| 摘要 |
The invention relates to a jack (1) that comprises, on the one hand, a rod (2) that can be driven in translation by a driving system (5, 6), and, on the other hand, a system for blocking the expansion of the rod that comprises at least one bolt (9) mounted so as to move between an engagement position, in which it defines an abutment means for the rod in the expansion direction thereof, and a release position, in which it is spaced away from the rod and allows the expansion thereof, wherein the bolt is associated with a barrel (14) having a first stable position in which it maintains the bolt (9) in the engagement position and a second stable position in which it maintains the bolt (9) in its release position, said barrel system (14) being designed so that it can be alternatively switched from the first stable position to the second stable position under the action of the rod (2) driven by a slight backward movement before expansion and at the end of the return stroke. |
