2025 series Tooling
(HK1006)
Alcoa Fastening Systems
8
P
P
RINCIPLE
RINCIPLE
OF
OF
O
O
PERATION
PERATION
PULL PISTON
SPRING
DAMPER VALVE
EXHAUST
AIR PISTON
Hydraulic Oil
Air Pressure
Exhaust Air
HYDRAULIC
PISTON
THROTTLE VALVE
(PULL POSITION)
HYDRAULIC
PISTON
THROTTLE VALVE
(RETURN POSITION)
When the trigger is depressed the throttle valve
moves to the down position. Pressurized air is
directed to the bottom of the air piston, causing
the piston to move upward (Fig.1a).
The air above the piston is exhausted and
directed through the center of the throttle valve
and out the bottom of the tool.
As the hydraulic rod moves upward, a column of
fluid is forced into the head, which moves the
pull piston back.
The attached nose assembly moves with the pull
piston to start fastener installation.
When fastener installation is completed, the
trigger is released.
Air pressure with the assistance of a spring
causes the throttle valve to return to its up
position. Pressurized air is re-directed to the top
of the air piston (Fig.1b), causing the air piston
and hydraulic rod to move downward.
The air from below the piston is exhausted
through the bottom of the tool. Spring pressure
returns the pull piston to its home position.
The damper valve impedes oil flow at pinbreak
helping prevent “Tool Kick”.
Fig. 1a
Fig. 1b
