The head holders must hold {HEAD ~ the suction heads} against {TAIL ~ displacement} or excessive deformation in the face of shocks or strains that may be exerted thereon during operation 
against
The head holders must hold { HEAD ~ the suction heads } against { TAIL ~ displacement } or excessive deformation in the face of shocks or strains that may be exerted thereon during operation
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH