Air spring type striking mechanism with return air spring

摘要

A pneumatic percussion power tool has a percussion tool housing in which a drive piston and a percussion piston are movable in an axial direction. The motion of the drive piston, which is generated by a crank mechanism, is transmitted to the percussion piston through a pneumatic spring in a first chamber so that the percussion piston cyclically strikes a ram or a tool. The backward motion of the percussion piston rebounding from the ram is supported by increasing air pressure in a third chamber that is supplied with air by the drive piston through a second chamber and a communicating channel.