{TAIL ~ a second coupling member} for coupling said device carriage to {HEAD ~ said shaft}; and, 
{ TAIL ~ a second coupling member } for coupling said device carriage to { HEAD ~ said shaft } ; and ,
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH