Pneumatic percussion tool assembly - has ring shoulder on floating bushing forming shock absorbing chamber together with housing

The pneumatic percussion tool consists of a body (1) in which an impact element is operating in a reciprocating motion, acting on a percussion element (2). Inside the ring-shaped part of the body a floating bushing (3) is fitted surrounding the impact element. The floating bushing has a shoulder forming together with a ring-shaped recess on the body (1) a damping chamber (4) connected via a channel (5) and bore (6) with a compressed air source. The other face of the shoulder (3) forms with the enlarged part of shell (7) a second damping chamber (8) communicating with damping chamber (4) via channel (9) and bore (10). After each completed impact the percussion element bounces back from the material of the workpiece and the shoulder on ther percussion element hits the bottom edge of the floating bushing forcing it to travel upwards towards the bushing (14).