a helical spring held within the housing, the helical spring biasing the slider against {HEAD ~ the second portion} of {TAIL ~ the arm} 
of
a helical spring held within the housing , the helical spring biasing the slider against { HEAD ~ the second portion } of { TAIL ~ the arm }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL