When the tool is applied to a fastener, a bias load is applied along the axis of the tool and {HEAD ~ the drivetrain assembly} 71 translates rearward compressing {TAIL ~ the spring} and contacting the pushbutton 
translates rearward compressing
When the tool is applied to a fastener , a bias load is applied along the axis of the tool and { HEAD ~ the drivetrain assembly } 71 translates rearward compressing { TAIL ~ the spring } and contacting the pushbutton
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH