GB2287458A

GB2287458A - Winding webs

Info

Publication number: GB2287458A
Application number: GB9504806A
Authority: GB
Inventors: Armin Hutzenlaub
Original assignee: Kampf GmbH and Co Maschinenfabrik
Current assignee: Kampf GmbH and Co Maschinenfabrik
Priority date: 1994-03-16
Filing date: 1995-03-09
Publication date: 1995-09-20
Anticipated expiration: 2015-03-09
Also published as: GB2287458B; GB9504806D0; DE4408863A1; JPH07267438A; DE4408863C2

Description

2287458 TITLE Apparatus for Winding a Web of Material This invention

relates to an apparatus for winding a web of material particularly, but not essentially a plastic foil, with a driven reel core bearing a winding reel, a contact roller extending parallel to the reel core and rotationally driven and a contact pressure system by means of which the contact pressure roller can be adjusted in position in a radial direction of the reel in accordance with the increasing diameter and/or the speed of the winding operation.

In practice it is comparatively difficult to obtain a uniform winding density in a wound roll. The winding density depends on a number of parameters, such as air inclusions, the elasticity of the material being wound, the speed of the web of material and surface roughness. The physical properties of the material to be wound may differ causing wrinkling, non-circularity and telescoping. One problem is that even slight changes in the parameters adversely effect the winding process.

The problem of air inclusions is also encountered in apparatus to which this invention relates and in accordance with DE 25 41 495 Al. According to this specification, air may get trapped between adjacent layers of the web during the winding process even though a contact roller is caused to bear against the outer periphery of the material being wound on the reel. This problem is particularly liable to arise with comparatively large or wide reels, as in the case of machine widths of 6 to 10 m. for example. In practical terms, a wedge of air is formed at the point where the web of material meets the reel. The pressure exerted by the contact roller is intended to push back this air wedge. A pressure in a direction towards the contact roller is thus caused to build up at the wed to reel junction and extending over the entire width of the reel. The said roller then naturally undergoes noticeable bending in the central zone, where it allows still more air to enter the junction. The air which has been entrained during the winding operation is thus prevented from remaining uniform over the entire width. In the apparatus already known an attempt is made to prevent this air inclusion problem from arising or to overcome it by paying particular attention to the contact pressure exerted on the reel by the contact roller. A very expensive control system is required in order to prov-ide an effective and complete winding control system by the combined use of a customary winding tension control and contact roller pressure control. Although all these measures may result in an improvement they cannot prevent the contact roller from bending in the middle which may have adverse consequences.

One of the objects of this invention is to provide, in an apparatus for winding webs of material, means by which the quality of the winding will be improved by simple measures but by which first and foremost the air inclusion occurring between adjacent layers in the case of large or wide webs will be smoothed out or almost avoided.

According to this invention there is provided apparatus for winding a web of material which includes a driven reel core bearing a winding reel, a contact pressure roller extending parallel to the reel and rotationally driven and a contact pressure system through which the contact pressure roller can be adjusted in position in the radial direction of the reel in accordance with the increasing wound diameter and/or the winding speed of the reel, in which apparatus the contact pressure roller is formed by a centrally positioned transverse member and a hollow roller rotatably mounted thereon by spaced bearings and supported in a manner free of bending in a zone extending between the said bearings.

it is a feature of this invention that, due to the particular arrangement of the bearings between the internal transverse member or crosspiece and the external rotatable hollow roller, the latter is supported in such a way that bending occurring in the zone between the bearings is substantially zero. This ensures that, regardless of the force exerted on the contact pressure roller, the line of contact between the latter and the web will be invariably straight with the loading thus remaining constant over this distance so that air inclusions occurring, if any, will be negligible. A particularly high winding quality is thus ensured as undesirable wrinkling which can take place therein as a result of the air inclusions is avoided. The dead weight of the roll is also compensated.

A particularly simple device which meets the requirements arising is formed when the transverse member is constructed as an internal tube and when the bearing serving to support the hollow roller on the internal tube is of the roller bearing type.

It is a feature of this invention that the bearings are mounted in a certain zone between the internal tube and the hollow roller, that is in a zone extending inwards. In particular, it has been found that especially good results are obtained if, for a hollow roller of a given over-all length, the bearings are in C 1 c each case positioned at a distance commencing from the ends of the hollow roller which is between 20% and 35% of the said over-all length of this latter. Ideal values are obtained when the distance from the outside to the bearing in each case is equal to 0.238 of the over-all length of the hollow roller. This provides a freely supported bearer with a symmetrical overhanging load which ensures that the contact roller supported by the bearing, will not bend in the part situated between these latter. Any slight negative flexure in the zones of the hollow roller which are outside the bearings can be advantageously utilised because the air occurring during the winding process can be discharged laterally in this position.

A device constructed in accordance with the invention can be built into existing machines in a simple manner.

For this purpose and for general assembly purposes it is of advantage for the bearings to be adjustable parallel to the longitudinal axis of the internal tube or hollow roller, a clamping device being interposed so that they can be secured in a preselectable position. This not only enables the bearings to be accurately adapted to the particular needs arising but also ensures that they can be mounted and dismantled with ease.

This purpose is further improved if the clamping system for the bearings is formed by a supporting ring secured to the internal tube, a carrier ring surrounding the bearing, a clamping ring operatively connected with the latter via a screw threading and clamping elements which can be subject to their action and optionally by a bearing ring supported against the internal wall of the hollow roller. To render this clamping system easily releasable and lockable the invention also provides that the clamping ring is to have an internal system of teeth through which the said ring can be operated in the release or clamping direction by means of a tool provided with a toothed pinion interacting with the aforementioned internal toothing.

It has also been found of advantage for the internal tube to be of stepped construction and to comprise, for example, a number of individual parts, and to be so designed that the part of the tube which is situated between the bearings if of greater diameter. This ensures that the bending moments occurring will be absorbed in the most satisfactory manner, at it is in the control zone that they are at their maximum.

To keep the weight occurring between the internal tube and the hollow roller within acceptable limits it has also been found of advantage for the internal tube and/or the hollow roller to be made of a low-density material, preferably carbon fibre or a composite thereof.

A preferred embodiment by way of an example of the invention is shown in the drawings and explained hereinafter in more detail. in the drawings:Figure I shows a schematic diagram of part of a winding apparatus with a contact pressure roller constructed in accordance with this invention, Figure 2 shows a side view of the apparatus shown in Figure 1, Figure 3 shows a part section through a contact pressure roller with driving device and contact pressure system, and Figure 4 shows an enlarged view of a clamping system.

Figures I to 3 show part of a winding device, for example of a quadruple reversing winding machine, of which the web is driven in a manner not shown in the drawing and is mounted likewise in a manner not shown in a machine housing or in a turning plate of a reversing winding machine. As is known, the web of material to be wound, for example a thin web of plastic foil, is guided by a contact roller 2, which in the example illustrated consists of a transverse member formed by an internal - Q - 0 tube 3 and an external tube rotatably mounted thereon through bearings 4 and constructed as a hollow roller 5. The total length of the hollow roller 5 is referenced L. The distance between the outer end of the hollow roller and each of the bearings 4 is referenced a and that part of the hollow roller which is situated between the bearings is referenced 1. The internal tube 3 is made up of more than one part and may comprise an internal tube part 3' of larger diameter, positioned between the bearings 4, and two tube parts 3" which are situated outside the bearings and of which the diameter is slightly smaller. A bearing journal 6 is provided at the outer end of each of the tube parts 3" and this in turn is supported in a bearing assembly 7 mounted displaceably, in a radial direction with respect to the lap 1, on the machine frame or bed 8 or on a part of the machine frame 8 which is rigidly connected therewith. For the displacement of the contact pressure roller 2 a contact pressure system 9 such as shown in detail in Figure 3 is employed. This contact pressure system includes a cylinder and piston unit (ram) 11 of which one end is connected to a bearing element 12 on the machine housing 8 and the other end to a connecting element 13. The bearing element 7 is rigidly connected to this latter and serves as a support for the bearing journal of the J r i M internal tube 3.

The bearing journal 6 is connected to the internal tube 3 by a securing part 14 formed thereon and integral therewith. As in the case of the external tube, the internal tube 3 may be made of a material of limited density, such as carbon fibres, in order to keep the mass within acceptable limits. A driving ring 15 is inserted into one end of the hollow roller 5 and is connected by a drive belt 16 with a drive pinion 17 of a drive motor 18. The hollow roller 5 can be driven in rotation by means of this latter system.

The axial arrangement adopted for the bearing 4 is such that the distance a extending in each case from the bearing 4 is equal of the said hollow roller 5. In ideal circumstances the distance amounts to 0.238 of the total length L of the hollow roller 5. With a bearing system constructed on these lines it is found that the central zone between the bearings, that is the part extending over the length 1, remains completely free of bending, so that air does not enter this zone during the winding operation. In the zone of the sections a a slight negative bending occurs which can be advantageously utilised for the lateral discharge of air entrained between the layers during the winding process.

end face of the hollow roller 5 to the to about 20 to 35% of the total length From Figures 3 and 4 it can be seen that the bearing is mounted in such a way that a clamping system 20 is interposed between the internal tube 3 and the hollow roller 5. This clamping system comprises a supporting ring 19 secured to the internal tube 3; a carrier ring 21 surrounding the bearing; a clamping ring 23 interacting with latter by a threading 22; locking elements 24 which can be subject to action therefrom and which may, for example, be of spherical construction, and a bearing ring 25 supported against the internal wall of the hollow roller 5.

By the use of this clamping system 20 it is possible to obtain a positive interlock for the bearings between the internal tube 3 and the hollow roller 5 and also to release them from each other. The bearings can thus be offset in the axial direction in such a way as to influence the bending effect of the hollow roller 5. For clamping and releasing the clamping system a tool 26 is provided which is insertable from the side into the hollow roller 5 and which, in the vicinity of its inner end is insertable into a boring 27 of the carrier ring 21. This tool bears a toothed pinion 29 which interacts with an internal toothing 28 of the clamping ring 23 and which according to the direction of rotation causes the clamping system to be either released or clamped.

1 _k W Needless to say, the invention is not limited to the example illustrated and allows for variations within the scope of the claims. The bearing ring 25 resting against and adhesively connected to the internal wall of the hollow roller, by bonding adhesive or the like for example, can be omitted so that the spherical clamping elements 24 can act directly on the said internal wall of the hollow roller 5. O-rings could equally well be used in place of the said spherical clamping elements.

Claims

1. Apparatus for winding a web of material which includes a driven reel core bearing a winding reel, a contact pressure roller extending parallel to the reel and rotationally driven and a contact pressure system through which the contact pressure roller can be adjusted in position in the radial direction of the reel in accordance with the increasing wound diameter and/or the winding speed of the reel, in which apparatus the contact pressure roller is formed by a centrally positioned transverse member and a hollow roller rotatably mounted thereon by spaced bearings and supported in a manner free of bending in a zone extending between the said bearings.

2. Apparatus in accordance with Claim 1, wherein the transverse member is formed by an internal tube.

3. Apparatus in accordance with Claim 1 or 2, wherein the bearings serving to support the hollow roller on the transverse member take the form of roller bearings.

4. Apparatus in accordance with any one of Claims 1 to 3, wherein the bearings are positioned in zones inwardly of the hollow roller and between the transverse member 13 - comprising an internal tube and the hollow roller.

Apparatus in accordance with any one of Claims 1 to 4, wherein for a hollow roller of a given over-all length the bearings are in each case situated inwardly from the ends of the hollow roller a distance equal to between 20% to 35% of the over-all length of the hollow roller.

6. Apparatus in accordance with any one of Claims 1 to 5, wherein a clamping system is associated with the bearings and is adjustable parallel to the longitudinal axis of the transverse member or the hollow roller and can be secured in a preselectable position.

7. Apparatus in accordance with Claim 6 wherein clamping system for the bearings is formed by; a supporting ring secured to the transverse member, a carrier ring surrounding the bearing, a clamping ring operatively connected with the latter through a screw threading, clamping elements which can be acted clamping ring and preferably a bearing ring contacting the internal wall of the hollow roller.

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8. Apparatus in accordance with Claim 7, wherein the clamping ring has an internal system of teeth by which the clamping ring can be actuated in a release or in a clamping direction by means of a tool provided with a toothed pinion interacting with the said internal system of teeth.

9. Apparatus in accordance with any one of Claims 1 to 8, wherein the transverse member is of stepped construction in the zone of the bearings, that part of the member which is situated between the bearings having a greater diameter than the part of the member situated outside the bearings.

10. Apparatus in accordance with Claim 9, wherein the parts of the member which are of different diameter are formed by respective separate tubes which in the zone of the bearings are interconnected with one another by an overlap preferably secured by an adhesive or otherwise bonded.

11. Apparatus in accordance with any one of Claims I to 10, wherein the transverse member and/or the hollow roller are made of a material of low density preferably a carbon fibre composite material.

12. Apparatus in accordance with any one of Claims 1 to - is - 11, wherein bearing journals are positioned at the ends of the transverse member and are in each case mounted in a bearing assembly which under the action of a contact pressure system is adjustable in the radial direction with respect to the material being wound on the reel.

13. Apparatus in accordance with any one of Claims 1 to 12, wherein a drive ring is connected through a drive belt or the like with a drive pinion of a drive motor and is inserted in one end of the hollow roller.

14. Apparatus for winding a web of material onto a reel constructed and arranged to function as herein described and exemplified.

15. A contact pressure roller system for use in an apparatus for winding a web of material onto a reel constructed and arranged to function as herein described and exemplified with reference to the drawings.