Patent ID: 8517093

Claim:
A system for producing controlled vibrations within a borehole comprising: an encoder plate having a first surface with a first plurality of protrusions arranged in a first configuration, wherein the first surface includes an inner ring and an outer ring, and wherein the inner ring is configured to rotate relative to the outer ring, the encoder plate positioned within a housing in the borehole; an anvil plate having a second surface with a second plurality of protrusions arranged in a second configuration, wherein the anvil plate is positioned within the housing relative to the encoder plate so that the second surface faces the first surface; a movement mechanism configured to enable rotational and translational movement of the encoder plate relative to the anvil plate to allow the first plurality of protrusions to repeatedly impact the second plurality of protrusions, wherein a frequency of vibrations caused by the impacts is based on the first configuration and the second configuration; a rotation mechanism configured to control movement of the inner ring relative to the outer ring to selectively modify the frequency of vibrations caused by the impacts between the first plurality of protrusions and the second plurality of protrusions; and a vibration control mechanism configured to control an amplitude of the vibrations.