Hot hole vibration dampener

Claim 1

Shock absorber for deep hole drill pipe which can be installed in the pipe coaxially as an intermediate part in vertical alignment and comprises an outer pipe part and an inner pipe part which are movable coaxially relative to each other but are secured against twisting by means of torque transfer means disposed in the upper portion of the shock absorber, defining between them an annular chamber filled with hydraulic fluid and supporting ring shaped spring elements stacked one on top of each other in said annular chamber for shock absorption with attenuation, the annular chamber being sealed by an upper seal and a lower seal, of which the lower seal is coordinated with a lower equalizer piston which is independently movable coaxially within limits between the outer and the inner pipe parts, its bottom side closing off an equalizing chamber for the hydraulic fluid in the annular chamber, characterized in that due to its upper seal, the annular chamber for the spring elements is closed off at a distance below the torque transfer means, and the torque transfer means in turn is disposed in a separate, hydraulic fluid-filled annular chamber between the outer and the inner pipe parts which in turn is sealed by an upper seal and by a lower seal, of which the lower seal is coordinated with an upper equalizer piston which is independently movable coaxially within limits between the outer and the inner pipe parts, its bottom side closing off an equalizing chamber for hydraulic fluid in intermediate chamber communicating with the drill hole flushing circulation area through connecting holes, being located between the outer and the inner pipe parts below said equalizer piston.