Abstract: A diamond cutting tooth for use in a petroleum drag bit is provided with an extended and expanded effective diamond cutting surface by providing a linear sequence of triangular prismatic, synthetic, polycrystalline, diamond cutting elements generally along the line of direction of cutting within each tooth. Each element is offset from the preceding element in the sequence in a direction nonparallel to the line of cutting. More particularly, equilateral triangular prismatic diamond elements are laid within a V-shaped groove within a mold from which the cutting tooth is molded through conventional infiltration matrix techniques. The apical opening of the groove is 70 degrees, whereas the apical extent of each of the triangular apexes is 60 degrees. Each triangular element is laid on one side or other of the longitudinal groove.

Abstract: A ball element pivotally mounted on a sleeve that slides within the tubular valve member of a well safety valve has a radial slot extending across its width parallel to and offset from its pivotal axis. A bar extending in secant fashion across the valve member engages the slot, rotating the ball element to open and close the valve as the sleeve slides back and forth. An unslotted outer surface portion of the ball element mates with the valve seat during valve closing.

Abstract: The method and apparatus for actuating a perforating gun by pressure includes a pressure actuated gun firing head disposed on the perforating gun for detonating the shaped charges of the gun. The gun is attached to a pipe string and located downhole adjacent the formation to be perforated. The pressure actuated firing head includes a housing with a plug and piston. The piston has a firing pin adapted for engagement with the initiator of a perforating gun upon reciprocation within the housing. Initially, the piston is pressure balanced until the time of actuation. The plug is responsive to fluid pressure of a predetermined magnitude at the time of the actuation of the gun firing head. Upon effecting pressure on the plug, the plug unbalances the piston causing the piston to reciprocate. Upon reciprocation of the piston, the firing pin engages the initiator to detonate the shaped charges of the perforating gun. Pressure may be effected on the firing head through the pipe string, or the annulus, or both.