| 摘要 |
The tool head (1) contains a piston (4) which can be moved backwards and forwards between the percussion part of the tool and a piston strike surface (6). A spring (5) keeps the piston under tension in a position separated from the strike surface by a gap, and when the percussion part is struck the piston is moved backwards towards the strike surface against the force of the spring. A damping layer (8) is provided on the piston strike surface. |
