Auxiliary cut-off unit for web printing presses and method of forming severed pieces

Claim 1

An auxiliary in-line rotary cutoff unit adapted to be connected to and driven directly by a web printing press to provide the same with capabilities of producing from a longitudinally folded or unfolded continuous flexible web of one or more thicknesses of precise width printed pieces each having precisely uniform lengths cleanly and evenly severed on all cut edges and requiring no additional trimming, said cut-off unit comprising in combination, a frame, a pair of cooperating feed rolls supported by said frame and adapted to receive and feed a longitudinally folded or unfolded printed web directly from a web printing press, means operable to drive said feed rolls at a fixed surface speed substantially equal to the speed of the web discharged from said press, a rotary cutting member comprising a cylinder having at least one shearing blade extending longitudinally thereon and radially adjustable relative to the axis of said cylinder and said blade being engageable with said web as fed by said feed rolls, a drive shaft for said cylinder of said rotary cutting member supported by said frame, a bed knife supported stationarily by said frame adjacent said cylinder and adjustable towards and from said cylinder for precise shearing engagement with said shearing blade of said cylinder, and adjustable drive means interconnected to said drive shaft for said rotary cutting member adapted to be connected directly to drive means on said printing press, said adjustable drive means being adapted to vary the rotational speed of said rotary cutting member relative to the speed of said web fed thereto to cause said blade of said rotary cutting member to engage said stationary bed knife to sever said web transversely into precise desired uniform lengths smoothly and evenly at opposite ends of the pieces thus severed which comprise finally trimmed pieces having precise finished lengths and widths.