Method of and assembly for lapping consecutive sheets of web material

• US 20050073090A1
• Filed: 09/29/2004
• Published: 04/07/2005
• Est. Priority Date: 10/01/2003
• Status: Active Grant

• Current Assignee: Fabio Perini S.P.A. (Körber-Stiftung)
• Original Assignee: Fabio Perini S.P.A. (Körber-Stiftung)
• Inventors: White, Barton J.
• Granted Patent: US 7,407,161 B2
• Time in Patent Office: Days
• US Class Current: 271/314
• CPC Class Codes: B65H 29/6618 upon transfer from a first conveyor to a second conveyor advancing at slower speed
• 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 mechanism for offsetting or overlapping successive sheets of material in an interfolding machine includes a bed roll rotating at a first speed and a retard roll rotating at a slower, second speed and positioned adjacent the bed roll. As successive sheets are transferred from the bed roll to the retard roll, the sheets are engaged by a nip roller assembly positioned adjacent the retard roll and forming a nip through which the sheets pass. The retard roller forms a deflection or bubble in the individual sheet passing through the nip, which enables a successive sheet to be positioned beneath the previous sheet, thereby forming the overlap of the successive sheet with the previous sheet.

Claims

1. An assembly for lapping a first sheet of material with a consecutive second sheet of a material, comprising:

a first roll rotating at a first speed for conveying sheets of material;

a second roll positioned adjacent the first roll and rotating at a second speed; and

a roller assembly defining a nip with the second roll,

wherein the first and second rolls in combination with the roller assembly are operable to overlap the first sheet of material and the second sheet of material by feeding the leading end of each sheet into the nip while maintaining the sheet in engagement with the first roll, wherein the nip is operable to engage the leading edge of the sheet with the second roll while the trailing edge of the sheet remains in engagement with the first roll.

2. The assembly as recited in claim 1, wherein the first and second rolls each include a plurality of radially extending passages leading to a circumference defined by each of the first and second rolls, and wherein the successive first and second sheets of material are held at the circumference of the first and second rolls in a timed manner by a vacuum at the radially extending passages.

3. The assembly as recited in claim 1, wherein the roller assembly comprises:

one or more wheels;

a pin that supports each of the wheels, each pin having a first end and a second end, wherein a wheel is mounted to the first end of each pin; and

a housing configured to mount the pins.

4. The assembly as recited in claim 3, wherein the roller assembly further includes:

a collar mounted to each pin; and

a compression spring mounted on the pin and disposed between the collar and the housing for biasing the wheel toward the second roll.

5. The assembly as recited in claim 3, further comprising an adjustable position stop interconnected with each pin and engaged with the housing for adjustably mounting each pin.

6. The assembly as recited in claim 3, wherein the nip roll assembly further includes:

a shroud positioned adjacent to the one or more wheels, the shroud including one or more openings to receive a portion of the circumference of each of the one or more wheels.

7. The assembly as recited in claim 6, wherein the shroud includes a generally U-shaped plate structure having a first leg and a second leg to receive the one or more wheels therebetween.

8. The assembly as recited in claim 6, wherein the shroud includes a generally curvilinear portion and a generally linear portion adjacent to the second roll, the curvilinear portion configured to receive a trailing edge of the first sheet and the overlapping portion of an adjacent second sheet, the linear portion configured to disengage the trailing edge of the first sheet from the shroud.

9. The assembly as recited in claim 3, wherein the housing is mounted on a pivot which allows the roller assembly to rotate and adjustably position the wheel in relation to the second roll.

10. A interfolding machine to fold sheets of material, comprising:

a cutting assembly to cut the material into a series of sheets including a first sheet and a successive second sheet;

an overlap assembly comprising;

a first roll rotating at a first speed;

a second roll positioned adjacent the first roll and rotating at a second speed slower than the first speed; and

a roller assembly positioned adjacent to the second roll, wherein the first and second rolls in combination with the roller assembly are operable to overlap the first sheet with a consecutive second sheet; and

a first and a second folding roll configured to receive the overlapped sheets of material from the overlap assembly and to fold the sheets of material into a stack of interfolded sheets.

11. The interfolding machine as recited in claim 10, wherein the consecutive first and second sheets of material are held to a circumference of the first and second rolls by a vacuum at a plurality of passages extending radially to the circumference of the first and second rolls.

12. The interfolding machine as recited in claim 10, wherein the roller assembly includes:

one or more wheels;

a series of pins, each of which has a first end and a second end, wherein one of the wheels is rotatably mounted to the first end of the pin; and

a housing, wherein the series of pins are mounted to the housing.

13. The interfolding machine as recited in claim 12, wherein each pin is mounted to the housing for axial movement toward and away from the second roll, and wherein the roller assembly further includes:

a collar mounted to each pin;

a compression spring disposed between the collar and the housing for biasing the wheel toward the second roll; and

a stop secured to each pin end engageable with the housing to fix the position of the pin relative to the housing.

14. The interfolding machine as recited in claim 12, wherein the stop is adjustably coupled to a second end of the pin opposite the first end of the pin for varying the axial position of the pin relative to the housing, and thereby the position of the wheel relative to the second roll.

15. The interfolding machine as recited in claim 10, wherein the roll assembly further includes:

a shroud positioned adjacent to the one or more wheels, the shroud including one or more openings to receive a portion of the circumference of each of the one or more wheels.

16. The interfolding machine as recited in claim 15, wherein the shroud includes a generally U-shaped plate structure having a first leg and a second leg to receive the one or more wheels therebetween.

17. The interfolding machine as recited in claim 12, wherein the housing is mounted on a pivot which allows the roller assembly to rotate and adjustably position the wheels in relation to the second roll.

18. A method for overlapping a first sheet of material and a successive second sheet of, the method comprising the acts of:

supplying the first and second sheets to a first roll rotating at a first speed;

transferring a leading edge of the first sheet from the first roll to a second roll rotating at a second speed slower than the first speed;

creating a deflection in the first sheet using a roller assembly located adjacent to the second roll;

transferring a leading edge of the successive second sheet along the first roll into engagement with the second roll;

holding a trailing edge of the first sheet with the roller assembly as the second roll moves the leading edge of the second sheet beneath the trailing edge of the first sheet; and

disengaging the trailing edge of the first sheet from the roller assembly into engagement with the second sheet positioned beneath.

19. The method as recited in claim 18, the act of creating the deflection in the first sheet includes:

holding the leading edge of the first sheet between the second roll and a series of wheels forming a part of the roller assembly; and

holding the trailing edge of the first sheet with the first roll.

20. The method as recited in claim 19, wherein the act of holding the leading edge of the first sheet between the second roll and the series of wheels of the roller assembly includes applying an adjustable force to the series of wheels that holds the leading edge of the first sheet in a nip defined by a distance between the second roll and the wheels of the roller assembly.