US 12,290,956 B2
Drill bit comprising a centering tip
Jürgen Miebach, Lindlar (DE)
Assigned to COLT TECHNOLOGIES GMBH, Lindlar (DE)
Appl. No. 17/430,967
Filed by Colt Technologies GmbH, Lindlar (DE)
PCT Filed Feb. 13, 2020, PCT No. PCT/EP2020/053822
§ 371(c)(1), (2) Date Aug. 13, 2021,
PCT Pub. No. WO2020/165378, PCT Pub. Date Aug. 20, 2020.
Claims priority of application No. PCT/EP2019/053901 (WO), filed on Feb. 15, 2019.
Prior Publication US 2022/0134449 A1, May 5, 2022
Int. Cl. B27G 15/00 (2006.01)
CPC B27G 15/00 (2013.01) 18 Claims
OG exemplary drawing
 
10. A centering tip for a drill bit, the centering tip comprising:
a conical shape with an apex on a drill axis;
a lateral surface that has a taper angle;
a centering tip helical thread which spirals helically from said apex down said centering tip in a thread direction of rotation at a tip thread pitch, and
at least one tip recess in a side of the centering tip which provides a cutting edge, and which has a chip-transporting shape and connecting to said helical thread,
wherein said lateral surface comprises at least one step in said taper angle of said lateral surface with each step starting at a step-start position and said at least one step continues at least 90 degrees about said drill axis.