providing a positioning device comprising {TAIL ~ a hoist assembly} and an electric actuator having a brake assembly for interacting with the hoist assembly to impede the reduction of the volume of {HEAD ~ the enclosure}, 
providing a positioning device comprising { TAIL ~ a hoist assembly } and an electric actuator having a brake assembly for interacting with the hoist assembly to impede the reduction of the volume of { HEAD ~ the enclosure } ,
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH