Apparatus and method for transporting and perforating enlongated strips of material

Apparatus for perforating an elongated strip of material, comprising:

• an elongated, flat track plate having side edges and a first upper surface;
• means for intermittently moving said strip in a direction along said track plate comprising a vacuum drum assembly positioned at the downstream end of said track plate in said direction;
• means for intermittently rotating said drum to move said strip along said track plate;
• means for measuring rotation of said drum;
• a first vacuum box positioned at the upstream end of said track plate for receiving a first loop of said strip and maintaining tension on said strip;
• a second vacuum box positioned at the downstream end of said vacuum drum for receiving a second loop of said strip and maintaining tension on said strip;
• and conduit means interconnecting the low pressure sides of said first and second vacuum boxes for maintaining essentially the same pressure in both vacuum boxes;
• means positioned along said track plate for perforating said strip when said strip is stopped by said means for intermittently moving;
• and
• means for controlling operation of said means for perforating in response to said means for measuring.

An improved die apparatus for use in perforating elongated strips of material, said strips having edges and a width, said apparatus comprising:

• an elongated, flat track plate having side edges and a first upper surface;
• a plurality of gas flow apertures arranged along said track plate, each said aperture being extended through and angled relative to said first upper surface, whereby gas flowing through said apertures will support said strip above said first upper surface;
• at least one fixed die having a second upper surface substantially coplanar with said first upper surface, said fixed die being positioned along one of said side edges and having a plurality of die apertures spaced along said track plate opposite said strip;
• at least one pair of edge guide means, spaced apart greater than said width outside said track plate and said fixed die, for guiding said strip along said track plate and opposite said fixed die;
• and
• gas passage means, opening through each of said edge guide means, for permitting escape of gas flowing beneath said strip from said gas flow apertures.

A method for providing an elongated strip of material with a selectable length pattern of perforations along the length of said strip, comprising the steps of:

• (a) positioning said strip on an elongated track;
• (b) providing a plurality of punch and die sets along said track in position to perforate said strip;
• (c) actuating a first fraction of said plurality of punch and die sets to produce a first portion of said pattern of perforations;
• (d) moving said strip longitudinally along said track to permit production of a subsequent portion of said pattern of perforations, said subsequent portion being spaced longitudinally along said strip from said first portion;
• (e) again actuating said first fraction or actuating a different fraction or actuating all of said plurality of punch and die sets to produce said subsequent portion of said pattern of perforations;
• (f) repeating steps (d) and (e) until said pattern of perforations is completed;
• and
• (g) moving said strip longitudinally along said track to permit production of a subsequent pattern of perforations.

A method for providing an elongated strip of material with a selectable length pattern of perforations along the length of said strip, comprising the steps of:

• (a) positioning said strip on an elongated track;
• (b) providing a plurality of punch and die sets along said track in position to perforate said strip;
• (c) actuating all of said plurality of punch and die sets to produce a first portion of said pattern of perforations;
• (d) moving said strip longitudinally along said track to permit production of a subsequent portion of said pattern of perforations, said subsequent portion being spaced longitudinally along said strip from said first portion;
• (e) actuating all or actuating a fraction of said plurality of punch and die sets to produce said subsequent portion of said pattern of perforations;
• (f) repeating steps (d) and (e) until said pattern of perforations is completed;
• and
• (g) moving said strip longitudinally along said track to permit production of a subsequent pattern of perforations.