Automatic web threading apparatus and method

Apparatus for guiding, severing and conveying a traveling web in a web processing apparatus from one section of the apparatus to another section of the apparatus, the apparatus including a first roll on which the strip is supported and a second roll downstream in spaced adjacency to the first roll, the combination comprising:

• slitting means associated with the web to, cut a longitudinally extending web strip having an outer surface in the web on one side thereof;
• strip deflector means, including a doctor having a blade disposed to intercept the web strip on the first roll and an orifice means for projecting compressed air along the distal edge of the doctor blade and against the web strip, whereby the web strip is separated from the first roll and a first space is established and maintained between the web strip and first roll;
• foil means above the strip over the first roll for establishing a second space between the foil means and the outer surface of the strip over the first space, said foil means structured and arranged to establish in the second space a pressure lower than the pressure in the first space, whereby the strip is guided away from the first roll;
• a web strip knife disposed downstream of the foil means to intercept portion of the web strip guided away from the first roll;
• a support plate downstream of the knife for receiving the upstream portion of the severed strip and conveying the strip to the second roll for further processing.

A method for automatically guiding and conveying a traveling web strip in a web processing apparatus from one section of the apparatus to another section of the apparatus, the apparatus including a first roll on which the strip is supported and a second roll downstream in spaced adjacency to the first roll, the steps including:

• separating the oncoming web strip from the surface of the first roll to establish a first space between the web strip and the surface of the first roll;
• maintaining the first space between the traveling web strip and the first roll over which it is disposed;
• guiding an upstream portion of the strip away from the surface of the first roll and producing a bight portion in the web strip by using a foil means above the strip over the first roll and thereby establishing a second space between the foil means and the outer surface of the strip over the first space, said foil means establishing in the second space a pressure lower than the pressure on the side of the web in the first space facing the first roll;
• directing the bight portion the guided web strip onto
• a web severing means to sever the web strip;
• supporting the oncoming severed end of the web strip for a substantial distance;
• conveying the traveling web strip into the downstream section of the web processing apparatus.