{HEAD ~ A lock screw} is interlocked in {TAIL ~ engagement} between the cover and the at least one end frame to obviate displacement of the interconnecting means from their respective interconnections in releasable engagement with each other 
is interlocked in
{ HEAD ~ A lock screw } is interlocked in { TAIL ~ engagement } between the cover and the at least one end frame to obviate displacement of the interconnecting means from their respective interconnections in releasable engagement with each other
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH