Method and apparatus for creating a discontinuity in a stack interfolded sheets
First Claim
1. A method of creating a discontinuity in a stack of interfolded sheets, wherein the stack is formed at the discharge of a pair of folding rolls which are supplied with staggered first and second streams of sheets by a pair of bed rolls, each of which cooperates with a severing arrangement to sever the sheets from a web, wherein the severed sheets in the first and second streams of sheets converge at a location upstream of the pair of folding rolls, comprising the steps of:
- forming a gap in the first stream of sheets, wherein the gap is formed upstream of the folding rolls by folding at least one of the sheets in the first stream of sheets onto itself to create a folded sheet in the first stream of sheets which defines the gap, while maintaining the supply of sheets in the second stream of sheets, wherein the folded sheet is folded at a location upstream of the location at which the sheets in the first and second streams of sheets converge and before the first and second streams of sheets are supplied to the folding rolls; and
supplying the first stream of sheets, including the folded sheet, to the folding rolls along with the second stream of sheets, wherein the folding rolls are operable to interfold the sheets in the first and second streams of sheets, including the folded sheet in the first stream of sheets;
wherein the gap in the first stream of sheets is operable to form a discontinuity in the stack of interfolded sheets when the sheets in the first and second streams of sheets are interfolded by the folding rolls.
3 Assignments
0 Petitions
Accused Products
Abstract
A system and method for creating a discontinuity in a stack of interfolded sheets in which folding rolls cooperate to interfold staggered sheets supplied in two streams of sheets, each of which is severed from a web of material. When a desired sheet count is attained, a sheet in one of the streams of sheets is folded onto itself so as to create a discontinuity in one of the streams of sheets. The folded sheet is formed by maintaining a leading portion of the sheet in engagement with a separating one roll while maintaining a trailing portion of the sheet in engagement with another roll, with the two rolls being positioned to form a nip therebetween and rotating in opposite directions. Once the sheet has attained a predetermined position on the two rolls, engagement of the leading portion of the sheet with the separating roll is released while engagement of the sheet with the other roll is maintained to define a crease in the sheet, with the leading portion of the sheet being folded back onto the trailing portion of the sheet. The folded sheet forms a gap in the sheet supplied in one of the streams of sheets which, when the sheets are supplied to the interfolding rolls, functions to create a discontinuity in the interfolded stack to facilitate separation of a portion of the stack from the remainder of the stack.
45 Citations
21 Claims
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1. A method of creating a discontinuity in a stack of interfolded sheets, wherein the stack is formed at the discharge of a pair of folding rolls which are supplied with staggered first and second streams of sheets by a pair of bed rolls, each of which cooperates with a severing arrangement to sever the sheets from a web, wherein the severed sheets in the first and second streams of sheets converge at a location upstream of the pair of folding rolls, comprising the steps of:
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forming a gap in the first stream of sheets, wherein the gap is formed upstream of the folding rolls by folding at least one of the sheets in the first stream of sheets onto itself to create a folded sheet in the first stream of sheets which defines the gap, while maintaining the supply of sheets in the second stream of sheets, wherein the folded sheet is folded at a location upstream of the location at which the sheets in the first and second streams of sheets converge and before the first and second streams of sheets are supplied to the folding rolls; and supplying the first stream of sheets, including the folded sheet, to the folding rolls along with the second stream of sheets, wherein the folding rolls are operable to interfold the sheets in the first and second streams of sheets, including the folded sheet in the first stream of sheets; wherein the gap in the first stream of sheets is operable to form a discontinuity in the stack of interfolded sheets when the sheets in the first and second streams of sheets are interfolded by the folding rolls. - View Dependent Claims (2, 3, 4, 5)
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6. A method of creating a separation in a stack of interfolded sheets, wherein the stack is formed at the discharge of a pair of folding rolls located downstream of a pair of bed rolls, each of which interacts with a severing mechanism to alternately sever sheets from a pair of webs, wherein the sheets severed from the pair of webs converge at a location upstream of the pair of folding rolls, and wherein the sheets are discharged from the bed rolls to the folding rolls, comprising the steps of:
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folding one of the sheets onto itself upstream of the pair of folding rolls while the sheet is engaged with a first one of the bed rolls to form a folded sheet which defines a gap in the supply of sheets from the first bed roll while maintaining an uninterrupted supply of sheets from a second one of the bed rolls, wherein the folded sheet is folded at a location upstream of the location at which the pair of webs converge and before the sheets from the first and second bed rolls are supplied to the folding rolls; subsequently discharging the folded sheet from the first bed roll; and supplying the sheets from the first bed roll, including the gap and the folded sheet, to the folding rolls while maintaining the uninterrupted supply of sheets from the second bed roll, wherein the folding rolls are operable to interfold the sheets from the first and second bed rolls, including the folded sheet, and wherein the gap defined by the folded sheet is operable to form a separation in the stack of interfolded sheets discharged from the folding rolls. - View Dependent Claims (7, 8, 9, 10, 11)
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- 12. In an interfolded sheet stack forming system in which a stack of interfolded sheets is formed at the discharge of a pair of folding rolls which are supplied with first and second staggered streams of sheets, wherein the first and second streams of sheets converge at a location upstream of the pair of folding rolls, the improvement comprising separation means for forming a separation in the stack of interfolded sheets by folding at least one sheet from the first stream of sheets onto itself to form a folded sheet, wherein the separation means is located upstream of the location at which the first and second streams of sheets converge and wherein the separation means forms the folded sheet before the first and second streams of sheets are supplied to the folding rolls, wherein the folding rolls are operable to interfold the sheets in the first and second streams of sheets, including the folded sheet in the first stream of sheets, and wherein the folded sheet forms a discontinuity in the stack of sheets discharged from the folding rolls.
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16. A sheet interfolding system for forming a stack of interfolded sheets from a pair of webs, comprising:
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a pair of bed rolls to which the pair of webs are supplied; a severing arrangement cooperating with each bed roll to sever the webs into sheets, wherein the sheets from the pair of webs converge at a location downstream of the pair of bed rolls; a pair of folding rolls arranged to receive the sheets from the pair of bed rolls and to interfold the sheets to form a stack of interfolded sheets at a discharge defined by the folding rolls; wherein the sheets follow a supply path from the bed rolls to the folding rolls; and a selectively operable gap forming arrangement located upstream of the folding rolls and upstream of the location at which the sheets from the pair of webs converge, wherein the gap forming arrangement is operable to selectively move at least a leading portion of at least one sheet out of the supply path and to move a trailing portion of the same sheet downstream into a supply path to form a gap in the supply of sheets from one of the bed rolls by movement of the leading portion of the sheet out of the supply path, wherein the gap forming arrangement is further operable to subsequently return the leading portion of the sheet to the supply path to form a folded sheet; wherein the folding rolls are operable to interfold the sheets discharged from the pair of bed rolls including the folded sheet, and wherein the gap in the supply of sheets is formed before the sheets are supplied to the folding rolls and is operable to create a discontinuity in the stack of interfolded sheets to facilitate separation of a portion of the stack from the remainder of the stack. - View Dependent Claims (17, 18, 19, 20, 21)
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Specification