Abstract: A drilling derrick device for handling drill-pipe stands has at least one movable racking platform with pipe-stand receiving compartments, supported above the working deck of the derrick, at least one racking carriage associated with the racking platform and movable on the working deck and a pivotable drill-pipe robot having gripping arms to load and unload the racking platform and the racking carriage. The racking platform and the racking carriage are moved in synchronism relative to the drill-pipe robot which has a fixed position on the working deck in order to perform drill string dismantling and assembly operations.

Abstract: Tool for drilling bore holes and earth formations in which a bit body matrix, including tungsten carbide, has a plurality of carriers secured thereto, to each of which a cutting element is secured by soldering, after the body matrix has been produced, to avoid subjecting the diamond material embodied in the cutting element to the high temperatures required to produce the matrix body, which would have deleterious effects on the diamond. Each carrier has great rigidity and is provided with a plane surface confronted by the plane back surface of the cutting element to provide a desired narrow solder gap between the cutting element and carrier of uniform width, into which the solder is deposited to adhere the cutting element and carrier together, with the load being transmitted directly from the cutter element to the rigid carrier.