Web cutter

Claim 1

A web cutter, comprising: first and second cylindrical rollers mounted for rotation about mutually parallel axes, said first roller having a T-shaped longitudinal slot therein, said slot having a relatively narrow portion extending to the periphery of said first roller, a relatively wide portion adjacent said relatively narrow portion, and a shoulder portion providing the transition between said relatively narrow and relatively wide portions; an elongated T-shaped web cutting knife blade disposed in said slot, said blade having an enlarged head portion and a relatively narrow portion having a cutting edge disposed opposite said head portion, the relatively narrow portion of said blade being disposed within the relatively narrow portion of said slot with the cutting edge of said blade protruding a predetermined distance beyond the periphery of said first roller, the enlarged head portion of said blade being disposed in the relatively wide portion of said slot with the part of said head portion adjacent to and extending beyond the relatively narrow portion of said blade abutting against the shoulder portion of said slot; an elongated relatively compliant strip of resilient material having a given initial thickness disposed within the relatively wide portion of said T-shaped slot in contact with the enlarged head portion of said knife blade; a relatively rigid elongated load equalizing strip disposed within the relatively wide portion of said T-shaped slot in contact with said resilient strip; said first roller having a plurality of threaded holes therein disposed opposite said knife blade and communicating with the relatively wide portion of said slot; a corresponding plurality of set screws threadably mounted in said holes and abutting said load equalizing strip to urge said load equalizing strip toward the enlarged head portion of said knife blade, thereby compressing said resilient strip and prestressing said knife blade, the force exerted by said set screws and load equalizing strip on said resilient strip being sufficient to reduce the thickness of said resilient strip from said given initial thickness to a second prestress thickness, the difference between said thicknesses having a desired value; said rollers being disposed in juxtaposition with the peripheries thereof being spaced apart by a given distance slightly less than said predetermined distance, so that said blade is deflected a given distance into said slot upon engagement of said cutting edge with the periphery of said second roller, thus further compressing said resilient strip between the enlarged head of said knife blade and said load equalizing strip by an additional amount equal to the inward deflection of said blade, thE additional compression of said resilient strip, i.e., said given distance, being substantially less than the initial compression thereof, i.e., said desired value, so that substantial force is required to initially deflect said blade upon engagement of said cutting edge with the periphery of said second roller, the force between said cutting edge and said second roller being substantially constant during the engagement thereof; and means for rotating said first roller to bring said cutting edge into engagement with a web disposed between said rollers and the periphery of said second roller to sever said web.