EP1491681A1 - Device for threading a web - Google Patents

Abstract

A material web-threading apparatus (24) comprises a guide extending at least partially along the running path, a transporter (32) adapted to travel along the guide, a motor (28) connected to the transporter and/or the guide, and a clamp connected to the transporter. The clamp is movable and can be releasably attach with respect to the material web. An independent claim is also included for a method for threading a material web, comprising gripping a portion of the material web with a clamp; motivating the clamp and the portion of the material web at least partially along the running path using a linear motor, the linear motor including an electromagnetic rail and magnets (34); and transferring the portion of the material web to a delivery area.

Description

1. Technical field

The present invention relates to the production of a material web and, in particular, to a method and an apparatus for threading a material web.

2. Description of the related art

It is known to thread a material web into a machine for producing the material web during start-up and after a web break. For example, in a papermaking machine, a peel or lift nozzle (or a blow-off tube) can be used to peel an edge strip (or "tip") of the paper web made from, for example, a press roll or a drying cylinder. A transfer device or a so-called mini scraper can be used to transfer the edge strip to a subsequent section of the paper machine. Generally, in a first step, only the edge strip (or "tip") of the web is threaded into the machine, after which the edge strip is expanded to the full width of the web. In some cases, however, it is also possible to thread the full web width.

US Pat. No. 4,648,942 describes a paper machine with a pair of endless ropes which convey the tip from a receiving area (e.g. between a first and a second cylinder of a dryer group) to thread a paper web into the dryer group of the paper machine. US Pat. No. 5,987,777 discloses a "rope-less" threading method that uses multiple air jets to transfer the tip through at least a portion of a paper machine used. US Pat. No. 6,387,220 discloses a suction belt that can be used to transfer the tip over a distance.

The known methods mentioned above have been practiced more or less successfully. However, the operating speed of a modern paper making or processing machine increases in a range from 2000 to 2400 m / min. The known threading methods no longer function reliably and satisfactorily at these operating speeds.

According to a more recent development, US Pat. No. 6,425,513 describes a device for transferring a threading strip and / or a material web from a takeover area into a transfer area along a web travel path for producing and / or processing the web. The device contains a receiving device for moving the strip and / or the web along the web path through the machine at a conveying speed. Furthermore, the device contains at least one take-over unit for transferring the strip and / or the web from the take-over area into the transfer area with a displacement speed that is lower than the conveying speed. This device has the disadvantage that it is relatively complex.

There is a need in the art for a threading method and a threading device which: a) is suitable for modern paper production or processing machines and can be operated at high operating speeds and with all types of paper, b) an increased efficiency compared to known methods and is more reliable with a corresponding reduction in complexity, c) is designed to be relatively light and low Maintenance requirements are to be met and require fewer highly qualified operators and / or less qualified operators, and d) can be retrofitted into existing machines without significant modification of the modified machine.

SUMMARY OF THE INVENTION

The present invention provides a transport device with a clamp that is operated via a linear motor on a machine path to thread the tip and / or the web.

According to an embodiment thereof, the invention comprises a device for threading a material web along a running path, which comprises a linear motor with an electromagnetic rail, which extends at least partially along the running path, and a transport device, which is designed to move along the electromagnetic rail. The transport device contains at least one magnet. A clamp is connected to the transport device; the clamp is both movable and clampable with respect to the material web.

An advantage of the present invention is that it is suitable for modern paper making and processing machines and can be operated at high operating speeds and all types of paper.

Another advantage of the present invention is the increased efficiency and the increased reliability compared to known methods with a corresponding reduction in complexity.

Yet another advantage is a design that is relatively easy to use and requires little maintenance, less highly qualified Operators and / or less qualified operators required.

Another advantage of the present invention is that it can be retrofitted to existing machines without significant modification to the modified machine.

Yet another advantage is that the tip rail of the present invention has only a minimum number of moving elements, namely the conveyor and the clamp, which allows greater reliability.

Another advantage is that the electromagnetic rail of the present invention can be fixedly supported by the machine frames and can extend along multiple machine sections, the speed of travel of the conveyor being variable as it moves through the different machine sections according to the different machine speeds.

Another advantage is that conventional threading elements, for example ropes, rope sheaves, rope tensioning devices, air jets, vacuum belts, etc., are not required.

Another advantage of the present invention provides greater reliability in the threading process so that the machine downtime after a web break is reduced to a minimum.

