Method and apparatus for separating a continuous stream of connected business forms into exact count zig-zag folded stacks

• US 4,131,272 A
• Filed: 06/13/1977
• Issued: 12/26/1978
• Est. Priority Date: 06/13/1977
• Status: Expired due to Term

• Current Assignee: Paper Converting Machine Company (Barry-Wehmiller Group Incorporated)
• Original Assignee: Paper Converting Machine Company (Barry-Wehmiller Group Incorporated)
• Inventors: Hartnig, Richard E.
• Primary Examiner(s): Burr, Edgar S.
• Assistant Examiner(s): Heinz, A.
• Application Number:
  US05/806,110
• Time in Patent Office: 561 Days
• Field of Search: 270/61 F, 270/73, 270/79, 53/66, 53/116, 53/11 T, 225/100-101, 225/32, 93/93 DP
• US Class Current: 493/35
• CPC Class Codes: B65H 35/10 from or with devices for breaking partially-cut or perforated webs, e.g. bursters
• CPC Class Codes: Y10T 225/35 Work-parting pullers [bursters]

Abstract

A method and apparatus for separating a continuous stream of connected business forms into exact count zig-zag folded stacks wherein nip forming rolls are selectively engaged to burst the web stream at a predetermined point and prior to zig-zag folding.

Claims

1. In a method of separating a continuous stream of connected business forms into exact count zig-zag folded stacks for packaging, the steps of:

continuously advancing an elongated web along a linear path toward a station for zig-zag folding, said web including a longitudinally extending control margin and equally spaced apart lines of perforation defining business forms therebetween,

after a predetermined number of said lines of perforation have passed a point in said path, applying nipping forces to said web along transverse lines upstream and downstream of a given line of perforation and within the length of the business forms on either side of said given line of perforation, the downstream nipping force imparting a higher velocity to said web than the upstream nipping force whereby said web is burst along said given line of perforation,

removing at least said downstream nipping force from said web prior to the time the line of perforation subsequent to said given line of perforation passes the line of application of said upstream nipping force, and

zig-zag folding said web in said station along each said line of perforation, the line of perforation immediately preceding said given line of perforation being gripped incident to zig-zag folding at about the time of web bursting along said given line of perforation.

2. The method of claim 1 in which the position of said given line of perforation at the time of bursting is controlled by engaging said control margin upstream of said given line of perforation and downstream of said line of application of said upstream nipping force.

3. The method of claim 1 in which the web portion upstream of said given line of perforation is guided past the line of application of said downstream nipping force and into said station.

4. In apparatus for separating a continuous stream of connected forms into exact count zig-zag folded stacks for packaging, a frame,

means operably associated with said frame for continuously advancing an elongated web along a linear path toward a station for zig-zag folding, said web including a longitudinally extending control margin and equally spaced apart lines of perforation defining business forms therebetween,

means on said frame for applying nipping forces to said web along transverse lines upstream and downstream of a given line of perforation and within the length of the business forms on either side of said given line of perforation, the means for applying the downstream nipping force imparting a higher velocity to said web than the means for applying the upstream nipping force whereby said web is burst along said given line of perforation,

means on said frame controlling the application of said forces to a time after a predetermined number of said lines of perforation have passed a given point in said path and for removing at least said downstream nipping force from said web prior to the time the line of perforation subsequent to said given line of perforation passes the point of application of said up-stream nipping force, and

a pair of rolls on said frame downstream of said nip force applying means for zig-zag folding said web along each line of perforation.

5. The apparatus of claim 4 in which pin belt means for conveying at least a portion of said web is provided between said transverse lines, said pin belt means having a downstream end and said pair of rolls for zig-zag folding having a nip, said downstream end of said pin belt means and said zig-zag folding rolls nip being spaced apart less than the distance between said equally spaced lines of perforation.

6. In apparatus for separating a continuous stream of connected business forms into exact count zig-zag folded stacks for packaging, a frame, means operably associated with said frame for continuously advancing an elongated web along a linear path toward a station for zig-zag folding, said web including a longitudinally extending control margin and equally spaced apart lines of perforation defining business forms therebetween, means on said frame for applying nipping forces to said web along transverse lines upstream and downstream of a given line of perforation and within the length of the business forms on either side of said given line of perforation, the means for applying the downstream nipping force imparting a higher velocity to said web than the means for applying the upstream nipping force whereby said web is burst along said given line of perforation, and means on said frame controlling the application of said forces to a time after a predetermined number of said lines of perforation have passed a given point in said path and for removing at least said downstream nipping force from said web prior to the time the line of perforation subsequent to said given line of perforation passes the line of application of said up-stream nipping force, said means for applying said nipping forces including two pairs of rotating elements, the elements in each pair flanking said path, and a pin belt on said frame between said pairs of rotating elements for engaging the control margin which is upstream of said given line of perforation and downstream of said line of application of said upstream nipping force.

7. The apparatus of claim 6 in which said elements are equipped with axially spaced apart grooves, and guide bar means mounted on said frame extending through said grooves for directing the free edge of a burst web toward said station.

8. The apparatus of claim 6 in which a pivot arm is mounted on said frame, one of the elements for applying the downstream nipping force being mounted on said arm, and means on said frame for pivoting said arm after a predetermined number of lines of perforation have passed a given point in said path.