CALIBRATOR Russian patent published in 2015 - IPC E21B10/26 E21B17/10 

FIELD: mining.

SUBSTANCE: claimed calibrator comprises the body with connection thread at its ends and working elements reinforced with wear-proof insets. To up the calibrator efficiency, it is provide with the bush with seal fitted at outer surface of one of its ends between the bush outer surface and the body inner surface. Note here that said body is composed of a circular flat spring with coils making the working elements while the bush is fitted telescopically inside said spring to overlap its interturn gaps.

EFFECT: higher efficiency.

2 cl, 1 dwg