US 11,865,630 B2
Rotary tool
Masahiko Kuroda, Higashiomi (JP)
Assigned to KYOCERA Corporation, Kyoto (JP)
Filed by KYOCERA Corporation, Kyoto (JP)
Filed on Dec. 7, 2021, as Appl. No. 17/544,099.
Application 17/544,099 is a continuation of application No. 16/468,706, granted, now 11,213,901, previously published as PCT/JP2017/045095, filed on Dec. 15, 2017.
Claims priority of application No. 2016-242875 (JP), filed on Dec. 15, 2016.
Prior Publication US 2022/0088687 A1, Mar. 24, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. B23C 5/10 (2006.01)
CPC B23C 5/10 (2013.01) [B23C 2210/086 (2013.01); B23C 2210/088 (2013.01)] 5 Claims
OG exemplary drawing
 
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.