A spring 72 of adequate stiffness biases {TAIL ~ the drivetrain assembly} 71 forward in {HEAD ~ the tool housing} 
A spring 72 of adequate stiffness biases { TAIL ~ the drivetrain assembly } 71 forward in { HEAD ~ the tool housing }
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD