| 摘要 |
<p>The percussion unit is designed to be used in a piledriver operating at high speed. It is mechanically or pneumatically driven to its far end position in a guideway. At this end there is a buffer (6) with a closed hollow space holding a gas cushion (10). The buffer has a piston (7), with limited axial sliding motion, protruding parallel to the track of the striker (4). A guideway (1) is fitted with a stop face pressing the piston back against the cusion, short of a predetermined striker interval from the far end point. This provides for increase in percussion energy and/or more rapid striking sequence.</p> |
