The top cover of the improved assembly has {HEAD ~ an integral pressure blade} which extends downward to apply {TAIL ~ pressure} to the cover material 
The top cover of the improved assembly has { HEAD ~ an integral pressure blade } which extends downward to apply { TAIL ~ pressure } to the cover material
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH