The gripper and {HEAD ~ carriage} is then driven towards {TAIL ~ the trailing end} of the loaf being sliced until said gripper engages said end 
is driven towards
The gripper and { HEAD ~ carriage } is then driven towards { TAIL ~ the trailing end } of the loaf being sliced until said gripper engages said end
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH