DE2857325A1 - CRUSH ROLL ARRANGEMENT FOR A CARD WEB - Google Patents

Description

MASCHINENFABRIK RIETER AG, 84 06 Winterthur, Switzerland

Pinch roller arrangement for a card web

The present invention relates to a nip roller arrangement for a card web with two cooperating Work rolls such as those used in staple fiber spinning, especially when processing natural fibers will.

The squeezing of a very thin non-woven fabric, as e.g. is withdrawn by the customer of a card, the purpose of the impurities still contained in the fleece, especially the harder peel and seed parts by grinding reduce, which makes them less disruptive in the subsequent processing operations and also better from the Fiber material are excreted.

To achieve good results with such a nip roller arrangement is the evenness of the generated

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Squeezing pressures along the entire working width of the rollers, which are of the order of magnitude of about Im, are of decisive importance Meaning. If the pressure is too small, the impurities are insufficient or insufficient grind, i.e. the squeeze roller arrangement does not bring the desired effect, while too high pressures cause damage the fiber material lead. Many efforts have therefore already been made to uniformly load the nip rollers which have led to a number of proposed solutions, albeit still unsatisfactory.

For example, DT-PS 177.241 shows a nip roller arrangement for paper, textile goods * wood, leather and the like known, in which, in order to achieve higher Smoothness, the axes of the cylindrical nip are angled to each other. Such a crossed arrangement of the It is possible for squeeze rollers to have an even pressure distribution despite the lateral loading of the rollers on the bearing blocks to be achieved across the entire width of the roller. However, this known nip roller arrangement has significant disadvantages on:

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So it requires the use of self-aligning bearings, which must also be adjustable to set the pressure. Such a construction, especially the drive of the nip rollers, becomes complicated and expensive.

Another disadvantage is that a certain The angle of intersection between the nip rollers is only uniform if the bearing blocks are subjected to a very specific load Pressure distribution results. For example, if the bearing blocks are subjected to excessive loads, the edges will wear Pinch rollers, i.e. the pressure is greater on the side than in the middle of the rollers. To change the pressure between the rollers - while maintaining an even distribution - the crossing angle must therefore also correspond Getting corrected; a laborious and difficult to control operation.

Another disadvantage of this known nip roller arrangement is the fact that the rollers, which in their Axes are bent crookedly, a constant alternating bending stress are subject to, which among other things requires a corresponding bending work.

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According to another known proposed solution (DT-PS 904.150), a uniform pressure distribution is to be achieved in the case of a squeezing:; roller arrangement with two longitudinally supported work rolls can be achieved in that each work roll through at least one pressure-loaded carrier is supported, the carrier preferably being a carrier of the same strength should be.

In a further development of this idea (DT-PS 918.676) it became known that between the work roll and the support beam to train arranged pressure transmission member elastic. The disadvantage of this nip roller arrangement arises from the fact that the rotating squeegee roller with its cylindrical surface on the pressure-loaded carrier, or on the pressure transmission member, rubs with full pressure. This results in a corresponding loss of energy and a large one Risk of injury to the very sensitive roller surface.

Magnetic nip rollers for card webs are also known from US Pat. No. 3,457,618. Such nip rollers exist from a tubular, thin steel jacket, inside which a plurality of permanent magnets, evenly

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Spread over the entire width of the roller for the necessary magnetic flux. It is true that such nip rollers make it possible to achieve a uniform distribution of pressure. she however, have the disadvantage that they are very expensive to manufacture and that the adjustment of the squeezing pressures is impossible is.

The object of the present invention is now to provide a squeeze roller arrangement to propose which overcomes the mentioned disadvantages of the known arrangements and in particular allows a uniform and easily adjustable pressure distribution over the entire width of the rollers. Next should the Arrangement simple in construction, cheap and reliable.

This object is achieved with a nip roller arrangement for a card web with two cooperating work rollers, which are characterized in that at least one of the two rollers is designed as a hollow body, the im essentially cylindrical jacket under the action of an interior wetting and under excess pressure Medium is located, is elastically deformable in the radial direction, and the second roller is mounted at such a distance,

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that they localize the deformation of the deformable roller counteracts.

According to a variant of the inventive Squeeze roller arrangement, the second roller can also be radially elastically deformable outwards by a pressure medium Be hollow body.

According to further design variants, it is provided that the interior available for the pressure medium is passed through a rigid body located therein is reduced, the rigid body in a special embodiment as Cylinder can be formed on the outer surface of which the jacket of the roller is supported in the pressureless state of the medium.

The invention is explained in more detail with reference to the following description of some design variants. The figures demonstrate:

1 shows the outlet members of a card, in elevation and in a schematic representation;

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2 shows a pinch roller arrangement according to the invention, in Longitudinal section and shown schematically;

Fig. 3a shows a section along the line A-A through the pinch and 3b

rolling the arrangement of FIG. 2, namely in Fig. 3a in the untensioned state and in Fig. 3b in the tense, stressed state;

4 shows a variant of the nip roller arrangement in longitudinal section;

Fig. 5 further variants of nip rollers, with only till 9

the nip rollers are shown without bearing and loading organs.

A customer 1 of a card transports a fiber fleece 3 (with a dot-dash line Line indicated) from below in the direction of rotation indicated by arrow f. Up to a point where it stripped from the doffer 1 by the tip set 4 of a pick-up roller 5 rotating in the same direction (arrow f_) and is taken away. The fiber fleece 3 comes with the substantially cylindrical, smooth surface of a

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lower work roll 6 in contact, with a transfer roll 7, which is normally a structured upper; (in FIG. 1, appropriately directed longitudinal grooves 8 are drawn in on its surface XVt * r ), ensures that the fiber fleece 3 is stripped from the tip clothing 4 and is deposited on the surface of the lower work roll 6. The arrows f and f indicate the direction of rotation of the rollers 6 and 7, the length shown being unrelated to the roller speed. A rotating brush 9 is also provided above the take-off roller 5 and ensures that any residual fibers are removed from the clothing tips 4 of the take-off roller 5.

The fiber fleece 3 is from the lower work roller 6 after transported to the right and comes in the contact area between the lower work roll 6 and the pinch point with this forming upper work roll 10 rotating in the direction of arrow f_. This is where the nonwoven fabric becomes subjected to a squeezing operation known per se, in which the impurities contained in the nonwoven fabric 3, such as shell parts, grains of sand, etc., are ground. The fiber fleece 3 is then, after leaving the nip, e.g.

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summarized by means of a funnel 11 and by two Rollers 12 and 13 drawn off as a sliver 14 (see also FIG. 2) and fed to a depositing device (not shown). the The position of the work rolls 6 and 10 shown in FIG. 1 can also be selected differently within the scope of this invention; in particular e.g. so that the axes of both rollers come to lie in a vertical plane.

In Fig. 2, the lower work roll 6 is a solid roll, the surface of which is substantially cylindrical, wherein Deviations from this form are entirely possible within the scope of the invention, as will be shown later. The lower one Work roll 6 is each in a side plate 15 and 16 of the card frame, not shown, by means of two Rolling bearings 17 and 18 rotatable, but not displaceable in space, supported.

The upper work roll 10 consists of a substantially cylindrical, thin jacket 19, which at both ends is tightly closed by a bottom 20 and 21 each, so that an overpressure can be built up inside 22. A suitable tight connection can be achieved, for example, by welding

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(see FIG. 5, where the weld seam is designated 23). But also a pressure-resistant press fit between floors 20 and 21 and jacket 19, or a push fit with pressure-tight seal (neither shown) are possible.

Each base 20 and 21 extends outward in an axis 24 and 25, which is concentric to the jacket 19 Axes 24 and 25 are rotatably mounted in two supports 26 and 27 by means of roller bearings 28 and 29, respectively. The support 26 and 27 are in turn guided displaceably on the two shields 15 or, respectively, which is shown in FIG. 2 by the axes m and η of connecting screws, not shown, which connect the supports and the plates slidably, schematically is indicated. For this purpose, the shield 15 further has a stop 30 for the support 26, which by a compression spring 32 clamped between an upper extension 31 of the shield 15 and support 26 against the stop 30 is pressed on, wherein the position of the stop 30 can be selected so that the entire force of the compression spring 32 is taken up by the stop 30. The same happens symmetrically on the κββ «*« η side. In this case the

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Compression spring 32 does not affect the surface pressure between the work rolls 6 and 10. This storage of the The purpose of work rolls 6 and 10 is to give the rolls a certain degree of evasion in the event that im

■ non-woven fabric 3 (Fig. 1) a non-grindable impurity, e.g. a metal splinter should be contained: if this is the case, then the upper pressure roller 10 can be overcome the compressive force of one or both compression springs 32 are raised, so that the non-grindable contamination between the work rolls can go through without damaging the roll surface, as is the case with rigid storage of the two work rolls 6 and 10 is the case.

It should also be noted that there are 15 and 16 holes in shields for the axes 24 and 25 of the work roll 10, which are larger than the diameter of the axes 24 and 25 so that they can cross the shields with enough space. .

