This is a standard range of power tool operated hoists; based on the pile-wind hauling drum principle. The gear units are both statically and dynamically irreversible and are backed up by a locking pin that has to be disengaged before operation.
The power tool may be either a low speed/high torque 230v ac drill if heavy loads are routinely applied to the flown bar or a heavy duty; battery operated drill if loads are very light.
Custom designed variations to this type of hoist are available, please call to discuss.