ROLLER GAUGER Russian patent published in 2008 - IPC E21B10/30 

FIELD: mining.

SUBSTANCE: invention relates to the mining industry, namely to supporting-centering and gauging devices for the bottom of the drilling string and can be used for drilling wells. The gauger contains case 1 with central channel 9 and longitudinal grooves on sides. Rollers 2 with shaped pivot journals 3 are accommodated in the grooves. The pivot journals are contained in inserts 7 with slots for interaction with support rings 8 rigidly connected with case 1. Ends of pivot journals 3 are made in the shape of cylinders 4, 5. The diameter of cross-section of cylinders 4 is larger than the diameter of cross-section of cylinders 5. Middle parts 6 are tapered. Pivot journals 3 are mounted so that external surfaces of the end cylinders can interact with internal surfaces of inserts 7 and external surfaces of middle parts 6 of pivot journals 3 can interact with external tapered surfaces of support rings 8. The tapered surfaces of middle parts 6 of pivot journals 2 and external surfaces of support rings 8 have equal taper angle.

EFFECT: higher reliability and efficiency of the device with leveled off service life of supports and equipment of the rollers.

4 cl, 3 dwg