{HEAD ~ each said lock rod} has a rib portion extending across the upper end thereof for {TAIL ~ engagement} with said blocking device 
{ HEAD ~ each said lock rod } has a rib portion extending across the upper end thereof for { TAIL ~ engagement } with said blocking device
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH