Improvements in Rock Drills.
Year: 1899

page_text: Date of Application, 12th Oct., 1899-Accepted, 18th Nov., 1899
COMPLETE SPECIFICATION.
Improvements in Rock Drills.
We, RUSSELL AVERY, of Sausalito, County of Marin, Miner, and HENRY COOK
CAMPBELL, of No. 528, California Street, in the City and County of San Francisco,
Attorney-at-Law, all in the State of California, 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 an improvement in apparatus for drilling rock and
the like, and it consists of mechanism by which the drill is supported and guided
in a straight line, and is automatically turned in unison with the movements of
the man who strikes the drill, by means of a direct connection between the turn-
ing mechanism and the body of the striker.
A device is employed for retracting the point of the drill a little from the face
of the rock at the instant of turning so that it will not bind in the hole.
Referring to the accompanying drawings, Fig. 1 is a general view of the
machine. Fig. 2 is a horizontal section of the same. Fig. 3 is a lateral section
on the linear. Fig. 4 is a detail view of the ratchet sleeve. Fig. 5 is a detail
view of the sleeve carrying the drill clamps.
The drill shank B passes longitudinally through an exterior casing which is
here shown as composed of the parts A A¹ screwed together.
The rear end of the part A has a bushing P made in two parts to screw into
the casing, and the hole through the bushing is sufficiently large to allow the
drill to turn freely in it.
The part A is formed with an interior hub, and into this hub screws another
split bushing U having a hole similar to the bushing P so that the drill is
centrally supported in the casing by these bushings, and may be removed there-
from at any time by unscrewing the bushings to allow it to slide out.
Within the rear portion of the casing is a sleeve C having a flange C.
The body of the sleeve surrounds the drill which passes through it without
contact with its interior, and a spring Ca surrounding the outside of the sleeve
has one end abutting against a washer in the interior of the casing A, and the
other end pressing against the flange C¹ of the sleeve so as to press the sleeve
forward.
Around the hub which projects into the interior of the part A¹ of the casing,
is fitted a sleeve D D formed in two diameters, the larger diameter being approxi-
mately equal to that of the flange C, and arms D2 project from this part of the sleeve
into corresponding slots e made in the flange C, thus uniting the sleeve and the
flange so that when the sleeve D¹ is turned the sleeve C, with its flange C¹, will
also be turned, but the arms 12 are slidable loosely in the grooves in the flange,
so that there is a certain amount of independent movement of the two sleeves.
Gripping jaws L are fulcrumed exterior to the flange C, and have springs O
which normally act to separate the jaws.
The approaching edges of the jaws lie upon opposite sides of the drill shank,

page_text: and when the jaws are closed inwardly by pressure from the sleeve D', as will
be hereafter described, they press the jaws and cause them to grip the drill shank,
so that the parts being then turned around will also act to turn the drill.
This turning of the sleeves C 1) is effected by means of a pawl and ratchet
mechanism. The ratchet teeth are formed upon the outside of the sleeve D), and
the pawl E is carried by a ring F which turns loosely on the outside of the
toothed part of the sleeve D as shown.
A slot is made through the side of the casing A', and through this slot projects
an arm, the inner end of which is fixed to the pawl carrying ring F. The
length of the slot is sufficient to allow this arm such movement in the direction
of the circumference, as will be sufficient to advance the pawl and turn the
toothed sleeve I) sufficiently to turn the drill the required distance at each
movement.
The outer end of the arm F is connected by a cord of proper length with the
belt or other convenient attachment upon the person of the one who uses the
hammer to strike the drill, so that when this man swings back the hammer, he
partially turns his body and pulls upon the lever arm F, thus turning the ring F,
and by the engagement of the pawl E it turns the sleeve 1) and this, acting
through the arms D2, will turn the sleeve C which carries the grips L, and as
these grips press upon the drill, they will turn the drill freely in its supporting
bushing P and U previously described.
If two men are striking the drill, each one may have a cord connecting himself
with the arm F¹ so that when one man swings back, he turns the drill for the other
one to strike, and when this other one swings back he turns the drill for the
first man to strike, thus alternating.
In order to loosen the drill after each stroke to prevent its binding in the
rock, and to retract it sufficiently to allow it to turn freely, we have shown a ring K
fixed within the casing A', and having upon one side teeth J.
Similar teeth J are made in the contiguous portion of the larger part D of
the sleeve, and when the sleeve D 1 is turned by the movement of the pawl
ring F, it will cause the teeth J to move over the teeth J. This acts to push
the sleeve D D away from the ring K and by the pressure of the lugs or pro-
jections upon the grips L these grips are pressed against the drill, thus grip-
ping it and pulling it back, because the action of the teeth J J pushes the
sleeve back and acting through the gripping jaws upon the sleeve C, this
sleeve C is also pushed back against the tension of its surrounding spring C3, and
as this sleeve C C carries the gripping jaws, it will be seen that the drill will be
retracted at the instant when it is being turned by the action of the pawl and
ratchet.
As soon as the teeth J have passed over the highest points of the teeth J¹, they
will be in position to drop into engagement with said teeth, and the spring C
immediately pushes the sleeve C, the gripping jaws L and the drill forward until
the drill point again rests against the rock ready for a new stroke.
The manner of supporting these parts carried by the casing A A¹ so as to direct
the drill and keep it in a straight line, and also to allow it to be withdrawn
from the hole and then moved to one side for the purpose of cleaning out the
hole, and then allowing the drill to be brought back exactly into position without
changing its alignment with the hole is as follows:
R is a column or standard fixed solidly within the drift or other part where
the drilling is being carried on. This column is rectangular or polygonal, and
has a sleeve Q fitting and slidable upon it. Qis a clamp fixed to the
casing A A and turnable about the sleeve Q and also slidable longitudinally
with this sleeve. When the drill is to be set to work in any particular
direction, the casing is moved until the drill stands in the line desired.
collar T is then moved along the column 1 until it contacts with the clamp Q
and is fixed in that position. The sleeve Q1 which also abuts against the collar T
is fixed to the column by a set screw S. The clamp Q is then turned about the
A

page_text: sleeve until the casing and drill have been turned to give the drill a proper
alignment, and the clamp is then rigidly secured upon the sleeve Q. The drill-
ing may then go on by one or two men striking the head of the drill which is
automatically turned at each stroke, as previously described, until it is necessary
to clean or inspect the hole.
By loosening the bushings P and U, as before described, the drill can be
withdrawn from the casing sufficiently to clear the hole.
By loosening the set screw S without loosening the clamp Q the sleeve Q¹
may be moved along the column R until the drill and casing have been moved
transversely out of line with the drill hole, but without changing the alignment
of the drill.
The inspection or cleaning having been accomplished the sleeve Q is then
moved back until it contacts with the fixed collar T, and is again locked in place
by the set screw S. The drill will now be exactly in line with the hole in the
rock and can be again introduced and the work proceed.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
1st. In a rock drill, a casing through which the drill is guided and movable,
a fixed support or column, a sleeve slidable longitudinally upon the column, and
means for securing it thereto, and a clamp fixed to the drill-carrying casing and
turnable about the sleeve to give direction to the drill, with means for securing
it upon the sleeve, and preserving alignment.
2nd. In a rock drill having a casing and a support therefor, a drill extending
axially through the casing and guided thereby, a mechanism for intermittently
turning the drill and a cord connecting the mechanism with the belt of the
hammer wielder whereby the drill is raised and turned at each swing of the
body in making the stroke.
3rd. A rock drill having an adjustably supported guide, a pawl and ratchet
mechanism connected by a cord with the belt of the hammer wielder, whereby
the drill is intermittently turned between the hammer strokes, and a mechanism
by which the drill is automatically raised from the bottom of the hole after each
stroke to allow it to turn.
Dated this 12th day of October 1899.
For the Applicants,
GEDGE & FEENY,
Chartered Patent Agents, 60, Queen Victoria Street, London, E.C.