The left axis 25 of the roller 10 has a coaxial bore

33, with which the interior 22 with that of a pump

34 coming supply line 35 for a medium displaced by the pump 34 in excess pressure is connected. Between the

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rotating bore 33 and the stationary supply line 35 is a pressure-tight rotary connection (not shown). A pressure measuring device 36 is also connected to the line 35.

The pump 34 is fed with the liquid 38 contained in a storage container 37. However, a compressible medium, for example a gas, can also be used without further ado, since the only requirement of the medium is that it is under a sufficient excess pressure. When using a gaseous medium, a compressor can be used instead of a pump 34. The storage container 37 is then no longer required. The radial files f drawn inside the work roll indicate the

Radial forces that the pressure medium exerts on the jacket. Under the effect of these radial forces, the jacket 19 is elastically deformed in the radial direction by the amount r .. -r ₀ , which leads to a bulge, as is shown schematically in FIGS. 3a and 3b.

In the unpressurized state of the work roll 10 (FIG. 3a), the distance M between the centers of the work _{rolls 6 and is equal to the sum of the radii r and R Q of} the two rolls

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6 and 10, i.e. in the unpressurized state, the upper work roll 10 is in contact with the lower work roll 6 without load or, if necessary with a minimal burden. The upper work roll 10 is thus not deformed, i.e. remains in the Circular cross-section. To achieve this, the axes of the rollers 6 and 10 can be fitted with the appropriate supports, in contrast to the embodiment of FIG. 2, in the simplest form can also be stored at a fixed distance M. The surface pressure between the work rolls is according to the invention by the deformation of the work roll 10 resulting from the overpressure in the interior 22 is brought about, as is clear from FIG. 3b emerges.

Fig. 3b shows that the effect of the excess pressure Shell 19 of the upper work roll 10 increases in diameter. However, since the distance M between the centers of the rollers 6 and 10 is kept constant, the roller 10 is locally prevented by the roller 6 from being deformed as it is necessarily has to support against the roller 6. This results in the squeezing of the fiber fleece (Fig. 1) necessary surface pressure.

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In Fig. 3b the deformation, i.e. the diameter teeth, is the Roller 10, drawn exaggeratedly large for reasons of clarity. In reality, however, they are very small, only " amounts perceptible through precise measurements. The experience '"" has shown, however, that even the smallest deformations of the hollow roller 10, on the order of magnitude of V10 mm in radius, sufficient to generate sufficient surface pressure. The compression springs 32 are to be dimensioned so that the distance M between the two rollers 6 and 10 is maintained even when the hollow roller 10 is loaded can be, i.e. in such a way that the two rollers 6 and 10 cannot evade, but the roller 10 at its local position Deformation is prevented.

The uniformity of the surface pressure along the entire length the nip line between the two work rolls 6 and 10 can also be very much by means of the measures outlined below can be guaranteed to a high degree.

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For example, by suitable choice of the contour of the shell 19 of the upper roller 10 and / or the lower roller 6, for a Compensation of the not over the entire width of the roll in

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deformation with the same degree of effect. In the case of a roller 10 which is cylindrical in the unloaded state, z.3. the full roller 6 can be made correspondingly concave. Furthermore, the effective width L (Fig. 2) of the pair of rollers that the Corresponds to the width of the nonwoven running through, smaller than the total width of the rollers are selected. With that, the The influence of the radially non-deformable roll ends can be largely eliminated.

The two work rolls 6 and 10 are drivingly connected by two gear wheels 40 and 40. The fact that the
Rolls 6 and 10 are always axially parallel to one another, and
that the distance M between the centers is always constant
remains, creates optimal conditions for the gear pair 39, 40.

In Fig. 4, a variant of the nip roller arrangement is closed
that shown in Fig. 2, which differs from this essentially 'borrowed in that both work rolls as
Hollow bodies are formed and under the action of a
the inside of which is wetting, overpressured medium can be deformed in the radial direction.

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In Fig. 4 are an upper work roll 41 and a lower one

Work roll 42 is present, which has the same structure as

include the upper work roll 10 of FIG. However, the diameter of the rollers 41 and 42 can be different. " Even with this arrangement of the nip rollers the effective -.: .. width L is smaller than the total width of the rollers 41 and 42, This also largely eliminates the influence of the roll edges on the pressure distribution in the clamping point of the V-roll pair will. Furthermore, each work roll is under a different pressure. For this purpose, the upper work roll pressurized by means of a first pump 43 and via a supply line 44. By a second pump 46 with a supply line 47, on the other hand, the lower work roll 42 is subjected to excess pressure and is thus deformed. To control the The two pressure gauges 45 and 48 are used for pressure.

Both pumps 43 and 46 are by means of one in a common Reservoir 49 contained liquid fed. The pumps 43 and 46 can, however, also come from separate storage containers with the same or different liquid

can be fed. \

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. In FIG. 4, a possibility is shown more often, a work roll by heating or cooling the medium in its "... To influence the way of working. This measure can be used for Special applications of the squeegee roller arrangement can be advantageous if, for example, the contamination becomes brittle due to cooling. or can be made less sticky. For this purpose, the lower work roll 42 has a return line 50 which connects the interior of the roller with the reservoir. The liquid delivered by the pump can thus flow through the roller. The liquid is provided in the circuit, e.g. in the storage tank, by means of a "Heat exchanger 51 heated or cooled.

FIGS. 5 to 9 show further variants of work rolls which are used in the context of the arrangement according to the invention can find. In all of these variants, the roller pairs are supported in the same way as in the examples in FIG. 2 and 4, which is why one can only restrict oneself to the structure of the roller here.

Fig. 5 shows a work roll 52, in which the interior space available for the print medium passes through therein

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located, spherical, rigid body 53 is reduced. However, any other forms are also possible, from powdery material to the single cylindrical body which partially or completely fills the space. By reducing the space available for the printing medium, the overall volume is reduced of the required medium. In view of the fact that each medium has a certain compressibility this is advantageous because it enables the overpressure to be kept constant in the interior of the roller is secured.

The work roll 53 of FIG. 6 also consists, like all constructions according to the invention, of a jacket 54 which can be deformed in the radial direction and which is welded together at the two end faces 55 and 56 with a cylindrical body iT-p. Between the jacket 54 and the cylindrical body 57 there remains an annular gap 58 which extends over almost the entire length of the jacket and into which the feed line 59 for the pressure medium opens.

In Fig. 7 a further variant of the work rolls according to Fig. 6 is shown, in which the jacket 61 is in the unpressurized

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State of the medium on the outer surface of the cylindrical body 60, which corresponds to one of the inner surface of the jacket Has diameter, is supported. In Fig. 7 the upper half of the roller is shown in the unpressurized state, while the lower half (below the center line x) shows the work roll under overpressure.

In contrast to the roller of FIG. 6, there are between the end faces 62 and 63 no annular gap, but the cylindrical body 60 fills the whole of the jacket 61 in the unpressurized state defined inside of the roller. This variant offers the advantage that the jacket 61 is depressurized Condition of the very massive, dimensionally stable cylindrical Body 60 is supported and thereby directed.

Several connecting channels 65 connect the central medium supply bore 66 to the cylindrical periphery of the cylindrical body 60. This measure can promote the distribution of the pressure medium in the gap 64 between the jacket 6 \ and the cylindrical body 60. The same effect can also be achieved by structuring the surface of the cylindrical body 60, for example by making grooves, etc.

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In this solution one also dispenses with the use of an external pressure source. The pressure inside the roller is generated here simply by the fact that this is done with an adjustable pressure piston 67 that displaces the medium is provided. The one guided in a bore 68 of the hub 69, if necessary with a suitable seal (not shown) provided piston 67 is by means of an adjusting screw 70, which in a corresponding threaded nut 71 of the hub 69 is screwed against which the inside of the roller filling liquid is pressed. The advantage of this solution lies in the extraordinary simplicity of the device. Of course, it requires the use of pressure in particular resilient pressure media, so that the pressure and thus also the deformation of the shell 61 of the work roll over time remains constant. . i-- :;

The uniformity of the surface pressure between the two. Work rolls can also be solved differently by the Bottoms 73 and 74 (Fig. 8) are connected centrally by means of a continuous shaft 76, which outside the bottoms two Forms hubs 77 and 78 as a bearing point for the work roll. That between the jacket 72 and the one with a weld seam

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connected floors 73 and 74 contained interior is through annular partition walls 79 and 80 in individual chambers 81, ■ 82, 83 divided. The partitions 79 and 80 are so "-." designed so that they can follow a radial deformation of the jacket - ■ 72, while they are pressure-resistant on the front side. Suitable concentric, ring-shaped corrugated sheets can, for example, meet these conditions.

The individual chambers 81, 82 and 83 can be pressurized by means of suitable supply lines. A pump 84 and a supply line 85 apply the pressure p. To the chambers 83 and 83, while the chamber 8fi is loaded with the pressure p_ by means of a second pump 86 and via the line 87. The pressure p. Or p_ can be monitored by two pressure gauges 88 and 89. By correctly choosing the pressures p. and p_ can thus influence the shape of the envelope surface in the loaded state of the work roll (dashed line t). Usually one becomes P

select what is indicated in Fig. 8 by the different lengths of the arrows indicating the excess pressure.

j In Fig. 9, the equalization of the surface pressure

achieved in that the jacket 90 in the longitudinal direction of

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Qj η & Η \ $ Il Λ £ LQ

Roll has a different thickness. In the upper half of the drawing of the roller, for example, the jacket 90 is opposite the middle too graduated, while in the lower half the thickness gradually increases and decreases. Through these changes in thickness, which are drawn in Fig. 9 intentionally exaggerated, you can see the deformation resistance of the Influence shell 90 along the width of the roll, which in turn changes the shape of the shell in the loaded state as desired can be adapted to requirements. For example, the dash-dotted line r shows the outer shape of a jacket same thickness. By contrast, the dashed line s shows the deformation of a jacket 90 which is graduated in thickness shown.

You can also use the various measures shown here be combined in a squeeze roller arrangement to even out the surface pressure between the work rolls, to get the best results. For example, a work roll can have a jacket with different thicknesses and be divided into individual chambers.

The most important advantages of the nip roller arrangement according to the invention are:

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a) Parallel instead of crossed arrangement of the work rolls, so that every card can be equipped with a nip roller arrangement without complicated storage problems are to be managed, and the surface pressure between the work rolls while maintaining the Parallelism can be set in a simple manner.

b) Simple and cheap construction, which ensures high reliability of the pinch.

c) Very good retrofitting on existing cards, as there are no special requirements for the Storage must be provided.

d) High possibility of influencing and optimal evenness the surface pressure along the width of the rollers.

e) Easy switchover from operation with squeezing of the fiber fleece to operation without such. For this it is enough to release the excess pressure inside the work roll. This advantage is very great in practice Significance, since the question of the meaning of the fleece squeezing has to be re-examined each time the material is changed.

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Claims (1)

Claim ' Pinch roller arrangement for a card web with two cooperating Work rolls, characterized in that at least one of the two rolls is designed as a hollow body is, whose essentially cylindrical jacket is under the action of an interior wetting, under overpressure standing medium is, is elastically deformable in the radial direction, and the second roller in such Is mounted at a distance that it counteracts the deformation of the deformable roller locally. -24- 030602/0037 16- Subclaims 1. Squeeze roller arrangement according to claim, characterized in that that the second roller is also radially, elastically deformable outwards by a pressure medium Is hollow body. 2. nip roller arrangement according to claim, characterized in that that the interior that is available to the print medium is rigid due to one located therein Body is diminished. 3. Squeeze roller arrangement according to dependent claim 2, characterized in that the rigid body is a cylinder, 4. nip roller arrangement according to dependent claim 3, characterized characterized in that the jacket is in the unpressurized state of the medium on the outer surface of the cylinder supports. 5. nip roller arrangement according to claim, characterized in that that the medium is a liquid. -25- G306Ö2 / ÖÖ37 6. nip roller arrangement according to claim, characterized in that that the medium is a gas. 7. nip roller arrangement according to claim, characterized in that the interior is connected by means of a pressure line to a pressure source external to the roller is. 8. nip roller arrangement according to claim, characterized in that that the interior is provided with an adjustable pressure piston displacing the medium. 9. nip roller arrangement according to subclaims 5 and 8, characterized in that the liquid is as incompressible as possible. 10. nip roller arrangement according to claim, characterized in that that a heat exchanger is provided for the medium. 11. squeeze roller arrangement according to claim, thereby; § indicates that the inside of the '* 030602/0037 ' Roller is divided into individual chambers, of which at least one chamber is filled with pressure medium. 12. Squeeze roller arrangement according to claim, characterized in that that a plurality of juxtaposed, filled chambers with different Media pressure provided »iod .. 13. nip roller arrangement according to claim, characterized in that the jacket in the longitudinal direction of the Roll has a different thickness. 14. Squeeze roller arrangement according to claim, characterized in that the work rolls are pressed against each other at their two ends by means of energy storage devices. 15. Squeeze roller arrangement according to dependent claim 14, characterized in that the two energy accumulators each work against a fixed stop which absorbs the entire pressure force of the energy accumulator. -27- 030602/0037 16. Squeeze roller arrangement according to claim, characterized in that that the axes of the work rolls are arranged at a fixed distance from one another. MASCHINENFABRIK RIETER AG CG / eo / 50 12/29/1977 -28- G306G2 / 0G37