US3727818A

US3727818A - Apparatus for guiding webs in an extended condition

Info

Publication number: US3727818A
Application number: US00164585A
Authority: US
Inventors: W Probst
Original assignee: MASHINENFAB BENNINGER AG
Current assignee: MASHINENFAB BENNINGER AG
Priority date: 1970-07-31
Filing date: 1971-07-21
Publication date: 1973-04-17
Anticipated expiration: 1990-04-17
Also published as: FR2099413A5; BR7104879D0; JPS5325060B1; GB1348673A; CH518864A

Abstract

An apparatus for simultaneously guiding a number of webs, especially textile webs, in an expanded condition adjacent one another, comprising common drive means for the webs, and movable tension regulating rolls arranged between said common drive means. The tension regulating rolls impart a predetermined tension to the webs traveling thereover, and such tension regulating rolls are mounted to be movable so as to deflect or travel out of a reference position as a function of web elongation or contraction in order to correct the speed of the associated drive means. These tension regulating rolls extend over the entire width of the apparatus and are each individually associated with a given separate web for taking up the elongation or contraction of such associated web.

Description

[451 Apr. 117, i973 United States Patent 1 Probst I APPARATUS FOR GUIDING WEBS IN AN EXTENDED CONDITION 3,084,8Hl 4/l963 [75] lnventor: Willi Probst, Uzwil, Switzerland Primary Exammer Rlchard Schacher Attorney-Werner W. Kleeman [73] Assignee: Mashinenfabrik Benninger A.G., Uzwil, Switzerland July 21, 1971 ABSTRACT An apparatus for simultaneously guiding a num webs, especially textile webs, in an expan ber of ded condi- [22] Filed:

Appl' tion adjacent one another, comprising common drive means for the webs, and movable tension regulating rolls arranged between said common drive means. The

tension regulating rolls impart a predetermined tension to the webs traveling thereover, and such tension regulating rolls are mounted to be movable so [30] Foreign Application Priority Data as to deflect or travel out of a reference position as a function of web elongation or contraction in order to cor- O 7 wm I/ w on 5 2 l. 2 m ,6 MB u 6 v 2" m L d n u a .u n "u e u" m mm w m S Um 0 mm 7 9 U" LL 3 C I SL n Um NH 55 Fi ld of S h rect the speed of the associated drive means. These tension regulating rolls extend over the entire width of r the apparatus and are each individually associated the elongation 56] References Cited with a given separate web for taking up or contraction of such associated web.

5 Claims, 2 Drawing Figures UNITED STATES PATENTS l,79l,450 2/1931 Kellogg.......................... 226/109 X PATENTEI] APR 1 H973 SHEET 1 [IF 2 PATENTEDAPR I 11913 3'. 727. 818

SHEET 2 0F 2 APPARATUS FOR GUIDING WEBS IN AN EXTENDED CONDITION BACKGROUND OF THE INVENTION The present invention'relates to a new and improved apparatus for simultaneously guiding a number of webs, especially textile webs, in an expanded or ex tended condition adjacent one another.

In installations for the continuous handling of webs, I

, the successive treatment locations, into synchronism by means of tension regulators. In other words, it is desired to compensate at the treatment locations or stations all possible elongations or contractions of the web so that the goods are always subjected to a tension which is as uniform as possible during such time as .these goods pass through the installation. As a general rule there are mostly employed rollers for such tension regulation, for instance pendulum rollers, dancer rollers or compensation rollers which are preferably arranged directly after each drive location for the textile web. By means of such tension regulating rollers, on the one hand there is achieved or maintained a certain desired web tension by, for instance, pneumatically or hydraulically impinging the goods traveling over such rolls generally at the region of the relevant tension regulator rolls. On the other hand, through the action of a preferably electrical control and as a function of the deviation or deflection of the tension regulator rolls owing to elongation or contraction of the web between the preceding and the next successive drive mechanism there is undertaken at the drive mechanism associated with the tension regulator rolls a correction of the speed of movement or velocity of the goods.

I These known installations generally operate completely satisfactorily as long as they only work with a single web. But it is however oftentimes desired, whether such be because of the desirability of reducing the investment costs or enlarging the capacity of the equipment, to simultaneously guide through the installation a number of parallelly arranged webs in an extended or spread apart condition, that is, to be able to treat during a single pass through the equipment two or more webs simultaneously. This is only possible in a very limited way with the heretofore known state-ofthe-art installations and then only if additional operating personnel are employed since a continuous monitoring of the installation during its operation is required. A considerable limitation of this possibility is already present by virtue of the fact that only such webs can be simultaneously moved through the installation which possess as nearly identical quality to one another as possible, have been subjected to a similar pre-treatmerit and have been introduced in exactly the same fashion into the installation. An exact and uninterrupted monitoring of the installation is necessary because each tension regulator roll between successive drive mechanisms only always monitors a single web of the f webs which simultaneously pass thereover. Since, already independently of different elongation or contraction of simultaneously treated webs, it is practically not possible that all simultaneously moving webs possess exactly the same length between successive drive mechanisms, each tension regulating roll automatically can only regulate the tension of that web which at the section monitored by such roll is the shortest between two drive mechanisms, and similarly the velocity of the associated drive mechanism is only always controlled, owing to the deflection of the tension regulating roll, as a function of the elongation or contraction of the mo- 0 mentarily shortest web.

As a result the web or webs which simultaneously travel through the installation are subjected to a lower tension than the momentarily shortest web.-l-Iowever, what then becomes a particularly appreciable drawback is that possible simultaneous elongations of the remaining webs are not corrected at all. Hence in these remaining webs folds can appear, these webs can laterally deviate, in fact there can even occur at the treatment location, for instance at a treatment bath, an accumulation of the material or goods so that such can wind about the rollers, resulting in web rupture or damage to the equipment.

Although additionally in the case of passage of a single web through the known installations, and by means of a terminal switch associated with each tension regulating roll it is possible to immediately shutdown the installation during rupture of the web and, the thus triggered maximum deflection of the tension regulating roll, when passing a number of webs through such installation this so-called presence control is ineffectual, and therefore itis possible that one of the webs which is simultaneously guided through the installation can rupture without being noticed and cause considerable damage to the equipment and/or fabric.

Furthermore, installations are already also known to the art whichhave been especially designed so as to only permit operation with a number of expanded webs which are simultaneously passed in juxtaposition through the equipment. Nonetheless these prior art installations are in reality nothing more than two or a number of parallel installations which are arranged adjacent one another, corresponding in number to the number of webs, and wherein each such parallel adjacently arranged installation serves to process a single web and is equipped with an appropriate number of driveand regulating devices, but there being provided common treatment locations, for instance, bath vats and the like, for all of the webs. It should be readily apparent that such installation is very uneconomical if it is called upon to treat only a single web.

As already mentioned the passage from time to time of a plurality of webs through the installation is preferably then desired if, instead of working with webs having width for which the relevant installation has been designed, it is desired to treat webs which only possess a fraction of this width, for instance one-half, one-third or one-quarter of such width. Hence, if a multiplicity of such webs can be simultaneously passed through the equipment then this equipment can be utilized much more effectively. However with the last mentioned installations or equipment for the passage of a plurality or multiplicity of webs therethrough it is still, however, not possible, instead of for instance guiding two webs through the equipment, to only guide a single web therethrough which has twice the width.

SUMMARY OF THE INVENTION Accordingly, from what has been explained above it will be apparent that a real need still exists in the textile treating art for apparatus constructions which are capable of simultaneously guiding a number of webs in an extended or spread apart condition adjacent one another through such apparatus without experiencing the above drawbacks and limitations existent with the heretofore proposed hardware. Hence it is a primary objective of this invention to provide a novel construction of apparatus which effectively and reliably fulfills the existing need in the art and which for the most part overcomes or substantially minimizes at least the more significant drawbacks of the heretofore known state-ofthe-art equipment.

Another and more specific object of this invention relates to an improved construction of apparatus of the heretofore mentioned type which, while preventing the above-explained drawbacks and dangers of the prior art installations, is capable of equally handling single webs possessing a web width making full use of the entire width of the installation as well as multiple webs which otherwise only would make use of part of the width of the installation.

Therefore, from what has been stated with respect to the preceding objects it will be recognized that a further objective of this invention is to extend the economies and capabilities of web treating equipment of the character discussed above.

Now, in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the invention contemplates the provision of a new and improved apparatus for simultaneously guiding a number of webs, especially textile webs, in an extended or spread apart condition adjacent one another, and is of the type incorporating a number of successive drive mechanisms which are common to the webs and having arranged therebetween movable tension regulator or regulating rolls by means of which the goods passing over such rolls can be subjected to a predetermined tension. Furthermore, the deviation of such rolls from a reference position, owing to web elongation or contraction, can be effectively utilized for correcting the speed of the associated drive mechanism. According to important aspects of this invention individual tension regulating rollers associated with a respective individual web and extending over the entire width of the apparatus are arranged between each two successive drive mechanisms which are common for all of the webs, and wherein such individual tension regulating rollers serve to take-up elongations or contractions of such relevant web.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

FIG. 1 is a schematic elevational view of a preferred embodiment of inventive apparatus for the simultaneous continuous treatment of two textile webs in an extended or spread apart condition during three successive treatment stages; and

FIG. 2 is a schematic section of the equipment of FIG. 1 showing a variant form of the invention rendering possible automation of the control operation with respect to the web tension.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Describing now the drawings, and referring initially to FIG. 1 it will be understood that two textile webs have been designated by reference characters B1 and B2. These textile webs B1 and B2 are payed-off in an expanded or spread-out condition from any suitable non-illustrated winding rolls such as to move in the direction of the arrows to be guided through the illustrated installation for treatment purposes. Upon leaving the installation these webs are again wound-up by other suitable and thus non-illustrated winding devices. The details of the winding mechanism for paying-off and for winding-up the textile webs is not important to the concepts of this development and therefore has only been mentioned in the overall context of the environment of use of the installation. Now during its path of movement through the depicted installation the webs B1 and B2 which are in extended condition move continuously adjacent one another and successively pass through three treatment stages or locations 1, 2 and 3. Although as a matter of convenience there have been only shown three treatment stages it would obviously be possible to provide for a greater or even a lesser number of such treatment operations.

Now it will be understood that in front of the first, after the last, and in each case between the individual treatment stages 1, 2 and 3 there are arranged drive mechanisms for the transport of the webs B1 and B2. As a matter of convenience in illustration the drive mechanisms have been shown merely located between the first treatment stage 1 and the second treatment stage 2 and between the second treatment stage 2 and the third treatment stage 3, and in each case such respective drive mechanisms have been depicted in FIG. 1 in each instance by the driven respective pairs of squeeze rolls or rollers 4, 5. The drive of these squeeze roll pairs 4, 5 occurs separately for each such pair and can be carried out through the use of any suitable prime mover, typically a direct-current motor, which has not been particularly shown herein, and the speed of which can be regulated by a potentiometer 6. Now between successive drive mechanisms 4, 5 the webs Bl B2, are further guided over the expander rolls 7, the deflecting rolls 8 and, at the treatment stages, over the guide rolls 9. On the other hand, between the rolls 7 and 8 each of both webs B1 and B2 are separately and independently guided over a respective dancer roller or roll, such as the dancer roll 10 for the web B1 and the dancer roll 11 for the web B2. These dancer rolls 10, 11 each extend over the complete width of the installation. These rolls l0 and 11 are arranged in the lengthwise direction of the depicted installation, in other words are arranged behind one another in the throughpassage direction of the webs B1, B2 and each such roll, independently of the other roll, is conveniently displaceably mounted in any suitable fashion at, for instance vertical guide elements or the like.

Now at each

dancer roller

10 and 11 there engages therewith a

leverbar arrangement

12, 13, 14, by means of which each such dancer roll 10, 11 can be acted upon via the piston and the piston rod 16 of an associated pneumatic pressure cylinder 17. The impingement of each dancer roller or roll can be separately regulated through the agency of a pressure reduction valve 18, the adjusted pressure then can be read-off at a monometer 19. All of the pressure reduction valves 18 are connected at the side facing away from the associated cylinders 17 with a common pressure source through the agency of a conduit or line 20, as schematically illustrated at the lower left hand portion of F IG. 1.

Now at the pivot point 21 of the

angle lever

13, 14 of the

lever bar arrangement

12, 13, 14 provided for the dancer roll 10 of the web B1, in other words only at such and not also at the corresponding pivot point or pin of the

other leverbar arrangement

12, 13, 14 of the dancer roll 11 for the web B2, there is rigidly connected for rotation a gear or tooth segment 22. This tooth segment 22 meshes with a pinion 23 so that rotation of this pinion 23 in turn causes an appropriate adjustment of the potentiometer 6.

Having now had the benefit of the foregoing description of the exemplary embodiment of inventive installation or apparatus its. mode of operation is as follows: two fabric webs B1 and B2 which are to be simultaneously treated and the respective width of which corresponds, for instance, to approximately one-half of the width of the installation are guided over all of the rollers of the installation and introduced into the latter, with the exception that these webs are not both guided over the same dancer rollers or rolls 10, ll. Quite to the'contrary, each one of both webs is guided over one such dancer roll 10, 11. Now with the aid of the pressure reduction valves 18 it is possible to adjust the impingement of'each individual dancer roll 10, 11 to a value which corresponds, for each individual web between successive squeeze roll pairs 4, 5, to a certain desired fabric or web tension at least at the region of the dancer rolls l0, 1 1.

If for the time being the web B2 is not taken into consideration, then, insofar as the web B1 is concerned the same mode of operation prevails as is the case for the previously known installations. Thus, for instance, if at the treatment location or stage 2 there occurs an elongation of the web Bl then the dancer roll 10 moves upwardly at its guide arrangement until the drop in the fabric tension, owing to such fabric or web elongation, is again compensated. On account of this deviation or deflection of the dancer roll out of its reference position the' gear or tooth segment 22 is pivoted through the action of the leverbar or lever arrangement l2, l3, l4 and via the pivot pin 21 and therefore the potentiometer 6 is appropriately adjusted. Adjustment of the potentiometer 6 accordingly influences the drive motor of the associated pair of squeeze rolls 4, 5 in such a way that the speed of travel or conveying of the web B1 to the treatment stage 2 is reduced until synchronism has again been established. On the other hand, should the web B1 at the treatment stage 2 experience, for in stance, a shortening owing to contraction, then, in accordance with the thus resulting deviation or deflection of the dancer roll the speed of movement of the leading drive mechanism is increased until synchronism is again established.

However, as already previously explained, if the web B2 is not taken into account such could elongate or v thisis effectively prevented in that, the web B2 is separately guided over the dancer roll 11 which is only operatively associated with such web. Any deflections or deviations of the dancer roll 11, owing to possible elongation or contraction of the web B2, while not bringing about any changes in the speed of the leading drive mechanism as such was the case for the deflection of the dancer roll 10 as discussed above, still the pneumatic impingement of the dancer roll 11 via the pressure cylinder 17 associated therewith and regulated by the corresponding pressure regulating valve 19 nonetheless also subjects the web B2 at any instance of time and independent of the momentary tension of the web B1 to a predetermined uniform tension. Even though any shortening or elongation of the web B2 is only taken-up by the deflection of the dancer roll 11 upwardly or downwardly, as the case may be, still such is sufficient for the majority of situations which are encountered since the length differences of both webs B1 and B2, within a section between two drive mechanisms, is hardly ever so large that the freedom of deflection of the dancer roll is not sufficient for taking up such difference. If notwithstanding the above such should not at any time be the case, or should the web B2 rupture, then, the lower and upper terminal switches 24 and 25, respectively, at the ends of the maximum deflection path of the dancer roll 11 ensure for the immediate placing out of operation or putting into standstill the installation as soon as this dancer roll has moved to a maximum degree of deflection. Such terminal switches 24 and 25 are also provided for the dancer roll 10. By virtue of the provision of these terminal switches, both for the web Bl as well as also for the web B2, there is provided a continuous presence control, through the action of which the entire installation can immediately be shutdown in the event that one or the other web tears or markedly elongates or contracts.

Now in order to warn the operator of the installation and to perhaps give him the possibility, upon occurrence of the last-mentioned situation, through carrying out a control correction to again regulate the course of travel of the web prior to shutdown of the installation it would be possible to construct and design the terminal switches 24 and 25 in such a fashion that prior to reaching the terminal position of the relevant dancer roll and, therefore, prior to triggering of the stop com mand, the installation produces an optical or acoustical warning signal. By changing the adjustment of the pressure reduction valve 18 in the sense of a different impingement of both dancer rolls 10, 11 associated with a drive mechanism it is possible, in a great number of cases, to correct a displacement of the dancer roll 11 towards one terminal position brought about by virtue of a relative lengthening or shortening of the web B2 with respect to the web Bl, that is, to again bring back this dancer roll 11 during operation of the installation into its central or neutral position.

The variant construction of the invention as depicted in FIG. 2 illustrates the manner in which such a control can be automated, wherein in FIG. 2 there have been incorporated therein those components of FIG. 1 which are believed necessary for a complete understanding of what is involved. Further, it will be understood that in FIG. 2 the same reference characters have been employed for the same or analogous components appearing in the system of FIG. 1. Thus, it will be understood that both dancer rolls l and 11 operate in the same manner as described in conjunction with the installation of FIG. 1 and, in particular, here also the control or regulation takes place through the action of the potentiometer 6 in the same manner as previously considered in conjunction with the description of FIG. 1. However, with the arrangement of FIG. 2 there is additionally provided a balance beam or lever 26 pivotably mounted at one end at the shaft of the dancer roll 10 and at its other end exhibits a bifurcated or forked portion 11a which straddles the shaft of the dancer roll 11. An arm member 27 is hingendly connected between both ends of the balance lever 26, arm member 27 in turn being pivotably connected with a further arm member 28. This arm member 28 is pivotably mounted at its end, in other words at location 29, which is opposite the arm member 27 and at that location has rigidly connected for rotation therewith an actuation lever 30 for actuating two

pressure reduction valves

31 and 32.

If, for instance, during operation of a thus equipped installation the web guided over the dancer roller or roll 11 becomes longer than the web guided over the dancer roller 10 at the relevant treatment stage, then, the dancer roll 11 is upwardly displaced in its vertical guide in accordance with the relaxed fabric tension. Hence there is produced a difference in the positional level between both rolls l0 and 11 and as a consequence thereof a pivoting or rocking of the balance lever 26 about the axis of the roll 10 in an upward direction to assume an inclined position. Consequently, the arms or

arm members

27 and 28 are upwardly pulled and the arm member 28 rocks in counter clockwise direction about its pivot point 29. This pivotal movement is made use of in order to actuate both of the

pressure reduction valves

31 and 32 via the thus entrained rocking movement of the actuation lever 30, in such a manner that the pressure reduction valve 31 is opened to a greater extent and the pressure reduction valve 32 is somewhat closed. Consequently, by means of the slide 33 the base adjustment of the reduction valve 18 is changed in the sense that now both pressure cylinders 17 and pistons are differently impinged, and in the selected example under consideration the piston 15 associated with the dancer roll 10 is more strongly impinged with pressurized fluid medium and the piston 15 associated with the other dancer roll II is more weakly impinged than otherwise would correspond to the base position where both piston members 15 are equally impinged with the pressurized medium.

The thus resulting unequal impingement or action exerted upon the dancer rolls l0 and 11 has the result that both again tend to adjust themselves to the same level where the balance beam 26 again assumes its original position. With this readjustment of both dancer rolls 10, 1] simultaneously producing a positional dis placement of the dancer roll 10 then, as already explained in conjunction with the embodiment of FIG. 1, the therein described electrical control operation takes place through the agency of the potentiometer 6.

The arrangement of FIG. 2 does not require any personnel for monitoring the momentary position of the dancer rolls since both, after deflecting owing to elongation or contraction of the webs traveling over such rolls, tend to always again oscillate back into their central position, whereas during rupture of one of the webs the entire installation is immediately brought to stand still through the action of the thus responding

terminal switch

24 or 25.

Viewed in its functional aspects, with the described installation, the web Bl traveling over the dancer roll 10 always forms the control web which controls the entire synchronism of the installation. On the other hand the other web B2 is a pure follower web which, however, can be continuously controlled as to its presence" in the simplest and most reliable manner, and receives a predetermined web tension which can differ from that of the control or regulating web so that within certain limits the nature of the fabric of both webs can be different. In any case loosening of the follower web is prevented.

As should be readily apparent the described installation can also be operated in a manner where only a single web is passed therethrough, whereby then of course the single web is guided over the dancer rolls 10 whereas the remaining dancer rolls 11 are not utilized.

On the other hand, however, by increasing the number of dancer rolls associated with each section between two drive mechanisms by further corresponding rolls constructed as dancer rolls 11 it is possible to design the equipment so that it also can simultaneously guide therethrough more than two webs, whereby then the web which is guided over the dancer rolls 10 constitutes the control or regulating web and all of the webs guided over the dancer rolls l1 constitute the follower webs.

Finally, it is mentioned that in analogous manner it would be possible to utilize pendulum rolls instead of dancer rolls without departing from the basic concepts and teachings of this development.

While there is shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims. AC- CORDINGLY,

What is claimed is:

I. An apparatus for simultaneously guiding a number of webs, especially textile webs, in an expanded condition adjacent one another, comprising drive means common to all of the webs, tension regulating rolls movably arranged between said common drive means, said tension regulating rolls each imparting a predetermined tension to the web traveling thereover, said tension regulating rolls being mounted to be movable so as to deflect out of a reference position as a function of web elongation or contraction in order to correct the speed of the associated drive means, said tension regulating rolls extending over the entire width of the apparatus and each being individually associated with a given separate web for taking up the elongation or contraction of such associated web.

2. The apparatus as defined in claim 1, wherein said tension regulating rollers comprise dancer rolls which can be acted upon independently of one another in the sense of producing a predetermined web tension in the associated web guided by each such dancer roll and which by virtue of their range of deflection can take-up possible length differences of the webs with respect to one another.

3. The apparatus as defined in claim 1, further including a control mechanism operatively connected with only one of the available tension regulating rolls, and upon deflection of such movable tension regulating roll out of its reference position said control mechanism varies the operating speed of the associated drive means until such tension regulating roll again assumes its reference position.

4. The apparatus as defined in claim 1, wherein each tension regulating roll is movable through a given range of deflection into a given terminal position, means arranged at the ends of said deflection range of each tension regulating roll capable of releasing a warning signal prior to reaching such terminal position and upon such roll reaching such terminal position interrupting the driving action of all said drive means.

5. Apparatus for simultaneously guiding a number of webs, especially textile webs, in an expanded condition adjacent one another, comprising drive means common to all of the webs, tension regulating rolls movably arranged between said common drive means, said tension regulating rolls each imparting a predetermined tension to the web traveling thereover, said tension regulating rolls being mounted to be movable so as to deflect out of a reference position as a function of web elongation or contraction in order to correct the speed of the associated drive means, said tension regulating rolls extending over the entire width of the apparatus and each being individually associated with a given separate web for taking up the elongation or contraction of such associated web, a control mechanism operatively connected with only one of the available tension regulating rolls, and upon deflection of such movable tension regulating roll out of its reference position said control mechanism varies the operating speed of the associated drive means until such tension regulating roll again as sumes its reference position, pivotal balance beam means for interconnecting two adjacently situated tension regulating rolls with one another, said balance beam means being pivoted owing to a positional change of the other of said tension regulating rolls relative to said one tension regulating roll connected with said control mechanism and thereby changing the action to which the individual tension regulating rolls are subjected for such length of time until both said tension regulating rolls have again assumed their original relative position with respect to one another.

Claims

1. An apparatus for simultaneously guiding a number of webs, especially textile webs, in an expanded condition adjacent one another, comprising drive means common to all of the webs, tension regulating rolls movably arranged between said common drive means, said tension regulating rolls each imparting a predetermined tension to the web traveling thereover, said tension regulating rolls being mounted to be movable so as to deflect out of a reference position as a function of web elongation or contraction in order to correct the speed of the associated drive means, said tension regulating rolls extending over the enTire width of the apparatus and each being individually associated with a given separate web for taking up the elongation or contraction of such associated web.

5. Apparatus for simultaneously guiding a number of webs, especially textile webs, in an expanded condition adjacent one another, comprising drive means common to all of the webs, tension regulating rolls movably arranged between said common drive means, said tension regulating rolls each imparting a predetermined tension to the web traveling thereover, said tension regulating rolls being mounted to be movable so as to deflect out of a reference position as a function of web elongation or contraction in order to correct the speed of the associated drive means, said tension regulating rolls extending over the entire width of the apparatus and each being individually associated with a given separate web for taking up the elongation or contraction of such associated web, a control mechanism operatively connected with only one of the available tension regulating rolls, and upon deflection of such movable tension regulating roll out of its reference position said control mechanism varies the operating speed of the associated drive means until such tension regulating roll again assumes its reference position, pivotal balance beam means for interconnecting two adjacently situated tension regulating rolls with one another, said balance beam means being pivoted owing to a positional change of the other of said tension regulating rolls relative to said one tension regulating roll connected with said control mechanism and thereby changing the action to which the individual tension regulating rolls are subjected for such length of time until both said tension regulating rolls have again assumed their original relative position with respect to one another.