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