This mechanism comprises several assemblies of {TAIL ~ links} bearing on the tube section on either side of the weakened zone and {HEAD ~ a bearing surface} formed in a sleeve fixed with respect to the ground and with which is in contact a protuberance formed on one of the links of each assembly  
This mechanism comprises several assemblies of { TAIL ~ links } bearing on the tube section on either side of the weakened zone and { HEAD ~ a bearing surface } formed in a sleeve fixed with respect to the ground and with which is in contact a protuberance formed on one of the links of each assembly
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH