Interfolding method of sheet material and machine for carrying out such method

• US 6,228,014 B1
• Filed: 08/19/1999
• Issued: 05/08/2001
• Est. Priority Date: 08/21/1998
• Status: Expired due to Term

• Current Assignee: Mtc-Macchine Trasformazione Carta SRL, M.T.C. - Macchine Trasformazione Carta, Srl
• Original Assignee: Mtc-Macchine Trasformazione Carta SRL
• Inventors: De Matteis, Alessandro, Landucci, Sergio
• Primary Examiner(s): Gerrity, Stephen F.
• Assistant Examiner(s): TAWFIK, SAMEH
• Application Number:
  US09/378,017
• Time in Patent Office: 628 Days
• Field of Search: 493/424, 493/425, 493/426, 493/427, 493/428, 493/429, 493/430, 493/360, 493/433, 493/432, 493/440
• US Class Current: 493/424
• CPC Class Codes: B65H 2403/512 involving radial plate cam
• CPC Class Codes: B65H 29/56 for stripping from elements or machines for electrographic machines G03G
• CPC Class Codes: B65H 45/24 Interfolding sheets, e.g. cigarette or toilet papers

Abstract

A machine (1) for interfolding sheet material (4a, 4b) starting from a web (3a, 3b) of paper and the like. A sequence of offset sheets (4a, 4b) is formed on folding rollers (7a, 7b) which are counter-rotating with respect to each other and have a plurality of circumferential grooves (15a, 15b), in which oscillating folding arms engage (20a, 20b) so as to form a stack (17) of interfolded sheets (4a, 4b). The folding arms (20a, 20b) have pivots (21) very close to the periphery of the folding rollers (7a, 7b), inside or outside of the grooves (15a, 15b). Moreover they can be operated by a crank mechanism that allows to the grooves (15a, 15b) to be shallow enough also in case of rollers (7a, 7b) of enlarged diameter. For the same reason, the folding arms (20a, 20b) can have a bent portion.

Claims

1. A method for production of a stack of interfolded sheets comprising the steps of:

feeding of sheets in succession on folding rollers that comprise means for selectively holding the sheets on their surface so that a sequence of offset sheets is created;

alternately holding the sheets by means of folding rollers downstream of their point of contact in order to obtain an interfolded disposition; and

,

folding and formation of said stack of interfolded sheets by the use of folding arms each pivoting about a pivot which is located within a respective groove formed within the periphery of each of said folding rollers and pushing away alternatively the partially overlapped portions of sheets in succession that adhere to said rollers onto a stack formed below.

2. The method according to claim 1, wherein said folding arms have a curved shape so that they encircle a portion of said folding rollers.

3. The method according to claim 1, wherein said folding arms carry out an oscillation obtained through two distinct points thereof in a same plane, a first of said points being a pivot, a second point rotating about said first point.

4. The method according to claim 3, wherein said first pivot is located at a distance from an axis of rotation of each of said folding rollers which is slightly greater than a radius of each of said folding rollers.

5. The method according to claim 3, wherein said first point lays proximate the periphery of the folding roller inside said grooves.

6. An interfolding machine using sheet material for formation of stacks of interfolded sheets comprising:

folding rollers counter-rotating with respect to each other supplied of sheets in succession and having circumferential grooves;

means for holding alternatively the sheets that adhere to the folding rollers; and

,

interfolding means suitable for the formation of a stack of sheets comprising folding arms oscillating about a pivot and going into and out said grooves of said rollers, wherein said folding arms are pivotally connected to a pivot very close to the periphery of said folding rollers, wherein said pivot is inside the periphery of said folding rollers.

7. The interfolding machine according to claim 6, wherein a mechanical transmission operating said folding arms is provided comprising:

a pivot to which each folding arm is pivotally connected in a first point;

a connecting rod hinged to the folding arm in a second point; and

,

an oscillating crank lever hinged to said connecting rod.

8. The interfolding machine according to claim 6, wherein said folding arms have a circular portion so that they encircle a portion of said rollers.

9. The interfolding machine according to claim 6, wherein said mechanical transmission operating said folding arms comprises:

a pivot belonging to a connecting lever integral to the folding arms;

a rocking lever hinged to said connecting lever; and

,

cam means that engage with a pin protruding from said rocking lever whereby said rocking lever carries out an alternating motion that causes said connecting lever and said folding arms to oscillate about said pivot.

10. The interfolding machine according to claim 6, wherein said folding arms have a circular portion, so that they encircle a portion of said rollers.

11. The interfolding machine according to claim 6, wherein a mechanical transmission operating said folding arms is provided comprising:

a pivot to which each folding arm is pivotally connected in a first point;

a connecting rod hinged to the folding arm in a second point,

an oscillating crank lever hinged to said connecting rod.

12. The interfolding machine according to claim 6, wherein said mechanical transmission operating said folding arms comprises:

a pivot belonging to a connecting lever integral to the folding arms;

a rocking lever hinged to said connecting lever;

cam means that engage with a pin protruding from said rocking lever whereby said rocking lever carries out an alternating motion that causes said connecting lever and said folding arms to oscillate about said pivot.

13. An interfolding machine for making stacks of interfolded sheets comprising:

a first folding roller arranged for rotation in a first direction about a first axis through which a first vertical plane passes;

a second folding roller arranged for rotation in a second direction counter to said first direction about a second axis through which a second vertical plane passes;

each of said first and second folding rollers operatively arranged to receive sheets of material in succession and to hold said received sheets against said first and second folding rollers;

means for holding alternatively the sheets which adhere to the folding rollers; and

,

interfolding means operatively arranged to form a stack of sheets, said interfolding means comprising first and second folding arms, each of which oscillates about a first and second pivot, respectively, and arranged for movement into and out of grooves in each of said rollers, said stack being formed in a space located between said first and second vertical planes, wherein the first and second pivots are positioned between said first and second vertical planes.

14. An interfolding machine for making stacks of interfolded sheets comprising:

a first folding roller arranged for rotation in a first direction about a first axis through which a first vertical plane passes;

a second folding roller arranged for rotation in a second direction counter to said first direction about a second axis through which a second vertical plane passes;

each of said first and second folding rollers operatively arranged to receive sheets of material in succession and to hold said received sheets against said first and second folding rollers;

means for holding alternatively the sheets which adhere to the folding rollers; and

,

interfolding means operatively arranged to form a stack of sheets, said interfolding means comprising first and second folding arms, each of which oscillates about a first and second pivot, respectively, and arranged for movement into and out of grooves in each of said rollers, said stack being formed in a space located between said first and second vertical planes, wherein the first and second pivots are positioned between said first and second vertical planes, wherein said folding arms are curved at an angle of curvature that matches a circumference of said grooves.