| 摘要 |
The subject matter of the invention is a hammer drill with a percussion mechanism which contains a cylindrical guide tube which is provided with air-control openings and in which a drive piston operable via a motor is guided in a sliding manner, which drive piston pneumatically sets a striking body in a reciprocating movement, which striking body is freely movable axially in the guide tube and releases its energy directly or via an anvil to a tool guided in the hammer. In order to obtain effective sealing of the buffer zone as well as good thermal stability of the percussion mechanism and its reduction in weight in electro-pneumatic hammer drills of this type, the invention provides for at least the cylindrical guide tube (28) and the drive piston (17) moving relative to it and/or the striking body (22) freely movable axially in the guide tube or in the drive piston to be made at least partly of a ceramic material. <IMAGE>
|
