SCREW DRILL FOR FROZEN SOILS Russian patent published in 2021 - IPC E21B7/26 E21B10/44 E02F5/16 

FIELD: earthworks.

SUBSTANCE: invention relates to the production of earthworks, in particular to devices for the formation of wells. A screw drill for frozen soils contains a conical core with a screw blade consisting of a traction section with a constant pitch of blade turns and a destructive section with a pitch of blade turns having a constant increment relatively to the pitch of turns of the traction section of the blade. The screw blade is made with the same number of turns on the destructive and traction sections, equal to no more than two. An angle of inclination of the forming upper surface of the screw blade in the destructive section to the axis of rotation changes its value from 42° to 90°. An angle of rotation of the radius of the screw blade, at which its increment occurs, is in the range from 90° to 270°. The ratio of the radius of the screw surface at the end of the destructive section of the screw blade to the radius of the screw surface at the beginning of the destructive section of the screw blade is from 1.5 to 1.7.

EFFECT: energy intensity of drilling wells in solid and frozen soils, including frozen sand, is reduced.

1 cl, 3 dwg