As best seen in FIG 6 the guiding rail 105 in cross section has {HEAD ~ a pair} of {TAIL ~ first and second mounting legs} 107, 109 parallel to one another 
of
As best seen in FIG 6 the guiding rail 105 in cross section has { HEAD ~ a pair } of { TAIL ~ first and second mounting legs } 107 , 109 parallel to one another
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH