Each head holder 22 has a downwardly open recess 29, FIG 2, in {HEAD ~ direct communication} with {TAIL ~ the suction holes} 30 in the mounting pins 28 
Each head holder 22 has a downwardly open recess 29 , FIG 2 , in { HEAD ~ direct communication } with { TAIL ~ the suction holes } 30 in the mounting pins 28
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH