Longitudinally interfolding device and method

• US 4,052,048 A
• Filed: 03/11/1976
• Issued: 10/04/1977
• Est. Priority Date: 03/11/1976
• 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: Shirasaka, Fumitake
• Primary Examiner(s): Burr, Edgar S.
• Assistant Examiner(s): Heinz, A.
• Application Number:
  US05/666,224
• Time in Patent Office: 572 Days
• Field of Search: 270/39-41, 221/48, 221/50
• US Class Current: 270/40
• CPC Class Codes: A47K 2010/428 Details of the folds or interfolds of the sheets
• CPC Class Codes: B65H 45/221 incorporating folding triangles
• CPC Class Codes: B65H 45/24 Interfolding sheets, e.g. cigarette or toilet papers

Abstract

A longitudinally interfolding device and method for simultaneously interfolding a pair of partially superposed webs wherein the free margins of the webs are simultaneously over and under folded.

Claims

1. A method of interfolding elongated webs being advanced along a linear path having longitudinally extending first and second margins, comprising:

lapping a first pair of equal width webs to provide upper and lower webs having a central lapped portion which has longitudinal edges coincident with said margins and unlapped edge portions each one-half the web width outside said margins,

pulling said first pair of webs through a folding device positioned in said path and having transversely aligned first and second folding points (30,

     31) on said first and second margins respectively, said device having

a. a first folding edge (24) extending angularly forwardly in the direction of web movement in said path from said first point (30) across said path to intersect said second margin a spaced distance forwardly of said second point (31) to support thereabove said central lapped portion and to underfold the edge portion of said upper web,

b. a second folding edge (36) extending forwardly from said second point (31) coincident with said second margin and terminating a spaced distance rearwardly of the intersection of said first folding edge (24) with said second margin to overfold the edge portion of said lower web, said first and second folding edges (24,

     36) being generally co-planar,

c. a third folding edge (25) extending angularly forwardly across said path from slightly above said second point (31) to cross above said first margin a spaced distance rearwardly of the intersection of said first folding edge (24) with said second margin to complete the overfolding of the edge portion of the lower web prior to completion of the underfolding of the edge portion of said upper web,

pulling a second pair of completely folded webs beneath said device while positioning the overfolded edge portion of the lower web of said second pair in contact with the edge portion of the upper web of said first pair while the same is being folded about said first folding edge whereby the movement of the edge portion of the upper web of said first pair urges and draws the overfolded edge portion of the lower web of said second pair between the edge portion of the upper web of said first pair and the lapped central portion of the lower web of said first pair.

2. An interfolding device adapted to be positioned in a linear path of elongated webs being interfolded, said path having longitudinally extending first and second margins, comprising:

means on said device for lapping a first pair of equal width webs to provide upper and lower webs having a central lapped portion which has longitudinal edges coincident with said margins and unlapped edge portions each one half the web width outside said margins, said device having transversely aligned first and second folding points (30,

     31) on said first and second margins respectively, said device also having

a first folding edge (24) extending angularly forwardly in the direction of web movement in said path from said first point (30) across said path to intersect said second margin a spaced distance forwardly of said second point (31) to support thereabove said central lapped portion and to underfold the edge portion of said upper web,

a second folding edge (36) extending forwardly from said second point (31) coincident with said second margin and terminating a spaced distance rearwardly of the intersection of said first folding edge (24) with said second margin to overfold the edge portion of said lower web, said first and second folding edges (24,

     36) being generally co-planar,

a third folding edge (25) extending angularly forwardly across said path from slightly above said second point (31) to cross above said first margin a spaced distance rearwardly of the intersection of said first folding edge (24) with said second margin to complete the overfolding of the edge portion of the lower web prior to completion of the underfolding of the edge portion of said upper web, and

means operably associated with said device for pulling said first pair of webs through said device and for pulling a second pair of completely folded webs beneath said device while positioning the overfolded edge portion of the lower web of said second pair in contact with the edge portion of the upper web of said first pair while the same is being folded about said first folding edge whereby the movement of the edge portion of the upper web of said first pair urges and draws the overfolded edge portion of the lower web of said second pair between the edge portion of the upper web of said first pair and the lapped central portion of the lower web of said first pair.

3. The device of claim 2 in combination with a plurality of identical devices each positioned in longitudinally spaced relation in said path, elongated frame means beside said path and equipped with a support post for each device, and means interconnecting each device with its associated post for adjusting the alignment of each device relative to the remaining devices.

4. The structure of claim 3 in which the spacing between each device is of the order of about 4-8 inches.

5. An interfolding device adapted to be positioned in a linear path of elongated webs being interfolded, said path having longitudinally extending first and second margins, comprising:

means on said device for lapping a first pair of equal width webs to provide upper and lower webs having a central lapped portion which has longitudinal edges coincident with said margins and unlapped edge portions each one-half the web width outside said margins, said device having;

a pair of downwardly convergent folding edges (27,

     28) extending forwardly relative to web travel in said path and terminating respectively at first and second horizontally aligned points (30,

     31) on first and second margins of said path,

a first folding edge (24) extending angularly forwardly across said path from said first point (30) and intersecting said second margin a spaced distance forwardly of said second point (31) to support thereabove said central lapped portion and underfold the edge portion of said upper web,

a second folding edge (36) extending forwardly from said second point (31) and coincident with said second margin,

a third folding edge (25) extending angularly forwardly across said path from slightly above said second point (31) to cross above said first margin a spaced distance rearwardly of the intersection of said first folding edge (24) with said second margin,

a fourth folding edge (34) extending forwardly from said first point (30) and coincident with said first margin,

said third folding edge being positioned above the plane containing said first, second and fourth folding edges.

6. The structure of claim 5 in which said first and fourth folding edges (24, 34) are defined by a first plate-like tongue and said second folding edge (36) is defined by a second plate-like tongue (37), said tongues also being coplanar and being spaced apart to provide a throat (38).

7. The structure of claim 6 in which said device includes a generally trapezoidal plate defining said pair of downwardly convergent folding edges (27, 28) and a gusset plate connecting said generally trapezoidal plate at one of said pair of downwardly convergent folding edges (27) to said first plate-like tongue along said fourth folding edge (34).

8. An interfolding device adapted to be positioned in the path of travel of a pair of half-lapped webs to fold the same, said path having side margins defined by the lap of said webs, comprising a frame:

said frame being equipped with a turning edge extending transversely of said path to turn said half lapped webs, said turning edge terminating in a pair of points, one on each margin,

said frame including a pair of generally co-planar plates extending forwardly in said path in the direction of web travel, one of said plates being equipped with a side edge coextensive with one of said said margins, the other of said plates being equipped with an angled side edge extending forwardly from the other of said side margins toward said one side margin, said one plate being spaced from said angled side edge to provide a threading throat, and

a folding rod on said frame spaced above said plates and extending angularly across said path from said one margin to the other and intersecting said other margin within the length of said other plate to complete web folding within the length of said device.