US Patent 7275321 Folding knife assembly

A folding knife assembly includes a knife handle, a knife body, and a brake portion, wherein the knife body can be turned into or out of the knife handle, and the brake portion is movably coupled to a pivotal position of the knife handle and the knife body. If the knife body is folded completely into the knife handle, an end of a resilient element will press precisely on the periphery of the brake portion, such that the resilient element produces a torque to turn the brake portion into the knife handle. If the knife body is turned gradually out from the knife handle, the resilient element will produce a torque to turn the knife body out from the knife handle, and the knife body will be popped out automatically from the knife handle, so as to effectively prevent the knife body from being popped out accidentally by vibrations.