Each pair of bracing members defines a guide for {TAIL ~ the displacement} of the end supports of the support roller for {HEAD ~ the lower belt} 
Each pair of bracing members defines a guide for { TAIL ~ the displacement } of the end supports of the support roller for { HEAD ~ the lower belt }
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD