Segmented Drill Bit Geometry for Jam-Free Core Removal

The patent applies asymmetry by designing the inner lateral surfaces of the drilling segments with non-circular cross-sections. Specifically, the inner lateral surfaces have varying distances from the longitudinal axis, creating an asymmetric geometry that prevents uniform contact between the drill core and segment surfaces. This asymmetric design eliminates jamming by ensuring that fragments cannot get stuck in symmetric positions, thereby maintaining reliable drill core removal while enabling continuous drilling operation.

The patent applies the extraction principle by designing the cutting portion with segments that can be individually removed from the drilling shaft. The segments are fastened in a manner that allows them to be taken out separately without removing the entire cutting portion or damaging the drilling shaft. This enables easy drill core removal by extracting specific segments that may be obstructing the core, while maintaining the overall stable structure of the drilling shaft and cutting portion assembly during operation.

The patent applies local quality by varying the geometry of the inner lateral surfaces of the drilling segments along their length and circumference. Instead of using uniform circular cross-sections, the inner lateral surfaces have locally different distances from the longitudinal axis, creating zones with different contact characteristics. This local variation in geometry reduces the overall contact surface area between the segments and drill core, preventing jamming while maintaining manufacturability through controlled non-circular profiles.