into strips to width B of the blanks (Figure 4.2, lower illustration). The strips are then run through the shear again and cut into blanks having length A. On the route sheet, operations are listed as follows:
•Operation No. 1. Shear to width (B)
•Operation No. 2. Shear to length (A)
4.2.3 Triangular Blanks
Triangular blanks (Figure 4.3) are produced by shearing square or rectangular blanks, then splitting them to produce two blanks. In the upper illustration:
•Operation No. 1. Shear to length (A)
•Operation No. 2. Shear to double width (B)
•Operation No. 3. Split (C)
Although operation No. 2 states “Shear to double width,” this does not mean that the strip is to be cut twice the width of a single blank. It simply means that the square or rectangular blanks are to be made wide enough so splitting will produce two full blanks.
Figure 4.3 Triangular blanks made by shearing rectangular blanks sheared from wide and narrow strips.
For running strips the narrow way (Figure 4.3, lower illustration), operations are listed as follows:
•Operation No. 1. Shear to width (B)
•Operation No. 2. Shear to double length (A)
•Operation No. 3. Split (C)
4.2.4 Angular Edge Blanks
Wider blanks having one angular edge (Figure 4.4) can be produced by the same method employed for triangular blanks. For the upper illustration:
•Operation No. 1. Shear to length (A)
•Operation No. 2. Shear to double width (B)
•Operation No. 3. Split (C)
The function of some blanks renders it necessary to run them the narrow way (Figure 4.4, lower illustration). Operations are then as follows:
•Operation No. 1. Shear to width (B)
•Operation No. 2. Shear to double length (A)
•Operation No. 3. Split (C)
Figure 4.4 Angular edge blanks made by shearing rectangular blanks sheared from wide and narrow strips.
Added cuts
One or more extra cuts may be required to complete the blanks (Figure 4.5). Here is the order of operations for the blank in the upper inset:
•Operation No. 1. Shear to length (A)
•Operation No. 2. Shear to double width (B)
•Operation No. 3. Split (C)
•Operation No. 4. Trim (D)
In the lower illustration:
•Operation No. 1. Shear to width (B)
•Operation No. 2. Shear to double length (A)
•Operation No. 3. Split (C)
•Operation No. 4. Trim (D)
4.2.5 Parallelogram Blanks
Blanks in the shape of an angular parallelogram (Figure 4.6) are produced by shearing with the strip positioned at an angle to the shear blade. For the wide strips, upper illustration:
Figure 4.5 Blanks produced by added cutting of angular edge pieces.
Figure 4.6 Parallelogram-shaped blanks sheared from wide and narrow strips.
•Operation No. 1. Shear to length (A)
•Operation No. 2. Shear to width (B)
For narrow strips, lower illustration:
•Operation No. l. Shear to width (B)
•Operation No. 2. Shear to length (A)
4.2.6 Triangular Blanks
Triangular blanks with an acute angle at each of the three apexes (see Figure 4.7) are produced by splitting a parallelogram.
For wide strips (Figure 4.7, upper illustration):
•Operation No. 1. Shear to length (A)
•Operation No. 2. Shear to double width (B)
•Operation No. 3. Split (C)
For narrow strips (Figure 4.7, lower illustration):
•Operation No. 1. Shear to width (B)
•Operation No. 2. Shear to double length (A)
•Operation No. 3. Split (C)
Figure 4.7 Acute-angle triangular blanks made by shearing parallelogram-shaped blanks sheared from wide and narrow strips.
Figure 4.8 Trapezoidal blanks are sheared in a manner similar to acute angle triangular blanks.
4.2.7 Trapezoidal Blanks
Large trapezoidal blanks (Figure
