Jack for lifting and lowering vehicle has center cylindrical hollow spindle with female thread meshing with male thread of inner spindle, and male thread meshing with female thread of outer spindle

摘要

The jack has an outer cylindrical hollow spindle (4) as a lifting pillar which is movable but not rotatable in the axial direction, with a female thread with a first thread pitch, a driven inner cylindrical spindle (6) not movable but rotatable in the axial direction, with a male thread with a second thread pitch, and a center cylindrical hollow spindle (5) which is rotatable around its center axis and movable in the axial direction, with a female thread which meshes with the male thread of the inner spindle, and also a male thread which meshes with the female thread of the outer spindle.