Improvements in Rock Drills.
Year: 1894

page_text: Date of Application, 1st May, 1894-Accepted, 2nd June, 1894
COMPLETE SPECIFICATION.
Improvements in Rock Drills.
I SAMUEL LESEM, of Mining Exchange Building, Denver in the County of
Arapahoe, and State of Colorado, United States of America, Insurance Agent
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:
My invention relates to a rock drill which is provided with a reciprocating
plunger operated by solenoids; which is provided with a movable drill holder
adapted to hold a drill in close contact with a rock to be drilled, which has a
swinging hammer adapted to strike repeated blows upon the end of the drill, which
is arranged to turn the drill after each blow of the hammer so as to bring it into
proper position for drilling, which has means for withdrawing the drill slightly after
each blow of the hammer so as to provide for clearance, which is provided with a
screw mechanism adapted to move the drill holder and drill forward, and which has
all its mechanism connected in a simple and operative manner with the reciprocating
plunger so as to operate by the movement of said plunger.
To the ends specified, my invention consists in certain features of construction
and combinations of parts, as will be hereinafter described and claimed.
Reference is to be had to the accompanying drawings forming a part of this
Specification, in which similar figures of reference indicate corresponding parts in
all the views.
Figure 1 is a broken side elevation of the drill embodying my invention, showing
the hammer in contact with the drill;
Figure 2 is a vertical cross section on the line 2-2 in Figure 1, looking in the
direction of the arrow 2ª ;
Figure 3 is a similar section looking in the direction of the arrow 3*;
Figure 4 is a broken longitudinal section of the machine with the hammer thrown
back and supported on its cushion.
Figure 5 is a detail sectional plan on the line 5-5 in Figure 4; and
Figure 6 is a cross section through the drill holder on the line 6-6 in
Figure 4.
The machine is provided with a rectangular frame 10, which is supported upon
legs 12 adjustably secured thereto, and which has extensible rods 11 extending
longitudinally of it and provided with pointed ends 13 to engage the rock or to
assist in supporting the machine when it is placed on end, the machine being
adapted to be placed in any desired position and yet operate successfully. The
frame 10 is longitudinally slotted, as shown at 14, and the trucks 15 of the sliding
frame 16 are beld to run in this slot, and the sliding frame carries the operating
portion of the drill, all as hereinafter described.
Extending upward from the sliding frame 16 are supports 17, which at their
upper ends merge in a collar 18 in which the drill holder 19 is carried, and this
drill holder lies parallel with the frame and is also supported on another collar 20
which is carried on braces 21, these being secured to lugs 22 of the sliding frame,
as shown by dotted lines in Figure 1. The drill holder is in tubular form, the
holder having elliptical end openings 23 through which the drill 24 extends, and
this drill is also slotted and is held in the holder by a key 24".
The drill may be of any desired form. The drill is struck by a swinging
hammer 25, the shank 26 of which is pivoted in the sliding frame, as shown at 27,
in Figure 4, and the shank of the hammer is carried between rollers 28 in the
forked end 29 of the hammer lever 30, which lever is curved, as shown in the

page_text: drawings, and the two sides 29 of the fork 29 are bolted securely to the upper end
of the lever. The lower end of the lever is secured to a bolt or pin 31 which is
journaled in the sliding frame 16 and which turns with the swinging of the hammer
shank.
The hammer lever 30 projects downward beneath the fulcrum pin 31, and its
_ lower end enters a recess 32 in the center of the reciprocating plunger 33, with
which plunger the lever is connected by means of links 34, these being pivoted to
the lever and also the plunger so as to give the necessary freedom of movement to
the lever and permit the same to swing while the plunger reciprocates. The
plunger 33 is arranged to reciprocate in the solenoids 35, which are of the usual
kind, and are supported on the sliding frame 16. I have not shown any means for
applying the current to the solenoids alternately, but it will be seen that any usual
shifting mechanism may be employed for this purpose.
The plunger 33 lies between grooved rollers 36 which are journaled in frames 37
at the inner ends of the solenoids, and these rollers guide the plunger and prevent
it from contacting with the central tubes 40 of the solenoids. The two solenoids
are preferably bolted together by long bolts 38, but they may be held rigidly in
place in any convenient way.
The plunger 33 is cushioned so that there will be no excessive shock at the ends
of its stroke, and to this end abutment plates 39 are arranged loosely in the
tubes 40 of the solenoids, and the plates are held in place by bolts 42 which are
secured to the plates and also to the caps 43 on the outer ends of the tubes 40.
The spaces between the caps 43 and the plates 39 are filled with wool, as shown
at 44, and the wool serves as a cushion for the plates and absorbs the shock of the
plunger striking against the plate.
It will be seen that when the plunger 33 reciprocates the hammer lever 30 will
be tilted, and the hammer shank 26 operated so as to swing the hammer 25
backward and forward, and in the forward and up stroke of the hammer it is made
to strike upon the drill 24, as shown in Figure 1. When the hammer moves back
it is prevented from creating any great shock and vibration by a cushion block 45,
which is held, by a set screw 46 entering a slot 47 in the block, see Figure 4, to a
socket 48 on the rear end of the braces 21 or on any suitable support, and in the
socket is a cushion of wool 49 which forms a yielding support for the block 45.
The drill is turned, after each stroke of the hammer, by the following
mechanism :-
On the pin 31 is a crank 50 which connects with an upwardly-extending
connecting rod 51 which is steadied by a bolt 52 extending through a slot 53 in
the connecting rod and through one of the braces 21, and at the upper end of the
connecting rod is pivoted a pawl 54 which engages a ratchet wheel 55 secured to the
drill holder 19. It will thus be seen that every time the hammer swings backward,
the crank 50 will tip up, thus lifting the rod 51; and the pawl 54 turns the
ratchet wheel and drill holder, this motion being repeated at every stroke of the
hammer so that after each blow on the drill, the drill will be turned so as to bring
it into a proper position to receive another blow.
After each blow of the hammer, the drill holder and drill are also moved back
slightly to prevent the drill from being choked and also to permit it to be turned
easily, by a lever 58 which is fulcrumed on the supports 17, as shown at 59, and
which has a forked upper end 57 held between collars 56 on the drill holder. The
lever 58 is provided with several holes 60 which may receive fulcrum bolts 59, and
.by means of these the throw of the lever and the consequent movement of the
drill holder may be regulated.
The lower end of the lever 58 is provided with a transverse slot 61 through
which extends a pin 62 which connects the lever with a connecting rod 63 and
permits a certain amount of independent movement of the lever and rod, so as to
provide for a certain amount of lost motion in case the drill meets solid obstruction
during the stroke of the plunger 33. The rod 63 is split so that the lever 58 may
enter it, and in the front end of the connecting rod is a spring bolt 65, the head of

page_text: which engages the front edge of the lever, and the bolt is pressed normally into
engagement with the lever by a spring 66, as shown in Figure 4.
The lower or rear end of the rod 63 is pivoted to the hammer lever 30 and
consequently when the hammer swings back after striking a blow upon the drill,
the lower end of the lever 30 moves forward and the connecting rod 63 is also
pushed forward, thus tilting the lever 58 and pushing back the drill holder 19. It
will be seen that if, during this movement, the drill should meet a serious obstruction,
the slot 61 and spring 66 will permit the rod 63 to move independently of the
lever 58, so that no injury will be done to the machine and some such provision
as this is necessary as the plunger 33 has a positive stroke and does not stop during
its movement.
The continued forward movement of the drill holder and the drill mechanism is
produced by a screw 67 and the mechanism connected therewith, this screw being
held to turn in one end of the frame 10 to which it is attached and also in lugs 68
which are secured to the sliding frame and which are threaded to fit the screw, so
that when the screw is turned, the lugs and sliding frame will be caused to move
longitudinally on the screw. The screw 67 has a squared end 69 to enable it to be
turned by a wrench, if necessary, but it is turned automatically by means of the
swinging hammer and the nut 70, which is mounted on the screw between the
lugs 68. This nut 70 has ratchet teeth upon its periphery, as shown clearly in
Figure 3, and is engaged by a pawl 71 which has an upwardly-extending shank 72
which is secured to the hammer shank 26 by means of a suitable clamping
piece 73.
It will be seen then that when the hammer 25 is thrown back, as in Figure 4,
the pawl 71 is out of engagement with the nut 70, but when the hammer swings
forward and strikes the drill, the pawl swings into engagement with the nut and
thus turns the nut and advances the screw 67 and sliding frame 16 so as to, at all
times, hold the drill up to its work.
It will be seen from the above description that when the solenoids 35 are
alternately energized, the plunger 33 is reciprocated, the hammer lever 30 tilted on
its fulcrum, the hammer 25 swung into repeated contact with the drill 24, the
sliding frame advanced by the screw mechanism described so as to hold the drill to
its work, the drill drawn back and turned after every blow of the hammer, and
consequently a bole will be very quickly drilled.
It will be observed that the construction described is of great simplicity and that
there is very little about the mechanism to get out of repair.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is,
1. A rock drill, comprising a drill holder, a swinging hammer arranged to strike
a drill in the holder, a reciprocating electrically operated plunger, and an operative
connection between the plunger and the hammer, whereby the hammer is swung by
the movement of the plunger, substantially as described.
2. A rock drill, comprising a drill holder, a swinging hammer to strike a drill in
the holder, a reciprocating plunger, oppositely arranged solenoids to work the
plunger, and a lever connection between the plunger and the swinging hammer,
substantially as described.
3. A rock driH, comprising a supporting main frame, a sliding frame therein, a
drill holder supported on the sliding frame, a swinging hammer mounted on the
sliding frame, a reciprocating plunger mounted on the sliding frame, solenoids to
work the plunger, a lever connection between the plunger and the hammer, and
mechanisin actuated by the plunger for revolving and sliding the drill holder,
substantially as described.
4. A rock drill, comprising a main frame, a sliding frame therein, a drill holder
supported on the sliding frame, a swinging hammer mounted on the sliding frame
and adapted to swing against a drill in the holder, a reciprocating plunger,

page_text: solenoids supported on the sliding frame and adapted to work the plunger, a tilting
lever connecting the plunger with the hammer shank, and a lever mechanism
actuated by the hammer lever and adapted to slide and turn the drill holder,
substantially as described.
5. The combination, of the reciprocating plunger, the movable drill holder, the
hammer lever connected with the plunger, the swinging hammer operated by the
hammer lever, the tilting forked lever to move the drill holder longitudinally, and
the connecting rod pivoted to the hammer lever and having a flexible connection
with the forked lever, substantially as described.
6. In a rock drill, the combination with a movable tool holder, of a swinging
hammer operating lever, a lever pivoted to a fixed support and having a forked end
engaging the tool holder, and a rod pivoted to the hammer operating lever and
loosely connected with the lower end of the forked lever, substantially as
described.
7. In a rock drill, the combination with a movable drill holder, of a swinging
hammer operating lever, a pivoted lever having its upper end forked and engaging
the tool holder and its lower end transversely slotted, a rod having one end pivoted
to the hammer lever and its other end slotted to receive the lower end of the forked
lever, a pin passing through the rod and the slot of the forked lever, and a spring
bolt in the front end of the said rod, substantially as described.
8. In a rock drill, the combination with a drill holder provided with a ratchet
wheel, of a pivoted hammer operating lever, a crank on the fulcrum pin of said
lever and a connecting rod having its lower end pivoted to the said crank, and
provided at its upper end with a pawl engaging the ratchet wheel of the tool
holder, substantially as described.
9. In a rock drill the combination with a movable drill holder provided with a
ratchet wheel, of a pivoted hammer operating lever, a crank on the fulcrum pin of
the said lever, a pivoted lever having a forked upper end engaging the tool holder,
a rod pivoted to the hammer operating lever, and loosely connected with the lower
end of the forked lever, and a rod pivoted to the said crank and provided at its
upper end with a pawl engaging the said ratchet wheel, substantially as described.
10. In a rock drill, the combination, of the drill holder, the swinging hammer
adapted to strike the holder, the reciprocating plunger, the oppositely arranged
solenoids for working the plunger, and the tilting lever pivoted to the plunger
between the solenoids and slidably connected with the hammer shank, substantially
as described.
11. In a rock drill, the combination with the main frame, and a sliding frame
thereon, of solenoids, a reciprocating plunger therein, a pivoted hammer shank, a
swinging lever pivotally connected to the plunger, and having a slidable connection
with the hammer shank, a screw, a ratchet nut on the screw and a pawl secured
to the hammer shank and adapted to engage the ratchet nut, substantially as
described.
12. In a rock drill, the combination, with a solenoid and a reciprocating plunger
therein, of a cap plate on the outer end of the solenoid tube, an abutment plate
held loosely within the solenoid tube and connected with the cap plate, and a
packing of wool in the space between the cap and abutment plate, substantially as
described.
Dated this lot day of Mar 1901
let dar of May 1801
t day.
May
S. LESEM;
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.