Apparatus for shear-cutting a stack of amorphous steel strips

Apparatus for shear-cutting a stack of thin amorphous steel sheets along a cutting plane that extends transversely of said stack, comprising:

• (a) first and second blades each having a first surface for engaging said stack at one side thereof and a second surface that extends transversely of said first surface and generally parallel to said cutting plane, the first and second surfaces of each blade intersecting at a corner,
• (b) means for positioning said blades at the start of a cutting operation so that said corners are positioned at opposite sides of said stack and also on opposite sides of said cutting plane in juxtaposition thereto, and
• (c) means for moving one of said blades during a cutting operation so that the corner thereof moves toward the corner of the other blade in a direction parallel to said cutting plane, thereby causing the corners of said blades to shear-cut the stack along said cutting plane, and further characterized by:
• (d) said first surface of said one blade being disposed at a predetermined rake angle with respect to a reference plane extending through a point on the corner of said one blade and normal to said cutting plane and to the direction of motion of said one blade,
• (e) said first surface of said other blade being disposed at a predetermined rake angle with respect to a reference plane extending through a point on the corner of said other blade and normal to said cutting plane and to the direction of motion of said one blade,
• (f) the sum of said rake angles being a negative value of between 5 degrees and 35 degrees, and in which:
• the rake angle of either of said blades is considered to be negative if said first surface of the blade, in intersecting said second surface thereof at said corner of the blade, is so inclined as to make the corner less sharp than it would be if said first surface were located in said reference plane, and
• (g) both of said blades including their surfaces at said corners being of a cemented carbide cutting material that consists essentially of tungsten carbide particles and cobalt particles compacted under high pressure and sintered at a temperature exceeding the melting point of the cobalt, the tungsten carbide particles being, on average, of submicron size before compaction and constituting about 84 percent by weight of the cutting material, and the cobalt particles constituting more than 15 percent and about 16 percent by weight of the cutting material.