Burnishing drill
AssigneesAisan Kogyo Kabushiki Kaisha, Fuji Seiko Co., Ltd.
InventorsYasuhiro Suzuki, Tuguo Yoshikawa, Kazuhiro Shibata, Akio Fukui, Kiyotaka Shiga
Life of this patent
Estimating the term…
Abstract
A burnishing drill includes a cylindrical drill body connected at its forward end integrally with a shank. The forward end of the drill body includes a first pair of cutting edges inclined radially and rearwardly from the forwardmost central end of the drill body toward the shank at a first cutting angle. A second pair of cutting edges formed of diamond chips are disposed in a plane intersecting the plane in which the first pair of cutting edges are located. The second pair of cutting edges are inclined radially and rearwardly from a position inside a circle including the maximum external margins of the first pair of cutting edges toward the shank at a second cutting angle.
Claims6
A burnishing drill, comprising:
- a shank;
- a cylindrical drill body having a first end connected with said shank and an opposite second end having an external diameter smaller than the maximum external diameter of said drill body;
- a first pair of cutting edges for boring a new hole in a workpiece on said second end, said pair of cutting edges extending from a common apex on the longitudinal axis of said drill, radially outwardly with respect to said second end, to said external diameter of said second end and extending longitudinally rearward in the direction of said first end to define a first cutting angle of said first pair of cutting edges relative to the longitudinal axis of said drill;
- and
- a second pair of cutting edges for reaming the hole bored by said first pair of cutting edges on said cylindrical drill body disposed in a plane intersecting the planes of said first cutting edges;
- wherein each said first cutting edge has a guide face extending rearwardly from its outermost radial margin and each said guide face has a step portion associated therewith extending from said guide face to said maximum external diameter of said drill body.
A burnishing drill, comprising:
- a shank;
- a cylindrical drill body having a first end connected with said shank and an opposite second end having an external diameter smaller than the maximum external diameter of said drill body;
- a first pair of cutting edges for boring a new hole in a workpiece on said second end, said pair of cutting edges extending from a common apex on the longitudinal axis of said drill, radially outwardly with respect to said second end, to said external diameter of said second end and extending longitudinally rearward in the direction of said first end to define a first cutting angle of said first pair of cutting edges relative to the longitudinal axis of said drill;
- and
- a second pair of cutting edges for reaming the hole bored by said first pair of cutting edges on said cylindrical drill body disposed in a plane intersecting the planes of said first cutting edges;
- wherein each said first cutting edge has a slant face extending radially and rearwardly therefrom toward said shank, and each said slant face has a planar relief surface extending longitudinally rearwardly therefrom in the direction of said shank.
A burnishing drill, comprising:
- a shank;
- a cylindrical drill body having a first end connected with said shank and an opposite second end having an external diameter smaller than the maximum external diameter of said drill body;
- a first pair of cutting edges for boring a new hole in a workpiece on said second end, said pair of cutting edges extending from a common apex on the longitudinal axis of said drill, radially outwardly with respect to said second end, to said external diameter of said second end and extending longitudinally rearward in the direction of said first end to define a first cutting angle of said first pair of cutting edges relative to the longitudinal axis of said drill;
- and
- a second pair of cutting edges for reaming the hole bored by said first pair of cutting edges on said cylindrical drill body disposed in a plane intersecting the planes of said first cutting edges;
- wherein each said first cutting edge has a guide face extending rearwardly from its outermost radial margins;
- wherein each said guide face has a step portion associated therewith extending from said guide face to said maximum external diameter of said frill body;
- and
- wherein said second pair of cutting edges are disposed, with respect to the longitudinal direction of said shank and said cylindrical drill body, between said step portions and said first pair of cutting edges.
Dependencies are inferred from the claim text.