2
Fig. 1
Fig. 2
Fig. 3
Head valve bumper
Port between head valve and trigger valve
Resevoir of high pressure air
Trigger valve released
Passage for air release from head valve
Bumper
Hole in cilinder wall
Return chamber
Resevoir of high pressure air
Head valve closed
Exhaust is open
Exhaust sealed by head valve bumper
Trigger valve actuated
Air released from above head valve
Driving stroke
Piston is sealed against bumper
Trigger valve still actuated
Air flows into return chamber
Exhaust still closed
Head valve open
Head valve open
End of stroke trigger still pulled
At rest
