Web cutting device

Claim 1

A supplementary device mountable on a packaging machine for wrapping block-like articles in wrappers of material cut from webs, the device comprising, in combination: mounting means adapted to mount said device on such packaging machine; first guide means to define a first web feed path for a first web to such packaging machine; second guide means to define a second web feed path for a second web to such packaging machine; first web feeder means selectably operable to feed a first web along said first feed path; second web feeder means selectably operable to feed a second web along said second feed path; first cutter means disposed in said first path; second cutter means disposed in said second path; said first and said second cutter means each comprising a generally disc-shaped member rotatably displaceable relatively to a second member to bring mutually co-operable knife elements of said first and said second members into co-operative action, said generally disc-shaped member of each said cutter means having a plurality of individual ones of said knife elements spaced around the periphery thereof; means to urge said rotatable member into an orientation relative to said member in which each said knife element of said rotatable member is spaced from the associated one of said feed paths, said urging means comprising a respective polygonal plate member connected to each said rotatable member and having a plurality of flat sides each in correspondence with a respective one of said knife elements on the associated one of said rotatable members, said urging means additionally comprising a respective indexing member resiliently urged against the periphery of said polygonal plate member; actuator means operatively associated with each said cutter means to cause the respective one of said cutter means to perform a single web cutting operation on each actuation by said associated actuator means, said actuating mEans comprising means to counteract said urging means thereby to cause said rotatable member to be rotatably displaced such that a respective single one of said knife elements co-operates with said second member to make an incision through said web, and interaction between said polygonal plate member, on being rotatably displaced, and said respective indexing member causing the latter to be displaced and permitting said respective indexing member to be resiliently urged against the next succeeding flat side of said polygonal plate member after each incision through said web has been made; and control means to cause actuation of a selected one of said first and said second feeder means and to cause deactuation of the respective other one of said feeder means.