A working mechanism adaptable for producing virtually an infinity of different motions is provided which finds practical utility in a variety of contexts such as the handling of zigzag folded webs. The mechanism preferably includes at least one elongated working element pivotally supported at the inner end thereof and coupled by a pivotal link to an elongated, flexible, continuing closed-loop motion-imparting member such as a chain or belt. Advantageously, the mechanism may comprise a plurality of elongated working elements each coupled with a pair of closed loop path motion-imparting members to produce complex, variable speed motions heretofore difficult to achieve. In a web-handling device, the chain cam mechanism has a rotatable shaft pivotally supporting the inner ends of the elements, along with an endless chain cam-like member coupled via pivotal linkage arms to points intermediate the ends of the elements; the resultant path of travel of the outer or working ends of the elements is dependent upon the geometry of the components and can be readily changed to accommodate different working environments. A novel method and apparatus for handling zigzag folded webs makes use of a pair of identical, laterally spaced apart chain cam working mechanisms with respective working elements being joined at the outer ends thereof by means of corresponding, transverse web-engaging structures. The chain cam mechanisms create a motion serving to successively separate facially opposed and interconnected sheets, whereupon a trailing web-engaging structure engages the sheets and moves the same for further processing such as collation or stapling.