| 摘要 |
The present invention relates to a linear driver (1,101) and particularly, but not exclusively, to a linear driver for use in the field of civil engineering or construction, for example in the formation of piles or piers as foundations. The driver (1,101) comprises a weighted sleeve (12,111,113) slidable relative a driving member (2,102), and a valve arrangement (20,120) to control the linear movement of the weighted sleeve (12,111,113) relative to the driving member. Closing the valve arrangement (20,120) serves to stop movement of the weighted sleeve (12,111,113) and transfer momentum to the driving member (2,102) without physical impact between the weighted sleeve (12,111,113) and the driving member (2,102). |
