HAND DRILL FOR HOLE PERFORATION IN GROUND (VARIANTS) Russian patent published in 2005 - IPC

FIELD: drilling facilities adapted to make holes in ground, particularly for installing poles, fences and foundation piles, for planting trees and bushes, for forming inclined and horizontal wells, in which service lines, namely pipelines or cables, may be laid.

SUBSTANCE: hand drill has rod with sharpened lower bit point and handle secured to upper rod end, as well as cutting unit arranged in lower rod part above the bit point. Rod may be adjusted in length. Bit point is made as the first boring bit. In accordance with the first embodiment cutting unit includes at least two working members secured to rod and located one under another. Each working member is made as flight screw with 6-15° start angle, wherein two radial boundary parts of flight screw define upper and lower cutting blades with radial cutting edges. Diameter of working member near bit point of the rod is less than diameter of upper working member. Flight screws of neighboring working members are oriented so that lower cutting blades of one flight screw are turned around 180° in comparison with lower cutting blades of another flight screw. In the second embodiment cutting unit has at least four flight screws having constant outer diameter and 6-15° start angle. Two radial boundary parts thereof are arranged one after another. Lower boundary part has cutting edge.

EFFECT: increased labor productivity and usage convenience, possibility to perforate well with depth exceeding rod length.

14 cl, 3 dwg