BRIEF DESCRIPTION OF THE DRAWINGS

• Figur 1 eine schematische Seitenansicht eines Maschinenabschnitts mit einer Ausführungsform der Spitzenschiene der vorliegenden Erfindung;
• Figur 2 eine Querschnittsansicht des Systems nach Figur 1 entlang der Schnittlinie 2-2, die eine Ausführungsform der Spitzenschiene der vorliegenden Erfindung in einer ungeklemmten Position zeigt;
• Figur 3 eine Querschnittsansicht des Systems nach Figur 1 entlang der Schnittlinie 3-3, die eine Ausführungsform der Spitzenschiene der vorliegenden Erfindung in einer geklemmten Position zeigt;
• Figur 4 eine Seitenansicht des Systems nach Figur 2 mit Blickrichtung von Linie 4-4;
• Figur 5 eine Querschnittsansicht des Systems nach Figur 1 entlang der Schnittlinie 3-3, die eine alternative Ausführungsform der Spitzenschiene der vorliegenden Erfindung unter Verwendung von Abstoßungsmagnetisierung zur Schwebe- und/oder Antriebwirkung zeigt; und
• Figur 6 eine Querschnittsansicht des Systems nach Figur 1 entlang der Schnittlinie 3-3, die eine alternative Ausführungsform der Spitzenschiene der vorliegenden Erfindung unter Verwendung von Anziehungsmagnetisierung für Schwebe- und/oder Antriebswirkung zeigt.

The above and other features and advantages of this invention, as well as the manner in which they can be achieved, will be apparent from the following description of embodiments of the invention Connection with the accompanying drawings and become more understandable; in the drawings show:

• Figure 1 is a schematic side view of a machine section with an embodiment of the tip rail of the present invention;
• Figure 2 is a cross-sectional view of the system of Figure 1 along section line 2-2, showing one embodiment of the tip rail of the present invention in an unclamped position;
• Figure 3 is a cross-sectional view of the system of Figure 1 taken along section line 3-3, showing one embodiment of the tip rail of the present invention in a clamped position;
• Figure 4 is a side view of the system of Figure 2 looking from line 4-4;
• FIG. 5 is a cross-sectional view of the system of FIG. 1 along section line 3-3, showing an alternative embodiment of the tip rail of the present invention using repulsion magnetization for levitation and / or propulsion; and
• Figure 6 is a cross-sectional view of the system of Figure 1 taken along section line 3-3 showing an alternative embodiment of the tip rail of the present invention using attraction magnetization for levitation and / or propulsion.

Corresponding reference numerals show corresponding parts throughout the several views. The illustrations given herein represent a preferred embodiment of the invention in one form, and such illustrations are not intended to be taken as limit the scope of the invention in any way.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and particularly to Figure 1, there is shown an end group 10 of a papermaking machine which generally includes a last cylinder 12 of a dryer group, a gripping area 14, a calender 16, a web path 18, a roll 20 of the feed area 22 and a tip rail threading device 24 contains. The tip, the edge strip or the web 26 runs along the web path 18.

Although Figure 1 shows a particular embodiment of a paper making machine, the present invention is not limited to use with these machine elements. The threading device 24 can be used from a previous section to a subsequent section of a paper making machine. For example, the present invention can be used on a dryer group between a first and a second dryer cylinder, through the entire dryer group and / or from the last cylinders of a press section to the first cylinder of a dryer group, but is not limited to these application examples. The threading device 24 can be used with a machine to manufacture or process a web of material, the machine including at least one moving surface, such as a dryer fabric 68, for both conveying and defining a path of travel of the web of material. The at least one moving surface can be a band and / or a felt and / or a wire and / or a textile material and / or a cylinder and / or a roller. The web of material 26 can be a fibrous web in a papermaking machine. Generally can the present invention can be used where threading is appropriate with the aforementioned advantages over the prior art.

The threading device 24 includes a linear motor 28 with an electromagnetic rail 30 that extends along a portion of a web path 18. The linear motor 28 also contains a carriage or a transport device 32 with a magnet 34, which can be a permanent magnet or an electromagnet or a combination thereof. A clamp 36 is connected to the transport device 32.

Alternatively, the linear motor 28 can be a rotary motor, the electromagnetic rail 30 can be a guide or a tube connected to the rotary motor or a guide or a tube with a cable connected to the rotary motor and the transport device 32.

