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