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
B66F3/25—Constructional features
B66F3/30—Constructional features with positive brakes or locks
F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
F15B15/20—Other details, e.g. assembly with regulating devices
F15B15/26—Locking mechanisms
F15B15/261—Locking mechanisms using positive interengagement, e.g. balls and grooves, for locking in the end positions