater portion of the
movable frame in which the hammers are mounted.
In these drawings, H represents the drill-shaft in a tube H2 supported on a
standard by a sleeve and collar i which permit the drill to be moved longi-
tudinally, or to slide, on the standard, and also to be tilted up and down and turned
or shifted around. At its upper end, the drill-shaft is provided, at its surface,
with longitudinal grooves h², and upon this end is a shell, which I call the ratchet-
shell, consisting of a head portion ³ provided circumferentially with ratchet-teeth,
and a body-portion, the shell being secured upon the shaft in such a manner as
to turn with it, but yet to slide thereon, that is to allow the shaft to be moved longi-
tudinally without moving the shell, the securement being by short feathers or
splines which project from the head portion toward the center into the grooves
in the shaft, the feathers filling the grooves in width but not filling them in length.
Upon the end of the body-portion, the ratchet-shell is provided with a cleat 4*,

page_text: taking against the end of the body of an outer shell for a purpose presently to be
explained. Surrounding the ratchet-shell and turning loosely thereon, is this outer
shell, which I call the gear-shell, having a head portion and a body portion h³,
the head portion being provided at a part of its circumference with spur-teeth h³
and being cut away at the front portion at another part of its circumference,
leaving a flange at the back for a hanger or plate depending from the housing
of the striking-mechanism to take against, to hold the shell against displacement
inward. The gear-shell has a feed-pawl set through the opening through the
rim and projecting toward the center, and this pawl takes against one of the ratchet-
teeth on the head of the ratchet-shell, the pawl being held in engagement by a
spring set in a countersink 15 in the rim. At a portion of the circumference
opposite the teeth, the rim of the head of the ratchet-shell has an opening or
slot 6 through which takes a stop-pawl 4, against a ratchet-tooth, the stop pawl
being pivoted to the housing and having a suitable spring. It will be clear that as
the depending plate prevents the gear-wheel from being displaced inward, and the
cleat on the body of the ratchet-shell bears against the end of the body of the
gear-shell, this cleat serves to keep the ratchet-shell also from displacement
inward. The upper end of the shaft and the shells are set and turn in a boss 418
screwed into the upper end of the tube.
Mounted laterally outside of the housing of the striking-apparatus, is a rock-
shaft Khaving a crank-arm k projecting into the housing and at the other end to
this arm, to throw the arm up, the arm having teeth at its end, meshing with a
part-gear, being the spur-teeth h on the rim of the head of the gear shell. At the
other end, the rock-shaft has a lateral extension which is taken under by a cam e
on the main shaft E of the machine. It will be obvious that as the main-shaft
revolves, the cam coming under the extension at the rock-shaft, will move this
causing, from its arm, a partial rotation downward of the gear-shell, by the feed-
pawl, on which the ratchet-shell will be turned to the extent of one tooth, giving
this extent of the turn to the drill-shaft, while, as soon as the cam escapes from
under the lateral extension of the rock-shaft, the spring on the crank-arm will
throw the arm up, giving a partial rotation to the gear shell in the opposite direc-
tion, thus bringing its pawl into engagement with a higher tooth, the stop-pawl
acting to retain the ratchet-shell in position, while the feed-pawl is out of contact
with a tooth. The position of the cam upon the drilling-shaft, is such with relation
to, the actuating mechanism of the striking-device, and its operation so timed with
relation to the operation of the hammers, that the drill-shaft will be given a partial
rotation, between the blows of the hammers.
To the sleeve in the tube H preferably to a bracket projecting from the sleeve,
is attached an internally screw-threaded tube L, and this tube enters and is free to slide
into another tube M in the lower part of the housing of the striking-mechanism and
entering the other end of the screw-threaded tube through the tube in the housing
is a screw-shaft N, free to turn in the housing but fixed therein as by a collar
abutting against an off set in the tube, against longitudinal motion, whereby, upon
turning the shaft in one direction or the other, the machine will be advanced or
retired on its standard. This screw-shaft has upon it a loose collar provided at
its rear with teeth, and formed with or fixed to this loose collar is a screw gear-
wheel n². Behind the collar is a second collar, provided at its front end with
teeth, and arranged to turn with the screw-shaft by means of a spline and groove
or the like, but free to move on the shaft longitudinally. Upon the main-shaft E
is another screw gear-wheel e, from which the screw gear-wheel on the loose collar
on the screw-shaft is turned, and, by which, when it is connected with the spline-
collar behind it by the teeth on both, the shaft will be turned, but which will turn
idle, when it is not connected with or attached to the spline-collar.
In the lower part of the housing is a connecting-frame capable of limited
longitudinal movement, through which frame the screw-shaft is automatically
thrown into action to accomplish forward-feed of the machine or automatically

page_text: stopped, to discontinue the feed, the rear cross-piece of the connecting frame taking
into a groove n of the spline-collar, so that the spline-collar can be moved
longitudinally on the shaft by the frame. Projecting backward from the frame are
pins, which enter suitable holes in the housing, and, upon these pins, between the
housing, and the end of the frame, and spiral springs, which tend to push the
frame forward. As the frame is pushed forward, it carries with it the spline-
collar whereupon the teeth upon its front end catch into the teeth at the rear end
of the loose collar carrying the skene gear-wheel, forming a latch, so that, when
from the slanting toothed gear-wheel on the main shaft, the skene gear-wheel and
collar on the screw-shaft, are turned, the spline collar will be turned, and by it
the shaft; but, when the frame is pushed backward, it carries back with it the
spline-collar, whereupon the teeth upon its front end part from engagement with
the teeth at the rear end of the loose-collar carrying the screw gear-wheel
uncoupling the clutch, so that, when from the screw gear-wheel on the main-shaft,
the screw gear-wheel and the collar on the screw-shaft are turned, those will turn
idly and the shaft will not be turned.
The connecting frame has at its front end another pin o³ which projects into the
tube of the drill or into a channel along the under side thereof. In the lower part
of the tube or channel is a rod 20 which abuts against the pin of tye frame, the
other end being attached by means of a collar 2 surrounding it, to the drill-shaft,
to removed longitudinally thereby. Fixed in the tube is a disc, through which
the shaft passes freely; and, outside of the collar the shaft has an enlargement 23
which bears against the collar. Between the collar and the disc the shaft is
surrounded by a strong coil-spring, and into the end of the tube is screwed an end
bearing for the drill-shaft, the drill-shaft having screwed upon its end a square
socket to receive and hold the drill-tool. It will be obvious that when the drill
is pushed backward against the spring, as by excessive resistance, which would
otherwise result in more rapid feed of the machine than penetration of the drill-tool,
the rod will push against the front pin of the frame and the frame will uncouple
the clutch thus stopping the feed automatically.
To arrest the feed by hand, there is provided a cam shaft the cam of which 20
takes over the rear cross-piece of the connecting frame. The shaft is provided
with a handle outside the housing. By turning the handle bringing the broader
part of the cam against the cross-piece, of the frame, the frame will be drawn back-
ward and the clutch uncoupled. Upon turning the handle bringing the narrow
part or edge of the cam against the cross-piece of the frame, the frame will be
thrown forward, by the spring at the rear, and the clutch coupled.
Of the striking mechanism, to which the drill is here shown applied, A A
designates two hammers, having enlarged portions or heads aa², provided with
pins a a, and one or more reduced portion each, or stems, aa, provided with
outward-facing rounded notches a² as, near their ends. The hammers are mounted
one above the other but free to slide independently lengthwise, in a movable
frame B, consisting of two portions, an upright portion and a forward-extending
portion, the extension having, at the side of each hammer, an inward-projecting,
longitudinal tongue or guide-rib which takes into a corresponding groove a, to
steady each hammer and hold it in proper position against individual displacement
to or from the line of stroke, that is, in the present embodiment, against displace-
ment up or down, as the hammers, in this instance, are shown one above the other
(though they may be side by side) the movable frame having, furthermore,
tubes fixed in the front face of the main portion toward the hammers, and
which the ends of the stems of the hammers enter, free to slide therein. Upon the
stems of the hammers, are spiral springs, C, C2, which abut at one end against
the front face of the movable frame, over the tubes, and, at the other, against the
enlargements or heads of the hammers, these springs being the hammer actuating-
springs. The movable frame has grooves 6, in the sides of the upright portion, to
permit the frame to be guided in its movements, and has furthermore, an arm b

page_text: fixed in it near its top and projecting backward beyond its rear face by which arm
the frame can be moved, and recesses in the rear face, respectively, from above
downward and from below upward, each recess ending in a rounded opening into
which a tube is set, the recesses containing locking-levers or pawls, 60, to
engage the notches in the stems of the hammers as shown in Figure 13, and levers
carrying rollers that enter the notches, in order that upon pressure of the levers
outward, the pawls may readily slip out of engagement with the hammers and
release them to be actuated by the springs, and having their free ends projecting
beyond the plane of the rear face of the movable frame, to be struck and thrown
out of engagement with the notches. Behind the movable frame, is a stationary
frame or the block D, consisting of a main portion d, and upright strips or pieces d³,
confining the shafts at their bearings in the frame, the main portion d, having a
recess or jaw, into which the movable frame is set, with its grooves upon guide-
bars d, and with its arm in a cleft ³.
Projecting into the jaw from the top and bottom of the block, are springs dd,
which, being opposite the recesses in the movable frame, are in position to act
against the locking-levers, as required, the locking-levers being thrown out of
engagement with their notches in the hammers by striking against stops ds. Set
into the block at the rear, and at its lower part, is the main-shaft E, having spur-
wheels e, ², and crank or crank bends e³, e, also a cam e, and, above the main-shaft,
a second shaft F, with spur gear wheels. the gear-wheels e and fande and f²
respectively, on the two shafts intermeshing, cranks, at the ends of the shafts
and a crank, between the gear-wheels, or intermediate in the length of the shaft,
the two shafts being so geared that the cranks or crank-bends on the main shaft
and the cranks on the ends of the second shaft, will be respectively in position
relatively diametrically opposite, and the cranks carrying links, G, G³, which turn
on them at one end (the rear end) and at the other end take over the pins on the
hammer-heads, the cranks on the main-shaft bearing the links which take over the
pins on the head of the lower hammer, and those on the second shaft carrying the
links which take over the pins on the head of the upper hammer. It will be
obvious that as the main shaft revolves, the hammers will be drawn back one after
the other, by tye links. Upon the intermediate crank of the second shaft, is
journaled a box, into which an arm passes, through the cleft d³, the box
sliding slightly but freely on the arm. It will be obvious that as the second shaft
is turned and its intermediate crank or crank-bend revolves, with its box, the arm
will be moved up and down, carrying with it the movable frame, which is in this
manner moved up and down, whereby the hammers by it carried, will be recipro-
cated and there will be a period of rest at the end of each movement up and down,
before the opposite movement begins, it being clear that the period may be
made greater or less by well known means, for example, greater by having the box
larger in vertical diameter the end of the arm,
As already described, the stems of the hammers are provided near their ends,
with notches, and the movable frame with pawls. Now the intermediate, crank on
the second shaft is so set that when the upper hammer is drawn back with its spring
or springs compressed to the fullest extent, the movable frame will be at its upper-
most limit of motion, bringing the upper pawl or pawls against the upper pawl
spring or springs, and forcing the pawl into the notch or notches, of the upper
hammer, retaining it until upon movement of the frame in its contrary direction,
about centrally, the pawl or pawls will strike against the stop on the stationary
frame, and, releasing the stems or stem, the upper hammer will be shot forward by
the actuating springs or spring to deliver its blow; while the lower hammer is
drawn back its spring or spring compressed to the fullest extent, the movable frame
will be at its lowermost limit of motion, bringing the lower pawl or pawls against
the lower pawl spring or springs and forcing the pawl into the notch or notches of
the lower lammer, retaining it until, upon movement of the frame in the contrary
direction, about centrally, the pawl or pawls will strike against the projection on

page_text: the stationary frame, and releasing the stem or stems, the lower hammer will be
shot forward by the actuating spring or springs to deliver its blow. Otherwise
stated, the shafts are so geared with other, that they act upon the respective
actuating springs through their cranks and connecting links alternately, and the box
mounted on the shaft is so arranged with relation to the other moving parts of the
machine, and its operation is so timed, that each hammer respectively is at the
outward limit of the motion of the frame farthest removed from, the drill-tool or
part holding the drill-tool when its spring is compressed and the notch in the
hammer is enterred by its pawl, and it is carried to a point opposite the drill-tool
when its locking-lever is moved from the hammer releasing it.
