The invention contemplates a precisely adjustable threaded mechanism, as for focus adjustment of an aerial camera lens, wherein inner and outer threaded members are normally in {HEAD ~ circumferentially continuous radially stressed play free engagement} to the extent of requiring a characteristic maximum torque for {TAIL ~ their rotary adjustment} 
The invention contemplates a precisely adjustable threaded mechanism , as for focus adjustment of an aerial camera lens , wherein inner and outer threaded members are normally in { HEAD ~ circumferentially continuous radially stressed play free engagement } to the extent of requiring a characteristic maximum torque for { TAIL ~ their rotary adjustment }
OTH OTH OTH OTH OTH OTH 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 HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL