| 摘要 |
A stroke (16) is produced if pressure (P) is put on the working space (11",10) between piston (5,7) and housing (1,2,3). The movement of the piston is limited either by a pole (28') or a flexible wire, that is fixed to the housing in the raking space and surrounded by a spring (23,31) that reverses the movement (22) of the piston. If the movement is limited by a pole, an impact element (53) is mounted on the pole at a variable but fixed position, that can be accessible through a window (58) in the piston. In case of a wire the movement is limited by the length of the wire only. Between the moving piston and the housing a gasket (40) can be mounted. |
