Sheet folding apparatus with vacuum grip

• US 5,842,964 A
• Filed: 07/01/1997
• Issued: 12/01/1998
• Est. Priority Date: 07/01/1997
• Status: Expired due to Fees

• Current Assignee: Fred Huber & Associates
• Original Assignee: Fred Huber & Associates
• Inventors: Huber, Manfred, Cogswell, John A.
• Primary Examiner(s): Sipos, John
• Assistant Examiner(s): DAY, CHRISTOPHER WILLIAM
• Application Number:
  US08/886,480
• Time in Patent Office: 518 Days
• Field of Search: 493/395, 493/396, 493/397, 493/398, 493/399, 493/400, 493/401, 493/402, 493/403, 493/405, 493/415, 493/416, 493/417, 493/418, 493/422, 493/424, 493/432, 493/433, 493/434, 493/435, 493/436, 493/442, 493/450, 493/454
• US Class Current: 493/434
• CPC Class Codes: B65H 45/16 Rotary folders

Abstract

A sequentially timed vacuum grip system holds a sheet and transports it through a folding nip defined by a pair of folding cylinders. At the nip, the folded edge of the sheet is released and simultaneously picked-up by the paired companion cylinder. Additional folds are achieved in the same manner by the use of additional cylinder pairs.

Claims

1. Apparatus for producing a tri-fold in a paper sheet comprising:

a first cylinder and a second cylinder, each rotating relative to each other about parallel axes and defining a first nip therebetween;

first synchronized vacuum means defined on said first cylinder for gripping the sheet in a selected first mid portion location thereof, drawing the sheet thereby into said first nip, and for releasing said selected first mid portion location upon arrival in said first nip;

second synchronized vacuum means defined on said second cylinder for gripping the sheet with said second cylinder when the sheet arrives at said first nip, in synchronization with said release by said first synchronized vacuum means, for drawing the sheet thereby past said first nip, and for selectively releasing said selected first mid portion location;

a third cylinder and a fourth cylinder, each rotating relative to each other and relative to said first and second cylinders about parallel axes, defining a second nip between said third and fourth cylinders and defining a third nip between said second and third cylinders; and

third synchronized vacuum means defined on said third cylinder for gripping the sheet in a selected second mid portion location thereof in synchronization with said release of said second synchronized vacuum means, drawing the sheet into said second nip, and for releasing said selected second mid portion location upon arrival in said second nip.

2. The apparatus for producing a tri-fold in a paper sheet of claim 1 further comprising fourth synchronized vacuum means for gripping the sheet with said fourth cylinder when the sheet arrives at said second nip, in synchronization with said release by said third synchronized vacuum means, for drawing the sheet thereby past said second nip, and for selectively releasing said selected second mid portion location.

3. A process for producing a tri-fold in a paper sheet comprising:

(a) moving the sheet along a path tangential to paired first and second counter rotating cylinders positioned on parallel axes to form a first nip therebetween;

(b) actuating a first synchronized vacuum grip on said first cylinder when a first selected mid portion location of the sheet is superimposed thereon and thereby gripping the sheet at said selected mid-portion location;

(c) drawing said first selected mid portion of the sheet into said first nip between said first and second cylinders to form a first fold and to define a first folded edge;

(d) releasing said first synchronized vacuum grip on said first cylinder to thereby release said first selected midportion of the sheet;

(e) actuating a second synchronized vacuum grip on said second cylinder when the sheet arrives in said first nip in synchronization with said release of step d to thereby grip the sheet;

(f) moving said first folded edge of the sheet along a path defined by the surface of said second cylinder, past a third nip formed between said second cylinder and a third cylinder, said third cylinder counter rotating relative to said second cylinder on an axis parallel to said axis of said second cylinder;

(g) actuating a third synchronized vacuum grip on said third cylinder when a second selected location in the mid portion of the folded sheet is superimposed thereon to thereby grip said second selected location of the sheet;

(h) releasing said second synchronized vacuum grip in synchronization with said actuation of said third synchronized vacuum group of step g to thereby transfer the sheet to said third cylinder;

(i) drawing the sheet into a second nip formed between said third cylinder and a fourth cylinder, said fourth cylinder counter rotating relative to said third cylinder on an axis parallel to said third cylinder to form a second fold; and

(j) releasing said third synchronized vacuum grip.