| 摘要 |
The axial movement of the work bar (6) occurs through track engagement between it and a piece and relative rotation between them via a drive component. The arrangement is convertible between two function conditions, i.e. a first in which the drive component is arranged to produce lifting and lowering and a second in which lifting and lowering can occur manually. The transition between these two conditions occurs by maintaining the release of a non-rotary connection between a first part rotary and tractive-proof first part connected to the work bar and a rotary and tractive-proof part connected with the component. |
