| 摘要 |
A pneumatic drive for a hammer tool has a cylinder; a piston slidably received in the cylinder and dividing the inner space of the cylinder into two cylinder chambers; a drive output member formed as a piston rod attached to the piston and projecting from the cylinder; a pressure-responsive valve for admitting compressed air alternately to the cylinder chambers; and a plurality of spaced, serially arranged cylindrical discharge ports in the cylinder wall for releasing compressed air alternately from the cylinder chambers dependent upon the position of the piston with respect to the discharge ports. |
