Wire support rods used when pulling the wire into the paper machine

Abstract

A wire support rod (10) for use when drawing in a wire into a paper machine, comprising a support tube (1) made of CFK and a telescopic rod (3) and a bearing arrangement, by which the telescopic rod (3) is axially movably supported inside the support tube (1), wherein at least one shrink hose (2) is arranged on the support tube (1) in such a way that it constitutes a surface on which the respective wire is supported when used in order to draw in the wire.

Description

Technical Field

[0001] The present invention relates to a wire support rod used when pulling (or introducing) a wire into a papermaking machine. The wire support rod comprises a support tube made of carbon fiber reinforced plastic (CFRP), a telescopic rod, and a bearing structure, by which the telescopic rod is axially displaceably supported within the support tube. The present invention also relates to a support tube for such a wire support rod. Background Art

[0002] Wire support rods have long been known as aids for pulling an endless wire into a paper machine. Here, the term "wire" also refers to felts and other clothing of a paper machine. Furthermore, all machines for producing paper or paper-like fibrous webs, such as primarily board machines, tissue machines, or pulp machines, are considered paper machines.

[0003] During the pull-in process, the endless wire is first suspended loosely beside the corresponding part of the paper machine using a plurality of wire support rods, wherein one side of each wire support rod is connected to the paper machine table for support. To this end, the respective telescopic rod is pulled out of a support tube so that it can be fastened or supported on the paper machine table. The other side of the wire support rod is supported by a frame or a building, or is held by an overhead crane. The support tube of the wire support rod is then moved toward the paper machine, wherein the telescopic rod is slowly moved back into the support tube until the support tube with the suspended wire is laterally adjacent to the rollers in the paper machine that support the wire. The wire is then pulled laterally over the wire support rods or their support tubes onto the rollers until the wire is in the desired position in the paper machine. During this process, the wire slides on the surface of the wire support rods or their support tubes.

[0004] The bearing of the telescopic rod in the support tube is designed such that it firstly allows displacement relative to one another and secondly also forms a sufficiently stable connection between the telescopic rod and the support tube for the support net in the extended state.

[0005] In the prior art, wire support bars for pulling an endless wire into a paper machine are described, for example, in patent document GB 503118 A. As described there, some wire support bars have also been required for transporting the endless wire.

[0006] Patent document DE 1945230 A points out that when the wire is pulled over the wire support rods during the drawing-in process, sensitive surfaces of the wire may be damaged. As a solution to this problem, it is proposed that the entire frame holding the wire support rods be designed so that it can be moved into the paper machine and remain there. This prevents the wire from being pulled laterally over the wire support rods. However, this solution involves a significant structural design outlay and, for space reasons, cannot be implemented in every paper machine. Summary of the Invention

[0007] The object of the present invention is to provide a better, more flexible and inexpensive solution for drawing a wire into a paper machine, in which it is ensured that the surface of the wire is not damaged during the drawing-in process.

[0008] For a net support rod, this technical problem is solved according to the net support rod of the present invention. Further advantageous embodiments of the invention can be found in the description. This advantageous technical solution is characterized in that at least one shrink hose is arranged on the support tube in such a way that the shrink hose constitutes a surface on which the corresponding net is supported when in use to pull in the net. The surface on the support tube is made so smooth by the shrink hose that the net is not damaged even if it is pulled over it. In addition, the shrink hose is relatively cheap and can be easily laid. The surface of a CFRP support tube without any other covering is too rough and would damage the net when the net is pulled over it. On the other hand, CFRP is a preferred material for the support tube, which makes the net support rod lighter, thereby simplifying the handling of the net support rod and the transportation of the net support rod.

[0009] The present invention thus makes it possible to provide a lightweight, easy-to-handle, and inexpensive net support rod. Even with relatively large net widths, this net support rod remains lightweight and can be flexibly manufactured for different net widths. Furthermore, and particularly importantly, there is no risk of sensitive net surfaces being damaged when the net is pulled in.

[0010] Another advantage is that if the shrink hose is damaged, it can be easily replaced and refurbished. This makes it easy to repair the net support rod. It is also possible to remove only a portion of the shrink hose and replace it with a new one. Since the new shrink hose is installed simply by heating, repairs can be carried out on site without significant effort.

[0011] A shrink hose is a thermoplastic hose that shrinks radially under the action of heat, such as from a hot air blower. This makes it easy to attach the shrink hose to the support tube. Shrink hoses are manufactured by radially stretching the extruded hose while hot and then cooling it while stretched. This initially maintains the stretch in the shrink hose. Upon reheating, the shrink hose shrinks again. The present invention particularly preferably uses a shrink hose made of rigid PVC to create a wear-resistant surface. In this case, since the shrink hose is attached to a tube with a constant diameter, a low shrinkage factor is sufficient. The outer diameter of the support tube is preferably between 80 mm and 250 mm. This depends primarily on the width of the mesh and the desired rigidity of the support tube. The length of the support tube should be at least as great as the width of the mesh to be drawn in. Typical lengths of support tubes are between 3 and 14 m, preferably between 8 and 13 m.

[0012] The telescopic rod is usually designed as a tube and has a length of between 2 and 5 m, preferably between 3 and 4 m. Thus, the wire can be suspended at a sufficient distance beside the paper machine before it is brought close to the rollers in the paper machine by moving on the telescopic rod.

[0013] CFRP is the abbreviation for carbon fiber reinforced plastic. The support tube is particularly preferably made of CFRP with continuous fibers. A thermosetting plastic, such as epoxy resin, is preferably used as the matrix material.

[0014] It is also advantageous if the shrink hose is arranged side by side in the form of multiple shrink hose segments. This makes it easier to install the shrink hose. This is particularly advantageous for particularly long support tubes. Furthermore, if the surface is damaged, individual shrink hose segments can be removed more easily and replaced with new ones. This makes repairs faster and more cost-effective.

[0015] In particular, the support tube is designed as a wound CFRP tube. Due to the winding method, the support tube can be designed with a low wall thickness while still having high flexural rigidity. This offers the advantage of low weight.

[0016] In a preferred embodiment, the telescopic rod is manufactured as a metal tube, in particular made of aluminum or an aluminum alloy. Thus, a good compromise between rigidity and weight can still be achieved when the diameter is small.

[0017] Alternatively, the telescopic rod is manufactured as a tube made of carbon fiber reinforced plastic, in particular as a wound carbon fiber reinforced plastic tube. This is advantageous especially when, for example, a slightly larger diameter is desired but still light in weight.

[0018] Furthermore, the bearing structure of the telescopic rod is designed to have at least one sliding bushing made of plastic, particularly POM, and preferably two sliding bushings made of plastic, particularly POM. POM is the abbreviation for polyoxymethylene, also known as polyoxymethylene. POM is a thermoplastic that has high rigidity, good dimensional stability, and a low coefficient of friction. Therefore, this thermoplastic is particularly well-suited for bushings used to support the telescopic rod in the support tube. Compared to known rolling bearings, a bearing structure with these bushings requires less installation space and is lighter in weight. The sliding bushings can be easily manufactured by injection molding.

[0019] In particular, the one or two sliding bushes are fastened to the telescopic rod by a press fit. This is particularly easy to achieve when the telescopic rod is made of metal and the sliding bushes are made of POM.

[0020] In another advantageous embodiment, the support tube is provided with a metal header at each end. These headers are preferably secured in the support tube by a press fit. This protects the CFRP support tube from damage at its edges. Furthermore, the headers make it easier to secure the support tube in a frame, building, or overhead crane housing.

[0021] Furthermore, one of the head parts may be designed to guide and / or support the telescopic rod when it moves in the support tube.

[0022] The present invention also relates to a support tube for a net support rod. The technical problem described above is solved by the support tube for a net support rod according to the present invention. The support tube is designed for use in a net support rod, in particular for a net support rod designed according to the above description. Further advantageous embodiments of the support tube according to the present invention can be found in the description. The technical solution of the present invention is characterized in that at least one shrink hose is arranged on the support tube so that it forms the surface on which the net is supported when used to pull in the net.

