{HEAD ~ Device} for keeping {TAIL ~ the spatial attitude} of a member, constrained to a swinging support, with respect to a fixed element 
for keeping
{ HEAD ~ Device } for keeping { TAIL ~ the spatial attitude } of a member , constrained to a swinging support , with respect to a fixed element
HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH