Patent attributes
A pneumatic tool includes a drive part configured to be driven by compressed air, a control valve configured to switch the presence or absence of operation of the drive part, an on-off valve part configured to switch the presence or absence of operation of the control valve, and a timer part configured to control the operation of the on-off valve part and switch the presence or absence of operation of the control valve after a lapse of a predetermined time. The timer part comprises a timer piston configured to move in one direction and perform timekeeping, and a timer piston housing configured to support a shaft of the timer piston. The timer piston housing is provided with a groove on a guide surface of the shaft of the timer piston, the groove being configured to expand a flow path formed between the shaft and the guide surface.