It may be here noted that delivery of a blow takes place at a time when the
reciprocatingly-moving frame having reached its extreme position in one direction
or the other, is about to retrace its course, that is, at a moment when it is deprived
of motion, having no motion either in one direction or the other. The delivery of
a blow being practically instantaneous under the quick action of the springs, it may
be said that the movement of the hammer at that to me is all in one direction, that
is, in the direction of the object to be struck.
The advantage of reciprocation of the operative part to and from the line of
direction of its action, is, first, that, by reciprocation, more than one hammer can be
employed, instead of having to use a single hammer, thus dividing the labor and
consequent wear and tear and, secondly, that, by reciprocation, or alteration, as
distinguished from constant motion onward, or succession, a period of rest is afforded,
at the end of each movement, namely just before return, and just then the striking
can be performed.
It will be obvious that the screw-device may be employed for causing the striking-
device to advance or recede by itself.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1) In a rock-drilling machine comprising a striking-device composed of two
hammers reciprocating in the direction of impact and also in a line crossing that of
the impact, mechanism for imparting the desired movements to the striking
mechanism, a drill-tool, and a rock-shaft connected with the drill-tool, or to a part
holding a drill-tool, and receiving motion from the operating mechanism of the
striking-device, substantially as described.
2) In a rock-drilling machine comprising a striking-device composed of two
hammers reciprocating in the direction of the impact and also in a line crossing
that of impact, mechanism for imparting the desired movements to the striking-
mechanism, a drill-tool, and a rock-shaft connected to the drill-tool or to a part
holding a drill-tool or to a part holding a drill-tool by a ratchet-feed, and receiving
motion from the operating mechanism of the striking device, substantially as
described.
3) In a rock-drilling machine comprising a striking device composed of two
hammers reciprocating in the direction of impact and also in line crossing that of
impact, mechanism for imparting the desired movements to the striking-device, a
standard upon which the machine is mounted, a connection between the standard
and the operating mechanism of the striking-device, and a screw receiving motion
from the operating-mechanism and imparting a longitudinal movement to the
connection, substantially as described.
4) In a rock-drilling machine comprising a striking-device composed of two
hammers reciprocating in the direction of impact and also in a line crossing that of
impact, mechanism for imparting the desired movements to the striking-device, a
standard upon which the machine is mounted, a longitudinally-movable connection
between the standard and the operating mechanism, and a clutch attaching the
connection to the operating mechanism, substantially as described.

page_text: 5) In a rock-drilling machine comprising a striking-device composed of two
hammers reciprocating in the direction of impact and also in a line crossing that of
impact, mechanism for imparting the desired movements to the striking-device, a
standard upon which the machine is mounted, a longitudinally-movable connection
between the standard and the operating mechanism a drill-tool holder having a
limited longitudinally-movement, and a connection between the tool-holder and the
clutch, substantially as described.
Date: 10 £ N 1000
THEODORE WELD STERLING.
Per G. G. M. Hardingham,
191, Fleet Street, London, E.C., Associate Agent.
THEODORE WELD STERLING.
Per G. G. M. Hardingham,
191, Fleet Street, London, E.C., Associate Agent.