Masahiro Hakozaki has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
Abstract: A drill includes a blade portion provided with spiral cutting blades along a cutting direction from a tip end to a rear end, and a shank portion formed consecutively on a rear side of the blade portion. The blade portion includes distal-side cutting blades provided from the distal end of the blade portion along the cutting direction and angled at a constant first torsion angle, intermediate grooves formed at a variable torsion angle that varies gradually from the first torsion angle to a second torsion angle, and rear-side grooves formed at the constant second torsion angle. The rear-side grooves are longer than the distal-side cutting blades in the cutting direction, and the second torsion angle is greater than the first torsion angle.
Abstract: A drill includes a blade portion provided with spiral cutting blades along a cutting direction from a tip end to a rear end, and a shank portion formed consecutively on a rear side of the blade portion. The blade portion includes distal-side cutting blades provided from the distal end of the blade portion along the cutting direction and angled at a constant first torsion angle, intermediate grooves formed at a variable torsion angle that varies gradually from the first torsion angle to a second torsion angle, and rear-side grooves formed at the constant second torsion angle. The rear-side grooves are longer than the distal-side cutting blades in the cutting direction, and the second torsion angle is greater than the first torsion angle.