The support members comprising {HEAD ~ support arms} pivotally attached between {TAIL ~ brackets} positioned on the mounting surfaces 
pivotally attached between
The support members comprising { HEAD ~ support arms } pivotally attached between { TAIL ~ brackets } positioned on the mounting surfaces
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH