TRACTIVE UNIT WITH CATERPILLAR FOR OPEN HOLES Russian patent published in 2008 - IPC E21B23/14 

FIELD: mining; transportation.

SUBSTANCE: tractive unit can include tracklaying assembly including set of rollers and continuous caterpillar located rotatable around rollers. Electric motor can be implemented with ability of caterpillar rotation around rollers. With opposite ends of tracklaying assembly can be pivotally connected top and bottom levers, pivotally connected to track unit body. It can be provided links unit for application of the outward force to the tracklaying assembly for displacement of tracklaying assembly into open position and home return of tracklaying assembly. For actuation of affection lever or links unit it can be provided lead-screw, connected to the second electric motor, or guide bar connected to hydraulic system.

EFFECT: provides transportation of instruments in open holes for stratums appraisal and operation at immersion into mud in wells with high temperatures.

45 cl, 31 dwg, 2 tbl