The actuator assembly 1 wherein one of {HEAD ~ said at least one knob} is positioned on {TAIL ~ the distal end} of each guide rail 
is positioned on
The actuator assembly 1 wherein one of { HEAD ~ said at least one knob } is positioned on { TAIL ~ the distal end } of each guide rail
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH