US Patent 7562454 Knife blade opening mechanism

A folding knife incorporates an opening assist mechanism that functions to drive the blade from the closed to the open position. The knife may be either automatic or semi-automatic. In one embodiment a pair of spring arms, one located to each lateral side of the blade is interconnected at their forward ends with a pin and a roller sleeve. The spring arms apply pressure to the tang of the blade when the blade is closed.