The head holders must hold {HEAD ~ the suction heads} against displacement or {TAIL ~ 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 displacement or { TAIL ~ 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 OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH