| 摘要 |
<p>The device exploits the striking mass rebound energy, which depends on the hardness of the material on which the tool operates. It is based on the functioning of the device as in the European Patent No. 0085279, and in providing adequate means to vary the distributor stroke during the piston upward-moving phase, as to anticipate or to postpone the percussion phase when the tool operates respectively on a less or more hard material. In this first case, the anticipation of the percussion stroke causes a decrease in the volume of the cylindrical chamber where the pressurized oil works and therefore, under the same power, it causes an increase in the blows frequency, if the working oil flow mantains unaltered.</p> |
