Abstract: In a folding knife or hand tool having a handle and a blade pivotally connected to the handle, a spring loaded crossbolt 1 is fitted to the blade tang. One end of crossbolt 1 protrudes through an arcuate slot in the handle, crossbolt slot 32. A locking collar 19 on crossbolt 1 engages locking counterbores A 34 and B 36 located on the blade side of the opposite ends of crossbolt slot 32. When finger pressure is applied to the end of crossbolt 1, locking collar 19 is forced to disengage locking counterbore A 34 and retreat to a relieved area on the blade, collar relief 52. This permits the blade to be extended by forward finger pressure on crossbolt 1. When the blade is fully extended, spring pressure forces locking collar 19 into the opposite locking counterbore B 36, thus locking the blade. Reversing the sequence will close and lock the blade.

Abstract: A method of hardening the surface of titanium and its alloys, and other structural metals which form hard carbides, by treating the surface thereof with a moving, discontinuous carbon arc.The metal surface to be hardened, and a carbon electrode are made opposite poles of an electric current source, and moved and/or rotated with respect to each other so that a multiplicity of discontinuous electric arcs are produced between the carbon electrode and the metal surface.Carbon particles transfer through the arc and alloy within craters of the instantly liquified and chilled substrate, producing a surface layer which, in the case of titanium, is hard and tough and adherent enough to form the working surface of abrasive cutting tools.The process improves the appearance and durability of consumer items and reduces friction and wear on machine parts.

Abstract: In a folding knife or tool having a handle and a blade pivotally connected to the handle, a control plate 28 slides in a shaped cavity 52 between handle plates 46,68, and swings, and also swings on, a crankpin 24 attached to the blade tang, and embodies a cam surface 36 at the distal end. A stem portion 30 of the control plate 28 protrudes to the surface of the handle whereby it may be manipulated by the user to cause the blade to open or close, and then to cause the cam surface 36 to engage a ramp 62 and spur 60 to thereby interpose a mechanical block to reverse blade rotation. Further pressure upon the stem 30 will then remove running clearances, tightening the blade solidly against wobble, and the control plate 28 against dislodgement.