Smith International, Inc., a California Corporation v. Hughes Tool Company, a Delaware Corporation

Hughes Tool Co. appeals a declaratory judgment which held two patents invalid for obviousness, for anticipation by prior art, and for failure to properly claim the patentable art.

A. Rotary Drilling Problem.

Rotary drilling for oil and gas wells uses a rock bit threaded onto a drill pipe “string” which is lowered into a hole and rotated. The rock bit, in addition to having a “head” for such threading, has three rotatable cones with teeth or other cutting elements. These elements turn on bearings located in the interior of each cone and on three shafts or axles suspended from the “head.” When the bit is lowered and rotated under great weight against the bottom, a drilling fluid is pumped down through the drill pipe, to the drill bit and then through nozzles in the bit to pick up loosened cuttings and carry them to the outside of the pipe and eventually to the surface between the drill pipe and the well casing.

Two types of bit are in use, the roller bearing bit and the journal bearing bit. In the first, free-turning rollers separate the cylindrical surfaces on the inside of the shaft; in the second, the cylindrical surfaces oppose and engage each other. Either type performs…