Patent ID: 9109397
Filing Date: 2015-08-18
Classification: E21B

Abstract:
1. Drill string component for positioning between a top hammer drill rig and a drill bit for percussive drilling and including a pipe-shaped element which transfers rotational movements from the drill rig to the drill bit, and which is arranged to enclose at least one rod element of a drill string extending along a longitudinal axis for transferring impact pulses from a percussion drilling machine belonging to the top hammer drill rig to the drill bit, wherein the pipe-shaped element is arranged concentrically surrounding said at least one rod element, and wherein a vibration-damping structure is arranged adjoining to and rotatable with at least a part of an inside of the pipe-shaped element in a space formed inwardly of said inside for reducing emissions of noise from the drill string component when in operation and being outside a bore hole.