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