Router cutting bit
AssigneeThe Boeing Company
InventorsJames P. Duffy, Frances T. Kendra, Alfred J. Smith
Life of this patent
Estimating the term…
Abstract
A router bit for providing smooth finish cuts in soft metal, such as aluminum, includes a plurality of helical cutting edges that are disposed at a helix angle of 45 degrees. The cutting edges each include a cutting face having a positive rake angle of approximately 18 degrees, and a land portion having a primary relief angle of approximately 14 degrees, and a secondary relief angle of approximately 20 degrees. The bit shank is preferably 3/8 inch in diameter to increase rigidity. The combination of these specific angles and the shank diameter provides a cutting bit that can cut soft aluminum with a resultant finish that meets or exceeds aircraft industry standards.
Claims7
A router bit for making smooth cuts in soft metal comprising:
- an elongated generally cylindrical body having a shank portion and a cutting end portion;
- and a plurality of helically extending parallel cutting edges in said cutting end portion that are disposed at substantially a 45 degree helix angle with respect to a longitudinal axis of said router bit body, said cutting edges each including a cutting face disposed at a positive rake angle of substantially 18 degrees, and a land portion having a primary relief angle of substantially 14 degrees, and a secondary relief angle of substantially 20 degrees;
- whereby, said helix angle, rake angle, primary relief angle, and secondary relief angle, work in combination with one another to provide a smooth finish cut when said router bit is employed to cut soft metal.
A router bit for making smooth cuts in soft aluminum comprising:
- an elongated generally cylindrical body having a shank portion and a cutting end portion;
- and a plurality of helically extending parallel cutting edges in said cutting end portion that are disposed at substantially a 45 degree helix angle with respect to a longitudinal axis of said router bit body, said cutting edges each including a cutting face disposed at a positive rake angle of substantially 18 degrees, and a land portion having a primary relief angle of substantially 14 degrees, and a secondary relief angle of substantially 20 degrees;
- whereby, said helix angle, rake angle, primary relief angle, and secondary relief angle, work in combination with one another to provide a smooth finish cut when said router bit is employed to cut soft metal.
A router bit for making smooth cuts in soft metal comprising:
- an elongated generally cylindrical body having a shank portion and a cutting end portion;
- and a plurality of helically extending parallel cutting edges in said cutting end portion that are disposed at substantially a 45 degree helix angle with respect to a longitudinal axis of said router bit body, said cutting edges each including a cutting face disposed at a positive rake angle of substantially 18 degrees, and a land portion having a primary relief angle of substantially 14 degrees, and a secondary relief angle of substantially 20 degrees;
- whereby, said helix angle, rake angle, primary relief angle, and secondary relief angle, work in combination with one another to provide a smooth finish cut, which exceeds 125 rms, when said router bit is employed to cut soft metal.
A router bit for making smooth cuts in soft aluminum comprising:
- an elongated generally cylindrical body having a shank portion and a cutting end portion;
- and a plurality of helically extending parallel cutting edges in said cutting end portion that are disposed at substantially a 45 degree helix angle with respect to a longitudinal axis of said router bit body, said cutting edges each including a cutting face disposed at a positive rake angle of substantially 18 degrees, and a land portion having a primary relief angle of substantially 14 degrees, and a secondary relief angle of substantially 20 degrees;
- whereby, said helix angle, rake angle, primary relief angle, and secondary relief angle, work in combination with one another to provide a smooth finish cut, which exceeds 125 rms, when said router bit is employed to cut soft metal.
Dependencies are inferred from the claim text.