Soil-displacement drill and method for forming a smooth foundation pile with such a soil-displacement drill

A method for forming a smooth bore foundation pile in a substrate using a soil-displacement drill comprising a drill pipe and a cylindrical widening that is attached to an end of the drill pipe, comprising:

• drilling the drill into the substrate,
• introducing material for forming the smooth bore foundation pile into the drill pipe, and
• withdrawing the drill from the substrate,
• wherein the drill is a soil-displacement drill for soil-displacing drilling into a substrate for forming a smooth bore foundation pile, the drill comprising:
• a drill pipe with a pipe casing having a first outer diameter;
• and
• a cylindrical widening configured as a displacer and having an outer casing with a second outer diameter that is greater than the first outer diameter of the drill pipe;
• a screw blade for screwing the drill into the substrate;
• and
• an outlet opening for passage of material that is introduced into the drill pipe for forming the smooth bore foundation pile;
• wherein the cylindrical widening is provided at a first end of the drill pipe, a first end of the cylindrical widening being remote from the drill pipe and provided with the outlet opening,
• wherein the screw blade protrudes relative to the outer casing of the cylindrical widening and wherein a first end of the screw blade is arranged at the first end of the cylindrical widening,
• wherein the drill has a flap arranged at the bottom of the cylindrical widening and movable between:
• a first position in which the flap is positioned outside an imaginary extension of the screw blade beyond its first end, such that the screw blade can screw unhindered into the substrate;
• and
• a second position in which the flap prevents the material, when unscrewing the drill from the substrate, from entering a screw slot that is formed in the substrate by the screw blade,
• wherein, during drilling of the drill into the substrate, the flap remains in the first position and, on withdrawal of the drill from the substrate, the flap remains in the second position.

A soil-displacement drill for soil-displacing drilling into a substrate for forming a smooth bore foundation pile, comprising:

• a drill pipe with a pipe casing having a first outer diameter;
• and
• a cylindrical widening configured as a displacer and having an outer casing with a second outer diameter that is greater than the first outer diameter of the drill pipe;
• a screw blade for screwing the drill into the substrate;
• and
• an outlet opening for passage of material that is introduced into the drill pipe for forming the smooth bore foundation pile;
• wherein the cylindrical widening is provided at a first end of the drill pipe, a first end of the cylindrical widening being remote from the drill pipe and provided with the outlet opening,
• wherein the screw blade protrudes relative to the outer casing of the cylindrical widening and wherein a first end of the screw blade is arranged at the first end of the cylindrical widening,
• wherein the drill has a flap at the bottom of the cylindrical widening movable between:
• a first position in which the flap is positioned outside an imaginary extension of the screw blade beyond its first end, such that the screw blade can screw unhindered into the substrate;
• and
• a second position in which the flap prevents the material, when unscrewing the drill from the substrate, from entering a screw slot that is formed in the substrate with the screw blade.

A soil-displacement drill for soil-displacing drilling into a substrate for forming a smooth bore foundation pile, comprising:

• a drill pipe with a pipe casing having a first outer diameter;
• and
• a cylindrical widening configured as a displacer and having an outer casing with a second outer diameter that is greater than the first outer diameter of the drill pipe;
• a screw blade for screwing the drill into the substrate;
• and
• an outlet opening for passage of material that is introduced into the drill pipe for forming the smooth bore foundation pile;
• wherein the cylindrical widening is provided at a first end of the drill pipe, a first end of the cylindrical widening being remote from the drill pipe and provided with the outlet opening,
• wherein the screw blade protrudes relative to the outer casing of the cylindrical widening and wherein a first end of the screw blade is arranged at the first end of the cylindrical widening,
• wherein the drill has a flap movable between:
• a first position in which the flap is laying along an outer surface of the cylindrical widening without extending below it, or against an outer surface of a drill tip;
• and
• a second position in which the flap is positioned radially between the outlet opening and an outer edge of the screw blade, such that the flap prevents the material, when unscrewing the drill from the substrate, from entering a screw slot that is formed in the substrate by the screw blade.