| 摘要 |
<p>A pusher comprises a body with a plurality of piston holes provided on a front surface thereof, pistons slidably fitted to the piston holes and each having a front end extending in front of the body, an oil passage provided in the body and communicated with a bottom portion of each piston hole, a pressure chamber provided in the body and communicated with the oil passage, a threaded shaft threadably fitted to a threaded hole which is provided in the body and communicated with the pressure chamber, and oil filled in the bottom portion of each piston hole, the oil passage and the pressure chamber, where the piston is adapted to be pushed in front of the body by the threadable advancing of the threaded shaft at force larger than the advancing force of the threaded shaft.</p> |
