{HEAD ~ These types} of {TAIL ~ harmonic drive transmissions} are known per se from the state of the art 
of
{ HEAD ~ These types } of { TAIL ~ harmonic drive transmissions } are known per se from the state of the art
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH