Power driven striking tool

Abstract

An airflow regulation arrangement for regulating the impact of the strikes delivered from a striking member (6) to an intermediate member (10) and a bit, thus reducing the vibration, and also for regulating the impact of recoils of the striking member (6) is disclosed for use in an electrical hammer (1). The airflow regulation arrangement comprises an air inlet (14) provided in an air chamber (5) in a cylinder (3) of the electrical hammer (1), exhaust ports (15) provided in a second air chamber (9), and air passages (16) in communication with the air inlet (14) and the exhaust ports (15). The air passages (16) are connected to choke passages (17), the cross sectional area of which is one fifth to one sixth of that of the air passages (16). In a forward stroke of the striking member (6), the compressed air forced out of the second air chamber (9) is gradually released out of the cylinder (3) after passing through the air passages (16) the choke passages (17), which causes a gradual pressure increase in the second air chamber (9) as the striking member (6) moves forward, thereby appropriately braking the striking member (6) and checking the excessive acceleration and the impact of the strikes of the striking member (6).