DE1276416B - Device for keeping constant the tension of a belt, strip, web or the like continuously guided through a container. - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

B 65b

German KL: 47 k -3/04

Number: 1276 416

File number: P 12 76 416.8-53 (J 30857)

Filing date: May 17, 1966

Opening day: August 29, 1968

The invention relates to a device for keeping the tensile stress of a continuously constant and tape, strip, one guided to form a loop through one or more containers Web or the like, with a fluid being fed into the loop.

The guidance of a web od. Ä. Through one or more containers is in the most varied of applications necessary. For example, in many continuous machining processes tapes, strips or webs guide the web through one or more liquid containers be, with a corresponding number of deflections of the web with subsequent guidance are necessary on the other side of the track. Assign such webs by soaking in the baths in itself there is an increased sensitivity of the surface, this is particularly true for with with a special coating, such as film strips, the layer side opposite any touch is sensitive. In order to avoid damaging the web surface, you have provided the tracks with special edges or existing edge areas, such. B. the Perforation areas in film strips, used to guide the web, thereby closing the surface save. However, the effectiveness of such edge guides is often reduced after a long period of operation, namely when the web is elongated The original thickness is reduced or, if the edge areas, the correspondingly higher stresses are exposed to wear and tear.

Damage is also possible when using deflection and tensioning rollers with a particularly smooth surface the railway is not excluded. If you provide the roles with a liquid or gaseous Film to prevent physical contact between the roll and the web surface is true the risk of damaging the web is significantly reduced, but other problems arise. Such so-called air bearings have to be fed through very narrow lines, and therefore media that are free of any contamination are required in order to clog the channels to avoid. In addition, self-steering air bearings are used for transporting long, continuously closed processing webs etc. quite sensitive in maintaining the necessary state of equilibrium, because, for example, vibrations and other disturbances very easily influence the steady state can.

By the German patent specification 944 902 a device for keeping constant the
Tensile stress of a belt, strip, web or the like that is guided continuously through containers.

Applicant:

International Business Machines Corporation,

Armonk, N. Y. (V. St. A.)

Representative:

Dipl.-Ing. W. Willich, patent attorney,

7030 Boeblingen, Sindelfinger Str. 49

Named as inventor:

John Bascom Little, Chappaqua, N.Y. (V. St. A.)

Claimed priority:

V. St. v. America May 27, 1965 (459 269)

Winding and unwinding device for magnetic tapes known, in which each drive of the two reels one a belt loop receiving vacuum chamber is assigned. These chambers are initially used for Recording of a certain length of tape as a buffer for the very fast start and stop movements the tape through the scanning station; in addition, the location, d. H. the length of the loops for each Determination of the drive direction of the individual coils determined and evaluated. That through this facility However, the technical principle that has become known serves a significantly different purpose and is already because of the use of negative pressure for tracks, belts etc. guided through liquids not applicable.

Another drive arrangement for tape-shaped recording media, in particular magnetic tapes, is described in German Patent 1,019,108. Here are located on both sides of the scanning device, namely in each case between this and the supply reels, also loops, in which, however, too their maintenance, in contrast to the previously described arrangement, is constantly compressed Air is blown in. Here, too, the length of the loops is determined by appropriate control means held almost constant.

By the German patent specification 1055 349 is still a device for monitoring the tension of material webs running over rollers known, in which pneumatic or hydraulic measuring nozzles are provided adjacent to the material web which deform the web as a function of its tension. The resulting

809 598/267

Changes in the back pressure or the deflection of the liquid container, height-adjustable arranged over nozzles are used to monitor and control the running pipe or by means of the height adjustability evaluated respective web tension. The supply of the entire liquid container that is in this of gases or liquids through the measuring nozzle case has a built-in overflow opening, Although it also causes a tensile stress to be generated. In a further advantageous embodiment of the invention the web, however, should with this device in manure has the inner container in its side walls Depending on the back pressure at the measuring nozzles, the holes or cutouts from to its lower edge Drives for the train are controlled. towards enlarged cross-section. After a be-der The invention is based on the object, a preferred embodiment of the invention grows To create means by means of which against Beruh- io the cross-section of these holes or cutouts for tion and damage to sensitive straps, do not continuously strip the lower edge of the inner container, Orbits or the like borrowed with the greatest possible care, creating special characteristics for the the layer side passed through the liquid container. Operation of the device according to the invention can, whereby those for guiding the web can be aimed.

