BLADED CALIBRATOR Russian patent published in 2011 - IPC E21B17/10 E21B10/30 

FIELD: mining.

SUBSTANCE: bladed calibrator includes hollow housing the outer surface of which is reinforced with rock cutting elements and provided with cleaning slots. Peculiar feature of calibrator is that cleaning slots in longitudinal section have stepped surface; at that, length of steps of slot increases towards the flow of cleaning agent. At that, stepped part of nozzle is made in the form of a separate part. Sharp edges of stepped part of cleaning slot are made from hard alloy or reinforced with wear-resistant material.

EFFECT: increasing operating efficiency of calibrator owing to improving the operation of its cleaning system.

3 cl, 2 dwg