It is {HEAD ~ an object} of {TAIL ~ the invention} to provide an integrally formed piston and seal therefor 
of
It is { HEAD ~ an object } of { TAIL ~ the invention } to provide an integrally formed piston and seal therefor
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH