AU2382599A - Folded towel stack - Google Patents

Description

AUSTRALIA

Patents Act 1990 ABC TISSUE PRODUCTS PTY LIMITED

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Folded towel stack The following statement is a full description of this invention including the best method of performing it known to us:- Background of the Invention This invention relates to a stack which can comprise either towels or tissues and to an apparatus and method of manufacturing such a stack which will hereinafter be referred to as a towel stack.

Background of the Invention Towel dispensers are commonly provided in public toilets for dispensing disposable paper towels to enable a person to hygienically dry their hands after washing them. Typically, such towels are provided in a 10 folded stack inside the dispenser and are withdrawn from an elongated aperture in the base of the dispenser so that as each tissue is withdrawn from i the dispenser, the next tissue moves to position protruding from the aperture.

The delivery of the next towel to the position protruding through the aperture is achieved by overlapping the folds of adjacent tissues in the tissue stack.

A number of towel stacks are already known. However various problems exist with such stacks. One common problem is towels tearing when they are pulled from the stack, because the stacks are too tight and there is too much friction between the folded towels and/or because the 20 towel material is of a poor quality. Also, with some types of folded towels, when one towel is pulled out several towels are dispensed simultaneously.

The present invention seeks to provide an alternative towel stack, which is more compact than existing stacks, whilst at the same time providing a interleaved folded towel structure from which a towel can be easily removed without tearing and without pulling out more than one tissue at a time, as can happen with existing towel stacks.

Summary of the Invention According to the present invention, there is disclosed a towel stack comprising:a plurality of discrete towel leaves, each leaf being folded so as to provide at least five full sized panels of a substantially identical size and two part panels one being located at either end of the leaf, the part panels being smaller than the full sized panels, typically half the size of a full panel, the towel leaves being interfolded such that there is approximately a one third overlap of one towel leaf with an adjacent towel leaf and in which an end

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part panel of one leaf is folded between two adjacent full panels of an adjacent towel leaf in the stack.

Preferably the stack is folded such that an end part panel and the adjacent full panel of each towel leaf define a first pair of panels and a pair of full panels adjacent that pair define a second pair of panels and in which the part panel at the end of an adjacent towel in the stack is disposed between the second pair of panels and the next pair of adjacent panels on the adjacent towel is folded between the first pair of panels.

S:i It is a preferred feature of the invention that when the towels are 10 stacked and interfolded there is one full panel and two part panels, where there is no overlap between adjacent towels in the stack.

It is preferred that the width of the towel leaf measured in the direction of the transverse folding of the leaf is between 175-225mm, typically around 203mm.

15 The length of the towel leaf is typically of the order of 300mm, such that each full panel has a length of approximately 50mm and each half panel is approximately 25mm long measured in the longitudinal direction of the unfolded towel leaf ie in a direction perpendicular to the folds. The towels are typically interleaved with a 100mm overlap.

20 When installed in the dispenser, only part, typically one full panel and ""-one half of a towel panel protrudes from the dispenser. This is beneficial in that it presents a double layer of towel to the user which is much stronger than a single layer, especially as people usually grasp a towel with wet hands between their thumb and fore-fingers. This helps ensure that the panel will protrude/depend correctly and be easy to grasp by a person seeking to draw a towel from the dispenser.

The invention also provides a method of producing a towel or tissue stack embodying the present invention comprising the steps of:providing a single continuous web of towel material; delivering the web to a knife roll for transversely cutting the web to form discrete towel leaves, the knife roll cooperating with a bed roll utilising a vacuum to hold the sheets to the bed roll and which provides a relief area for knife blades to pass through the sheet during cutoff; delivering the leaves from said knife roll/bed roll to a lap roll; delivering the leaves from the lap roll to a retard roll so that each leaf has a leading portion overlapping a trailing portion of the preceding leaf, the leaves being overlapped by a predetermined length, preferably approximately one third of the overall length L of a leaf; delivering the leaves from the retard roll to a folding roll; and transversely folding each leaf to have six folds to define five full leaf panels and two part panels disposed at either end of the set of five full panels on the towel leaf.

The invention also provides a machine for producing a towel or stack, each stack including a plurality of interfolded, interleaved towel leaves, with each leaf consisting of at least five full panels and two part panels one part 10 panel being disposed at either end of the five full panels, said machine including; a knife roll defining a series of knife blades, adapted to receive a continuous web of towel material which in conjunction with a bed roll which provides a relief area for the knife blades and is arranged to transversely cut 15 the web to form discrete lengths of a predetermined length L a lap roll means to which the discrete leaves provided by the knife roll :1 and bed roll are delivered and is adapted to arrange the leaves so that a following leaf is located behind a preceding leaf; a retard roll which cooperates at the lap roll to overlap adjacent leaves 20 so that the leaves are overlapped by approximately one third of the predetermined length L; and a folding roll assembly including rolls defining gripper means and cooperating tucker means, sized and arranged to form six folds in each towel leaf.

Brief Description of the Drawings A specific embodiment of the invention will now be described, by way of example only, and with reference to the accompanying drawings in which:- Figure 1 is a perspective view of a pair of towel leaves according to the present invention; Figure 2 is a side view of a apparatus for forming a towel stack embodying the present invention; Figure 3 is a detailed view of the portion of the machine shown in Figure 2 which cuts and folds the web of towel material into interleaved towels; and Figure 4 is a similar view to Figure 1 showing a third towel leaf interfolded with the pair of leaves shown in Figure 1.

Detailed Description of a Preferred Embodiment Figure 1 schematically illustrates a towel stack 10. Two towels from the stack 10a and o10b are illustrated. The choice of material from which the towel is made is not critical but typically such towels are provided in a crepe paper material and although such towels are typically paper based, principally because they are disposable and thence desirably made from inexpensive material, the towels may include a dispersed polymeric binder !'.":materials, although it is desirable that the material that the towel is made should be able to have a memory to retain folds.

Each towel is folded to provide an end panel 12, a series of five full size panels 14 to 22 and a further end panel 24. The end panels 12, 24 are approximately half the size of the full panels. As can be seen, when the towels are interfolded, they interlap by approximately one third of the total :i length of the towel with one half towel panel being located between a pair of panels 16b, 18b of sheet o10b and panel 22a and part of panel 20a being located between panel 14b and end panel 12b of towel 20 Typically the length of the unfolded towel leaf measured perpendicular to the folds will be 300mrm with the two end half panels having a length of measured in the same direction and each of the full panels will have a length of 50mm. Thus when the panel is interfolded the cross-sectional area of the stack is 200mm by 50mm. This provides a compact towel which can fit in a relatively small dispenser and yet still provide a towel of sufficient size for a person to satisfactorily dry their hands.

When a towel stack folded as shown in Figure 1 is placed in a dispenser machine, one full panel such as 22B and one half panel such as panel 24B will project from the dispensing slot in the base of the dispenser.

With reference to Figure 4 it can be seen that it is a feature of the invention that when the towels are stacked and interfolded there is one full panel 18B and two part panels, ie half of 20B and half of panel 16B which do not overlap, indicated by area in Figure 4.

Figures 2 and 3 illustrate a machine for manufacturing a towel stack embodying the present invention. The machine includes a web or roll of crepe towel material 50 mounted on a shaftless unwind stand which is fed via a feeding apparatus 54 to an embosser 56 and thence to a folding mechanism generally indicated at 58 which will be described in more detail below. The machine includes an operator control panel 60 and a discharge tray onto which interfolded towel stacks are dispensed for manual separation into individual stacks.

The folder is shown in more detail in Figure 3. The schematic drawing shows a number of features including an idler gear 70, a urethane covered :pressure roll 72, a knife roll 74 and a cooperating bed roll 76 which provides a relief area for serrated knife blades of the knife roll. In the upper part of the 10 machine there is provided a urethane pull roll 78 and a cooperating steel pull roll 80, a count marker 82 and a slitter 84 which slits the web of material into webs having a width of 200mm. The machine also includes a lap roll 86, a urethane covered retard roll and a cooperating steel retard roll 88 and respectively which includes an adjusting means 92 and a folding roll 15 assembly comprising a fixed folding roll 94 and a moveable folding roll 96.

The machine also includes star wheel assemblies indicated at 98.

In use, the web is drawn into the folding station and the slitter 84 which includes adjustable blade holders with slitter blades, which run against anvil sleeves mounted on the steel pull roll 80, cuts the web of paper 20 material into the desired number of equal width webs of towel material. In the described embodiment, the width is 203mm. From there, the web passes between the pull rolls 80, 78. From the pull rolls the material then passes between the knife roll 74 and bed roll 76. The knife roll 74 carries serrated knife blades which cooperate with the bed roll to provide the proper cutoff length of the towels, the bed roll 76 utilising a vacuum to hold the sheets to the bed roll and which also provides a relief area for serrated knife blades of the knife roll to pass through the sheet during cutoff.

The towel then passes from the bed roll to the pressure roll 70 which is mounted in an eccentric bearing housing under and adjacent to the bed roll and which creates a tight drag on the sheet at the nip between the pressure roll 70 and bed roll 76 which assists in maintaining the correct sheet length during cutoff. From the pressure roll 70 the discrete leaves pass to the lap roll 86 located below the bed roll but before the retard rolls. The lap roll uses a series of vacuum holes to pickup towel leaves from the bed roll and transfer the leaves to the retard rolls 88, 90. The lap roll includes flipper bars which provide a space for one sheet to slide approximately one third of its length behind the preceding sheet. Air assist is used to blow the tail of the leading sheet away from the lap roll as the leading edge of the next sheet comes down from the upper roll.

Flipper bars are located on the lap roll 86 which hold the sheet away from the lap roll surface providing a space for the following sheet to slip underneath. Retard rolls are located between the lap roll and the forward folding rolls. The retard rolls turn at approximately two thirds of the speed of the lap roll. When the leading edge of a towel leaf enters the retard roll nip, the sheet slows down. At this point the flipper bars move the tail edge 10 of the sheet away from the lap roll, allowing the leading edge of the next sheet to slide down behind the preceding sheet causing the one third overlap required for interfolding the sheets. The two folding rolls 94,96 are mounted as short distance below the retard rolls. Their function is to interfold the sheets together. Each folding roll contains six rows of grippers and six rows 15 of tuckers which interact together to interfold the sheets. The grippers and tuckers alternate on the rolls and where one roll has a gripper opposing it on the other roll will be a tucker. The movements of these grippers and tuckers 0.*0 are governed by cams and cam followers mounted on the ends of the rolls. In use, a tucker will first tuck the sheet into the opposing gripper, the gripper 20 then closes holding the sheet, the next sheet comes down and again a tucker inserts it into a following gripper, the gripper will then open releasing the interfolded sheet and it approaches web guides forming a zig zag fold.

The apparatus includes a vacuum system comprising a vacuum pump, valves, slides and timing brackets, hoses etc.

Star wheel assemblies are located beneath the folding rails before the discharge bolt conveyor whose function is to move product away from the folding rolls and aids creating the proper back pressure to the folding rolls.

The apparatus also includes a count marker shaft located above the slitters comprising a count shaft, marker finger, air cylinder and a counter.

This system adjusts and keeps track of the product count as well as marking the sheets, separating the end of one count and the start of the next chart count.

Referring once more to Figure 1, the discharge bolt conveyor is located under the folding rolls and the star wheel assemblies and comprises a tray with a series of pulleys and endless drive bolts. The discharge bolt conveyor 8 moves product away from the folding rails whilst again at the same time creating proper back pressure to the folding rolls.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

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Claims (6)

1. A towel stack comprising:- a plurality of discrete towel leaves, each leaf being folded so as to provide at least five full sized panels of a substantially identical size and two part panels one being located at either end of the leaf, the part panels being smaller than the full sized panels wherein the towel leaves are interfolded such that there is approximately a one third overlap of one towel leaf with an adjacent towel leaf and wherein an end part panel of one leaf is folded between two adjacent full panels of an adjacent towel leaf in the stack. 10

2. A tissue or towel stack as claimed in claim 1 wherein the part panel is approximately half the size of a full panel

3. A tissue or towel stack as claimed in claim 1 or claim 2 wherein the stack is folded such that an end part panel and the adjacent full panel of each towel leaf define a first pair of panels and a pair of full panels adjacent that 15 pair define a second pair of panels and in which the part panel at the end of an adjacent towel in the stack is disposed between the second pair of panels and the next pair of adjacent panels on the adjacent towel is folded between ~the first pair of panels.

4. A tissue or towel stack as claimed in any preceding claim arranged so 20 that when the towels are stacked and interfolded there is one full panel and two part panels, where there is no overlap between adjacent towels in the stack.

A method of producing a towel stack as claimed in any preceding claim comprising the steps of:- providing a single continuous web of towel material; delivering the web to a knife roll for transversely cutting the web to form discrete towel leaves, the knife roll cooperating with a bed roll utilising a vacuum to hold the sheets to the bed roll and which provides a relief area for knife blades to pass through the sheet during cut-off; delivering the leaves from said knife roll/bed roll to a lap roll; delivering the leaves from the lap roll to a retard roll so that each leaf has a leading portion overlapping a trailing portion of the preceding leaf, the leaves being overlapped by a predetermined length, preferably approximately one third of the overall length L of a leaf; delivering the leaves from the retard roll to a folding roll; and transversely folding each leaf to have six folds to define five full leaf panels and two part panels disposed at either end of the set of five full panels on the towel leaf.

6. A machine for producing a towel stack, each stack including a plurality of interfolded, interleaved towel leaves, with each leaf consisting of at least five full panels and two part panels one part panel being disposed at either end of the five full panels, said machine including; ~a knife roll defining a series of knife blades, adapted to receive a continuous web of towel material which in conjunction with a bed roll which 10 provides a relief area for the knife blades and is arranged to transversely cut the web to form discrete lengths of a predetermined length L a lap roll means to which the discrete leaves provided by the knife roll and bed roll are delivered and is adapted to arrange the leaves so that a following leaf is located behind a preceding leaf; 1P 15 a retard roll which cooperates at the lap roll to overlap adjacent leaves so that the leaves are overlapped by approximately one third of the predetermined length L; and o6 a folding roll assembly including rolls defining gripper means and cooperating tucker means, sized and arranged to form six folds in each towel 20 leaf. Dated this sixteenth day of April 1999 ABC TISSUE PRODUCTS PTY LIMITED Patent Attorneys for the Applicant: F B RICE CO