Patent attributes
A fastening tool is provided, wherein a relief valve piston (65) is arranged that blocks an air passage from an air plug (58) to an accumulator chamber (50) and that opens/closes a flow path of a discharge port of compressed air from the accumulator chamber (50) to the atmosphere. When a state in which a trigger lever (21) is pulled while a push lever is released continues for a prescribed time or longer, a portion of the compressed air in the accumulator chamber (50) is released to the outside from the discharge port to notify the operator that the trigger lever (21) has not returned. If the trigger lever (21) is not returned even after the notification, the compressed air in the accumulator chamber (50) is discharged to the atmosphere at once and an air passage from an air plug (58) to the accumulator chamber (50) is blocked.
