Knife folding blade

This knife folding blade, includes a handle (2) defining a recess within which a blade (1), articulated in the vicinity of one end of the handle, is capable of being retracted. The handle (2) includes: - first means adapted to lock the blade (1) in the folded position to prevent the inadvertent exit of said blade out of the handle (2); - in the vicinity of the blade hinge zone on the handle, ▪ second means (6, 22) adapted to unlock said first locking means, said second means being actuated by the user, ▪ third means adapted to inducing rotation of the blade about its axis of articulation after unlocking.