Method and apparatus for the production of numerically correct stacks

• US 5,088,707 A
• Filed: 08/09/1990
• Issued: 02/18/1992
• Est. Priority Date: 08/19/1989
• Status: Expired due to Fees

• Current Assignee: Winkler & Dunnebier Maschinenfabrik und Eisengiesserei KG
• Original Assignee: Winkler & Dunnebier Maschinenfabrik und Eisengiesserei KG
• Inventors: Stemmler, Kurt
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): NEWHOLM, THERESE
• Application Number:
  US07/565,231
• Time in Patent Office: 558 Days
• Field of Search: 270/31, 270/32, 270/39, 270/40, 270/41, 270/47, 270/52, 270/52.5, 270/95, 493/351, 493/360-363, 493/409, 493/412-417, 493/405
• US Class Current: 270/39.02
• CPC Class Codes: B65H 2701/11231 Fan-folded material or zig-zag or leporello
• CPC Class Codes: B65H 45/24 Interfolding sheets, e.g. cigarette or toilet papers
• CPC Class Codes: B65H 45/28 Folding in combination with cutting cutting machines B26D

Abstract

A method and apparatus for producing numerically correct partial stacks from individual leaves or sheets interfolded in a U-shaped or zigzag form on an interfolder. A double stream is formed from one or more streams of sheets by staggering or guiding together. This double stream is then continuously folded into zigzag form and piled up in a continuously growing stack, from which partial stacks of a specific size are separated. Gaps are formed in the streams of sheets which simplify the introduction of separating elements into the stack. For this purpose, sheets are removed from the streams of sheets and optionally placed accurately in position on successive sheets.

Claims

1. A method of producing numerically correct partial stacks of individual sheets which are of U-shape or zigzag-shape and which are interfolded so as to overlap, comprising:

providing at least one continuously moving length of material;

producing at least one continuously produced stream of neighboring sheets of equal length from said at least one continuously moving length of material by cross-separation or cross-perforation;

providing a first produced stream and a second produced stream;

said double stream being guided together and staggered, so that neighboring sheets lying opposite to one another are offset with respect to one another;

forming a gap in one of the streams by removing at least one removable sheet;

temporarily storing sheets which have been removed from the continuously produced stream;

afterwards returning said removed sheets to the stream by placing the removed sheets on the sheets of the first produced stream or on the sheets of the second produced stream in such a way that the first neighboring and first removed sheets or the second neighboring and second removed sheets are aligned congruently with respect to one another;

continuously folding said double stream in U-shape or zigzag shape;

piling up said double stream in the form of a stack;

dividing the stack which is continuously being formed into numerically correct partial stacks; and

separating off said partial stacks from said stack by the introduction of separating elements in a separating zone of the stack.

2. A method as claimed in claim 1, further comprising storing temporarily the sheets removed from the first and second continuously produced streams;

and

afterwards delivering said removed sheets during the machine cycle to the length of material, so that they are aligned congruently with respect to the neighboring sheets which are to be separated off.

3. A method as claimed in claim 2, further comprising guiding the neighboring sheets underneath the length of material.

4. A method as claimed in claim 2, further comprising guiding the neighboring sheets on the length of material.

5. A method as claimed in claim 3, further comprising moving the neighboring sheets on an equal circular path during cross-separation or cross-perforation, interim storage and returning to the length of material.

6. A method as claimed in claim 2, further comprising placing several removable sheets on a neighboring sheet.

7. A method of producing numerically correct partial stacks of individual sheets which are of U-shape or zigzag-shape and which are interfolded so as to overlap, comprising:

providing at least one continuously moving length of material;

producing at least one continuously produced stream of neighboring sheets of equal length from said at least one continuously moving length of material by cross-separation or cross-perforation;

providing a double stream of these sheets;

said double stream being guided together and staggered, so that neighboring sheets lying opposite to one another are offset with respect to one another;

creating a gap in the zigzag folding of the stream by removing at least one removable sheet;

temporarily storing sheets which have been removed from the continuously produced stream;

afterwards returning said removed sheets to the stream by placing the first removed sheets one after the other, individually and congruently, on the first neighboring sheets and placing the second removed sheets one after the other, individually and congruently, on the second neighboring sheets;

continuously folding said double stream in U-shape or zigzag shape;

piling up said double stream in the form of a stack;

dividing the stack which is continuously being formed into numerically correct partial stacks; and

separating off said partial stacks from said stack by the introduction of separating elements in a separating zone of the stack.

8. A method as claimed in claim 7, comprising directly placing the first or second removed sheets on the first or second neighboring sheets following the gap.

9. A method as claimed in claim 7, comprising placing the first or second removed sheets on the first or second neighboring sheets which are arranged immediately before the next gap.

10. A method as claimed in claim 7, further comprising introducing separating elements into the gap in the zigzag folding of the double stream in order to divide up the stack.

11. A method of producing numerically correct partial stacks of individual sheets which are of U-shape or zigzag-shape and which are interfolded so as to overlap, comprising:

providing at least one continuously moving length of material;

producing at least one continuously produced stream of neighboring sheets of equal length from said at least one continuously moving length of material by cross-separation or cross-perforation;

providing a double stream of these sheets;

said double stream being guided together and staggered, so that neighboring sheets lying opposite to one another are offset with respect to one another;

forming a gap in the stream by removing at least one removable sheet;

temporarily storing the removable sheets of the continuously produced streams by the same storage device;

afterwards delivering said removable sheets, as required, to the first continuously produced stream or to the second continuously produced stream;

continuously folding said double stream in U-shape or zigzag shape;

piling up said double stream in the form of a stack;

dividing the stack which is continuously being formed into numerically correct partial stacks; and

separating off said partial stacks from said stack by the introduction of separating elements in a separating zone of the stack.

12. A method of producing numerically correct partial stacks of individual sheets which are of U-shape or zigzag-shape and which are interfolded so as to overlap, comprising:

providing at least one continuously moving length of material;

producing at least one continuously produced stream of neighboring sheets of equal length from said at least one continuously moving length of material by cross-separation or cross-perforation;

providing a double stream of these sheets;

said double stream being guided together and staggered, so that neighboring sheets lying opposite to one another are offset with respect to one another;

forming a gap in the stream by removing at least one removable sheet;

temporarily storing sheets which have been removed from the continuously produced stream;

returning the removable sheets which had been removed for the formation of a first gap to the continuously produced stream after a second gap following the first gap;

continuously folding said double stream in U-shape or zigzag shape;

piling up said double stream in the form of a stack;

dividing the stack which is continuously being formed into numerically correct partial stacks; and

separating off said partial stacks from said stack by the introduction of separating elements in a separating zone of the stack.

13. An apparatus for producing numerically correct partial stacks comprising:

a pair of feed rollers for supplying a double stream length of material;

a cross-separating or cross-perforating means for defining a cutting gap;

a pair of folding rollers rotating in the opposite direction of each other and defining a folding gap for zigzag folding of the double stream to form a stack;

a shaft arranged after the double stream and receiving the stack;

distributors which are coordinated with the pair of folding rollers and which are arranged on both sides of the shaft;

a separating means which is arranged downstream of the pair of folding rollers and which can be introduced into the stack from the side;

a storage table which goes into the shaft; and

at least one removing means arranged between the cutting gap and the folding gap and tangent to the double stream, said removing means including a storage arrangement means for receiving, storing and returning the neighboring sheets;

means for activating said at least one removing means depending upon the machine cycle and a desired number of neighboring sheets in order to form a partial stack.

14. An apparatus as claimed in claim 13, wherein said storage arrangement means is constructed as a storage roller, or storage belt.

15. An apparatus as claimed in claim 13, wherein said cross-separating or perforating arrangement includes a cutter roller constructed as a storage roller.

16. An apparatus as claimed in claim 13, wherein said cross-separating or perforating arrangement includes a blade roller constructed as a storage roller.

17. An apparatus as claimed in claim 13, further comprising suction air gripping elements for said storage arrangement.

18. An apparatus as claimed in claim 14, wherein the storage roller or the storage belt, together with the folding rollers of the pair of folding rollers, form a common receiving and returning gap.

19. An apparatus as claimed in claim 13, further comprising several storage arrangement means for each continuously produced stream.