FI121630B - Arrangement and method of tip drawing in a fiber web machine - Google Patents

Description

ORGANIZATION AND METHOD FOR FIXING BY FIBER MACHINE

The invention relates to an arrangement for threading with a fiber web machine comprising one or more rope nips formed by a threading rope for feeding a threading strap between the threading ropes and a threading means for feeding a threading strap to the rope nip. The invention also relates to a method of threading a fiber web machine.

Further, at least some of the web threads utilize fiber web machines for threading ropes. Such parts include, for example, unsupported clearances. In successful threading, the threading strap is first fed to a rope nipple where the threading ropes are closed and the threading strap is trapped between the threading ropes 15. The threading ropes travel at the speed of the fiber web machine and pass the thread web through the fiber web machine to the next holding point, such as a roll nipple. Typically, a threading strap is fed between the threading ropes by a suitable export device a few meters. 20 arrangements for threading are disclosed, for example, in European Patent 1431454.

However, there are problems with the cable entries. When the threading device enters the threading strap into the rope nipple, 25 tails are initially formed, mainly due to airflows and air resistances, which passes the rope nip. Depending on the case, the double tail can be up to five to ten meters in length. As the head tapping progresses, the double tail may catch on actuators, frame structures, δ cm in the forming machine.

TJs or other protrusions. As the double tail engages, it pulls the actual tether between the tether ropes Ee, which interferes with the tapping. The threading strap can drop even Q_ ____ off the threading ropes completely. The same problem occurs without the actual attachment of the sl-J double tail to any solid, since the air resistance tends to retard the double-tail speed. Even then,

CM

35 double tails pull the tail strap off the tail ropes. When the actual strap is shortened short enough, such as, for example, to one third of the required length, the strap 2 is no longer trapped between the strands, but drips between the strands, whereby the stroke fails.

The object of the invention is to provide a novel arrangement for the export of the head 5 of a fiber web machine, which is simple in design and which avoids the problems caused by the double tail before. Another object of the invention is to provide a novel method of threading a fiber web machine that is clear and reliable. Characteristic features of the arrangement of the present invention are that the arrangement comprises cutting means adapted to cut the threading strap when it is in the rope nip. Correspondingly, the feature of the method according to the invention is that when the strap is in the rope nip, the strap is cut off and the strap is further fed to the rope in question. The arrangement is secure and easy to fit into various positions to ensure the success of the threading. The construction of the arrangement can be selected according to the particular need. The method can be widely applied to various fiber web machines without the need for major modifications. The end result is a much higher probability of successful hair removal.

The invention will now be described in detail with reference to the accompanying drawings illustrating some embodiments of the invention, wherein o δ C 1, Figure 1 is a plan view of the arrangement according to the invention, viewed from above,

(M

Fig. 2 shows a side view of the arrangement according to the invention fitted in the position of Fig. 1, Fig. 3 shows another embodiment of the arrangement according to the invention as shown in Fig. 2,

CD

Figure 4 shows a third embodiment of the arrangement according to the invention as shown in Figure 2.

35 3

Figure 1 shows in principle an arrangement according to the invention for threading a fiber web machine. Fiber web machines are, for example, paper and board machines, where production is started by means of a threading tape. 5 In practice, the threading strap is passed through a fiber web machine and spread into a web. Figure 1 shows only one position of a fiber web machine in which the arrangement according to the invention is realized. There may be several similar positions in a fiber web machine.

The fiber web machine comprises one or more rope nips 12 formed by the threading ropes 10 and 11 for feeding the threading strap 13 between the threading ropes 10 and 11. The tail ropes are endless and are supported by loops on a plurality of rope wheels, only a portion of which is shown in Figures 2-4. The rope sheaves are generally described by reference numeral 14. In the figures, the first rope rope 10 comes from the upper bevel with the second rope rope 11 coming down. The tensioning ropes 10 and 11 meet with the paper guide roll 15, thereby forming a rope nip 12. The rope nose 10 and 11 pass through the same 20 paths to the next paper guide roll 16. The rope guide may be several tens of meters long and the tension ropes can form very diverse paths. Typically, the threading ropes are offset from the actual web path, which allows the web to pass despite the threading ropes 25. The rope nipple may also be formed on the rope pulley. o δ, The fiber web machine also includes a threading means 17 for feeding the tension tape 13 into the rope nip 12. In the figures,

(M

The lines consist of a vacuum conveyor belt, although x 30 other suitable devices may be used. According to the invention, the arrangement comprises cutting means 18 adapted to S cut off the threading strap 13 when it is in the rope nip 12

CD

o (Figure 2). Cutting can be avoided before double tail 19

CVJ

problems easily and simply. Fig. 1 35 shows the situation just after the cut-off strap 13 where the formed double tail 19 has turned sideways.

4 The cutting of the threading strap in the rope nip 12, and thus also between the threading ropes 10 and 11, allows the double tail 19 to fall while the actual threading strap 13 continues to travel unimpeded by the threading ropes. Similarly, in Method 5, the rope nipples are each alternately fed with a threading strap 13 in the threading, according to the invention.

According to the invention, the cutting means 18 are arranged in the immediate vicinity of the rope nip 12. In other words, an attempt is made to break the double tail as early as possible in order to avoid the adverse effects of the double tail. Cutting is safe when the threading strap is in the rope nip and thus pulled by the rope outlet. In the embodiment of Figure 2, the threading strap 13 is cut after the rope nip 12 by a mechanical shear 20. This shear 20 has a pendulum arm having a counter blade 22 corresponding to the blade 21 arranged in the body of the shear 20. The cutting device is supported on the fibrous web machine frame structures (not shown). Other types of rotating or moving blades are also possible.

Fig. 3 illustrates a situation in which the threading strap 13 is cut before the rope nip 12. Again, the threading strap V has already been in the rope nip, whereby the threading strap is tightened when it is cut off. Regardless of the cut, the threading strap goes directly x x 30 straight to the rope nipple after cutting, thereby avoiding the formation of a double tail. Here,

'sT

the cutting means 18 is arranged as a medium-cutting o cutting device 20. For thinner web grades,

(M

just air blowing. Water or other suitable fluid 35 may also be used to ensure cutting.

5

In the embodiment of Figure 3, the cutting means 18 is supported on the threading means 17, which simplifies the construction. At the same time, the cutting means are precisely aligned with the passage of the headband. A third embodiment is shown in Figure 4, in which the threading strap 5 13 is cut by cutting against the belt conveyor. This avoids any possible rise of the headband. Regardless of the structure and placement of the solution means, cutting the threading strap is a quick process as the strap strap is constantly moving. The time of cleavage can be determined manually, but preferably the cleavage is fitted as part of the threading sequence, with a predetermined time between the start of the threading and the cleavage.

The length of time to feed the main export tape depends on many things. In post-rope nip trimming prior to trimming, the main tensioning strap is fed to the rope nip 12 until the tensioning strap 13 is simply between the tensioning ropes. In this case, the threading strap will surely continue its journey with the cable entry after cutting off the double tail. If the cut-off point is before the rope nip, the 20 threading straps will be cut when the double-tail portion has passed the cut-off device. Preferably, in addition, it is expected that the cutting device is provided with a clean, intact headband. After cutting, the main strap is fed to the rope nip 12 as long as before the cut, thereby securing a sufficient number of 25 strands between the ropes. Thanks to the double tail cut 2, the tassel ropes have a clean, clean tongue strap, a tin rib whose head remains on the tier ropes without the detrimental effects of the dual tail T.

(M

x cc

CL

I '

lO

I'm not

(M

Claims (10)

An arrangement for tip pulling in a fiber web machine, which comprises one or more rope nips (10, 11) formed from rope nip (12), which are intended to feed the tip pulling band (13) between the tip pulling ropes (10, 11), and tip pulling devices ( 17) for feeding the tip pull band (13) to the rope nip (12), characterized in that the arrangement comprises cutting tools (18), which are arranged to cut the tip pulling band (13) or when it is in the rope nip (12). Arrangement according to claim 1, characterized in that the cutting tools (18) are arranged in immediate connection to the rope nip (12). 15 Arrangement according to claim 1 or 2, characterized in that the cutting tools (18) are supported on the tip pulling devices (17). 4. Arrangement according to any of claims 1-3, characterized in that the cutting tool (18) has been arranged as a mechanical cutting device (20). 5. Arrangement according to any of claims 1-4, characterized in that the cutting tools (18) are arranged as a cutting device (20) which utilizes a medium. (M A method of tip pulling in a fiber web machine, which comprises one or more of the tip drawing ropes (10, 11) formed x 30 rope nip (12), to which each alternately at the tip drawing, a tip drawing tape (13) is measured. , characterized in that, when the lo-tip belt (13) is in the rope nip (12), the tip-pull belt (13) and the tip-pull belt (13) are still fed to the rope nip (12). 35 7. A method according to claim 6, characterized in that the tip-pull band (13) is cut after the rope nip (12). Method according to claim 6, characterized in that the tip-pull band (13) is cut before the rope nip (12). Method according to any of claims 6-9, characterized in that before the cutting, the tip-pull band (13) is measured at the rope nip (12) until the tip-pull band (13) runs in a layer between the tip-pull rope (10, 11). Method according to any of claims 6-9, characterized in that, after cutting, the tip pull band is measured at the rope nip (12) for as long as before cutting. o δ CVJ CM X cc CL 1 ^ sfr sfr LO 05 O O CM