GB2470837A

GB2470837A - Apparatus for folding sheet material

Info

Publication number: GB2470837A
Application number: GB201009383A
Authority: GB
Inventors: Karl Montgomery; Neil Mayne
Original assignee: DOYEN MEDIPHARM Ltd
Current assignee: DOYEN MEDIPHARM Ltd
Priority date: 2009-06-05
Filing date: 2010-06-04
Publication date: 2010-12-08
Also published as: GB201009383D0; GB0909736D0

Abstract

An apparatus to fold sheet materials is disclosed, for use in particular with fabric or multilayered materials. The material is delivered from a belt (11, Figure 1) over a folding plate 12 having a generally triangular shape. The distal apex of the plate induces a fold parallel to the longitudinal axis of the material as the material is drawn over the plate. The material passes through a pair of spaced apart parallel bars 15, 16 which reorient the folded material. A first driven roller 17 whose axis is parallel to the axis of the drive belt assists in moving the material, and a second driven roller 18 tensions the material. The fold is confirmed by a third driven and nip rollers 19, 20 acting in co-operation to pull the material through the pair of bars. To aid in maintaining appropriate tension in and orientation of the material, the second driven roller 18 may be moveable in the horizontal and/or vertical plane/s, and the belt may be pivotally mounted about an axis perpendicular to its plane to alter the horizontal direction of its axis in response to a sensed alignment of the sheet material.

Description

AN APPARATUS FOR FOLDING SHEET MATERIAL

Field of the Invention

The present invention relates to an apparatus for folding sheet fabric material. The apparatus is intended particularly to fold non-woven fabric and for fabric comprising a plurality of layers.

BackEround to the Invention In many industries, for example the printing industry, the product being made is in the form of a sheet of material. The uses of such products is wide and can range, for example, from wrapping paper for presents to medical dressings. The material from which the product is made can therefore have markedly different properties. This often results in different machines for handling the process being required depending on the material in question.

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Often, prior to final packaging, the material is supplied in rolled up form for ease of S..

transport and handling. In such cases the width of the material is typically greater *.....

* than is suitable for passing on to the end user. Therefore, in order to save space and *: : :* 20 ease handling of the final product the sheet material is folded along an axis parallel to * the length of the material. Often, folding along separate, parallel axes occurs to : further reduce the width. Lengths of folded material can then be cut and packaged. S.

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Within the printing industry, where the substrate material is paper, the folding process is well developed. Typically a fold is introduced by running the paper over a triangular plate to induce a fold along the central axis of the paper. The folded material then passes through a pair of bars which confirms the fold line. Usually the folded paper subsequently passes around a roller to bring its direction of travel back into a plane parallel to that of its original direction of travel. If required this step can be repeated to form a second fold.

The above method is suitable for strong, thin materials such as paper as the paper can be pulled through the machine under tension -the tension being utilised in part to induce the fold -and the paper's strength is such that the tension does not deform the paper.

More delicate, non-woven materials cannot however be easily folded by simply passing through the same machine outlined above. The tension exerted by the machine on the material to draw it over the fold-forming elements and maintain the fold, tends to stretch the material. This leads to poor fold formation and moreover the loss of accurate tracking of the material through the machine. The material can therefore easily become misaligned, causing blockages and resulting in expensive downtime. In addition, and particularly where thicker and multilayered materials are * * **** . under consideration, the passage of the matenal around a roller can cause damage to ****** * S the material. * ** * * * S... * *SS

* 20 It will be appreciated that on passage of the material about the roller, the outside of *:. the material, furthest from the roller travels a larger distance than that portion of the material adjacent to the roller's surface. The shear forces thus set up within the material are sufficient to distort its shape and separate layers from one another. Such an outcome is obviously undesirable.

It is an object of the present invention to provide an apparatus which addresses the above problems and gives improved folding of sheet materials, particularly weaker or multilayered materials. It is a further object of the invention to provide a method of folding sheet material.

Summary of the Invention

According to the invention there is provided an apparatus to fold sheet materials, the apparatus comprising: a driven endless belt to convey sheet material from a supply and deliver sheet material to a folding plate, a folding plate to receive at a first proximal edge material from the belt and having two distal edges, meeting at an apex, the apex inducing a fold in sheet material, as

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material passes thereacross; a pair of parallel bars spaced apart to allow passage of material therebetween to 0**S * receive folded material from the folding plate and orientate the folded material in the *..*.. * I

* plane perpendicular to the driven belt the plane passing substantially through the * central axis of the driven belt; S..

* 20 a first driven roller whose axis is parallel to the axis of the drive belt and below the *:. apex of the conic or triangular portion of the folding plate, a second driven roller substantially parallel to the driven roller, said second driven roller acting to tension material, and a driven roller to pull material through the pair of bars, the third driven roller being in close association with a nip roller, material passing between the third driven and the nip roller and thereby being compressed between the third and the nip roller.

By control of the passage of the material, and altering the tension in the material through the second driven roller, the flow and the integrity of material is maintained.

Conveniently the second driven roller is moveable in a horizontal plane to alter the tension in the material and reduce shear forces.

Preferably the folding plate is angled downwardly from the belt to assist the folding process.

Optionally the second driven roller is moveable in the vertical plane. This changes the amount of material in contact with the second roller and thus the tensive force acting on the material. Further optionally, when the folding plate is angled downwardly, the * *._ * second roller is vertically higher than the first roller to provide the required tensive *SSa.i * * force. * .-* * * a... a.. a

The driven belt is preferably pivotally mounted about an axis perpendicular to the *:. motion of the belt and the plane of the belt. The alignment of the belt and hence that of the fabric is thereby improved.

Optionally, the apex of the distal edge is rounded, with, further optionally, a radius of less than 10mm. The folding plate is conveniently triangular in shape.

The apparatus advantageously includes sensors to determine the alignment of sheet material, the senses being linked via processor means to the driven endless belt, the processor means acting to alter the alignment of the endless driven belt to adjust the alignment of sheet material.

Further advantageously, the endless driven belt is mounted to a frame, the frame being pivotally mounted about an axis perpendicular to the plane of the driven belt. Yet further advantageously the frame can be pivoted by up to /. 25mm from a mean position.

Brief Description of the Drawings

The invention is now described with reference to the accompanying drawing which show by way of example only one embodiment of an apparatus for folding fabric material. In the drawings: Figure 1 is an illustrative side view of the apparatus; S...

Figure 2 is an illustrative view of the flow of material through the apparatus; and * ..*.. * S

Figure 3 illustrates the folding of a sheet of fabric material. *... 4.

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Detailed Description of the Invention

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* Apparatus for folding a length of woven fabric material, for example paper is known in the art. The fabric material is typically prepared and supplied as a roll which is fitted into the apparatus, the material being unrolled before passing through the rest of the apparatus. Once the material has been folded it is usually cut into sections before further treatment or being conveyed to a packaging section.

During the folding process means are provided which enable the rolled and folded material to be maintained in the correct alignment within the apparatus and to prevent damage or wrinkling of the fabric material. Additionally, where the fabric material comprises a series of layers, shear forces act to separate the layers from one another.

If certain types of fabric material are to be handled by the apparatus action has to be taken to reduce the forces or their effect.

The apparatus as illustrated below produces a single fold, halving the width of the fabric. If required the machine can be adapted along the lines of the illustrated embodiment to provide a further fold parallel to the original fold.

Using conventional apparatus non-woven materials tend to stretch out of shape and the unrolled and in particular, folded material becomes misaligned with respect to the apparatus. Moreover, thicker fabric can be subject to shear forces which act to tear or distort the fabric. When such damage to the materials occurs, this results in material S... * . S...

* wastage, but can also lead to the requirement for the process to be halted to remove *S. S** * S : blockages and damaged material. 5,SS

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To sunimarise the present invention and with reference to the Figures, the unrolled fabric 10 is laid on to a steering belt 11 which conveys the fabric 10 in the direction shown by the arrow A. In order to ensure the fabric 10 remains in contact with the belt 11, a press roller 11 A presses onto the fabric 10. The fabric 10 passes from the belt 11 over a fold plate 12 which has a centrally disposed apex 13 directed away from the belt 11 in the direction of travel of the fabric 10. The angle formed by the two edges of the apex is chosen to suit the fabric.

To minimise damage to the fabric the apex can be rounded with the radius of curvature of the apex being chosen according to the use of the apparatus. If the radius is too large, for example then problems with folding can be encountered. Typically, in order to provide good folding the radius is kept at less than or equal to 10mm.

Passage of the fabric 10, under tension, over the fold plate 12 acts to cause the sheet of fabric 10 to be folded along a central longitudinal axis line 14 (see dotted line -Figures 2 and 3). The fold is confirmed by the passage of the fabric 10 between two fold bars 15, 16 which bars 15,16 are held in parallel, spaced apart arrangement. The angle of the bars relative to the folding plate is chosen to suit the fabric.

The fabric 10 then passes around first and a second driven rollers 17, 18 which act to pull the fabric 10 through the apparatus. After passing over the second driver roller 18 the fabric 10 passes between two further rollers 19, 20 which co-operate to further * * ** confirm the fold in the fabric 10. From the diagrams it can be seen that the folded ***.

fabric is now moving (in the direction shown by arrow B in Figures 2 and 3) in a : *..* plane parallel to that in which it was originally moving but at right angles to the *S*.

original motion. If no more folds are to be introduced then the folded fabric can (if * convenient or of assistance to the machine layout) be simply passed around a turn bar to convey it in its original direction. However it will be appreciated that where the inclusion of a further fold is required then carrying out the above process, utilising a second fold plate, will result in a further 90° turn in direction which can be used to return the fabric to its original direction.

The tracking or alignment of the fabric 10 is controlled in a number of ways to ensure correct tension on the fabric 10. Monitoring of the alignment is achieved through sensors at various sections of the apparatus. For example, detectors 21 determine the alignment of the fabric 10 as it leaves the steering belt 11. If the alignment is found to require adjustment then one action which can be taken is alteration of the horizontal direction of the axis of the steering belt 11. The frame 22 onto which the steering belt 11 is mounted can be pivoted in the required direction about an axis 23 with a freedom of movement of +1-25mm being typical, although this value will be chosen to suit the machine and process.

As with the other adjustments below, this not only changes the director of flow of the belt but also changes tension forces into the fabric 10 to correct any imbalance of forces.

The driveable nature of the first and second rollers 17, 18 taken in conjunction with the drive on the belt 11 can be utilised to ensure that the correct forces act on the fabric 10. In particular, fine adjustment of the drive force can be made and the ratio of : * force exerted by a drive roller with respect to another carefully controlled. S...

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The second roller 18 has been found to be especially important in the control of the * fabric flow. The location of the second roller 18 acts to introduce a bend in the opposite sense to that introduced by the first roller 17, and the shear forces this produces on the fabric 10 counteract forces already acting on the fabric 10: introduced at least in part by the roller 17.

The control exerted is increased in the apparatus by mounting the second roller 18 moveably with respect to the elements of the apparatus. Thus the second roller can be moved laterally of its axis along the arc shown by the arrow C. In addition the roller 18 can also be moved in the horizontal direction perpendicular to the arc C or in the vertical direction. The latter motion brings a greater or lesser area of the roller 18 into contact with the fabric 10 which feature is at least in part utilised to modify the shear forces. Although the embodiment shown in the figures is not so constructed, the control could also be achieved through the rollers 19, 20 also being moveably mounted.

It will of course be understood that the invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible within the scope of the invention. 6 6 e. * * **.

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Claims

CLAIMSI. An apparatus to fold sheet materials, the apparatus comprising: a driven endless belt to convey sheet material from a supply and deliver sheet material to a folding plate, a folding plate to receive at a first proximal edge material from the belt and having two distal edges, meeting at an apex, the apex, inducing a fold in sheet material, as material passes thereacross; a pair of parallel bars spaced apart to allow passage of material therebetween to receive folded material from the folding plate and orientate the folded material in the plane perpendicular to the driven belt the plane passing substantially through the central axis of the driven belt; a first driven roller whose axis is parallel to the axis of the drive belt and below the apex of the conic or triangular portion of the folding plate, * a second driven roller substantially parallel to the driven roller, said second *S..S.: *..: 20 driven roller acting to tension material, and *e..SS: a third driven roller to pull material through the pair of bars, the third driven * roller being in close association with a nip roller, material passing between the S..Sthird driven and the nip roller and thereby being compressed between the third and the nip roller.
2. An apparatus according to Claim 1, wherein the second driven roller is moveable in a horizontal plane to alter the tension in the material and reduce shear forces.
3. An apparatus according to Claim I or Claim 2, wherein the folding plate is angled downwardly from the belt.
4. An apparatus according to any preceding claim, wherein the second driven roller is moveable in the vertical plane.
5. An apparatus according to Claim 4, wherein when the folding plate is angled downwardly, the second roller is vertically higher than the first roller.
6. An apparatus according to any preceding claim, wherein the driven belt is pivotally mounted about n axis perpendicular to the motion of the belt and the plane of the belt.

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7. An apparatus according to any preceding claim, wherein the apex of the distal edge is rounded. *
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* 8. An apparatus according to Claim 7, wherein the radius of the apex is less than 10mm. S. * S * 5.5 * S..
9. An apparatus according to any preceding claim, wherein the folding plate is triangular in shape.
10. An apparatus according to any preceding claim, the apparatus including sensors to determine the alignment of sheet material, the senses being linked via processor means to the driven endless belt, the processor means acting to alter the alignment of the endless driven belt to adjust the alignment of sheet material.
11. An apparatus according to Claim 10, the endless driven belt being mounted to a frame, said frame being pivotally mounted about an axis perpendicular to the plane of the driven belt.
12. An apparatus according to Claim 11, wherein the frame can be pivoted up to 25mm from a mean position.
13. An apparatus substantially as herein described with reference to and as illustrated in the accompanying drawings. S... * S* 55 5..* * 20 * .. * . S **..S *S.S S. * S..S *.SS