The electromagnetic rail 30 contains a plurality of electromagnets 38 (FIG. 2) which extend sequentially along the electromagnetic rail 30. Alternatively, the electromagnetic rail 30 may include multiple permanent magnets or a combination of electromagnets and permanent magnets. A plurality of supports 40 are connected to the electromagnetic rail 30 to define their path. The support 40 may be connected at one end to a suitable structure 42, which may be a machine frame, and at the other end to a rail bracket 46. The rail bracket 46 may be a continuous bracket or may include several straight and curved sections , The electromagnets 38 can be temporarily and sequentially energized, with the rate of sequential excitation extending to machine speed and beyond. The Electromagnetic rail 30 may be installed between the front of the rollers or cylinders of the machine on the drive side and / or the operator side of the machine. Furthermore, the threading device 24 may be installed in addition to an existing conventional threading device (not shown) if necessary.

The transport device 32 is designed for movement along the electromagnetic rail 30. The transport device 32 can contain a frame 48, to which wheels 50 are connected via axles 52, the wheels 50 interacting with at least one guide surface 51 of the electromagnetic rail 30. Some of the wheels 50 can be provided for safety and / or for support during a standstill. As an alternative to this, the transport device 32 can be guided by floating magnet pairs 54, as shown in FIG. 5 (repelling) or FIG. 6 (attracting), which can also be used for driving. The magnet 48 is connected to the frame 48. As the electromagnets 38 are temporarily and sequentially energized, they generate a driving force on the magnet 34 that results in a running speed that can range up to machine speed and beyond. The transport device 32 can be relatively small in the direction of the web path 18 (approx. 100 mm to 200 mm, but not limited to this area), or it can be divided into at least two sections (not shown), so that the transport device 32 is the curved parts of the can cross electromagnetic rail (for example, on the circumference of the rollers or cylinders).

The clamp 36 is supported by the transport device 32 and contains a fixed flexible clamping element 56 and a pivotable flexible clamping element 58, which together the tip, the edge strip or the web 26 during a threading process hold on between yourself. As an alternative to this, the clamp 36 at 56 can contain an adhesive strip, thanks to which the pivotable flexible clamping element 58 can be dispensed with. At least one elastic member 60 and a roller 62 cooperate and are for holding the tip, the edge strip or the web 26 with respect to the transport device 32 during a threading process, as shown in FIG. 3, or for holding the pivotable flexible clamping element 58 in an inoperative position, as shown in Figure 2, actuated. The pivotable flexible clamping element 58 rotates about the pivot 64. The clamp 36 is designed to grip the tip, the edge strip or the web 26 in the gripping area 14 and to feed the same to the feeding area 22, so that the transport device 32 carries the tip , the edge strip or the web 26 is transferred along the web path 18 from the gripping area 14 to the feed area 22. The transfer process can occur near or at machine speed and can range from 0 m / min to 2400 m / min and beyond. As shown in FIG. 4, when the transport device 32 enters the gripping area 14, the roller 62 engages with the stationary wedge 66, which swivels the pivotable flexible clamping element 58 into a clamped position, as shown in FIG. 3. An oppositely rotated stationary wedge (not shown) may be disposed in the feed area 22 to release the clamp 36 to the position shown in FIG. 2 and thereby release the tip, the edge strip or the web 26.

The clamp 36 can extend in the region of the width of the web 26. The fixed flexible clamping element 56 and a pivotable flexible clamping element 58 are thin and flexible clamping elements which are designed in such a way that they temporarily deform when a curved part of the electromagnetic rail 30 enters or leaves become. Clamp 36 may include a knife or a weakened edge (both not shown) to sever the tip, thereby forming a new beginning of the tip.

The threading device 24 is compatible with machine sections in which the tip, the edge strip or the web 26 is supported by a wire, a felt or a textile, such as a dryer fabric 68. A tip, edge strip, or web 26 that is clamped can be passed through a wire, felt, or textile nip, or a combination thereof, using the threading device 24.

The rate of sequential excitation of the electromagnetic rail 30 may be uniform or variable along the web path 18 as determined by the speed and position controls 70, which may control the sequential excitation of the electromagnetic rail 30. The variable speed may be useful when the electromagnetic rail 30 extends over two or more machine sections operating at different speeds, the electromagnetic rail 30 then spanning at least one interface (not shown) between the two machine sections.

The electromagnetic rail 30 may include a return section 72 which guides the transport device 32 from the feed region 22 to the gripping region 14, the electromagnetic rail 30 forming an endless loop, as shown in FIG. 1. The return section 72 can include a parking area 74 that can be deactivated, wherein at least one transport device 32 can be parked and waiting for the next threading process.

The threading device 24 can include a starting mechanism 76 that can be used to start a threading process. The starting mechanism 76 accelerates the transport device 32 and pushes the transport device 32 during the simultaneous sequential excitation of the electromagnetic rail 30 from the parking area 74 into an active part of the electromagnetic rail 30. The starting mechanism 76 can be actuated via spring load, compressed air actuation, hydraulic actuation and the like , A start control 77 may be used to operate the start mechanism 76.

The parking area 74 may include at least one bypass portion 78. At least one cleaning trolley 80 can be pushed from the bypass part 78 onto the electromagnetic rail 30 in order to clean it.

A threading device for threading a full-width web into a machine may include two electromagnetic rails 30, similar to that described above, one on each machine side and each electromagnetic rail 30 carrying a conveyor 32, also similar to that described above.

The linear motor 28 may be in the form of a linear induction motor, a synchronous linear motor, a Romag motor, a claw-pole motor, a homopolar inductor motor, an alternating-pole motor or a Traklec motor or the like. The operation can be based on three-phase alternating current, the phase change frequency determining the speed of the transport device 32. A variable frequency drive can be used to change the operating frequency.

As an alternative to this, the transport device 32 can have at least one electromagnet with or without a magnet 34 included, and the electromagnetic rail 30 may include at least one permanent magnet with or without an electromagnet. Therefore, just like the transport device 32, the electromagnetic rail 30 can either be excited or passive. Superconducting materials can be used in the linear motor 28.

Using the basic principles of electromagnetism, electromagnets or magnets in front of the transport device 32 and on the electromagnetic rail 30 are excited in such a way that they attract the transport device 32, while electromagnets or magnets in front of the transport device 32 and on the electromagnetic rail 30 are excited in such a way that they repel the transport device 32. As an alternative to this, the drive of the transport device 32 can function with attraction or repulsion force alone. Other excitation sequences are also possible based on the special shape of the linear motor 28.

In use, the threading device 24 grips the tip, the edge strip or the web 26 with the clamp 36 connected to the transport device 32, the transport device 32 having at least one magnet. The transport device 32 and a tip, an edge strip or a material web 26 move along the electromagnetic rail 30, which extends at least partially along the web path 18. The transport device 32 and the electromagnetic rail 30 comprise the linear motor 28. The tip, the edge strip or the material web 26 is transferred to the feed area 22. Both the gripping process and the transfer process may include engagement of the roller 62 with the stationary wedge 66. The transport device 32 can, if necessary, by the start mechanism 76 from the Parking area 74 can be started to quickly reach the machine speed. The drive of the transport device 32 with the tip 26 can include sequential excitation of the electromagnetic rail 30.

Although this invention has been described as having a preferred embodiment, the present invention may be further modified within the spirit and scope of this disclosure. Therefore, this application is intended to embrace any variations, uses, or adaptations of the invention using its general principles. Furthermore, this application is intended to encompass such deviations from the present disclosure which fall within known or common practice in the art to which this invention relates and which fall within the limits of the appended claims.

Claims (50)

