Hitachi NV 83A2 Technical Data And Service Manual page 17

(2) When the trigger and pushing lever are operated:
Cylinder ring
(F)
When the piston passes the middle vent, some of the air pressure passes into the
return air chamber. This supplies auxiliary air to ensure complete return of the piston.
When the cylinder moves down,
compressed air from the head cap
section enters the passage to the
feed piston.
(D)
Compressed air is applied
to the upper side of the
exhaust valve, forcing it
downward and closing
the exhaust vent.
(E)
The air pressure applied to the left-side surface of the feed piston
overcomes the spring force on the right-side, and moves the feed
piston to the right. The feeder then catches the next nail.
(E) As the piston moves downward, the air below the piston
is forced into the return air chamber.
(D)
Although air pressure is applied
to both the upper and lower
surfaces of the cylinder, the
cylinder is forced downward due
to the larger effective area of the
upper surface.
Accordingly, the upper portion of
the cylinder is opened, and the
compressed air forces the
piston downward.
(B)
When the trigger and pushing lever are
operated simultaneously, the safety
valve and trigger valve are opened.
The trigger and pushing lever are operated
(A)
simultaneously.
(Note)
If either the trigger or pushing lever are
operated individually, compressed air will
not enter the valve air passage, and the
nailer will not function.
(C) When the trigger and pushing
lever are operated
simultaneously, the exhaust
vents are closed.
Fig. 5
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