The US men's 4 ×100 meters relay team failed to qualify for the Olympic final after dropping the baton in their heat on Thursday.Victory seemed a formality as Darvis Patton approached Tyson Gay on the final changeover but the pair made a mess of it and the baton tumbled to the floor.The US were chasing their 16th gold medal in the 4×100m relay and were hoping to make up for Athens four years ago when they were surprisingly beaten by Britain.Gay has endured a miserable Olympics after a