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