required by the container loop in the web 15 Furthermore, according to a particularly useful automatic is maintained. This object is a moderate embodiment of the invention for the invention been solved in that the change in the effective cross-section of the holes tape, the strip or the web in one of the cutouts or flaps, slotted plates or the like. Liquid container located, be arranged adjustable above and below. That way it is open inner container is guided, the width of which 20 is easily possible, empirically optimal Beetwas is larger than the web width and in the operating conditions for the device according to the Er range the inside of the loop to constantly find fluid.

feeding lines are arranged. The invention is hereinafter based on the

With the device according to the invention, drawings are explained in some exemplary embodiments.

thus eliminated the difficulties discussed by 25 tert. It shows

the liquid through which the web is passed F i g. 1 a device for managing a single

which must, even as a kind of fluid bearing, mutually coated path through several fluid

is turned. The liquid strains the loops in the container while maintaining a uniform

the individual containers, and at the same time one uses tensile stress,

the damping effect inherent in the liquid, 30 F i g. 2 shows the diagrammatic representation of a section

whereby a tape guide is obtained, which even with one of the liquid containers according to F i g, 1,

strongly fluctuating parameters works stably, so F i g. 3 shows a section on the line 3-3 of

has the desired insensitivity. F i g. 4, in which an alternative version for

With the aid of the device according to the invention, change in the liquid level in a container

a web can be shown without any contact with the layer- 35

side by a larger number of liquid F i g. 5 shows another embodiment of the inner container be carried out, with a uniform container and

Tension in the web automatically maintained. F i g. 6 becomes a further embodiment of the interior. In the simplest form of the device container with arranged in its lower part according to the invention is in the path between two 40 holes for the exit of the liquid from the inner rollers, which rest on the opposite non-coating chamber in the liquid container, th side, a loop is formed, which in accordance with FIG. 1, a web 10 is suspended under liquid that is lighter in the container, the tension being drawn off a supply roll 5, after-looping together with the side walls of the interior through a number of liquid-filled chambers forms a separate chamber into which 45 Container 20 is passed and finally pumped onto a Aufdig liquid. The pumped-in take-up roll 6 is wound up. The amount of liquid in the containers 20 is greater than the leakage losses through each other, but if the gaps between the belt and the inner chamber contain different liquid manure depending on the processing process, the loop will enlarge until the gaps. If the web 10 is z. B. around the underside of the loop with the underside of the loading 50 an exposed photographic film, so the holder comes into contact, whereby the leak container 20-1 is filled with developer solution, the losses are greater. If the amount of leakage is then greater than the amount of leakage 20-2 with rinsing water and the container 20-3 is greater than the amount of liquid supplied, then fixation soda or some other fixative is used. In between, reduce the loop accordingly. See the last container 20-3 and the receptacle-In this way the system is always stabilized 55 roll 6 is then a drying device, again in a position of equilibrium, in which the liquid weight in the loop is doubled - Adjusted the required processing time, th force of the effective train on the tape as soon as the web 10 speaks into the first container 20-1. With the appropriate design of the container and the solution contained therein and the tape guide, the system is self-wetted, its surface is sensitive to damping and is also suitable for changing operating conditions, any damage or stresses, while in each If the coated upper surface 10 A must therefore be carefully treated in accordance with the coated surface of the tape from any stress, while remaining free. the underside 10B does not need to be protected. According to an advantageous embodiment of FIG. 65 and therefore passed over rollers of the usual type, the invention is the liquid level of the liquid can.

container can be changed relative to the inner container. Before describing the construction of the containers

can be achieved by a in the bottom of the river, some basic principles of mechanics and

5 6

the fluid mechanics are discussed, from which control of each station is possible, whereby the damping

chen makes use of the described facility. fungus and self-control at an optimal value

In a frictionless system the tension is in can be held.

the web 10 is the same over its entire length. If As in Fig. 1, a braking torque acts on the roller 5 in relation to the embodiment, FIG. 5 shows play, the web 10 is guided by each of the bobbins 20 required for the take-up roll 6 over rollers 21 and 22, at which the moment is equal to the braking torque. However, since Rei the bottom 10 B of the web is applied. Due to the loss of exercise, the winding torque is larger than the amount of fluid lying on the web in the container, corresponding to the amount of friction force. The container 10 is greater than the braking torque acting on the roller 5. io consist of an outer container 23 with a resistance created by the friction is overflow opening 24 and an inner container 30, also increased by the resistance that the rollers 21 and 22 are rotatably mounted and liquid on the path drawn through the container which in turn to take up the exerted on the rollers, and this resistance is greater than the forces exerted is stationary and stable. The one caused by the friction. As a result, the outer container 23 is not only increased by means of a spindle arrangement, 25 is vertically movable with respect to the inner container 30, but there is also a non-uniform distribution of the borrowed bearings. On the inside, i.e. the upper side, web tension over the length of the web is the result. 10 A of the web loop 10 C by means of lines, the voltage between the roller 5 and the loading 26 and 27 (27 lies in F i g. 1 behind 26) and the nozzle container 20-1 results from the loading by the roller 5 20 When the liquid in the container in question was pumped, there was resistance. The tension between the containers 20-1 and 20-2 is increased by the friction 23 up to the level of the overflow opening 24, from where and the tough resistance of the first container 20-1. they are caught, filtered, reactivated, if necessary. Each additional container increases the resistance accordingly (depending on the requirements of the process), so that the voltage reaches its 25 and, via a pump, again the lines 26 and the maximum value on the take-up reel 5 . 27 is forwarded.

Her is, as will be explained, in each of the loading The inner container 30 is, as shown in FIG. 2 shows as above

container formed an automatic adaptation to this unequal and open at the bottom housing and in the

moderate stress distribution provided. Outer container 23 immersed; it consists of the same

If a weight of two ropes is evenly borne 30 rather front and rear wall 31 or 32 and Seig, then the effective ten walls 33 and 34 on each of the ropes with a rectangular cross-section. Force equal to half the weight. If a roller rests on lugs 31A, 31B and the front and back of a web, the web tension wall 31 and 32, the rollers 21 and 22 are rotatably causing force equal to half the weight. Stocked. Front and rear walls 31 and 32, respectively, the web now moves with constant velocity 35 from the bottom edge to a V-shape ausgeschnitkeit forward, there remains the web tension, if th. The cutouts 31 thus formed C serve as the friction neglected above , unchanged. By means of reverse overflows with variable openings, exercise, acceleration forces and the viscosity through which the liquid in the loop 10 C of the web 10 resisted, the liquid in the external container 30 on the output side of the system is now increased. Because in 40 long can. Instead of being V-shaped, these can have a kind of liquid run over each of the containers on the track, also parabolic or hyperbolic, as the roller rests on, one can say that the drawing shows first.

Approximate value is the weight of the liquid which, in the arrangement described, hits the liquid emerging through the nozzles of the lines 26 and 27 in the U-bend of the web, twice as large as the force causing the web tension. 45 fluid on the coated surface 10A of the track loop 10 C due to the friction and the viscous resistance and if the ratio between the front fluid and the rear wall 31 or 32 is absorbed, the weight of the in the mutual distance is slightly greater than the liquid located in the web loop in each case equal to the width of the web 10. With increasing liquidity of the sum of the tensions in the input volume in the path loop, this corresponding and output sections of the path is correspondingly loaded and therefore decreases, increasing, the forces. deeper into the inner container 30. As soon as the

Another factor is the dynamic lowest point of the loop below the top of the loop. When the webs sink from a width to approximately overflow-like cutouts 31 C , the 60 cm and a thickness of the order of 55 initially enclosed liquid begins to escape. Tenth of a millimeter through several successive The loop continues to descend until the overflowing containers are transported, so uncut sections can be exposed to such an extent that just as much regularities in the elasticity of the path can escape liquid as the disturbances approaching the loop in a continuous trans - Is performed, minus the liquid that cause between port, which, if no precautions are taken, 60 the web edges and the adjoining front or extremely critical vibrations, possibly with Zer- rear wall 31 or 32 emerges as leakage. Result in disruption of the railway. Since liquids in this layer are the weight of the viscous and incompressible in the loop, they have inherently sensitive liquids equal to the sum of the good damping characteristics. Therefore the creation of tensions in the two arms of the loop is caused by vibrations in the web 10 through the speaking forces.

Liquids in the containers as a result of their attenuation.

preventive effect. If you increase this separately, the loop rises 10 C higher and

Lungs on each container is also a separate one thereby restricts the escape of liquid through the

Overflow cutouts so that more liquid collects in the loop 10C. As soon as the weight the fluid has adapted to the new web tension, sinks as long as less fluid escapes can than is fed, the web loop deeper into the inner container 30, and the earlier cutout size will be restored.

On the other hand, when the web tension decreases, the excess weight causes the looped body or be lowered. While at a low liquid level, the web tension determining force is equal to the weight of the enclosed liquid, the liquid begins 5 As soon as it rises above the lowest point of the orbit loop, it exerts a buoyancy force on it. The web tension force is now equal to the weight of the above the liquid level trapped liquid. This is the top part

lent liquid an enlargement of the loop, io of the trapped liquid, which continues a the effective exit cross-section becomes larger and the function of the web tension remains, while the

thus increasing the leakage of liquid. Is then the total volume of the enclosed liquid without Lots of liquid leaked out, so that the weight is related to the web tension, the height

of the liquid in the loop of the web tension at the liquid level and the inflow speed

has fitted, then the reduced drain 15 speed is in the loop. As the overflow opening

Cutouts 31C, 32C now partially or fully effect the amount of liquid in the loop wrinkles, and the loop moves up to even completely below the liquid level.

their original location, in the equilibrium between, the outflow takes place through them partially into the

see outflow and inflow of the liquid. Air space above the liquid level and partly

If the inflow through lines 26 and 27 20 increases wisely or directly into the liquid outside, so that the inflow exceeds the outflow, container. There is of course the discharge into the air the weight of the one in the loop increases more than that in the liquid. By settling in Liquid and enlarges the loop, so that the height of the liquid level is it a larger exit area becomes effective. Here- possible, the effective discharge characteristics of the this in turn increases the drainage and changes the 25 overflow openings. Another advantage of adjusting the height of the the loop is an "overflow" level of liquid so much that in this way the will ensure that the increased inflow is compensated for changing the damping characteristic of the device, bar is the occurrence of certain vibrations in

With a decrease in the inflow, the orbit can therefore be controlled,

the now greater drainage increases the weight of the liquid.

in the loop. The loop then decreases so workstation the drag and friction,

far, that the exposed "overflow opening" is one whereby the web tension is increased. The chip

The decrease corresponding to the now reduced inflow is therefore greatest on the take-up reel 6.

flow is allowed and the system is stabilized again. 35 To compensate for this tension, the

In all the cases described, for an increase in the mode of action in the container 20-3, a corresponding reduction in the web tension and the increase in the liquid level in the loop 10 C flow, the resulting changes occur in the flow compared to the previous container 20-2 (cf. Track position and the runoff not one after the other, but fig. 1). The container 20-2 in turn positions itself practically at the same time and follows the changes 40 with a higher liquid level in the loop, wrestling in the input parameters with only very little than the first container 20-1. Though in the Darringer delay. Thus, the device works position according to FIG. 1 the spindle assemblies 25 as a real servo device with completely independent from the lowest level at 20-3 to the highest at control. Any change in an input pair 20-1 is different, so this is not necessarily a meter has to disturb the balance of the 45 meter. If z. B. the method requires that forces result by which the equilibrium of one of the containers is immediately restored to a very intense liquid. An increase in
Web tension thus results after restoration
of equilibrium in a larger volume of the
liquid collected in the loop at un- 50
changed position of the railway loop. An increase in the

Liquid inflow at constant web tension has a longer loop and therefore an increased one Result in drainage, but the volume of the liquid remains unchanged.

The above, greatly simplified explanation is basically valid, but is supported by a Explanation to supplement what happens when the outer container 23 with its liquid level for

must have circulation, a significantly different setting would be for this container to the corresponding one Attenuation of the web necessary.

From this, without an attempt to mathematically capture the interplay of the dynamic To make forces - if that is at all possible - evident that through the system own flexibility the various processing speeds, liquid ratios and Fluctuations in the web properties can be absorbed. Through the ability to self-regulate along with the damping by the liquid there will also be large fluctuations in the

Interaction with the inner container 30 and 60 parameters automatically balanced. Another

Its cutouts, which act as overflow openings, are compensated by manual setting of the

31 C and 32 C is brought. The liquid level The liquid level and thus the effect character

in the outer container 23 can be achieved through the overflow pipe 24 teristics of the drainage openings,

certainly. By adjusting the spindle arrangement 25 In the embodiment according to FIGS. 3 and 4,

the outer container 23 and thus its fluid 65 can also provide a better insight into the structure

sigkeitsspiegel relative to the inner container 30, its the container, the arrangement of the spray nozzles and

Overflow openings 31C and 32 C to the band loop the operation of the escape of the enclosed

10 C and the liquid in it - liquid from the loop through the overflow

allow openings in the outer container, the liquid level adjustment consists of an overflow pipe 28, which by means of a stuffing box 29 through the bottom of the outer container 23, which is now stationary is, is slidably arranged. By loosening the stuffing box 29 and moving the overflow pipe vertically 28 the liquid level can therefore be adjusted to any desired height.

Instead of the shape of an inverted V for the cutout 31C or 32C in FIG F i g. 1 to 4 shows FIG. 5 a modified form with maximum dynamic rigidity, in which also very small changes in the shape of the track loop result in a maximum change in the drainage area to have. The inner container 30 is shown here as a simple sleeve with open ends and without cutouts the front and rear walls 31 and 32, respectively. The belt loop 10 C must now be under the straight line lower edge of the front and rear walls sink to form a drainage opening. There is no further recognizable that the rate of change of the effective area of the discharge opening in relation to on the loop size is much higher than in the V-shape of the cutouts. The result is a less flexible, "stiffer" system. In Fig. 5 results in the shape of a segment of a circle for the drainage opening, limited by the straight lower edge of the inner container and the circular arc shape of the lowest part of the belt loop. While in the present illustration the drain below the liquid level takes place, you can achieve by appropriate adjustment of this level that the drain either completely above the mirror, i.e. in the air, or partly in the air and partly in the liquid takes place in it.

A compromise between the straight edge according to FIG. 5 and the V-shape according to FIGS. 1 to 4 forms that in FIG. 6 shown embodiment. One could speak of a step function here, which approximates the inverted V but is achieved through holes 35 made in the Front and rear walls 31 and 32 of the inner container 30 are arranged, namely pyramid-shaped, so that when the orbit loop drops, the speed of the change in flow increases, as it is also the case with the inverted V cutouts. The holes 35 in the illustrated Arrangements can also be selected to be of different sizes in order to achieve a non-uniform distribution. The remaining details regarding the adjustability of the liquid level, either in of the shape shown or with the riser pipe arrangement according to FIG. 3 are in the embodiment of FIG F i g. 6 unchanged.

Of course, although not shown, the cutouts that act as drainage openings can in the embodiments shown also be designed to be changeable, for. B. by the arrangement of flaps on the outside of the inner container 30, through the shape and size of the drainage opening (s) can be varied. This can also be done by arranging simple slotted plates, which are attached to the outside of the walls 31 and 32. These panels would be in the shape according to FIG. 5 to below the lower edge to change its shape from the straight to the desired one To change the shape of the curve. In the embodiment according to FIG. 6, certain Holes 35 can be optionally closed. In the arrangement shown in the remaining figures you can optionally change the curve of the overflow opening by such a slide. The optimal shape is expediently obtained using the approximation method for each combination of parameters so to get the maximum servo performance together with the necessary damping.

Claims (8)

Patent claims: 1. Means for keeping constant the tension of a continuously forming a Loop through one or more containers guided tape, strip, web or the like., Wherein a fluid is fed into the loop, characterized that the tape, strip or web (10) in one in the liquid container (23) located, top and bottom open inner container (30) is performed, the Width is slightly larger than the width of the web and is constantly in the area of the inside of the loop Liquid supply lines (26,27) are arranged. 2. Device according to claim 1, characterized in that the liquid level of the Liquid container (23) can be changed relative to the inner container (30). 3. Device according to claims 1 and 2, characterized in that the change the liquid level of the liquid container (23) relative to the inner container (30) in the bottom of the liquid container (23) a height-adjustable overflow pipe (28) is arranged. 4. Device according to claims 1 and 2, characterized in that the change the liquid level of the liquid container (23) relative to the inner container (30) of the liquid container (23) has a permanently installed overflow opening (24) and by means of a lifting device (25) is adjustable in height. 5. Device according to claims 1 to 4, characterized in that the inner container (30) in its side walls has holes (35) or cutouts (31 C, 32 C) of enlarged cross-section towards its lower edge. 6. Device according to claim 5, characterized by holes or cutouts from the lower edge of the inner container towards not continuously enlarged cross-section. 7. Device according to claims 5 and 6, characterized in that the change the effective cross-section of the holes or cutouts flaps, slotted plates or the like. are arranged adjustable. 8. Device according to claim 1, characterized in that the lines (26,27) with nozzles are provided. Documents considered: German Patent Specifications No. 944 902,1019 108; German interpretative document No. 1 055 349. 1 sheet of drawings 809 598/267 8.68 © Bundesdruckerei Berlin