Cutting duct bend segments - uses pins through location holes in blank moving in guide groove in shear table

摘要

The development of a segment of a fabricated duct bend has sine curved edges. The process allows the correct curve for any duct dia. and segment angle to be cut on a normal sheet metal shear (14, 15). A guide channel (18) is laid out on the shear table, in a curve found by calculation or laying out from the rivet holes of a reference development. When the pins are placed through the corresponding rivet holes (4,6) of a blank (1) and the blank is moved towards the shear, the cutting direction (19) is always tangential to the required curve.