[0023] As mentioned above, it is advantageous if the shrink tube is arranged in the form of multiple shrink tube segments arranged side by side. It is also advantageous if the support tube is designed as a wound CFRP tube. Alternatively, the support tube is provided with metal head components at each end, wherein these head components are secured in the support tube by a press fit. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Further advantageous features of the present invention will be described with reference to the accompanying drawings based on exemplary embodiments. Identical components are denoted by the same reference numerals.

[0025] Figure 1A schematic diagram showing a mesh support bar according to the invention having a support tube according to the invention;

[0026] Figure 2 A schematic diagram showing the layout of the shrink hose;

[0027] Figure 3 A schematic diagram showing a shrink fit (or shrink fit) sliding bushing;

[0028] Figure 4 Schematic diagram showing the shrink head components. DETAILED DESCRIPTION

[0029] Figure 1 A mesh support rod 10 according to the present invention is shown. It comprises a support tube 1 according to the present invention, which is provided with a shrink hose 2 on its outer side. The shrink hose 2 is arranged so that it forms the surface with which the mesh contacts during retraction. The support tube 10 is made of CFRP, preferably produced as a CFRP tube using a winding method. This allows the support tube to be designed to be particularly lightweight while exhibiting good flexural rigidity. Furthermore, there is a telescopic rod 3, which is axially displaceably supported in the support tube 1 via a bearing arrangement. The telescopic rod 3 is preferably designed as a metal tube, in particular, made of aluminum or an aluminum alloy.

[0030] To pull the endless net into the paper machine, the net is first suspended into the desired ring shape next to the paper machine using a plurality of net support rods 10. To this end, the telescopic rods 3 are extended and their free ends are secured or placed in the appropriate position on the paper machine's table. The opposing ends of the support tube 1 are secured to a frame, a building, or an overhead crane. Once the endless net is suspended into the desired ring shape, the support tube 1 with the net on it is pushed toward the paper machine, so that the telescopic rods 3 are pushed into the support tube 1. This brings the net laterally closer to the paper machine's rollers where it is to be supported. The net is then pulled laterally onto the rollers in the paper machine. During this process, the net slides on the surface of the net support rods 10. Because this surface is formed by the smooth shrink hose 2, the sensitive net is protected from damage.

[0031] Optionally, as shown here, the support tube 1 is provided with metal headers 5 at each end. These headers are preferably secured to the support tube 1 by a press fit. These headers 5 protect and reinforce the edges of the support tube 1. Furthermore, these headers are suitable for accommodating the net support rod 10 in a bracket or securing it to an overhead crane. Furthermore, one of these headers 5 can be designed to guide and / or support the telescopic rod 3 as it is extended from the support tube 1.

[0032] The illustrated embodiment also includes two sliding bushings 4, preferably made of POM and designed here as rings. These serve as bearings for the telescopic rod 3 in the support tube 1 and enable axial movement of the telescopic rod 3. POM is a well-suited material for these sliding bushings due to its high rigidity, dimensional stability, and low coefficient of friction. The sliding bushings 4 are preferably press-fitted onto the telescopic rod 3.

[0033] The shrink tube 2 is preferably made of hard PVC, as this forms a smooth and wear-resistant surface. The shrink fitting temperature is generally between 50-100° C. In particular, the shrink tube 2 can be composed of a plurality of ring segments, which are laid side by side on the support tube 1 .

[0034] exist Figure 2 1 shows how to apply the shrink tube 2 used in the technical solution of the present invention to the support tube 1. First, the stretched shrink tube is pulled onto the support tube 1 at room temperature. The shrink tube 2 is then heated, for example with a hot air blower, causing it to shrink and be securely applied to the support tube 1. The shrink tube thus forms a surface that contacts the web during its insertion and over which the web is drawn.

[0035] Figure 3 The schematic diagram shows how the sliding bushing 4 can be fastened to the telescopic rod 3. The sliding bushing 4 is first heated above room temperature (RT), causing it to expand slightly and allowing it to be pushed onto the desired position on the telescopic rod 3. Upon cooling, the sliding bushing 4 contracts, so that it fits securely onto the telescopic rod 3 via a press fit. This creates a stable and reliable bearing arrangement for the movement of the telescopic rod 3 in the support tube 1, which requires little installation space and adds almost no additional weight.

[0036] Figure 4 The figure depicts the installation of the head components 5 in the support tube 1. The metal head components are cooled to a point where they can be inserted into the support tube 1. When they return to room temperature (RT), they expand and securely fit into the support tube 1 through a press fit. The head components 5 reinforce and protect the edges of the support tube 1 from damage. Furthermore, these head components provide a way to guide the telescopic mast 3 as it is moved, or alternatively, to secure or accommodate the telescopic mast to a frame, a building, or an overhead crane.

[0037] Reference Signs List

[0038] 1 support tube

[0039] 2 shrink hose

[0040] 3 retractable poles

[0041] 4 sliding bushings

[0042] 5 head parts

[0043] 10 net support rods

[0044] RT

Claims

1. A wire support rod (10) for use when pulling a wire into a papermaking machine, comprising a support tube (1) made of carbon fiber reinforced plastic and a telescopic rod (3) and a bearing structure, wherein the telescopic rod (3) is supported axially movably inside the support tube (1) by means of the bearing structure, It is characterized in that At least one shrink tube (2) is arranged on the support tube (1) in such a way that the shrink tube (2) forms a surface on which the corresponding net is supported when used for pulling in the net.

2. The net support rod (10) according to claim 1, characterized in that The shrink hose (2) is arranged side by side in the form of a plurality of shrink hose sections.

3. The net support rod (10) according to claim 1 or 2, characterized in that: The support tube (1) is designed as a wound carbon fiber reinforced plastic tube.

4. The net support rod (10) according to claim 1, characterized in that The telescopic rod (3) is made of a metal tube.

5. The net support rod (10) according to claim 4, characterized in that The telescopic rod (3) is made of aluminum or aluminum alloy.

6. The net support rod (10) according to claim 1, characterized in that The telescopic rod (3) is manufactured as a tube made of carbon fiber reinforced plastic.

7. The net support rod (10) according to claim 6, characterized in that The telescopic rod (3) is manufactured as a wound carbon fiber reinforced plastic tube.

8. The net support rod (10) according to claim 1, characterized in that The bearing structure of the telescopic rod (3) comprises at least one sliding bushing (4) made of plastic.

9. The net support rod (10) according to claim 8, characterized in that The bearing structure of the telescopic rod (3) comprises two sliding bushings (4) made of plastic.

10. The net support rod (10) according to claim 8 or 9, characterized in that The sliding bushing (4) is made of polyoxymethylene.

11. The net support rod (10) according to claim 8 or 9, characterized in that: The sliding bushing (4) is fastened to the telescopic rod (3) by press-fitting.

12. The net support rod (10) according to claim 1, characterized in that The support tube (1) is provided with a metal head component (5) at each of its two ends, wherein the head components (5) are fastened in the support tube (1) by press fit.

13. The net support rod (10) according to claim 12, characterized in that One of the head parts (5) is designed to guide and / or support the telescopic rod (3) when the telescopic rod (3) moves in the support tube (1).

14. A support tube (1) for a net support rod (10), wherein: The support tube (1) is designed as a carbon fiber reinforced plastic tube. It is characterized in that At least one shrink tube (2) is arranged on the support tube (1) in such a way that the shrink tube (2) forms a surface on which the net is supported when used for pulling in the net.

15. The support tube (1) according to claim 14, characterized in that The shrink hose (2) is arranged side by side in the form of a plurality of shrink hose sections.

16. Support tube (1) according to claim 14 or 15, characterized in that The support tube (1) is designed as a wound carbon fiber reinforced plastic tube.

17. The support tube (1) according to claim 14, characterized in that The support tube is provided with a metal head component (5) at each of its two ends, wherein the head component (5) is fastened in the support tube (1) by press-fitting.

18. The support tube (1) according to claim 14, characterized in that The net supporting rod is a net supporting rod according to any one of claims 1 to 13.

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