B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
B66F3/00—Devices, e.g. jacks, adapted for uninterrupted lifting of loads
B66F3/24—Devices, e.g. jacks, adapted for uninterrupted lifting of loads fluid-pressure operated
B66F3/247—Devices, e.g. jacks, adapted for uninterrupted lifting of loads fluid-pressure operated pneumatically actuated