The worm gear in the second housing has a central hub and to which is attached {TAIL ~ a support} carrying {HEAD ~ the work head} 
The worm gear in the second housing has a central hub and to which is attached { TAIL ~ a support } carrying { HEAD ~ the work head }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD