US3837593A

US3837593A - Supporting-roller reeling apparatus

Info

Publication number: US3837593A
Application number: US00291408A
Authority: US
Inventors: G Dorfel
Original assignee: Ahlstrom Corp
Current assignee: Lenox Machine Co Inc
Priority date: 1971-09-24
Filing date: 1972-09-22
Publication date: 1974-09-24
Anticipated expiration: 1991-09-24
Also published as: SE373175B; JPS4844666A; DE2147673A1; CA973860A; JPS52127B2; AT324114B; GB1366743A; FI51686C; DE2147673B2; FI51686B

Abstract

In a reeling apparatus for moving webs, such as paper webs, irregular tensions on the web due to thickness variation in the same are eliminated by providing an even pressure along the reel between the reel and at least one driven supporting roller supporting the reel and rotating it by circumferential contact. The invention is specifically applicable to the reeling of barrel shaped reels or reels of similar form deviating more or less regularly from the ideal cylindrical shape. It provides sensor means in contact with the reel for sensing the mantle shape thereof, said sensor means operating measurement converter means transmitting signals based upon said mantle shape. These signals are received by a control unit controlling the deflection or bending of the supporting roller, which thus must be of the known type having controllable deflection. The sensor elements may be mounted onto several load roller arranged closely together above the reel and independently vertically movable but loading the reel with an even line pressure. This may be achieved by having said load rollers pneumatically or hydraulically controlled and thus also pneumatically or hydraulically interconnected.

Description

United States Patent [1 1 Diirfel Sept. 24, 1974 1 SUPPORTING-ROLLER REELING APPARATUS [75] Inventor: Gerhard Walter Diirfel,

Weilheim-Teck, Germany [73] Assignee: A. Ahlstrom Osakeyhtio,

Noormarkku, Finland 22 Filed: Sept. 22, 1972 21 Appl. No.: 291,408

[30] Foreign Application Priority Data Primary Examiner-John W. Huckert Assistant Ekarriiner Edward J. McCarthy cally interconnected.

[5 7] ABSTRACT In a reeling apparatus for moving webs, such as paper webs, irregular tensions on the web due to thickness variation in the same are eliminated by providing an even pressure along the reel between the reel and at least one driven supporting roller supporting the reel and rotating it by circumferential contact. The invention is specifically applicable to the reeling of barrel shaped reels or reels of similar form deviating more or less regularly from the ideal cylindrical shape. It provides sensor means in contact with the reel for sensing the mantle shape thereof, said sensor means operating measurement converter means transmitting signals based upon said mantle shape. These signals are received by a control unit controlling the deflection or bending of the supporting roller, which thus must be of the known type having controllable deflection. The sensor elements may be mounted onto several load roller arranged closely together above the reel and independently vertically movable but loading the reel with an even line pressure. This may be achieved by having said load rollers pneumatically or hydraulically controlled and thus also pneumatically or hydrauli- 8 Claims, 9 Drawing Figures EEEYQ 583 Pmgmmsmmm SUPPORTING-ROLLER REELING APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to reeling apparatuses for moving webs, such as paper webs or similar and of the character comprising at least one driven supporting roller of the known type having controllable deflection, said roller supporting the reel and driving the same by circumferential contact.

2. Description of the Prior Art Supporting-roller reeling apparatuses of the type described are known e.g. from the US. Pat. specification No. 1,970,911 and the British Pat. specification No. 700,436.

Since in this type of apparatus the reels are composed of many layers of a web material, such as paper, there will be variation in the thickness of the reel over the width of the track, from small differences in thickness to considerable differences in diameter. Very often the track is somewhat thicker in the middle than on the sides owing to, for example, a slight looseness in a supporting roller of the paper machine wire or an insignificant space between the supporting rollers, with the result that barrel-shaped reels are formed, in which case the difference between the diameters of the middle of the reel and the sides can be several millimeters. Such deviations from the cylindrical shape cause an uneven contact between the reel and the supporting roller when normal straight supporting rollers are used, since the reel is pressed against the supporting roller at an uneven pressure or, when the reel itself is very stiff, only at certain points. This results in irregular tension on the track.

The purpose of the invention is to develop a supporting-roller reeling apparatus of the type described above with the linear pressure of the reel against the supporting roller always as even as possible.

SUMMARY OF THE INVENTION According to the present invention there is thus provided a reeling apparatus of the character once described, which comprises sensor elements mounted to act in conjunction with the circumference of the reel to sense the mantle shape thereof, measurement converters operated by said sensors and creating signals based on the shape of the reel mantle, and control unit means receiving said signals and controlling in response thereto the deflection or bend of the supporting roller.

The shape of the upper surface of the reel imparts signals which are used to bend the supporting roller into such a shape that it will touch the reel evenly. In principle the type of control elements is free. Electric, pneumatic, or hydraulic control elements can be used, but undoubtedly an electric system is often preferred because of the easy transfer and convertibility of the signals.

It is practical for the sensor elements to be rollers on the circumference of the reel. t

Furthermore, a system composed of several load rollers placed next to each other above the reel over its entire width can be provided.

This system can be provided in addition to sensor elements. However, in the preferred embodiment of the invention they also work as sensor elements and the operation of the measurement converters is derived from them.

This is materialized in one of the first embodiments so that, independent of other moving parts, the load rollers without exception press against the circumference of the reel at the same pressure. The movements of at least some of the load rollers operate the measurement converters.

Individual load rollers then adapt to the shape of the reel under the same pressure. The apparatus guarantees that, regardless of the reel shape, an even pressure is obtained over the width of the reel. The signals indicating the required changes in the load rollers are transferred through the measurement converter into the control apparatus.

The load rollers are advantageously narrow rollers, their diameter exceeding their axial length. Only enough space is left between the load rollers for the supporting elements of the roller shafts to fit between the rollers, and the load rollers are designed so as to extend over the entire width of the apparatus.

Because the load rollers are then quite next to each other, the apparatus creates practically a constant linear pressure over the entire linear width. This embodiment has an additional advantage in that even narrower tracks can be reeled, in which case the outermost rollers are left without function.

As to the details of this embodiment, the load rollers, for example, can be attached to the bearing transversal bar in a manner known as such and each load roller can be provided with a hydraulic or pneumatic load device, in which case the load devices have equal working surfaces and are in a hydraulic or pneumatic contact with each other.

Another embodiment of the invention comprises suitable load rollers situated in a plane running through the reel axis and attached with swivel bearings to the bearing transversal bar. The swivel axis of these load rollers is mainly fixed in relation to the bearing transversal bar, and at least some of them operate the measurement converters with the help of pressure directed at the rollers from the reel.

The load apparatus according to this embodiment of the invention does not always adapt automatically to the reel shape when an attempt is made to obtain a constant linear pressure, but it is subjected to uneven pressure from the reel mantle line which deviates from a straight line when differences in thickness appear in the track. The measurement converters observe this pressure and convert it into a suitable signal for bending the supporting rollers. Owing to the mobility of the bearing transversal bar, even conical reels can be adjusted.

In an advantageous embodiment of the invention the load rollers are supported by the bearing transversal bar through bearing brackets, and measurement converters have been coupled between the bearing brackets and the bearing transversal bar.

The loads directed at each individual bearing bracket in the ideal case, that is, when the reel is cylindrical, can be calculated arithmetically from the sum of the total load of the load apparatus and possible additional forces. But when the reel is, for example, barrelshaped, a greater force than in the ideal case appears in the middle; this force is used for a certain adjustment of the supporting roller bend.

For example, three load rollers can be provided, and two bearing brackets with measurement converters each shared by the central load roller and one of those on the side, while the outer bearing brackets have been attached directly to the bearing transversal bar.

This apparatus can naturally be used only for broad reels which always touch all three load rollers.

When modifying the invention further, the supporting roller can be provided with a measument converter to create a signal corresponding to its bend.

This is an important characteristic in that it opens a possibility for direct influence on the supporting roller bend and for taking it into consideration in the control. This is important, for example, when barrel-shaped reel must be reeled so that their central axis is straight. In this case, the eccentricity of the supporting roller can be compared to the eccentricity of the load rollers with the help of the measurement converter on the supporting roller, and the eccentricities can be adjusted to the same value by regulating the supporting roller bend. This means that the reel no longer forms a curve on either side, and thus, it is reeled into a symmetrical barrel-shape.

It is advisable, in order to level down slight asymmetry in the reel circumference and the material layer, to provide the average values of the signals and several adjoining measurement converters and form a new signal from them.

Thus, the control unit receives a signal the variations of which due to small deviations from an even cylinder form of the reel have been alleviated.

The reel has a significant weight which is received by the supporting roller and which requires a specific bend of the latter. Besides, since the reel naturally obtains more weight during its formation, the bend in the supporting roller based on this weight naturally changes respectively all the time.

In order that this portion of the bend which is independent of the shape of the reel could be taken into consideration, it is practical to provide the apparatus with a correction signal generator which gives the control unit a correction signal corresponding to the supporting roller bend based on the reel weight.

This correction signal cancels the weight error and has the effect that the control is based purely on the quantities obtained from the shape of the reel.

It is appropriate to provide the control unit with a signal modifier into which the different signals are fed and which prepares from them a signal which serves to regulate the supporting roller bend.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a schematic side view of a supportingroller reeling apparatus according to the invention, partly as a section and without the framework consisting of the supporting structure of the system;

FIG. 2 shows a schematic frontal view of a supporting-roller reeling apparatus according to FIG. 1;

FIG. 3 is a picture corresponding to FIG. 2 with differently fitted measurement converters;

FIG. 4 is a picture corresponding to FIG. 2 with additional measurement converters on the supporting roller;

FIG. 5 shows an embodiment of the invention with measurement converters which require a force directed from the reel to the load rollers;

FIGS. 6-9 illustrate the operation of the embodiments shown in FIGS. 2-5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a supporting-roller reeling apparatus in which paper reel 1 is reeled without a shaft in the direction of arrow 1. Reel 1 rests on both supporting

rollers

2 and 2 of which at least one is driven and which extend on a parallel axis transversally over the entire width of the track. Although two supporting rollers are shown in the figure, the invention is not limited to this embodiment. It is also possible to use only one supporting roller 2 and to guide the reel axis in a suitable manner.

Supporting

rollers

2, 2 are so-called floating rollers. Supporting roller 2 consists of hollow roller 101. Stationary crosshead 102 extends through the entire length of hollow roller 101 and sticks out at both ends where it is attached with bearings to the base of the apparatus. Hollow roller 101 has been attached with bearings to crosshead 102.

The opposite sides have been designed so that gaskets 103 of crosshead 102 which are parallel to the axis extend against the inner surface of hollow roller 101. They divide the space between the inner surface of hollow roller 101 and cross head 102 into two

longitudinal chambers

104 and 105 of which longitudinal chamber 104 is situated on the working side, that is, towards reel 1.

Longitudinal chambers

104 and 105 have also been gasketed in the axial direction at both ends of hollow roller 101.

Pressure fluid can be conducted into

longitudinal chambers

104, 105 through a channel in crosshead 102. With the help of pressure fluid in longitudinal chamber 104, hollow roller 101 is supported against crosspiece 102, in which case the latter can bend under pressure inside hollow roller 101 without hollow roller 101 observing the respective bend. In addition, a regulatable bend can be obtained in hollow roller 101 by regulating the pressure prevailing in

longitudinal chambers

104, 105. When the pressure in longitudinal chamber 104 is higher than that in longitudinal chamber 105, a convex bend appears in hollow roller 101 on the side on which longitudinal chamber 104 is situated, because it is attached with bearings at both ends to crosshead 102. Respectively, a concave bend appears in hollow roller 101 in relation to the space between the rollers when the pressure is higher in longitudinal chamber 105.

Above reel 1, on suitable guide rails, there is movable bearing transversal bar which stretches over the track of material and rides on reel 1, that is, rises higher respectively when the diameter of the reel increases.

Below bearing bar 8 there are vertical stop plates 6 with inbuilt cylindrical chambers 50 which are sometimes locked with diaphragms 5. Pressure pieces 51 are situated against those sides of diaphragms 5 which are on the side of cylindrical chambers 50. These pieces are operated by levers 4 which turn around an axis parallel to the reel axis under cylindrical chambers 50 and diaphragms 5. The turning axis and diaphragms 5 are almost vertically on top of each other. Outside this plane, a load roller 3 has been attached with bearings to each lever 4; the roller is a relatively thin one and rolls on reel 1. At the same time, load roller 3 affects reel 1 with a pressure which is dependent on the pressure in cylindrical chamber 50. Cylindrical chambers 50 situated one after another along bearing transversal bar 8 are interconnected through leveling pipe 7 in order to maintain an equal pressure in all adjacent cylindrical chambers 50, and consequently, the contact pressures of load rollers 3 are equal regardless of the height at which the load rollers are situated. Furthermore, it is important that the axis of pressure rollers 3 and the turning axis of lever 4 are tangential to reel 1; then changes in the turning axis have no significant influence on the distance of the axis of load rollers 3 from the turning axis, or on the lever arm under which load roller 3 transmits its power to reel 1. The load rollers not only work to load reel 1 but their shape also follows the shape of its mantle. When the mantle shape deviates from a cylindrical shape, movements appear in load rollers 3 and these movements are transmitted through lever 4 to

measurement converters

10, 11, 12, the output signals of which are used to regulate the bend in supporting roller 2 in the manner described below.

It can be seen in FIG. 2 that bearing transversal bar 8 moves along side rails 52 in a vertical direction. Load rollers placed densely next to each other with space only for bearings in between, cover reel 1 almost completely and have an almost even linear pressure effect owing to leveling pipe 7 which connects individual cylindrical chambers 50.

In the embodiment illustrated in FIG. 2, the control unit consists of measurement converters l0, l1, 12, which are electromagnetic sensors. It is evident, however, that, depending on the system of the used control unit, pneumatic or hydraulic sensors can also be used. The same naturally applies to other control elements, also.

The output signals of measurement converters 10, ll, 12 are received by average value calculator 19 which calculates the average value of the output signals of measurement converters and 12 on both sides and compares this average value to the output signal of measurement converter 11. The resulting signal indicates the bend in the mantle line of reel 1 and is fed into control unit 21 which also has another input at which it receives a signal from correction or set value potentiometer 20. Correction potentiometer 20 takes into consideration the corrections indicated by the weight of reel 1 and the load roller apparatus plus possible additional forces. The output of control unit 21 is situated at an electrohydraulic servo-valve to which pipe 31 conducts pressure oil and which gives return oil from pipe 32. Servo-valve 24 feeds pressure oil in a suitable manner into pipe 106 which leads into chamber 104 of supporting roller 2 which is on the side of the supporting roller which faces the reel or into pipe 107 which leads to chamber 105 of supporting roller 2.

If the output signal of measurement converters 10, ll, 12 changes, control unit 21 begins operating and causes servo-valve 24 with a respective pressure distribution to change the bend in supporting roller 2 until the output signal of measurement converters 10, ll, 12 has again returned to the set value set by correction or set value potentiometer 20.

FIG. 3 shows another embodiment of the control unit in which, according to FIG. 3, measurement converter pairs 10, 12 are situated on the right side, in the middle and on the left side of reel 1, one pair at each point; their output signals are modified into three average values by respective

average value calculators

26, 27, 28. The average values from

average value calculators

26 and 28 are fed into the positive input of summing unit 29, while the average value from average value calculator 27 is fed into the negative input of summing unit 29 after a matching amplification by factor 2 in amplifier 27 A. In addition, summing unit 29 receives one more signal from correction or set value potentiometer 20. The output signal of summing unit 29 is amplified in amplifier 30 and is then fed into electropneumatic signal converter 22 which converts the electric output signal of amplifier 30 into a pneumatic signal, for which it receives the necessary compressed air from pipe 13. The pneumatic signal operates the pneumatically controlled hydraulics-differential-pressure-control valve which, as shown in the embodiment according to FIG. 2, regulates the pressures in

pipes

106 and 107 and thereby the bend in supporting roller 2.

In regard to the system of measurement converters 1 10, 11, 12 and the modification of their output signals, the embodiment according to FIG. 4 mainly corresponds to the embodiment according to FIG. 2. In addition, there is, however, power measurement converter 9 which is in contact with the side of supporting roller 2 facing away from reel 1, for example, through a roller, and directly observes the bend in supporting roller 2. The output signal of measurement converter 9 is amplified in amplifier 25 and is then fed as an input signal into control unit 21 which can thus also directly regulate the bend in the supporting roller. The output signal of control unit 21 is modified further in a manner corresponding to that illustrated in FIG. 3.

FIG. 5 shows an embodiment which deviates from those described above in that load rollers 33 do not rest, as load rollers 3 do, all at an equal pressure on reel 1, but they have been fixed by bearing brackets to supporting bar 8. There are three load rollers 33 for four bearing brackets 34 of which the two in the middle are each shared by two adjacent supporting rollers 33. The two outer bearing brackets 34 have been attached directly to bearing transversal bar 8. Both central bearing brackets 34 have been attached to the bearing transversal bar through

measurement converters

35, 36.

Measurement converters

35, 36 transmit signals corresponding to the pressure directed at them, in which case the changes are minute so that load roller 33 mainly appears to be a turning axle stationary in relation to the bearing transversal bar.

The average value of the output signals of

measurement converters

35, 36 is calculated in average value calculator 37 and is fed as the real value to summing unit 29. In addition, summing unit 29 receives a correction signal and a set value signal through conduit 39. The set value signal from conduit 39 is a signal porportional either to the real value of a load pressure regulation already available or to the set value thereof. The load pressure regulation regulates the total load of bearing transversal bar 8 on load rollers 33 and each increase or decrease in the load. The output signal of summing unit 29 is further modified in the manner described in connection with FIG. 3 to regulate the bend in supporting roller 2.

FIG. 6 illustrates the operation of the apparatus according to FIG. 2. This embodiment can be used in connection with reels which do not deviate too much from a cylindrical form and reels which in themselves are not too stiff. The load roller system can then be adjusted to a straight mantle line. The control unit receives the set value from correction or set value potentiometer 20. If the center points of the load rollers which have been provided with measurement converters I0, 11, 12 are situated on a straight line, average calculator 19 transmits a signal which does not affect any bend in supporting roller 2. If the center point of the central load roller is above or below the straight line connecting the center points of the supporting rollers on both sides, the average value calculator transmits a signal on the basis of which control unit 21 begins operation to eliminate the bend in supporting roller 2 until the center points are on the same straight line again.

FIG. 7 corresponds to FIG. 3. The apparatus operates in the same manner and is meant for the same uses as those shown in FIGS. 2 and 6. The difference lies only in that the measurements are obtained at points situated far apart from each other and are modified into signals for summing unit 29 in another manner.

FIG. 8 illustrates the operation of the embodiment according to FIG. 4 supplemented with measurement converter 9 on supporting roller 2. This embodiment is suitable even for stiffer reels and distinctly barrelshaped reels. By regulating the straight mantle line as in FIGS. 6 and 7, considerable modifications would be necessary in such reels. To avoid these, the operation of the reel is guided so that reel 1 with a straight central line or neutral line 60 is obtained. The bend in supporting roller 2 is observed directly by the control unit through measurement converter 9. The regulation takes place so that the bend in the upper mantle line detected by

measurement converters

10, 11, 12 is the same as the bend in the lower mantle line or supporting roller 2. In this manner, symmetric pressure on reel 1 is achieved which helps the reel obtain a symmetric barrel shape.

FIG. 9 illustrates the operation of the apparatus according to FIG. when a slightly barrel-shaped reel 1 is modified. When supporting roller 2 is straight, this reel 1 mainly presses central load roller 33 with the result that

measurement converters

35, 36 observe too strong a force which is higher than the value that should theoretically be directed at both central bearing brackets when the pressure is distributed evenly over the entire width of reel 1.

When such deviation occurs, supporting roller 2 bends downwards according to FIG. 9. When, so to say, more space is then created in the middle of the reel, the overload on the central load roller is eliminated and all load rollers receive an equal pressure. The supporting roller bend is regulated so that all supporting rollers are subjected to the same pressure. In all embodiments of the invention, the reel rests on supporting roller 2 at a constant pressure over the entire width of the reel and, accordingly, the prevailing tension on the track is also evenly distributed.

The described embodiments illustrate barrel-shaped reels. However, they are also applicable when reel 1 shows, besides barrel-shaped deviation, also conical deviation from a cylindrical shape, that is, it is thicker at one end. Load rollers themselves according to FIGS. 6-8 adapt to such deviation without loosing their evenly distributed pressure. In embodiment 9, the bearing transversal bar has been attached with bearings so that it can settle in a slanted position which corresponds to the conical shape of reel 1.

What is claimed is:

1. In a reeling apparatus of the type in which web material is wound into a reel supported by at least one driven roller in rolling contact engagement with the outer mantle of web material on the reel, the improvement which comprises an internally pressurizable roller disposed in rolling contact engagement with said mantle to support said reel; sensor means disposed for contact with the mantle at locations across the width thereof to sense the contour of the mantle and establish signals corresponding to such mantle contour; and control means responsive to said signals and operable to vary the internal pressure of said roller in accordance with said signals to adjust the deflection of the roller according to the sensed mantle contour and thereby correspondingly adjust the contact pressure between the roller and reel mantle to maintain a generally uniform contact pressure over the width of the mantle.

2. The improvement according to claim 1 wherein said sensor means includes a plurality of sensing rollers supported to follow the diametral variations of said mantle and disposed'in rolling contact engagement therewith at axially spaced apart locations along the reel.

3. The improvement according to claim 2 wherein said sensing rollers are positioned in generally tandem alignment along a line generally parallel to the winding axis of the reel.

4. The improvement according to claim 3 wherein said sensing rollers are supported for individual independent movement transversely to the reel winding axis, and to apply the same contact pressure to said mantle.

5. The improvement according to claim 4 wherein said sensing rollers are supported from a common beam structure, and including fluid pressure operated means connected to said sensing rollers to urge same into rolling contact engagement with said mantle.

6. The improvement according to claim 2 wherein said sensor means includes for each of said sensing rollers a transducer responsive to the movement of the sensing roller in following the diametral variations of the mantle and establishing a signal corresponding to the mantle diameter at the mantle contact location of the sensing roller.

7. The improvement according to claim 6 wherein said control means includes a sensor disposed to sense the deflection of the internally pressurizable roller and establish a control signal corresponding to said deflection under the weight of the reel.

8. The improvement according to claim 6 wherein said control means includes signal comparator means coupled to said transducers for response to the signals thereof and operable to establish a pressurization control signal, and valve means responsive to said pressurization control signal and flow connected with said internally pressurizable roller to regulate the internal pressure thereof in accordance with said pressurization control signal.

Claims

2. The improvement according to claim 1 wherein said sensor means includes a plurality of sensing rollers supported to follow the diametral variations of said mantle and disposed in rolling contact engagement therewith at axially spaced apart locations along the reel.