Abstract: Two-stage double-acting hydraulic cylinders are described, in which a first, inner stage includes a piston rod and head movable within a cylinder and a second, outer stage has a cylindrical body adapted to move longitudinally between stop positions intermediate the ends of the first cylinder. The two stages are hydraulically linked to each other through the alternate introduction of hydraulic fluid selectively through an extension pressure fluid port and a retraction pressure fluid port a limited motion of the outer stage is obtained in a power stroke. Hydraulic power means of this kind is of particular value in powered apparatus for digging and transplanting trees, where minimization of the overall height of the apparatus is desirable.

Abstract: Two-stage double-acting hydraulic cylinders are described, in which a first, inner stage includes a piston rod and head movable within a cylinder and a second, outer stage has a cylindrical body adapted to move longitudinally between stop positions intermediate the ends of the first cylinder. The two stages are hydraulically linked to each other through the alternate introduction of hydraulic fluid selectively through an extension pressure fluid port and a retraction pressure fluid port a limited motion of the outer stage is obtained in a power stroke. Hydraulic power means of this kind is of particular value in powered apparatus for digging and transplanting trees, where minimization of the overall height of the apparatus is desirable.