Patent ID: 11865630
Assignee: KYOCERA CORPORATION
Field: Machine tools (Mechanical engineering)
Classification: CPC B | IPC B

Claim 0:
1. A rotary tool comprising:
a cylindrical body including a rotational axis and extending from a first end to a second end;
a plurality of outer peripheral cutting edges positioned on an outer periphery of the body to form a spiral shape from a side of the first end toward a side of the second end, wherein rotational trajectories of the plurality of outer peripheral cutting edges do not entirely overlap with each other; and
a discharge groove positioned along the plurality of outer peripheral cutting edges, wherein,
in a cross section of a rotational trajectory of the rotary tool including the rotational axis,
the plurality of outer peripheral cutting edges comprise:
a first convex section having a convex curved shape, a second convex section having a convex curved shape and positioned adjacent to the first convex section on the side of the second end,
a first concave section having a concave curved shape and positioned contiguously on the side of the second end with respect to the first convex section, and a second concave section having a concave curved shape and positioned contiguously on the side of the second end with respect to the second convex section,
the first convex section comprises:
a first region having a convex curved shape and including an apex in the first convex section and
a second region having a convex curved shape and positioned between the first region and the first concave section,

the second convex section comprises:
a third region having a convex curved shape and including an apex in the second convex section and
a fourth region having a convex curved shape and positioned between the third region and the second concave section,

a first radius of curvature of the first region is greater than a second radius of curvature of the second region and a third radius of curvature of the third region is greater than a fourth radius of curvature of the fourth region.