Cutting blade edge application method and apparatus
A method and apparatus applying a cutting edge to a cutting blade are provided that may allow the cutting edge to be created using a shearing process such that a majority of the edge is sheared without excessive breakout.
1 . An apparatus for applying a cutting edge to a cutting blade, comprising:
a die adapted to retain a blade blank in a stationary position; and
a punch adapted to shear material from the blade blank to form a cutting edge having an angle from horizontal in the range of 25 to 40 degrees, the punch further having a working end with a shear angle and a relief angle, and configured to have a minimum clearance from the die in a amount of less than or equal to 2% of the blade blank thickness.
2 . The apparatus of claim 1 , wherein the shear angle is in the range of 8 degrees to 30 degrees.
3 . The apparatus of claim 2 , wherein the shear angle is approximately 12 degrees.
4 . The apparatus of claim 3 , wherein the relief angle is approximately 16 degrees.
5 . The apparatus of claim 1 , wherein the die retains the blade blank at an angle of approximately 60 degrees with respect to horizontal and the punch travels vertically such that a cutting edge angle of approximately 30 degrees is applied to the blade blank.
6 . The apparatus of claim 1 , wherein the clearance is approximately 0.5% of the blade blank thickness.
7 . The apparatus of claim 1 , wherein the clearance is approximately between 0.001 inches and 0.002 inches, and the blade blank thickness is approximately 0.2 inches.
8 . The apparatus of claim 1 , wherein the shear angle is formed by having a punch where the working end has no angle and orienting the blade blank and die at an angle relative to the punch working end.
9 . The apparatus of claim 1 , wherein the shear angle is adapted to shear material from the blade blank from an interior portion of the blade blank to an outside edge of the blade blank.
10 . An apparatus for applying a cutting edge to a rotary cutting blade, comprising:
a die adapted to retain a blade blank in a stationary position at an angle of 60 degrees with respect to horizontal; and
a punch adapted to move substantially vertically and shear material from the blade blank to form a cutting edge having a cutting edge angle of approximately 30 degrees, the punch further having a working end with a shear angle of approximately 12 degrees and a relief angle of approximately 16 degrees, and wherein the punch and die are configured to have a minimum clearance from each other in the range of approximately 0.001 inches to 0.002 inches.
11 . A method of applying a cutting edge to a cutting blade, comprising:
providing a die configured to retain a blade blank;
positioning the blade blank in the die;
providing a punch having a shear angle and a relief angle, the punch adapted to move relative to the die and shear material from the blade blank;
orienting the punch and die such that there is an angle between the punch and blade blank in the range of approximately 25 to 40 degrees and a minimum clearance of less than or equal to 2% of the thickness of the blade blank; and
shearing material from a leading edge of the blade blank by moving the punch in at least a first direction until a cutting edge has been applied to a desired portion of the blade blank.
12 . The method of claim 11 , wherein the shear angle is in the range of 8 degrees to 30 degrees.
13 . The method of claim 12 , wherein the shear angle is approximately 12 degrees.
14 . The apparatus of claim 13 , wherein the relief angle is approximately 16 degrees.
15 . The method of claim 11 , wherein the punch has a width that is less than the width of the cutting edge, and shearing material from the leading edge includes moving the punch in the first direction and a second direction.
16 . The method of claim 15 , wherein the first direction is vertical and the second direction is horizontal.
17 . The method of claim 11 , wherein shearing material from the leading edge includes beginning to shear the material from an interior portion of the blade blank towards an outside edge of the blade blank.
18 . The method of claim 11 , wherein the minimum clearance is approximately between 0.001 inches and 0.002 inches.
19 . A rotary mower, comprising:
a power source; and
a rotary cutting blade operationally coupled to the power source, the rotary cutting blade having a cutting edge applied by a process comprising
providing a die configured to retain a rotary cutting blade,
positioning the rotary cutting blade in the die,
providing a punch having a shear angle and a relief angle, the punch adapted to move relative to the die and shear material from the rotary cutting blade,
orienting the punch and die such that a cutting edge angle in the range of approximately 25 to 40 degrees is applied to the rotary cutting blade, and a minimum clearance of less than or equal to 2% of the thickness of the rotary cutting blade is maintained between the punch and die, and
shearing material from a leading edge of the rotary cutting blade by moving the punch in at least a first direction until the cutting edge has been applied to a desired portion of the rotary cutting blade.
20 . The rotary mower of claim 19 , wherein the shear angle is in the range of 8 degrees to 30 degrees.
21 . The rotary mower of claim 19 , wherein the shear angle is approximately 12 degrees.
22 . The rotary mower of claim 19 , wherein the relief angle is approximately 16 degrees.
23 . The rotary mower of claim 19 , wherein the clearance is approximately 0.5% of the blade blank thickness.
24 . The rotary mower of claim 19 , wherein the clearance is approximately between 0.001 inches and 0.002 inches, and the blade blank thickness is approximately 0.2 inches.
25 . The rotary mower of claim 19 , wherein the cutting edge angle is approximately 30 degrees.