Separation unit and a dispenser comprising a separation unit

Abstract

A separation unit for separating a web material along preformed lines of weakness. The separation unit has a width direction and includes at least a first roller having a rotational axis extending in the width direction and a web width extending in the width direction, and at least a second roller having a rotational axis extending parallel with the rotational axis of the first roller and a web width extending in the width direction. The second roller is positioned at a distance from the first roller. Each of the first and the second rollers is provided with at least one protrusion element extending perpendicularly from the axes. Each of the protrusion elements has a maximum width in the width direction, a maximum radial extension from the rotational axes, an inner portion adjacent to the rotational axes, and an outer portion remote from the rotational axes.

Claims

1. A separation unit for separating a web material along preformed lines of weakness, said separation unit having a width direction and comprising at least a first device having an axis extending in said width direction and a web width extending in said width direction, and at least a second device having a rotational an axis extending parallel with said axis of said first device and a web width extending in said width direction, said second device being positioned at a distance from said first device, said distance extending in a direction perpendicular to said width direction, wherein each of said first and said second devices is provided with at least one protrusion element extending perpendicularly from said axes, wherein each of said protrusion elements has a maximum width in said width direction, a maximum extension from said axes, an inner portion adjacent to said axes, and an outer portion remote from said axes, wherein said outer portions of said protrusion elements on said first device are arranged in a staggered relationship with said outer portions of said protrusion elements on said second device, wherein said outer portions of said protrusion elements on said first device are partially overlapping with said outer portions of said protrusion elements on said second device with a overlap length, thus forming an undulating passage for a web material between said devices, wherein said overlap length is between 2-40 mm, wherein the separation unit is configured to separate the web material along a preformed line of weakness as the preformed line of weakness passes through the undulating passage.

2. The separation unit according to claim 1, wherein said distance between said axes of said first and said second devices is adjustable.

3. The separation unit according to claim 2, wherein the separation unit further comprises biasing means, wherein said adjustment is enabled by the biasing means.

4. The separation unit according to claim 1, wherein said protrusion elements are formed integral with said first and/or second device.

5. The separation unit according to claim 1, wherein said protrusion elements are separate units attached to said first and/or second device.

6. The separation unit according to claim 1, wherein each of said first and said second devices is provided with a plurality of protrusion elements being spaced along said axes and protruding perpendicularly from said axes.

7. The separation unit according to claim 6, wherein at least one of said first and said second devices comprises at least a first, a second and a third protrusion element, wherein the spacing between said first and said second protrusion elements along the width direction of said at least one of said first device and said second device differs from the spacing between said second and said third protrusion elements along the width direction of said at least one of said first device and said second device.

8. The separation unit according to claim 6, wherein said protrusion elements are arranged with same spacing along the width direction of said first device and said second device.

9. The separation unit according to claim 6, wherein each of said first and said second devices has a central portion and peripheral portions in said width direction, and wherein said spacing between said protrusion elements is greater in said central portion than in said peripheral portions.

10. The separation unit according to claim 6, wherein said spacing between each two protrusion elements is equal to or greater than said maximum width of each protrusion element.

11. The separation unit according to claim 1, wherein said distance between said axes of said first and said second devices is between 8-100 mm.

12. The separation unit according to claim 1, wherein said maximum extensions of said protrusion elements are between 5-50 mm.

13. The separation unit according to claim 1, wherein the maximum widths of said protrusion elements are between 4-20 mm.

14. The separation unit according to claim 1, wherein said protrusion elements have different maximum extensions and/or different maximum widths.

15. The separation unit according to claim 1, wherein said protrusion elements have same maximum extensions and same maximum widths.

16. The separation unit according to claim 1, wherein each protrusion element has a maximum width along the width direction within the overlap length, and the sum of said maximum widths within the overlap length of all protrusion elements on one of said devices is between 5-30% of a web width of that device.

17. The separation unit according to claim 1, wherein said protrusion elements are disc elements.

18. The separation unit according to claim 1, wherein said maximum extensions of said protrusion elements are equal to or greater than said maximum widths of said protrusion elements.

19. The separation unit according to claim 1, wherein the separation unit is configured to separate the web material along a preformed line of weakness as the preformed line of weakness passes through the undulating passage by a pinch force, wherein the pinch force is configured to break a preformed line of weakness, but also configured to not damage the web material.

20. The separation unit according to claim 19, wherein said pinch force is configured to separate a preformed line of weakness having a perforation strength between 20-80 N/m.

21. A dispenser for a web material, comprising a housing defining a web material reservoir; a dispensing opening; a control unit; a separation unit according to claim 1.

22. The dispenser according to claim 21 for containing a web material comprising preformed lines of weakness, said web material being Z-folded to form a stack.

23. The dispenser according to claim 22, wherein said preformed lines of weakness are perforation lines formed by alternating bonds and slots and having a perforation strength between 20-80 N/m.

24. The dispenser according to claim 21 for containing a web material comprising preformed lines of weakness, said web material being in the form of a roll.

25. The dispenser according to claim 21, wherein the dispenser further comprises a feeding mechanism.

26. The dispenser according to claim 21, wherein said web material is contained in said reservoir, and wherein a leading portion of said web material is supported in a dispensing path from said reservoir to said dispensing opening.

27. The dispenser according to claim 26, wherein said leading portion extends upwardly from the top of the said stack of said web material.

28. The dispenser according to claim 22, wherein said web material comprises: at least a first web layer divided into sheet products defined between longitudinally separated lines of weakness extending across the first web layer; and at least a second web layer divided into sheet products defined between longitudinally separated lines of weakness extending across the second web layer, wherein the webs are interfolded so that the lines of weakness of the first web layer are offset from the lines of weakness of the second web layer in a longitudinal direction of the first web layer.

29. A separation unit for separating a web material along preformed lines of weakness, said separation unit having a width direction and comprising at least a first device having an axis extending in said width direction, and at least a second device having an axis extending parallel with said axis of said first device, said second device being positioned at a distance from said first device, said distance extending in a direction perpendicular to said width direction, wherein each of said first and said second devices is provided with at least one protrusion element extending perpendicularly from said axes, wherein each of said protrusion elements has a maximum width in said width direction, a maximum extension from said axes, an inner portion adjacent to said axes, and an outer portion remote from said axes, wherein said outer portions of said protrusion elements on said first device are arranged in a staggered relationship with said outer portions of said protrusion elements on said second device, wherein said outer portions of said protrusion elements on said first device are partially overlapping with said outer portions of said protrusion elements on said second device with a overlap length, thus forming an undulating passage for a web material between said devices, wherein the ratio between said overlap length and said maximum extension of said protrusion elements is between 4-80%, wherein the separation unit is configured to separate the web material along a preformed line of weakness as the preformed line of weakness passes through the undulating passage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, of which:

(2) FIGS. 1a, 1b and 1c show a separation unit according to the present invention;

(3) FIG. 2 shows the separation unit according to the present invention seen in the width direction;

(4) FIG. 3 shows protrusion elements having different dimensions and differently shaped outer portions;

(5) FIGS. 4 and 5 show a dispenser comprising the separation unit according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(6) FIGS. 1a and 1b show a separation unit 1 according to the present invention. The separation unit 1 comprises a first roller 2 and a second roller 3, each extending in a width direction and comprising plurality of protrusion elements 4 being spaced along the rollers 2, 3 and protruding perpendicular from the rollers 2, 3. The rollers 2, 3 are positioned at a distance d.sub.1 from each other, wherein the distance d.sub.1 is extending in a direction perpendicular to the width direction of the rollers 2, 3. In the embodiment shown in FIG. 1a, the first roller 2 comprises six protrusion elements 4, and the second roller 3 comprises four protrusion elements 4. The rollers 2, 3 has a web width W (FIG. 1c). Each of the protrusion elements 4 has a maximum width w in the width direction and a maximum radial extension r from the rollers 2, 3. In the embodiment shown in FIG. 1a, the maximum widths w and the maximum radial extensions r of all the protrusion elements 4 are the same. Each protrusion element has an inner portion 6 adjacent to the rollers 2, 3, and an outer portion 5 remote from the rollers 2, 3, wherein the outer portions 5 of the protrusion elements 4 on the first roller 2 are arranged in a staggered relationship with the outer portions 5 of the protrusion elements 4 on the second roller 3, which is best seen in FIG. 2. The outer portions 5 of the protrusion elements 4 have a slightly curved shape. The outer portions 5 of the protrusion elements 4 on the first roller 2 are partially overlapping with the outer portions 5 of the protrusion elements 4 on the second roller 3 with a radial overlap length L. Such a configuration of the protrusion elements forms an undulating passage for a web material between the rollers 2, 3 (FIG. 1c).

(7) In the embodiment shown in FIGS. 1a and 1b, no protrusion elements are placed in the central portion C of the rollers 2, 3. Such an arrangement of the protrusion elements allows the user to easily access the leading end of the web material 16 in the central portion C of the separation unit 1 (FIG. 1c).

(8) As may be seen in FIGS. 1a and 1b, the spacing d.sub.2 between each two protrusion elements 4 is equal to or greater than the maximum width w of each protrusion element 4. Such a configuration enables the protrusion elements 4 to be relatively scarcely distributed, which provides an optimal pinch force.

(9) Another advantageous feature of the separation unit according to the present invention is that the maximum radial extensions r of the protrusion elements are equal to or greater than the maximum widths w of the protrusion elements. As may be seen in FIGS. 1a and 1b, the protrusion elements are formed as relatively large and thin discs, which optimizes the pinch force.

(10) FIG. 2 illustrates the separation unit 1 seen in the width direction. It is clearly shown that the outer portions 5 of the protrusion elements 4 on the first roller 2 overlap with the outer portions 5 of the protrusion elements 4 on the second roller 3.

(11) As previously mentioned, the protrusion elements 4 may have different maximum widths w and maximum radial extension r. In FIG. 3, protrusion elements having different maximum widths w and different maximum radial extensions r are shown.

(12) As mentioned above, the shape of the outer portions 5 of the protrusion elements 4 may vary. In FIG. 3, four possible shapes of the outer portions 5 are depicted. Thus, the outer portions may have a smooth surface, or may be provided with a ribbed surface.

(13) FIG. 4 schematically shows a dispenser 7 with a separation unit 1 according to the present invention. The dispenser 7 has an outer front wall 8, two outer side walls 9 and a housing 10. The housing 10 is intended for holding a pile of a continuous length of accordion-like folded web of towels of tissue paper or nonwoven comprising bundles 12 of a continuous length of accordion-like folded web of towels of tissue paper or nonwoven. The bundles 12 comprise connecting means 13 between the bundles 12. The dispenser 7 comprises a guiding element 14 in the form of a curved plate which extends over a segment of the web-supporting roller surface 15. The at least one web 16 is arranged to be fed through the guiding element 14 when the dispenser 7 is in use, and at least one part of the guiding element 14 is arranged to bear against the web 16. The guiding element 14 thereby holds the at least one web 16 in place on the roller surface 15 so that it does not move backwards or sidewards during the use of the dispenser, or in case of web-breakage.

(14) The unit subsequent to the guiding element 14 is separation unit 1 described above. The separation unit 1 provides an optimal pinch force acting on the web material 16, and allows the web material 16 to be separated at the desired position. The separation unit 1 depicted in FIG. 4 is configured such that both of the rollers 2, 3 are positioned inside the housing 10. It is also conceivable that one of the rotational axes is located in the outer front wall 8, such that when the outer front wall 8 is opened, the pinch force caused by the separation unit 1 is released.

(15) The dispenser 7 illustrated in FIG. 4 comprises a stack of interfolded webs 16, whereby the dispenser 7 is configured so that a preceding stack of interfolded webs in the housing 10 has to be lifted to position a new, succeeding stack in the housing 10 underneath the preceding stack to refill the dispenser 7. Stacks of interfolded webs in the dispenser 7 may be interconnected via connecting means 13, such as adhesive, adhesive tape or mechanical fasteners, such as hook and loop fasteners, at the bottom and/or top of each of the refill stacks. The web 16 is arranged to be fed upwards within the housing 10, around the roller 15 located at the top of the dispenser 7 and downwards towards the separation unit 1 and the dispensing opening 17.

(16) In FIG. 5 the dispenser 7 is depicted in the state when no web material 16 is loaded. The separation unit 1 is positioned within the housing 10 at the same level as the dispensing opening 17, such that the perforated web 16 is separated along the preformed lines of weakness at the moment of dispensing with almost no effort from the user's side.

(17) It should be noted that the dispenser 7 according to the present invention may be any type of automatic or non-automatic dispenser for dispensing at least one web, i.e. a plurality of webs may be dispensed simultaneously, or a plurality of different webs may be dispensed by the dispenser 7 one at a time.

(18) The dispenser 7 is a free-standing, but the dispenser may also be mounted on any suitable object in any suitable manner. Furthermore, a dispenser housing 10 of a dispenser according to the present invention need not necessarily contain an entire web 16 that is to be dispensed by the dispenser 7. At least one web 16 may for example be stored outside the housing 10 and merely be fed through the housing 10 when the dispenser 7 is in use.

(19) Although the present invention has been described with reference to various embodiments, those skilled in the art will recognise that changes may be made without departing from the scope of the invention. It is intended that the detailed description be regarded as illustrative and that the appended claims including all the equivalents are intended to define the scope of the invention.