Device for threading a web of material along a walkway, comprising: a guide extending at least partially along the walkway; a transport device designed to move along the guide; a motor connected to the transport device and / or the guide; and a clamp connected to the transport device, which is movably and releasably attachable with respect to the material web. Apparatus according to claim 1, wherein the motor is a linear motor, which contains both the guide as an electromagnetic rail and the transport device with at least one magnet. The apparatus of claim 2, wherein the web is a fibrous web in a papermaking machine. Apparatus according to claim 2, wherein the linear motor is a linear induction motor, a synchronous linear motor, a Romag motor, a claw pole motor, a homopolar inductor motor, an alternating pole motor or a Traklec motor. The device of claim 2, wherein the electromagnetic rail includes a plurality of electromagnets. Apparatus according to claim 2, wherein the electromagnetic rail contains a plurality of permanent magnets. Apparatus according to claim 2, wherein the electromagnetic rail forms an endless loop. Apparatus according to claim 2, wherein the electromagnetic rail includes a parking area for the transport device. The apparatus of claim 8, further comprising a starting mechanism in the parking area. Apparatus according to claim 2, wherein the electromagnetic rail includes a bypass portion for the transport device. The device of claim 2, further comprising a plurality of supports extending along the electromagnetic rail. The apparatus of claim 11, wherein the electromagnetic rail includes at least one rail support connected to the plurality of supports. Apparatus according to claim 12, wherein the transport device includes a transport device frame which is designed for movement along the rail support. Apparatus according to claim 12, wherein the transport device comprises a plurality of wheels connected to the transport device frame and designed to roll along the rail support. The apparatus of claim 13, wherein the transport frame and the rail support contain a plurality of pairs of levitation magnets. Apparatus according to claim 2, wherein the transport device contains at least one electromagnet. The device of claim 2, wherein the magnet is an electromagnet. Apparatus according to claim 2, wherein the clamp includes both a fixed flexible clamping element and a pivotable flexible clamping element. Apparatus according to claim 18, wherein the clamp includes a roller connected to the pivotable flexible clamping element and the transport device includes a transport device frame and an elastic member which is connected to the pivotable flexible clamping element and the transport device frame. 20. The apparatus of claim 19, further comprising at least one stationary wedge configured to engage the roller. The apparatus of claim 1, further comprising a cable connected to both the motor and the transport device. Apparatus according to claim 1, further comprising an adhesive strip connected to the transport device. Machine for producing a web of material, comprising: at least one moving surface for both conveying and defining a path of travel of the material web; a linear motor with an electromagnetic rail extending at least partially along the path; a transport device which is designed to move along the electromagnetic rail and contains at least one magnet; a clamp connected to the transport device, which is movably and releasably attachable with respect to the material web. The apparatus of claim 23, wherein the at least one moving surface is a tape and / or a felt and / or a wire and / or a textile and / or a cylinder and / or a roller. The apparatus of claim 23, wherein the machine is a papermaking machine and the web is a fibrous web. The machine of claim 23, wherein the linear motor is a linear induction motor, a synchronous linear motor, a Romag motor, a claw pole motor, a homopolar inductor motor, an alternating pole motor or a Traklec motor. The machine of claim 23, wherein the electromagnetic rail includes a plurality of electromagnets. The machine of claim 23, wherein the electromagnetic rail includes a plurality of permanent magnets. The machine of claim 23, wherein the electromagnetic rail forms an endless loop. The machine of claim 23, wherein the electromagnetic rail includes a parking area for the transportation device. The machine of claim 30, further comprising a starting mechanism in the parking area. The machine of claim 23, wherein the electromagnetic rail includes a bypass portion for the conveyor. The machine of claim 23, further comprising a plurality of supports extending along the electromagnetic rail. 34. The machine of claim 33, wherein the electromagnetic rail includes at least one rail support connected to the plurality of supports. 35. The machine of claim 34, wherein the conveyor includes a conveyor frame adapted to move along the rail support. 36. The machine of claim 35, wherein the conveyor includes a plurality of wheels connected to the conveyor frame and configured to roll along the rail support. 36. The machine of claim 35, wherein the transport frame and the rail support include a plurality of floating magnet pairs. The machine of claim 23, wherein the transport device includes at least one electromagnet. The machine of claim 23, wherein the magnet is an electromagnet. The machine of claim 23, wherein the clamp includes both a fixed flexible clamp and a pivotable flexible clamp. 41. The machine of claim 40, wherein the clamp includes a roller connected to the pivotable flexible clamp and the transporter includes a conveyor frame and an elastic member connected to the pivotable flexible clamp and conveyor frame. 42. The machine of claim 41, further comprising at least one stationary wedge configured to engage the roller. The machine of claim 23, further comprising an adhesive strip connected to the transport device. Method for threading a material web, in which: grips part of the material web with a clamp; drives the clamp and the portion of the web of material at least partially along the path of travel using a linear motor, the linear motor including an electromagnetic rail and at least one magnet; and transferred the part of the material web to a feed area. 45. The method of claim 44, wherein the portion of the web is a tip, an edge strip, or the web. The method of claim 44, wherein the web is a fibrous web in a papermaking machine. The method of claim 44, wherein in both the gripping and transferring steps, a roller of the transport device is engaged with a stationary wedge. The method of claim 44, further comprising starting the transport prior to the gripping step. The method of claim 44, wherein the driving step sequentially energizes the electromagnetic rail. The method of claim 44, wherein in the gripping step, an adhesive strip grips the web of material.

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