Figure 14-19.—Pneumatic drill.
Figure 14-20.—Pneumatic circular saw.
. Wear safety shoes, safety glasses or impact
goggles, gloves, hearing protection, and a hard hat.
. Never rest an air tool on your toes.
. Do not allow horseplay.
. Never point an air hose at yourself or others.
. Always keep both hands on the handle of the tool
while operating.
. Always bleed the airline before removing it from
the tool.
CRAWLER-MOUNTED ROCK DRILL
This section provides only the basic terminology
and procedures used in rock drilling operations. The
extensive knowledge and skills, required to perform as
an effective rock drill operator, must be gained through
formal training or on-the-job-training experience.
A component of quarry operations that contains all
items of equipment needed to drill is the crawler-
mounted rock drill (fig. 14-21). This drill is a self-
propelled unit, designed primarily to drill vertical and
angular blast holes in rock.
NOTE: Consult the operator’s and maintenance’s
manual to obtain information on the type of rock drill
you are assigned.
MAIN FRAME
The main frame is a steel fabrication, designed to
withstand the strain imposed by operation over adverse
terrain. The main frame provides a mounting base for
the various components of the rock drill.
Track oscillation is controlled by two hydraulic
cylinders, connected to brackets welded to both sides of
the main frame and to brackets welded to the track
frame.
The cylinders permit 20-percent track
oscillation, dampen sudden oscillation shocks when
tramming over rough terrain, and stabilize the unit when
setting up on uneven ground.
TRACTION DRIVE
The tracks are driven by a traction device that
consists of a parking brake, an axial piston motor, a
brake valve, and a planet gear reduction. The traction
drive is equipped with spring-loaded, hydraulically
released brakes. The brakes are released automatically
when hydraulic fluid is directed to the motors to move
the unit. The
motors in the
uncontrolled
brake valve, located within each of the
hydraulic circuit, prevents the unit from
runaways on grades. Each brake is
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