| 摘要 |
<p>A double-acting hydraulic cylinder having two concentrically disposed jackets and at least two pistons arranged for coaxial movements relative to said cylinder, one of said pistons being annular and arranged for axial movement in an annular chamber, means being provided to communicate a space between the inner piston and an end section of that inner jacket, with the opposite end of the annular chamber in a manner ensuring that the operative, pressurized medium actuates the two pistons for displacement thereof in a predetermined order and at approximately the same speed in the outwards and inwards directions of said pistons.</p> |
