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US 2020/0346290 A1Published application
Drill
AssigneeOsg Corporation
InventorKatashi HIROSAWA
Life of this patent
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AssigneeOsg Corporation
InventorKatashi HIROSAWA
Estimating the term…
A drill includes a leading end portion. The leading end portion is flat and has at least two cutting blades extending from a rotation center toward outside in a radial direction. The each cutting blade includes an arc-shaped portion. An inside linear portion is formed in a linear shape and connects to one end of the arc-shaped portion on the rotation center side. An outside linear portion is formed in a linear shape and connects to another end of the arc-shaped portion on an opposite side to the one end. The arc-shaped portion has a cutting edge provided with an arc-shaped portion chamfered surface. The inside linear portion and the outside linear portion each has a cutting edge provided with a linear portion chamfered surface. A drill axis direction width of the arc-shaped portion chamfered surface is smaller than a drill axis direction width of the linear portion chamfered surface.
A drill whose leading end portion is flat and has at least two cutting blades extending from a rotation center toward outside in a radial direction, each of the cutting blades including an arc-shaped portion formed in an arc shape, an inside linear portion formed in a linear shape and connecting to one end of the arc-shaped portion on the rotation center side, and an outside linear portion formed in a linear shape and connecting to another end of the arc-shaped portion on an opposite side to the one end, the arc-shaped portion having a cutting edge provided with an arc-shaped portion chamfered surface that is chamfered, and the inside linear portion and the outside linear portion each having a cutting edge provided with a linear portion chamfered surface that is chamfered,
Dependencies are inferred from the claim text.