What Does Cone Bit Mean?

A cone bit is a tool made of tungsten or hardened steel that crush rocks during the drilling process. It is generally made of three rotating conical pieces with hard teeth that break up rock into smaller pieces. It is a commonly used tool in trenchless drilling operations.
Another name for the cone bit is roller cone bit.

Trenchlesspedia Explains Cone Bit
Howard Hughes, Sr. is credited with the invention of the "Sharp–Hughes" rock drill bit. He received a patent for it in 1909. His son, the iconic Howard Hughes, Jr., became one of the wealthiest men in the world by capitalizing on the invention during the Texas oil boom.

The ability to crush rock while drilling made the cone bit an excellent tool. The modern version of the bit, the tri-cone rotary drill bit, uses a combination of spinning and rotation of hardened materials to disintegrate rock as it is thrust deeper into the ground. High-velocity fluid is forced through the annulus of the drill string, which removes broken rock pieces and carries them back to the surface.