According to another embodiment of the invention, the pockets are defined by inturned edges on {HEAD ~ the covers} which embrace {TAIL ~ a boundary} of a recess formed in the surface of the movable element exposed to hot gases of combustion 
embrace
According to another embodiment of the invention , the pockets are defined by inturned edges on { HEAD ~ the covers } which embrace { TAIL ~ a boundary } of a recess formed in the surface of the movable element exposed to hot gases of combustion
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH