TM 5-3820-239-15
of the hole under normal feed pres-
(2) Operate the drill from the remote
sure.
control manifold (fig. 2-8) by fol-
(6) Move the DRILL control on and off
lowing the procedure:
in short bursts until the coupling is
(a) Blow out main air line hose, check
loose on the shank piece.
lubricator for oil, and connect main
(6) Shut off the DRILL control.
air line. If drill is new, remove air
(7) Place the ROTATION selector in the
hose at drill and turn on air supply
reverse position.
when oil vapor emerges from hose.
(8) Use the FEED control to raise the
Reconnect hose to drill.
drill, allowing the shank piece to
(b) Install drill steel & bit in drill
drop clear of piston action. Keep the
and close centralizer arms above
shank piece clear of hammer range
bit.
when using reverse rotation to un-
(c) Position drill guide to the desired
screw threads. Threads can be dam-
aged by the hammer blows when not
guide extension cylinder until the
in full contact.
foot piece is firmly against the
(9) Operate the DRILL control at part
throttle to unscrew the shank piece
(d) Turn drill blow control on, use the
`from the coupling.
feed motor control to move drill
(10) Shut off the DRILL control.
until bit is just above rock. Put ro-
(11) Retract the drill to the top of the
tation control in forward. Turn on
drill guide.
drill control to rotate bit slowly.
(12) Lubricate the threads at both ends of
Feed bit down into rock and collar
the coupling.
hole.
(13) Screw a coupling on one end of the
(e) After collaring hole, turn drill con-
trol on full and adjust feed to al-
extension rod by hand.
(14) Align the extension rod and coupling
low steel to rotate freely.
with the shank piece and screw the
(f) After hole is bottomed, shut off
other end into the coupling resting
drill. Use the drill blow control to
on the centralizer.
clean out hole. After hole is
(15) Screw the coupling to the shank piece
cleaned, shut off all air blow, and
retract drill steel from hole.
by hand, as tightly as possible.
(16) Place the ROTATION selector in the
(g) If needed, add another drill steel
conventional (left-hand) rotation po-
to deepen hole or move drill to
sition, and operate the DRILL control
next position for new hole as re-
quired and repeat cycle.
at part throttle to tighten up the ex-
tension rod at both ends.
e. Adding Extension Rods.
(1) Shut off the drill control at the re-
Caution: Do not use the hammer
mote control manifold.
control to tighten parts since damage
(2) Use the feed control to retract the
to threads on the shank piece end ex-
drill to free the bit from the bottom
tension rod may occur if the shank
of the hole.
piece is struck before the threads are
(3) Place the ROTATION control in the
in full contact.
neutral position to stop rotation.
(17) Repeat the entire procedure for each
Caution: The drill power can be
extension rod added.
cedure must be done with no rotation.
Do not use reverse rotation to loosen
a. Shut off the DRILL control at the remote
control manifold.
b. Use the FEED control to retract the drill
(4) Use the FEED control to lower the
steel from the hole.
drill, and hold the bit at the bottom
2-9