Method and apparatus for transverse cutting

A method of operating an orbital saw to transversely sever superposed elongated web plies into shorter length products comprising the steps of

• advancing, along a linear path, said superposed elongated web plies having a cross sectional area of at least about 3.5 square inches (2200 mm.sup.2),
• providing a 4-bar linkage including first and second bars extending generally parallel to each other, each of said first and second bars having a pair of ends, and third and fourth bars to provide at least one degree of pivotal freedom of said third and fourth bars relative to said first and second bars,
• connecting said first and second bars adjacent the ends thereof with said third and fourth bars,
• rotatably mounting a disc blade having a center on each of said third and fourth bars with each of said third and fourth bars being equipped with means for rotating said disc blades,
• rotating said first bar about a first axis to orbit said blades with the orbit of said blades intersecting said linear path and with the centers of said disc blades being at least 30" (750 mm) apart while skewing said first axis at a minor acute angle to said linear path, and
• rotating said second bar about a second axis different from said first axis to compensate for said skewing and to orient said disc blades perpendicular to said web plies in said linear path when severing said web plies.